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Question 1
Correct
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A 31-year-old homosexual male is complaining of recent weight loss and blurred vision. A fundoscope was performed showing retinal haemorrhage. What is the single most appropriate option?
Your Answer: Cytomegalovirus (CMV)
Explanation:This question presents a 31-year-old homosexual male with symptoms of weight loss and blurred vision, along with retinal hemorrhage seen on fundoscopy. The most likely cause of these symptoms in a patient with HIV is Cytomegalovirus (CMV) infection.
CMV is a common opportunistic infection in individuals with HIV, particularly those with low CD4 counts. It can cause retinitis, leading to retinal hemorrhage and blurred vision. Weight loss is also a common symptom of HIV infection, which can be exacerbated by opportunistic infections like CMV.
The other options listed (Mycobacterium avium, Haemophilus influenzae, NHL, and Pneumocystis jiroveci) are also opportunistic infections commonly seen in HIV patients, but CMV is the most likely cause in this case based on the symptoms provided. Therefore, the single most appropriate option is Cytomegalovirus (CMV).
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This question is part of the following fields:
- Microbiology
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Question 2
Incorrect
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A 32-year-old male has recently had a splenectomy following a motorcycle accident. He is up to date with all vaccinations which were offered as part of his childhood vaccination scheme. It is July. Which of the following vaccinations does he require in the first instance?
Your Answer: Haemophilus type B, pneumococcus, BCG, meningitis ACWY
Correct Answer: Pneumococcus, meningococcal type B and C, Haemophilus type B
Explanation:Acquired asplenia or hyposplenia can occur following splenectomy. Hyposplenism is used to describe reduced (‘hypo-‘) splenic functioning and is associated with increased risk of sepsis from polysaccharide encapsulated bacteria. In particular, patients are at risk from Streptococcus pneumoniae, Haemophilus influenzae, and meningococcus. The risk is elevated as much as 350-fold.
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This question is part of the following fields:
- Microbiology
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Question 3
Correct
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A 27-year-old woman presents with a 4cm bleeding ulcer on her labia minora. The woman admits she is sexually active. Which lymph nodes will the ulcer drain to?
Your Answer: Superficial inguinal
Explanation:Chancroid is a sexually transmitted infection caused by the bacterium Haemophilus ducreyi. It typically presents as painful genital ulcers that can bleed and have a characteristic appearance. In this case, the 4cm bleeding ulcer on the woman’s labia minora is likely due to chancroid.
When a chancroid ulcer is present, it can drain to the lymph nodes in the groin region. The lymph nodes that are most commonly affected in this case are the superficial inguinal lymph nodes. These nodes are located in the groin area and are responsible for draining lymphatic fluid from the lower extremities, external genitalia, and perineum.
Therefore, in this scenario, the bleeding ulcer on the woman’s labia minora would likely drain to the superficial inguinal lymph nodes. It is important to consider the possibility of chancroid in sexually active individuals presenting with genital ulcers, as prompt diagnosis and treatment are essential to prevent complications and further spread of the infection.
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This question is part of the following fields:
- Microbiology
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Question 4
Correct
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An elderly man presents with complaints of a chronic cough with haemoptysis and night sweats on a few nights per week for the past four months. He is known to smoke 12 cigarettes per day and he had previously undergone treatment for Tuberculosis seven years ago.
His blood pressure was found to be 143/96 mmHg and he is mildly pyrexial 37.5°C. Evidence of consolidation affecting the right upper lobe was also found.
Investigations;
Â
Hb 11.9 g/dl
WCC 11.1 x109/l
PLT 190 x109/l
Na+ 138 mmol/l
K+ 4.8 mmol/l
Creatinine 105 μmol/l
CXR Right upper lobe cavitating lesion
Aspergillus precipitins positive
Which of the following is most likely the diagnosis?Your Answer: Aspergilloma
Explanation:This question presents a case of an elderly man with a chronic cough, haemoptysis, night sweats, and a history of smoking and previous tuberculosis treatment. The patient also has evidence of consolidation in the right upper lobe on chest X-ray and positive Aspergillus precipitins.
The most likely diagnosis in this case is aspergilloma. Aspergilloma is a fungus ball that develops in a pre-existing cavity in the lung parenchyma. It is commonly seen in patients with pre-existing cavitary lung diseases such as tuberculosis. Symptoms of aspergilloma may include cough, haemoptysis, and fever. The presence of positive Aspergillus precipitins further supports the diagnosis.
The other options provided in the question are less likely based on the clinical presentation and investigations. Allergic bronchopulmonary aspergillosis typically presents with asthma-like symptoms and eosinophilia. Invasive aspergillosis is a severe infection that occurs in immunocompromised individuals. Reactivated tuberculosis would typically present with symptoms similar to the initial infection. Lung cancer would have a different presentation on imaging and would not be associated with positive Aspergillus precipitins.
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This question is part of the following fields:
- Microbiology
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Question 5
Correct
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A 25-year-old pregnant female suddenly developed a rash on her torso. It started as macules and then became vesicles. After 3 days she died. During her post-mortem, positive findings suggestive of pneumonitis were found. Which one of the following is the most common cause?
Your Answer: Varicella zoster virus (VZV)
Explanation:The most likely cause of the rash and subsequent death in this pregnant female is Varicella zoster virus (VZV) infection. VZV is the virus responsible for causing chickenpox and shingles. In pregnant women, VZV infection can lead to severe complications, including pneumonitis, which is inflammation of the lungs.
The presentation of macules (flat, red spots) that progress to vesicles (fluid-filled blisters) is characteristic of VZV infection. The virus can spread throughout the body, leading to systemic symptoms and potentially fatal complications.
Chorioamnionitis is an infection of the placental tissues and amniotic fluid, which can occur during pregnancy but would not typically present with a rash and vesicles. Herpes simplex virus can also cause vesicular rash, but it is less common in pregnant women and does not typically lead to pneumonitis. Listeriosis and rubella are other infections that can cause rash, but they are less likely to present with the specific progression of macules to vesicles seen in this case.
Overall, given the clinical presentation and findings during the post-mortem examination, Varicella zoster virus (VZV) is the most likely cause of the rash and subsequent complications in this pregnant female.
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This question is part of the following fields:
- Microbiology
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Question 6
Correct
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What is not included in the clinical assessment of a client on ART?
Your Answer: Waist circumference
Explanation:The clinical assessment of a client on antiretroviral therapy (ART) is crucial in monitoring their progress and ensuring the effectiveness of their treatment. Weight and height, not waist circumference measurements are important indicators of overall health and can help healthcare providers track changes in body composition and nutritional status. Tuberculosis screening is essential as HIV-positive individuals are at a higher risk of developing tuberculosis. CD4 count testing is used to assess the immune system’s strength and response to treatment. Viral load testing measures the amount of HIV in the blood and helps determine how well the treatment is working. Liver function tests are important as some antiretroviral medications can affect liver function. Overall, a comprehensive clinical assessment including these components is essential in managing HIV/AIDS and ensuring the well-being of individuals on ART.
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This question is part of the following fields:
- Clinical Evaluation
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Question 7
Correct
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A pregnant female recently underwent her antenatal screening for HIV and Hepatitis B. Which of the following additional tests should she be screened for?
Your Answer: Rubella, Toxoplasma and Syphilis
Explanation:During pregnancy, it is important for women to undergo screening for certain infectious diseases that can potentially harm the fetus. HIV and Hepatitis B are two infections that can be transmitted from mother to baby during pregnancy, childbirth, or breastfeeding. Therefore, it is crucial to screen for these infections in pregnant women to prevent transmission to the baby.
In addition to HIV and Hepatitis B, pregnant women should also be screened for Rubella, Toxoplasma, and Syphilis. Rubella is a viral infection that can cause serious birth defects if contracted during pregnancy. Toxoplasmosis is a parasitic infection that can also lead to birth defects or complications in the baby. Syphilis is a sexually transmitted infection that can be passed from mother to baby during pregnancy and can result in serious health issues for the baby.
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This question is part of the following fields:
- Microbiology
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Question 8
Correct
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What is the recommended timeframe for initiating Antiretroviral Therapy (ART) after diagnosis or linking to care?
Your Answer: Within one week
Explanation:Initiating Antiretroviral Therapy (ART) within one week of diagnosis or linking to care is recommended for several reasons. Firstly, starting ART early can help to suppress the HIV virus quickly, reducing the viral load in the body and preventing further damage to the immune system. This can lead to better long-term health outcomes for the individual living with HIV.
Additionally, starting ART early can also help to reduce the risk of HIV transmission to others. When the viral load is suppressed, the risk of transmitting the virus to sexual partners or through sharing needles is greatly reduced.
Overall, initiating ART within one week of diagnosis or linking to care is crucial in order to improve health outcomes for individuals living with HIV and to prevent further transmission of the virus.
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This question is part of the following fields:
- Clinical Evaluation
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Question 9
Correct
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Which protein in the HIV genome is responsible for binding to the host CD4 cells?
Your Answer: gp120
Explanation:The protein in the HIV genome responsible for binding to host CD4 cells is gp120. This protein is found on the surface of the virus and plays a crucial role in the initial stages of infection. When HIV comes into contact with a CD4 cell, gp120 binds to the CD4 receptor on the cell’s surface. This binding allows the virus to enter the cell and begin the process of replication, ultimately leading to the destruction of the immune system.
The other proteins listed in the question (p17, gp41, p32, p10) are also important components of the HIV genome, but they do not play the same role as gp120 in binding to host CD4 cells. Gp41, for example, is another envelope glycoprotein that helps facilitate the fusion of the virus with the host cell membrane, while p17, p32, and p10 are structural proteins that help maintain the integrity of the virus particle.
In summary, gp120 is the protein in the HIV genome responsible for binding to host CD4 cells, allowing the virus to enter and infect these immune cells.
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This question is part of the following fields:
- Microbiology
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Question 10
Correct
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What should be done if a child under two years tests HIV-positive?
Your Answer: Initiate ART as soon as possible
Explanation:Children under two years of age are at a higher risk of rapid disease progression if they are HIV-positive. Therefore, it is crucial to initiate antiretroviral therapy (ART) as soon as possible to prevent further complications and improve the child’s health outcomes. Waiting for confirmatory results before starting treatment can delay necessary care and potentially worsen the child’s condition. Additionally, providing cotrimoxazole prophylaxis can help prevent opportunistic infections in HIV-positive children. Confirming the HIV diagnosis with a rapid test can help ensure accurate results and guide appropriate treatment decisions. Overall, the priority should be to initiate ART promptly to give the child the best chance at a healthy life.
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This question is part of the following fields:
- Clinical Evaluation
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Question 11
Correct
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Which of the following is the drug of choice for the treatment of Chlamydia trachomatis infection during pregnancy?
Your Answer: Amoxicillin
Explanation:Chlamydia trachomatis is a common sexually transmitted infection that can be passed from mother to baby during childbirth, potentially leading to serious complications for the newborn. Therefore, it is important to treat chlamydia infection in pregnant women to prevent transmission to the baby.
Among the options provided, amoxicillin is the drug of choice for the treatment of Chlamydia trachomatis infection during pregnancy. This is because amoxicillin is considered safe to use during pregnancy and has been shown to be effective in treating chlamydia. Tetracycline, on the other hand, is not recommended in pregnancy due to the risk of harm to fetal development. Metronidazole is not effective against chlamydia, and while it is currently not thought to pose an increased risk in pregnancy, it is not the preferred treatment for chlamydia. Clindamycin and cephazolin are not typically used to treat chlamydia infections.
In conclusion, amoxicillin is the most appropriate choice for treating Chlamydia trachomatis infection in pregnant women due to its safety and effectiveness in this population.
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This question is part of the following fields:
- Pharmacology
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Question 12
Correct
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When is Enhanced Adherence Counseling (EAC) indicated for patients struggling with adherence to treatment?
Your Answer: For patients with challenges remembering to take their treatment.
Explanation:Enhanced Adherence Counseling (EAC) is particularly indicated for patients facing challenges with remembering to take their treatment, as part of efforts to tackle barriers to good adherence. It focuses on providing patients with practical skills to adhere to ART and developing an individualized adherence plan.
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This question is part of the following fields:
- Counselling
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Question 13
Correct
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A 19-year-old woman is diagnosed with acute purulent meningitis after returning from a recent holiday abroad. Which of the following investigations is the least relevant?
Your Answer: PCR of CSF for Mycobacterium TB
Explanation:Amoebic, bacterial and fungal meningitis may present acutely but this is not common in tuberculous meningitis. Amoebic meningitis is caused by Naegleria fowleri as a result of swimming in infected freshwater. The organism may be found in fresh CSF specimens with phase contrast microscopy.
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This question is part of the following fields:
- Microbiology
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Question 14
Correct
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A 20-year-old boy returning from vacation in India presented with a history of fever, myalgia, headache and abdominal pain for 4 days duration. He revealed that he had bathed in a river during his vacation. On examination, he had severe muscle tenderness, hypotension (BP - 80/60 mmHg) and tachycardia (140 bpm). What would be the first step in management?
Your Answer: IV normal saline
Explanation:Leptospirosis is a bacterial infection caused by the spirochete Leptospira. It is commonly transmitted to humans through contact with water, soil, or food contaminated with the urine of infected animals, such as rodents. Symptoms of leptospirosis can range from mild flu-like symptoms to severe complications such as kidney failure and liver damage.
In this case, the patient’s history of bathing in a river in India, along with symptoms of fever, myalgia, headache, and abdominal pain, are highly suggestive of leptospirosis. The presence of severe muscle tenderness, hypotension, and tachycardia indicate that the patient is in a state of shock and requires immediate medical attention.
The first step in managing a patient with suspected leptospirosis who is in shock is to initiate resuscitation with IV fluids to stabilize their blood pressure and improve tissue perfusion. This is crucial in preventing further complications and organ damage. IV antibiotics, such as Doxycycline or Penicillin, should also be started promptly to treat the underlying infection.
While other investigations such as abdominal and chest X-rays may be necessary to rule out other possible diagnoses, the priority in this case is to address the patient’s hemodynamic instability and initiate appropriate antibiotic therapy. Once the patient is stabilized, further diagnostic tests and management can be pursued as needed.
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This question is part of the following fields:
- Microbiology
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Question 15
Correct
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A 4 year old girl presents to the clinic with sore throat and a small painful ulcer in her mouth since yesterday and small painful ulcers on palms and soles that are not itchy. She is febrile (38.5 degree Celsius) and is refusing to eat for the past two days. Which of the following will be the most likely cause of this presentation?
Your Answer: Coxsackie virus
Explanation:The most likely cause of this 4-year-old girl’s presentation is Coxsackie virus. Coxsackie viruses are known to cause hand, foot, and mouth disease (HFMD) and herpangina, which are characterized by symptoms such as sore throat, fever, and painful ulcers in the mouth. The presence of small painful ulcers on the palms and soles further supports the diagnosis of Coxsackie virus infection. Additionally, the refusal to eat and fever are common symptoms of HFMD. Treatment for Coxsackie virus infection is usually symptomatic, as the disease is self-limiting in most cases.
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This question is part of the following fields:
- Microbiology
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Question 16
Correct
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A new-born male is admitted to NICU with convulsions, limb hypoplasia and rudimentary digits. Which of the following is the most likely cause?
Your Answer: Varicella
Explanation:The most likely cause of the symptoms described in the new-born male admitted to NICU with convulsions, limb hypoplasia, and rudimentary digits is Varicella. Infection with chickenpox (Varicella) during the first half of pregnancy can result in congenital varicella syndrome. This syndrome is characterized by cerebral, cortical, and cerebellar hypoplasia, as well as limb hypoplasia and rudimentary digits.
The other options listed (Cytomegalovirus, Herpes simplex, Listeriosis, and Toxoplasmosis) can also cause congenital infections with various symptoms, but in this case, the presentation of convulsions, limb hypoplasia, and rudimentary digits points towards Varicella as the most likely cause.
Prevention of congenital varicella syndrome includes administering the varicella vaccine, even before pregnancy, to ensure immunity. Pregnant women who are exposed to Varicella infection should receive varicella immunoglobulin. In cases where infection occurs during pregnancy, treatment with antiviral medication such as acyclovir may be necessary.
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This question is part of the following fields:
- Microbiology
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Question 17
Correct
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How should Dolutegravir (DTG) dosing be adjusted when an individual is also receiving rifampicin-containing TB treatment?
Your Answer: Increase the DTG dose to 50 mg 12-hourly
Explanation:When an individual is receiving both Dolutegravir (DTG) and rifampicin-containing TB treatment, there is a potential for drug interactions that can affect the efficacy of DTG. Rifampicin is known to increase the metabolism of DTG, leading to lower DTG concentrations in the body. To counteract this effect and ensure that DTG remains effective in treating HIV, the dosing of DTG should be increased to 50 mg 12-hourly.
Therefore, the correct answer is: Increase the DTG dose to 50 mg 12-hourly. This adjustment helps to maintain adequate levels of DTG in the body and ensures that the antiretroviral therapy remains effective during TB treatment.
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This question is part of the following fields:
- Pharmacology
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Question 18
Incorrect
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Which one of the following congenital infections is most characteristically associated with chorioretinitis?
Your Answer: Treponema pallidum
Correct Answer: Toxoplasma gondii
Explanation:Chorioretinitis is a condition characterized by inflammation of the choroid and retina in the eye. Among the congenital infections listed, toxoplasmosis caused by Toxoplasma gondii is most characteristically associated with chorioretinitis. In infants with congenital toxoplasmosis, chorioretinitis is a common manifestation and can lead to vision impairment or blindness if left untreated. Therefore, when chorioretinitis is present in a newborn or infant, healthcare providers may consider toxoplasmosis as a possible cause and conduct further testing to confirm the diagnosis.
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This question is part of the following fields:
- Microbiology
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Question 19
Correct
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What is the recommended approach for managing drug interactions between DTG and rifampicin?
Your Answer: Seek expert advice and adjust DTG dose accordingly
Explanation:When managing drug interactions between DTG (dolutegravir) and rifampicin, it is important to consider that rifampicin can reduce the concentrations of DTG in the body. This can potentially lead to decreased effectiveness of DTG in treating HIV infection.
The recommended approach for managing this interaction is to seek expert advice and adjust the DTG dose accordingly. This may involve increasing the dose of DTG to compensate for the reduced concentrations caused by rifampicin. It is crucial to consult with a healthcare professional or pharmacist who is knowledgeable about HIV treatment to ensure that the DTG dose is adjusted appropriately to maintain therapeutic levels.
Discontinuing rifampicin is not typically recommended, as it is often a necessary medication for treating other conditions such as tuberculosis. Administering DTG and rifampicin together may not be sufficient to overcome the interaction, and replacing DTG with efavirenz is not necessarily the best solution as efavirenz may have its own set of interactions and side effects.
In conclusion, seeking expert advice and adjusting the DTG dose accordingly is the most appropriate approach for managing drug interactions between DTG and rifampicin to ensure optimal treatment outcomes for individuals with HIV infection.
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This question is part of the following fields:
- Pharmacology
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Question 20
Correct
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Which of the following is the most common complication of untreated syphilis in pregnant women?
Your Answer: Congenital syphilis
Explanation:Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. If left untreated in pregnant women, syphilis can be transmitted to the fetus during pregnancy or childbirth, leading to congenital syphilis. Congenital syphilis can result in a range of serious complications for the newborn, including stillbirth, neonatal meningitis, and other severe health issues.
Placental abruption, premature rupture of membranes, and stillbirth can also occur as complications of untreated syphilis in pregnant women, but congenital syphilis is the most common complication. This is because the bacterium can easily cross the placenta and infect the fetus, leading to a higher likelihood of congenital syphilis compared to other complications. Therefore, it is crucial for pregnant women to receive timely screening and treatment for syphilis to prevent these serious complications for both themselves and their babies.
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This question is part of the following fields:
- Microbiology
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Question 21
Correct
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Which condition is NOT mentioned as a risk factor for cardiovascular disease in people living with HIV?
Your Answer: Regular exercise
Explanation:Cardiovascular disease is a common comorbidity in people living with HIV, and there are several risk factors that can contribute to its development. Chronic immune activation, low CD4 count, high HIV viral load, and exposure to certain classes of antiretroviral (ARV) drugs are all known to increase the risk of cardiovascular disease in this population.
Regular exercise, on the other hand, is actually a protective factor against cardiovascular disease. Exercise has been shown to improve cardiovascular health, reduce inflammation, lower blood pressure, and improve lipid profiles. Therefore, regular exercise is not mentioned as a risk factor for cardiovascular disease in people living with HIV, but rather as a beneficial lifestyle factor that can help reduce the risk of developing cardiovascular complications.
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This question is part of the following fields:
- Epidemiology
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Question 22
Correct
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What is the recommended action if a pregnant mother is diagnosed with drug-resistant TB?
Your Answer: Discuss with an expert or healthcare provider
Explanation:When a pregnant mother is diagnosed with drug-resistant TB, it is crucial to seek guidance from an expert or healthcare provider due to the complexity of the situation. Drug-resistant TB requires specialized treatment and management, especially in the case of a pregnant woman where the health of both the mother and the unborn child must be considered.
Starting TB preventive therapy immediately may not be sufficient in the case of drug-resistant TB, as the treatment regimen needs to be tailored to the specific drug resistance profile of the bacteria. Initiating ART without delay is important for managing HIV infection in pregnant women, but it may not address the drug-resistant TB infection.
Referring the mother to a virologist or calling the HIV hotline may not be the most appropriate actions in this situation, as the primary concern is the management of the drug-resistant TB infection. Therefore, discussing the case with an expert or healthcare provider who has experience in treating drug-resistant TB in pregnant women is the recommended course of action. This will ensure that the mother receives the most appropriate and effective treatment to protect both her health and the health of her unborn child.
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This question is part of the following fields:
- Clinical Evaluation
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Question 23
Correct
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Which of the following serology results is consistent with chronic hepatitis B infection:
Your Answer: HBsAg positive and anti-HBc IgG positive
Explanation:Disease state vs Serology
Acute hepatitis: HBsAg, HBeAg, anti-HBc IgM
Chronic hepatitis B (low infectivity): HBsAg (>6/12), anti-HBe, anti-HBc IgG
Chronic hepatitis B (high infectivity): HBsAg (>6/12), HBeAg, anti-HBc IgG
Cleared infection: Anti-HBs, anti-HBe, anti-HBc IgG
Vaccinated: Anti-HBs -
This question is part of the following fields:
- Clinical Evaluation
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Question 24
Correct
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Congenital Cytomegalovirus (CMV) infection affects how many pregnancies?
Your Answer: 1 in 150
Explanation:Congenital Cytomegalovirus (CMV) infection is a common viral infection that can be passed from mother to baby during pregnancy. It is estimated that CMV affects about 1 in 150 pregnancies. Of those pregnancies affected by CMV, about 30% will transmit the virus to the fetus. And of those fetuses that are infected with CMV, about 30% will show symptoms of the infection.
Therefore, out of 200 pregnancies, 1 will be affected by CMV. Out of those affected pregnancies, 30% will transmit the virus to the fetus, resulting in about 0.3 fetuses being infected. And out of those infected fetuses, about 30% will show symptoms of the infection, resulting in about 0.09 fetuses being affected.
So, the overall likelihood of a fetus being affected by congenital CMV infection is about 1 in 1500 pregnancies.
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This question is part of the following fields:
- Epidemiology
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Question 25
Correct
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A 14-day-old baby presented in NICU with signs and symptoms of hydrocephaly, seizures and chorioretinitis. Which of the following infectious agents is most probably the cause in a case like this?
Your Answer: Toxoplasmosis
Explanation:In a case like this, the most probable infectious agent causing the symptoms of hydrocephalus, seizures, and chorioretinitis in a 14-day-old baby is Toxoplasmosis. Toxoplasmosis is a parasitic infection caused by the protozoan Toxoplasma gondii. This infection can be transmitted from mother to fetus during pregnancy, leading to congenital toxoplasmosis in the newborn.
The symptoms of congenital toxoplasmosis can vary, but commonly include hydrocephalus (enlargement of the brain), seizures, and chorioretinitis (inflammation of the retina). Other symptoms may include jaundice, anemia, and developmental delays.
To prevent maternal and fetal toxoplasma infection, pregnant women are advised to take precautions such as wearing gloves when gardening or handling cat litter, and cooking meat thoroughly. Treatment for affected babies typically involves a combination of pyrimethamine, sulfadiazine, and folic acid.
While other infectious agents such as Cytomegalovirus (CMV), Herpes simplex, Listeriosis, and Syphilis can also cause similar symptoms in newborns, the presence of hydrocephalus, seizures, and chorioretinitis in this case points towards Toxoplasmosis as the most likely cause.
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This question is part of the following fields:
- Microbiology
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Question 26
Correct
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What is the maximum duration of isoniazid (INH) dosing for TB-exposed neonates?
Your Answer: 6 months
Explanation:Isoniazid (INH) is a medication commonly used for the treatment and prevention of tuberculosis (TB). When it comes to TB-exposed neonates, it is important to provide them with the appropriate duration of INH dosing to ensure effective treatment and prevention of the disease.
The maximum duration of isoniazid (INH) dosing for TB-exposed neonates is typically recommended to be 6 months. This duration is based on clinical guidelines and studies that have shown that a 6-month course of INH is effective in preventing the development of active TB in neonates who have been exposed to the disease.
While longer durations of INH dosing may be considered in certain cases, such as if the neonate is at high risk for developing TB or if there are other complicating factors, the standard recommendation is to provide a 6-month course of treatment. This duration strikes a balance between providing adequate protection against TB and minimizing the potential for side effects or complications associated with prolonged medication use.
Overall, the 6-month duration of isoniazid (INH) dosing for TB-exposed neonates is based on evidence-based guidelines and recommendations to ensure the best possible outcomes for these vulnerable patients.
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This question is part of the following fields:
- Pharmacology
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Question 27
Correct
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A 72-year-old woman who presented with headache and neck stiffness was started on IV ceftriaxone after undergoing a lumbar puncture. The CSF culture shows listeria monocytogenes. What is the treatment of choice?
Your Answer: Change to IV amoxicillin + gentamicin
Explanation:Listeria monocytogenes is a bacterium that can cause serious infections, particularly in immunocompromised individuals and the elderly. When treating listeria meningitis, the treatment of choice is a combination of ampicillin and gentamicin. Ampicillin is effective against listeria monocytogenes, while gentamicin is added to provide synergistic activity and improve outcomes.
In this case, the patient was initially started on IV ceftriaxone, which is not the optimal treatment for listeria monocytogenes. Therefore, the best course of action would be to change the antibiotic regimen to IV ampicillin and gentamicin. This combination therapy has been shown to be effective in treating listeria meningitis and reducing mortality rates.
The other options provided, such as IV amoxicillin, IV ciprofloxacin, IV co-amoxiclav, and continuing IV ceftriaxone as monotherapy, are not recommended for the treatment of listeria monocytogenes. It is important to promptly switch to the appropriate antibiotics to ensure the best possible outcome for the patient.
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This question is part of the following fields:
- Microbiology
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Question 28
Correct
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Regarding Human Papillomavirus, what percentage of women develop antibodies?
Your Answer: 50%
Explanation:Human Papillomavirus (HPV) is a common sexually transmitted infection that can lead to various health issues, including genital warts and certain types of cancer. When a person is infected with HPV, their immune system produces antibodies to fight off the virus.
The percentage of women who develop antibodies against HPV after natural infection is estimated to be over 50%. This means that more than half of women who are exposed to HPV will have antibodies in their system to help protect them from future infections.
The options provided in the question are not accurate representations of the percentage of women who develop antibodies against HPV. The correct answer would be 0.5, as this represents 50% of women who develop antibodies after natural infection.
It is important to note that not all HPV infections result in symptoms, and many infections are cleared by the immune system within a couple of years. Vaccines, such as Gardasil, have been developed to help prevent HPV infection and reduce the risk of associated health issues.
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This question is part of the following fields:
- Epidemiology
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Question 29
Correct
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A urine culture of a 50-year-old patient with urosepsis has isolated a multi-drug resistant Escherichia coli. What is the most likely reason for the multidrug resistance?
Your Answer: Extended spectrum beta-lactamase (ESBL) production
Explanation:The most likely reason for the multidrug resistance in the isolated Escherichia coli from the urine culture of the 50-year-old patient with urosepsis is extended spectrum beta-lactamase (ESBL) production. ESBLs are enzymes that are capable of breaking down and inactivating a wide range of beta-lactam antibiotics, making the bacteria resistant to these drugs. This includes commonly used antibiotics such as penicillins and cephalosporins. ESBL production is a major mechanism of resistance in E.coli and can lead to treatment challenges as the bacteria become resistant to multiple classes of antibiotics. In such cases, alternative antibiotics such as carbapenems, cephamycins, and beta-lactamase inhibitors may be used to treat infections caused by ESBL-producing bacteria.
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This question is part of the following fields:
- Microbiology
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Question 30
Correct
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For pregnant women exposed to occupational needlestick injuries, which antiretroviral medication is preferred for PEP during the first trimester?
Your Answer: TLD
Explanation:Pregnant women who are healthcare workers and are exposed to occupational needlestick injuries are at risk of contracting HIV. In order to prevent HIV transmission to the fetus, post-exposure prophylaxis (PEP) is recommended.
Among the options provided, TLD (tenofovir/lamivudine/dolutegravir) is the preferred antiretroviral medication for PEP during the first trimester of pregnancy. This is because TLD is considered safe and effective for use in pregnant women, with minimal risk of adverse effects on the fetus. Additionally, TLD has a high barrier to resistance and is well-tolerated by most patients.
It is important to follow the recommendations of the National Department of Health (NDOH) or other relevant guidelines when selecting antiretroviral medications for pregnant women in their first trimester who have been exposed to HIV through occupational needlestick injuries. This ensures that the most appropriate and effective treatment is provided to protect both the mother and the developing fetus.
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This question is part of the following fields:
- Pharmacology
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Question 31
Correct
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Which of the following is true regarding breastfeeding?
Your Answer: Exclusive breastfeeding is recommended, but mixed feeding with formula milk is acceptable with ARV drugs.
Explanation:Breastfeeding is a complex issue, especially for mothers living with HIV. The World Health Organization (WHO) recommends exclusive breastfeeding for the first six months of a baby’s life, as breast milk provides essential nutrients and antibodies that help protect against infections. However, for mothers living with HIV, there is a risk of transmitting the virus to their baby through breastfeeding.
Mixed feeding with formula milk is not preferred over exclusive breastfeeding because formula milk does not provide the same level of protection against infections and may increase the risk of HIV transmission. Additionally, mixed feeding without proper guidance and support can lead to challenges in maintaining maternal viral suppression.
Antiretroviral (ARV) drugs can significantly reduce the risk of HIV transmission through breastfeeding. Therefore, the WHO Practice Statements emphasize that exclusive breastfeeding is recommended, but mixed feeding with formula milk is acceptable in the presence of ARV drugs and maternal viral suppression. It is important for mothers living with HIV to work closely with healthcare providers to develop a feeding plan that prioritizes the health and well-being of both the mother and the baby.
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This question is part of the following fields:
- Epidemiology
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Question 32
Correct
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A 27-year-old male patient complains of general malaise and pain in his perineum and scrotum, which started two days ago. He also experiences increased urinary frequency and burning pain while urinating. The patient has no significant medical history. During examination, his heart rate is 75/minute, respiratory rate 16/minute, blood pressure 118/80 mmHg, and temperature 37.6ºC. The prostate is tender and there is boggy enlargement on digital rectal examination. What investigation would be appropriate?
Your Answer: Screen for sexually transmitted infections
Explanation:If a young man presents with symptoms of acute prostatitis, it is important to test for sexually transmitted infections (STIs). This is because while Escherichia coli is the most common cause of acute prostatitis, STIs such as Chlamydia trachomatis and Neisseria gonorrhoeae can also be responsible, especially in younger men. Testing for other conditions such as measuring PSA or testing for HIV would not be appropriate in this case. Biopsy of the prostate is also not indicated for acute prostatitis, but may be useful in chronic cases.
Acute bacterial prostatitis is a condition that occurs when gram-negative bacteria enter the prostate gland through the urethra. The most common pathogen responsible for this condition is Escherichia coli. Risk factors for acute bacterial prostatitis include recent urinary tract infection, urogenital instrumentation, intermittent bladder catheterisation, and recent prostate biopsy. Symptoms of this condition include pain in various areas such as the perineum, penis, rectum, or back, obstructive voiding symptoms, fever, and rigors. A tender and boggy prostate gland can be detected during a digital rectal examination.
The recommended treatment for acute bacterial prostatitis is a 14-day course of a quinolone. It is also advisable to consider screening for sexually transmitted infections.
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This question is part of the following fields:
- Microbiology
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Question 33
Correct
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A 15-year-old girl known with HIV develops lipoatrophy over her thighs and abdomen.
Which of the following medications can cause this side effect?Your Answer: Zidovudine
Explanation:Lipoatrophy is a condition characterized by the loss of fat tissue in specific areas of the body, such as the thighs and abdomen. In individuals with HIV, lipoatrophy can be a side effect of certain antiretroviral medications.
Among the options provided, zidovudine is known to cause lipoatrophy as a side effect. Zidovudine is a nucleoside reverse transcriptase inhibitor (NRTI) commonly used in the treatment of HIV. NRTIs like zidovudine and stavudine are associated with fat loss, particularly in the subcutaneous tissue of the limbs and face.
Enfuvirtide, efavirenz, and raltegravir are other classes of antiretroviral medications that are not commonly associated with lipoatrophy. Enfuvirtide is an HIV-fusion inhibitor, efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI), and raltegravir is an integrase inhibitor. These medications may have other side effects, but lipoatrophy is not typically one of them.
Ganciclovir, on the other hand, is not an anti-HIV medication but is used to treat cytomegalovirus (CMV) infections. It is not associated with lipoatrophy.
In conclusion, among the options provided, zidovudine is the medication most likely to cause lipoatrophy in a 15-year-old girl with HIV.
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This question is part of the following fields:
- Pharmacology
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Question 34
Correct
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What is the primary consideration before performing resistance testing for clients failing a DTG-based regimen?
Your Answer: Concurrent TB treatment
Explanation:Resistance testing is a crucial step in determining the most effective treatment options for clients who are failing a DTG-based regimen. However, before conducting resistance testing, it is important to consider if the client is undergoing concurrent TB treatment. This is because TB treatment can interact with antiretroviral medications, potentially affecting their efficacy and leading to treatment failure.
If a client is receiving both TB and antiretroviral treatment simultaneously, it is important to assess the potential for drug interactions and resistance patterns that may arise. This information can help healthcare providers make informed decisions about adjusting the client’s treatment regimen to ensure optimal outcomes.
Therefore, the primary consideration before performing resistance testing for clients failing a DTG-based regimen is concurrent TB treatment. By addressing this factor, healthcare providers can better tailor treatment plans to meet the individual needs of each client and improve their chances of successful treatment outcomes.
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This question is part of the following fields:
- Clinical Evaluation
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Question 35
Correct
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A 32-year-old woman presents to the Labour Ward at 38 weeks’ gestation for an elective Caesarean section. She has human immunodeficiency virus (HIV), had been taking combined highly active antiretroviral therapy (HAART) during pregnancy, and her viral load today is 60 copies/ml. She is asking about breastfeeding and also wants to know what will happen to the baby once it is born.
Which of the following statements best answers this patient’s questions?Your Answer: Breastfeeding should be avoided and the baby should have antiretroviral therapy for 4–6 weeks
Explanation:Guidelines for HIV-positive mothers and breastfeeding
Breastfeeding is not recommended for HIV-positive mothers as it increases the risk of transmission to the child. Instead, the baby should receive a first dose of antiretroviral therapy within four hours of delivery and continue treatment for 4-6 weeks. Blood tests are taken at set intervals to check the baby’s status. Hepatitis B vaccination should be offered at birth only if there is co-infection with hepatitis B virus in the mother.
However, if the mother’s viral load is less than 50 copies/ml, breastfeeding may be considered in low-resource settings where the nutritive benefits outweigh the risk of transmission. In high-resource settings, breastfeeding is not advised. The baby will still need to undergo several blood tests to establish their HIV status, with the last one taking place at 18 months of life.
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This question is part of the following fields:
- Epidemiology
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Question 36
Correct
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An 18-year-old homosexual male presents 36 hours after having unprotected sex with his partner whose HIV status is not known. He is concerned about his risk of acquiring HIV. He is feeling well and shows no symptoms. The physician offers him a post exposure prophylaxis, which consists of 3 different antiviral drugs. Two of these drugs act by which of the following mechanisms?
Your Answer: Inhibition of viral reverse transcriptase
Explanation:The two drugs that act by inhibiting viral reverse transcriptase are the NRTIs (nucleoside reverse transcriptase inhibitors) and NNRTIs (non-nucleoside reverse transcriptase inhibitors). NRTIs work by competing with the natural nucleotides that the virus needs to replicate its genetic material, while NNRTIs bind to a different site on the reverse transcriptase enzyme to prevent it from functioning properly.
In the recommended regimens for post-exposure prophylaxis, the options include using 3 NRTIs, 2 NRTIs plus 1 NNRTI, or using a PI (protease inhibitor) or INI (integrase inhibitor). These combinations of antiviral drugs are effective in preventing the replication of HIV and reducing the risk of acquiring the infection after exposure.
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This question is part of the following fields:
- Pharmacology
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Question 37
Correct
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Which ART medication is preferred for clients newly initiating ART and weighing 20 kg or more?
Your Answer: Dolutegravir (DTG)
Explanation:When initiating antiretroviral therapy (ART) for clients with HIV who weigh 20 kg or more, it is important to consider factors such as tolerability, drug interactions, and resistance. Dolutegravir (DTG) is preferred in this population for several reasons.
Firstly, DTG has been shown to have improved tolerability compared to other ART medications. This means that clients are less likely to experience side effects that may impact their adherence to treatment. Additionally, DTG has few drug interactions, making it easier to incorporate into a client’s existing medication regimen without causing complications.
Furthermore, DTG has a high barrier to resistance, meaning that it is less likely for the HIV virus to develop resistance to this medication compared to others. This is important for long-term treatment success and preventing treatment failure.
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This question is part of the following fields:
- Pharmacology
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Question 38
Correct
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A 22-year-old woman presented to the medical clinic for her first-trimester pregnancy counselling. Upon interview and history-taking, it was noted that she was previously an intravenous drug abuser. There were unremarkable first-trimester investigations, except for her chronic Hepatitis B infection.
All of the following statements is considered true regarding Hepatitis B infection during pregnancy, except:Your Answer: A Screening for HBV is not recommended for a pregnant woman with previous vaccination
Explanation:Hepatitis B infection during pregnancy can pose a risk to both the mother and the fetus. Screening for HBV is crucial in pregnant women, regardless of previous vaccination status, as it helps in identifying those who may require interventions to prevent transmission to the baby.
The risk of fetal infection is higher with chorionic villus sampling than amniocentesis because chorionic villus sampling involves obtaining a sample of the placental tissue, which may contain the virus.
Women with a high viral load in the third trimester should be offered antiviral therapy to reduce the risk of transmission to the baby. Caesarean section does not reduce the risk of hepatitis B transmission, as the virus is primarily transmitted through exposure to infected blood or body fluids during childbirth.
Fetal scalp blood sampling in labor should be avoided to prevent potential exposure to the virus. Therefore, all statements are true except for the statement that screening for HBV is not recommended for a pregnant woman with previous vaccination.
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This question is part of the following fields:
- Epidemiology
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Question 39
Correct
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A homeless woman presented with a cough and fever for the last 3 months. She also complained of night sweats and weight loss. Her CXR showed lung opacities. What is the next appropriate step for this patient?
Your Answer: Acid fast bacilli
Explanation:This homeless woman is presenting with symptoms that are concerning for tuberculosis, including a chronic cough, fever, night sweats, weight loss, and lung opacities on CXR. Tuberculosis is a bacterial infection caused by Mycobacterium tuberculosis, which is an acid-fast bacilli. Therefore, the next appropriate step for this patient would be to perform acid-fast bacilli testing on a sputum sample to confirm the diagnosis.
The Mantoux test and interferon gamma testing are used to screen for tuberculosis infection, but they do not confirm an active tuberculosis disease. A bronchoscopy may be considered if there is difficulty obtaining sputum samples or if further evaluation of the lung opacities is needed. A CT scan may also provide more detailed information about the lung opacities, but it is not necessary for confirming the diagnosis of tuberculosis in this case.
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This question is part of the following fields:
- Microbiology
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Question 40
Correct
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According to the 2023 Guideline for the Prevention of Vertical Transmission of Communicable Infections, what documentation is recommended for managing records of HIV-positive women and their infants?
Your Answer: The Maternity Case Record and The Road to Health Booklet
Explanation:The 2023 Guideline for the Prevention of Vertical Transmission of Communicable Infections emphasizes the importance of proper documentation for managing records of HIV-positive women and their infants. The recommended documents for this purpose are The Maternity Case Record for the mother and The Road to Health Booklet for the HIV-exposed infant.
The Maternity Case Record is a comprehensive document that tracks the mother’s health care and treatment practices throughout her pregnancy, delivery, and postpartum period. It includes information on prenatal care, HIV testing and treatment, delivery details, and postpartum follow-up. By using this record, healthcare providers can ensure that the mother receives appropriate care and that her HIV status is properly managed.
The Road to Health Booklet is a similar document designed for infants, including those who are exposed to HIV. It tracks the infant’s growth, development, and immunization status, as well as any HIV testing and treatment they may require. By using this booklet, healthcare providers can monitor the infant’s health and ensure they receive the necessary care to prevent vertical transmission of HIV.
Overall, using these recommended documents allows for comprehensive and systematic tracking of health care and treatment practices for HIV-positive women and their infants, ultimately helping to prevent vertical transmission of HIV and improve health outcomes for both mother and child.
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This question is part of the following fields:
- Epidemiology
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Question 41
Correct
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A 21-year-old man presents with a three day history of general malaise and low-grade temperature. Yesterday he developed extensive painful ulceration of his mouth and gums. On examination his temperature is 37.4ºC, pulse 84 / min and there is submandibular lymphadenopathy. What is the most likely diagnosis?
Your Answer: Herpes simplex virus infection
Explanation:The most likely diagnosis for the 21-year-old man with general malaise, low-grade temperature, and painful ulceration of his mouth and gums is a Herpes simplex virus infection. This is indicated by the presence of gingivostomatitis, which is a characteristic feature of primary herpes simplex virus infection.
Herpetic gingivostomatitis is often the initial presentation during the first herpes simplex infection and is typically caused by HSV-1. It is more severe than herpes labialis (cold sores) and is the most common viral infection of the mouth. Symptoms of herpetic gingivostomatitis can include fever, anorexia, irritability, malaise, headache, submandibular lymphadenopathy, halitosis, and refusal to drink.
Other options such as Epstein Barr virus, Lichen planus, and HIV seroconversion illness are less likely in this case based on the presentation of symptoms. Epstein Barr virus infection may present with symptoms similar to infectious mononucleosis, Lichen planus typically presents with white, lacy patches in the mouth, and HIV seroconversion illness may present with a variety of symptoms but typically not with the characteristic ulceration seen in herpes simplex virus infection.
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This question is part of the following fields:
- Microbiology
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Question 42
Correct
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Which drugs are classified as protease inhibitors?
Your Answer: Darunavir, Ritonavir, and Telaprevir
Explanation:Protease Inhibitors: A Breakthrough in HIV and Hepatitis C Treatment
Protease inhibitors are a class of drugs that block the activity of the viral enzyme called protease, which is essential for the maturation of the virus. Initially used for the treatment of HIV, protease inhibitors are now also used for the treatment of hepatitis C infections. Telaprevir is a protease inhibitor specifically designed for hepatitis C virus.
Abacavir and rilpivirine are two other drugs used for HIV treatment. Abacavir is a nucleoside reverse transcriptase inhibitor (NRTI), while rilpivirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI). Protease inhibitors are often used as second-line therapy for HIV treatment, with ritonavir commonly used as a booster with other protease inhibitors.
For hepatitis C treatment, protease inhibitors such as telaprevir, boceprevir, simeprevir, and danoprevir are used in combination with interferon and ribavirin. These drugs inhibit NS3/4A protease, which is a promising development in hepatitis C management. They are said to decrease the treatment duration, but their high cost is a major limiting factor for their use.
In conclusion, protease inhibitors have revolutionized the treatment of HIV and hepatitis C infections. While they are not without limitations, they offer hope for patients with these chronic viral diseases.
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This question is part of the following fields:
- Pharmacology
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Question 43
Correct
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Regarding PEP, what is the recommended regimen for pregnant healthcare workers in the first trimester who get a high-risk needle stick?
Your Answer: TLD
Explanation:Pregnant healthcare workers who experience a high-risk needle stick in the first trimester are recommended to be put on the TLD regimen for PEP. This regimen consists of tenofovir (TDF), lamivudine (3TC), and dolutegravir (DTG). This recommendation is based on the National Department of Health (NDOH), which suggests that this combination is safe and effective for pregnant women in their first trimester.
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This question is part of the following fields:
- Pharmacology
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Question 44
Correct
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A 34-year-old HIV positive man is referred to gastroenterology due to jaundiced sclera. Liver function tests are as follows:
Albumin 34 g/l
ALP 540 iu/l
Bilirubin 67 µmol/l
ALT 45 iu/l
What is the most likely diagnosis?Your Answer: Sclerosing cholangitis
Explanation:The most likely diagnosis for this 34-year-old HIV positive man with jaundiced sclera and abnormal liver function tests is primary sclerosing cholangitis. This is because HIV can cause strictures in the biliary tract, leading to inflammation and scarring of the bile ducts. The elevated ALP and bilirubin levels, along with the presence of jaundiced sclera, are consistent with this diagnosis.
Sclerosing cholangitis is a chronic liver disease characterized by inflammation and scarring of the bile ducts, leading to obstruction of bile flow. This can result in symptoms such as jaundice, fatigue, and itching. The liver function tests in this case show elevated ALP and bilirubin levels, which are indicative of cholestasis (impaired bile flow).
While other conditions such as hepatic abscess, fungal obstruction of the bile duct, duodenal adenoma, and primary biliary cirrhosis can also present with jaundice and abnormal liver function tests, the association of HIV with strictures in the biliary tract makes primary sclerosing cholangitis the most likely diagnosis in this case. It is important to consider the patient’s HIV status and the potential complications associated with the disease when making a diagnosis.
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This question is part of the following fields:
- Pathology
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Question 45
Correct
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What intervention is suggested for managing patients on a DTG-containing regimen when also receiving rifampicin-containing TB treatment?
Your Answer: Increase DTG dose to 50 mg 12-hourly
Explanation:When patients are on a dolutegravir (DTG)-containing regimen for HIV treatment and also receiving rifampicin-containing treatment for tuberculosis (TB), there is a potential for drug interactions between the two medications. Rifampicin is known to decrease the plasma concentrations of DTG, which can lead to reduced effectiveness of the HIV treatment.
To manage this interaction, the recommended intervention is to increase the dose of DTG to 50 mg 12-hourly. This adjustment helps to maintain adequate plasma concentrations of DTG despite the interaction with rifampicin. By increasing the dose, the therapeutic effect of DTG can be preserved, ensuring that the HIV treatment remains effective even in the presence of rifampicin-containing TB treatment.
Therefore, the correct answer to the question is: Increase DTG dose to 50 mg 12-hourly. This intervention is necessary to manage the drug interaction and maintain the efficacy of both HIV and TB treatments in patients receiving both medications.
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This question is part of the following fields:
- Pharmacology
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Question 46
Correct
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Which of the following best describe N. Meningitidis?
Your Answer: Gram negative cocci
Explanation:Neisseria meningitidis is a gram negative bacterium that is commonly referred to as meningococcus. This bacterium is known for causing meningitis and other forms of meningococcal disease, such as meningococcaemia, which is a severe and life-threatening form of sepsis.
The bacterium is classified as a coccus because of its round shape, and more specifically, as a diplococcus because it tends to form pairs. This characteristic can be seen under a microscope when the bacteria are stained and observed.
Among the options provided, the best description for Neisseria meningitidis would be Gram negative cocci, as it accurately reflects the shape and staining characteristics of this bacterium.
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This question is part of the following fields:
- Microbiology
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Question 47
Correct
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Which of the following statements regarding influenza virus is correct?
Your Answer: Influenza is a RNA virus
Explanation:Influenza is a RNA virus, which means its genetic material is made up of RNA instead of DNA. Host penetration is indeed affected by the glycoprotein haemagglutinin, which helps the virus attach to and enter host cells. Attachment of the virus to the host cell wall is aided by the enzyme neuraminidase, which helps the virus release from the host cell after replication. New influenza subtypes are generated via antigenic drift, which refers to minor changes in the virus over time. Antigenic shift, on the other hand, is when there is a major change in the virus due to the exchange of genes with strains that infect different species. This can lead to the emergence of pandemic strains.
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This question is part of the following fields:
- Microbiology
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Question 48
Correct
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A 50-year-old male presents to his doctor with severe groin pain that has been increasing for the past two days. He also reports developing a fever. He lives with his wife and has no other sexual partners. He is in good health and takes tamsulosin regularly. Upon examination, the doctor notes acute tenderness and swelling in the right testis, leading to a diagnosis of epididymo-orchitis. What is the most probable organism responsible for this patient's symptoms?
Your Answer: Escherichia coli
Explanation:Orchitis typically affects post-pubertal males and usually occurs 5-7 days after infection. It is important to note that the relief of pain when the testis is elevated, known as a positive Prehn’s sign, is not present in cases of testicular torsion.
Epididymo-orchitis is a condition where the epididymis and/or testes become infected, leading to pain and swelling. It is commonly caused by infections spreading from the genital tract or bladder, with Chlamydia trachomatis and Neisseria gonorrhoeae being the usual culprits in sexually active younger adults, while E. coli is more commonly seen in older adults with a low-risk sexual history. Symptoms include unilateral testicular pain and swelling, with urethral discharge sometimes present. Testicular torsion, which can cause ischaemia of the testicle, is an important differential diagnosis and needs to be excluded urgently, especially in younger patients with severe pain and an acute onset.
Investigations are guided by the patient’s age, with sexually transmitted infections being assessed in younger adults and a mid-stream urine (MSU) being sent for microscopy and culture in older adults with a low-risk sexual history. Management guidelines from the British Association for Sexual Health and HIV (BASHH) recommend ceftriaxone 500 mg intramuscularly as a single dose, plus doxycycline 100 mg orally twice daily for 10-14 days if the organism causing the infection is unknown. Further investigations are recommended after treatment to rule out any underlying structural abnormalities.
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This question is part of the following fields:
- Microbiology
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Question 49
Correct
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Which mechanism of action does Penicillin use?
Your Answer: Inhibit cell wall synthesis
Explanation:Penicillin uses the mechanism of action to inhibit cell wall synthesis in bacteria. Bacteria constantly remodel their peptidoglycan cell walls as they grow and divide. Penicillin works by binding to the enzyme DD-transpeptidase, which is responsible for forming peptidoglycan cross-links in the cell wall. By binding to this enzyme, penicillin prevents the formation of these cross-links, leading to an imbalance between cell wall production and degradation. This imbalance ultimately causes the bacterial cell to die. This mechanism of action makes penicillin an effective antibiotic for treating bacterial infections.
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This question is part of the following fields:
- Pharmacology
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Question 50
Correct
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If a patient has HIV what is the most likely cause of persistent watery diarrhoea?
Your Answer: Cryptosporidium
Explanation:Persistent watery diarrhea in a patient with HIV is most likely caused by Cryptosporidium. Cryptosporidium is a parasite that can cause infection and diarrhea in immunocompromised individuals, such as those with HIV. In immunocompetent individuals, this organism typically does not cause symptoms. However, in those with HIV, particularly those with low CD4 counts, Cryptosporidium can lead to prolonged, severe, or extraintestinal infection.
Other potential causes of persistent watery diarrhea in patients with HIV include Salmonella infection, colorectal cancer, and side effects of HAART therapy. However, in the context of HIV and diarrhea, Cryptosporidium should be the top consideration. It is important to consider the patient’s immune status and CD4 count when evaluating the cause of persistent diarrhea in HIV patients.
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This question is part of the following fields:
- Microbiology
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