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Question 1
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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:CMV is the best answer . Weight loss is mostly caused by HIV, which commonly presents with retinal haemorrhage and retinopathy when associated with CMV.
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This question is part of the following fields:
- Infectious Diseases
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Question 2
Incorrect
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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: Herpes simplex
Correct Answer: Varicella zoster virus (VZV)
Explanation:Varicella zoster virus (VZV) presents in this way and the rash transforms from macules to vesicles. Pneumonitis is a common complication of VZV infection.
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This question is part of the following fields:
- Infectious Diseases
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Question 3
Incorrect
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A 22-year-old female presents with a history of a whitish discharge from her vagina. She previously underwent a dental procedure and completed a 7 day antibiotic course prior to it. Which of the following microorganisms has most likely lead to this?
Your Answer: Nesseria Gonorrhea
Correct Answer: Candida
Explanation:Candida albicans is the most common cause of candidiasis and appears almost universally in low numbers on healthy skin, in the oropharyngeal cavity, and in the gastrointestinal and genitourinary tracts. In immunocompetent individuals, C. albicans usually causes minor localized infections, including thrush (affecting the oral cavity), vaginal yeast infections (if there is an underlying pH imbalance), and infections of the intertriginous areas of skin (e.g., the axillae or gluteal folds). More widespread and systemic infections may occur in immunocompromised individuals (e.g., neonates, diabetics, and HIV patients), with the oesophagus most commonly affected (candida esophagitis). Localized cutaneous candidiasis infections may be treated with topical antifungal agents (e.g., clotrimazole). More widespread and systemic infections require systemic therapy with fluconazole or caspofungin.
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This question is part of the following fields:
- Infectious Diseases
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Question 4
Incorrect
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A 30-year-old male presented with a history of bloody and mucoid diarrhoea since that morning. He is also complaining of abdominal spasm and bloating. Which of the following investigations is the most suitable one in this case?
Your Answer: Colonoscopy and Biopsy
Correct Answer: Stool culture and sensitivity
Explanation:In a case of sudden bloody and mucoid diarrhoea, stool culture and sensitivity are required to access which organism is causing the problem and to discuss appropriate antibiotics.
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This question is part of the following fields:
- Infectious Diseases
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Question 5
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: -
This question is part of the following fields:
- Infectious Diseases
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Question 6
Incorrect
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Which of the following is true of Koplik's spots?
Your Answer: They appear as red papules on the plamar surface of the hands
Correct Answer: Are diagnostic of measles
Explanation:Koplik’s spots are pathopneumonic for MEASLES. They are blue/white spots, small, occurring on the buccal mucosa. They typically occur next to premolars, not opposite to the incisors. They are not related to fever height. They are not on the hands. They usually occur BEFORE the rash.
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This question is part of the following fields:
- Infectious Diseases
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Question 7
Incorrect
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A 34-year-old man presents with haemoptysis and weight loss. History reveals he suffers from night sweats and upon auscultation you notice reduced breath sounds over the apex of his right lung and significant nail clubbing. You refer him to a pneumologist who administers the following antibiotics: rifampicin, ethambutol, pyrazinamide and isoniazid. What is the mechanism of action of the first drug?
Your Answer: Inhibit DNA synthesis
Correct Answer: Inhibit RNA synthesis
Explanation:Rifampicin specifically inhibits bacterial RNA polymerase, the enzyme responsible for DNA transcription, by forming a stable drug-enzyme complex with a binding constant of 10(-9) M at 37 C.
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This question is part of the following fields:
- Infectious Diseases
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Question 8
Correct
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An 80-year-old female presents to OPD with itching hands, elbows, axillae and groin. Other members residing with her at the retirement home also have similar complaints. Which of the following is the most likely diagnosis?
Your Answer: Scabies
Explanation:Scabies is due to an infestation of Sarcoptes scabiei and most commonly presents with these symptoms. The organism resides in burrows in a pattern specifically affecting the interdigital spaces and the skin folds of the arms and legs. The infection spreads from one person to another, especially in populated communities, through close contact.
Henoch-Schönlein purpura is a type of vascular inflammation.
Psoriasis rash is characterised by scaly plaques affecting the extensor surfaces of the body. Pemphigus vulgaris and bullous pemphigoid both are bullous disorders of the skin. They may present as crusted, weeping, diffuse lesions and there may be involvement in other sites; erosions in the mouth are typically involved in pemphigus vulgaris. Bullous pemphigoid involves the flexural areas and may be associated with a new medication. -
This question is part of the following fields:
- Infectious Diseases
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Question 9
Correct
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A man was admitted to the hospital and developed varicella zoster after 48h. Which of the following categories of people should be administered immunoglobulin only?
Your Answer: All pregnant women who are tested negative for antibodies.
Explanation:Immunoglobulin should be given to all seronegative women within 4 days. However, it is strongly advised to seek medical care immediately if the disease develops.
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This question is part of the following fields:
- Infectious Diseases
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Question 10
Correct
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An 18-year-old prospective medical student is tested for hepatitis B. Her liver tests show alanine transaminase (ALT) 120 U/L and serology shows her to be positive for HBsAg, HBcAb and HBeAg, with a viral load of 105 genome equivalents/mL.
A liver biopsy is reported as showing early fibrosis with evidence of moderate inflammation.
Which of the following treatments should be offered?Your Answer: Interferon alfa 2b
Explanation:Interferon alfa alone, not interferon alfa and ribavirin, has been shown to achieve HBeAg seroconversion for patients with HBeAg-positive chronic hepatitis B.
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This question is part of the following fields:
- Infectious Diseases
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Question 11
Incorrect
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A 25-year-old pregnant mother who is known to have hepatitis B gave birth to a male infant. She is now concerned about her child contracting hep B. Which of the following is the most suitable option for the baby in this case?
Your Answer: HepB vaccine once and Ig
Correct Answer: HepB full vaccine and Ig
Explanation:Hepatitis B full vaccine and Ig should be given to babies born to hepatitis B positive mothers. Hepatitis B vaccine alone or Ig alone is not sufficient to prevent the infection in the new-born baby.
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This question is part of the following fields:
- Infectious Diseases
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Question 12
Incorrect
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An 8-week-old baby was found to have bilateral cataracts. Further investigation revealed thrombocytopenia, a patent ductus arteriosus and hepatosplenomegaly. Which of the following is the most probable diagnosis?
Your Answer: Toxoplasmosis
Correct Answer: Rubella
Explanation:The clinical presentation is suggestive of congenital rubella syndrome. The classic triad of presenting symptoms includes sensorineural hearing loss, ocular abnormalities (cataract, infantile glaucoma, and pigmentary retinopathy) and congenital heart disease (patent ductus arteriosus and pulmonary artery stenosis). Other findings in congenital rubella syndrome include CNS abnormalities (mental retardation, behavioural disorders, encephalographic abnormalities, hypotonia, meningoencephalitis, and microcephaly), hepatosplenomegaly, and jaundice.
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This question is part of the following fields:
- Infectious Diseases
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Question 13
Incorrect
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A 45-year-old male presents to the clinic complaining of vomiting and early morning headaches. CT scan of the brain shows multiple ring enhancing lesions. Which of the following is the cause of this finding?
Your Answer: NHL
Correct Answer: Toxoplasmosis
Explanation:Toxoplasmosis is a disease caused by the obligate intracellular parasite Toxoplasma gondii. Transmission occurs either through ingestion of cysts found, for example, in raw meat or cat faeces, or from mother to foetus through the placenta.
The clinical presentation depends on the patient’s immune status: In immunocompetent individuals, 90% of cases are harmless and asymptomatic, with the remaining 10% displaying mild mononucleosis-like symptoms. In immunosuppressed patients (e.g., those who are HIV-positive), infection may result in cerebral toxoplasmosis (headache, confusion, focal neurologic deficits) or toxoplasma chorioretinitis (eye pain, reduced vision).
Treatment is indicated for immunosuppressed patients, infected mothers, congenital toxoplasmosis, and immunocompetent patients with more severe symptoms. The treatment of choice is usually a combination of pyrimethamine, sulfadiazine, and leucovorin (folinic acid), with the exception of new infections during pregnancy, which are treated with spiramycin. -
This question is part of the following fields:
- Infectious Diseases
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Question 14
Incorrect
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A 38-year-old woman returns from a summer holiday with a dry cough. Her CXR shows bilateral consolidated areas. Which antibiotic would you suggest?
Your Answer: Amoxicillin
Correct Answer: Ciprofloxacin
Explanation:Ciprofloxacin is a well-established broad-spectrum fluoroquinolone antibiotic that penetrates well into the lung tissues.
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This question is part of the following fields:
- Infectious Diseases
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Question 15
Correct
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If a patient has HIV what is the most likely cause of persistent watery diarrhoea?
Your Answer: Cryptosporidium
Explanation:When you have a patient with HIV and diarrhoea on the exam, think Cryptosporidium. In those who are immunocompetent this organism doesn’t usually cause symptoms, but in immunocompromised people like those with HIV, it causes infection and diarrhoea. Typically those with CD4 counts of <100 cells/µL1 have the greatest risk for prolonged, severe, or extraintestinal cryptosporidiosis.
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This question is part of the following fields:
- Infectious Diseases
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Question 16
Correct
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A 43-year-old female presented with a 5 day history of a productive cough with rusty coloured sputum. Chest X-ray showed lobar consolidation on her left side. The most likely causative organism would be?
Your Answer: Streptococcus pneumoniae
Explanation:Streptococcus pneumonia is the chief causative organism for lobar pneumonia in this age group patients. Typically patients present with rusty coloured sputum and a cough. Pneumocystis jiroveci is responsible for causing pneumocystis pneumonia among immunocompromised patients.
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This question is part of the following fields:
- Infectious Diseases
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Question 17
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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:Extended-spectrum beta-lactamases (ESBL) are enzymes that confer resistance to most beta-lactam antibiotics, including penicillins, cephalosporins, and the monobactam aztreonam. Extended spectrum beta-lactamase (ESBL) production is the main reason for multi-drug resistance among E.coli. Commonly used medications to treat ESBL-involved infections include carbapenems (imipenem, meropenem, and doripenem), cephamycins (cefoxitin and cefotetan), Fosfomycin, nitrofurantoin, beta-lactamase inhibitors (clavulanic acid, tazobactam, or sulbactam), non-beta-lactamases and colistin (if all other medications have failed.)
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This question is part of the following fields:
- Infectious Diseases
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Question 18
Correct
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A 40-year-old male returning from an African country, presented with lower abdominal pain and haematuria. Bladder calcifications were detected on abdominal x-ray. Which of the following is the most probable cause?
Your Answer: Schistosoma haematobium
Explanation:Schistosoma haematobium characteristically causes urinary tract disease. S.mansoni, S. mekongi, S. intercalatum, and S. japonicum cause intestinal tract and liver disease.
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This question is part of the following fields:
- Infectious Diseases
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Question 19
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:History and CXR are suggestive of tuberculosis. Acid fast bacilli should be seen on microscopy to confirm the diagnosis.
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This question is part of the following fields:
- Infectious Diseases
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Question 20
Incorrect
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Regarding neonatal meningitis, which of the following statements is true?
Your Answer: Is most commonly caused by Haemophilus influenzae
Correct Answer: Has an above average incidence in babies with a meningomyelocele
Explanation:The commonest time for bacterial meningitis is in the 1st month of life and group B Streptococcus is the commonest organism. The anterior fontanelle is full, but does not bulge with normal flexion. Neurological manifestations include seizures, irritability, poor tone, lethargy and tremors, however no findings of sensorineural deafness have been noted. One of the risk factors for introduction of meningeal infection is Meningomyelocele.
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This question is part of the following fields:
- Infectious Diseases
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Question 21
Correct
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A 32-year-old patient that has just returned from India, complains of dyspnoea. On examination, you notice grey membranes on the uvula and tonsils and a low-grade fever. What is the most likely diagnosis?
Your Answer: Diphtheria
Explanation:Characteristic findings on patients suffering from diphtheria are the grey membrane on the uvula and tonsils together with the low grade fever and dyspnoea. It’s of great importance that the patient has recently been to India where there is a know prevalence.
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This question is part of the following fields:
- Infectious Diseases
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Question 22
Incorrect
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A 55-year-old lady who a known case of normal pressure hydrocephalus (NPH) presented with complaints of weakness in her lower limbs, urinary incontinence and progressively worsening confusion. Which of the following statements is true regarding NPH?
Your Answer: Is not associated with raised intracranial pressure
Correct Answer: Is associated with gait disturbance
Explanation:Normal pressure hydrocephalus is a form of communicating hydrocephalus characterised by enlarged ventricles with normal opening pressure on lumbar puncture. For diagnostic purposes, a triad of urinary incontinence, gait abnormality and dementia is necessary. It is necessary to diagnose the condition early because it is reversible by placing a ventriculoperitoneal shunt. It is most common in patients aged more than 60 years.
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This question is part of the following fields:
- Infectious Diseases
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Question 23
Incorrect
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A 35-year-old female presented with complaints of earache and a high-grade fever. During examination, numerous small vesicles were found within the ear canal and her ear is very tender. Which one of the following organisms is most likely to be responsible for such a condition?
Your Answer: Varicella zoster
Correct Answer: Herpes zoster
Explanation:Herpes zoster is a viral disorder in which painful vesicular lesions are present in a specific dermatome area. High-grade fever may present as well due to infection. Varicella zoster, measles, herpes simplex and HIV do not present with tender lesions of a limited area.
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This question is part of the following fields:
- Infectious Diseases
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Question 24
Incorrect
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A 17-year-old man presents with fever and extensive preauricular swelling on the right side of his face. However, tenderness is present bilaterally. He also complains of acute pain and otalgia on the right aspect of the face. What is the most likely diagnosis?
Your Answer: Acute mastoiditis
Correct Answer: Mumps
Explanation:Mumps presents with a prodromal phase of general malaise and fever. On examination there is usually painful parotid swelling which has high chances of becoming bilateral. In OM with effusion there are no signs of infection and the only symptom is usually hearing loss. Acute otitis externa produces otalgia as well as ear discharge and itching. Acute OM produces otalgia and specific findings upon otoscopy. In acute mastoiditis the patient experiences ear discharge, otalgia, headache, hearing loss and other general signs of inflammation.
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This question is part of the following fields:
- Infectious Diseases
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Question 25
Incorrect
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A 20-year-old pregnant female in her first trimester met a child with chickenpox. She was investigated for the varicella antibody, which came back negative. She visited her GP. Which of the following measures is the most appropriate one?
Your Answer: Reassurance
Correct Answer: Ig
Explanation:After the exposure to chickenpox while pregnant, even if the patient is negative for antibodies she requires immunoglobulin to prevent further issues.
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This question is part of the following fields:
- Infectious Diseases
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Question 26
Correct
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A 32-year-old Indian male presents to the clinic with fever, cough and an enlarged cervical lymph node. Examination reveals a caseating granuloma in the lymph node. Which of the following is the most likely diagnosis?
Your Answer: TB adenitis
Explanation:Tuberculous lymphadenitis is a chronic, specific granulomatous inflammation of the lymph node with caseation necrosis, caused by infection with Mycobacterium tuberculosis or a related bacteria. The characteristic morphological element is the tuberculous granuloma (caseating tubercle).
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This question is part of the following fields:
- Infectious Diseases
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Question 27
Correct
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A keratitis with dendritic ulceration of the cornea is diagnosed in a 32-year-old patient. What is the most likely cause?
Your Answer: Herpes simplex virus
Explanation:The dendritic ulceration seen on fluorescein staining of the eye is pathopneumonic for keratitis caused by HSV (herpes simplex virus). Presentation is that of blepharoconjunctivitis. Treatment is required, the treatment is typically topical acyclovir. Topical steroids can make the infection worse. The other answer choices would not have this dendritic pattern seen on fluorescein staining.
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This question is part of the following fields:
- Infectious Diseases
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Question 28
Correct
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A woman presents with several painful ulcers on her vulva. What do you think has most likely caused this?
Your Answer: HSV
Explanation:Genital herpes is a sexually transmitted disease (STD). This STD causes herpetic sores, which are painful blisters (fluid-filled bumps) that can break open and ooze fluid.
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This question is part of the following fields:
- Infectious Diseases
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Question 29
Correct
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An 18-year-old woman has been diagnosed with human papillomavirus infection. What is the most significant long-term risk following this infection?
Your Answer: Cervical cancer
Explanation:Human-papilloma virus (HPV) can lead to cervical cancer. There are many different types, but the types associated with cervical cancer most commonly are 16, 18, 31, 33, and 35. The vaccination against HPV protects against the most common types of HPV that are seen in cervical cancer and is recommended for children/young teens. Cervical cancer has a clear association with HPV, making this the best answer over all of the other answer choices.
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This question is part of the following fields:
- Infectious Diseases
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Question 30
Incorrect
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Which of the following vaccines do not contain live organisms?
Your Answer: Polio (Sabin)
Correct Answer: Polio (Salk)
Explanation:Live virus vaccines include: Vaccinia (smallpox), Measles, Mumps, Rubella (MMR combined vaccine), Varicella (chickenpox), Influenza (nasal spray), Rotavirus, Zoster (shingles) and Yellow fever. Inactivated vaccines are Polio (IPV), Hepatitis A and Rabies.
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This question is part of the following fields:
- Infectious Diseases
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SESSION STATS - PERFORMANCE PER SPECIALTY
