Measles is a highly contagious viral infection that can lead to severe illness and complications, especially in young infants. In this scenario, the 8-month-old baby boy has come into close contact with another child with measles, putting him at risk for contracting the infection.

The most appropriate management in this situation would be to administer the MMR vaccine now, as well as measles immunoglobulin. This is because the baby is younger than 12 months and therefore at higher risk for severe illness from measles. The MMR vaccine can be given in place of immunoglobulin if administered within 72 hours of exposure, which is why it is recommended to give both the vaccine and immunoglobulin now.

It is important to protect young infants from measles, as they are more vulnerable to complications from the infection. By providing both the MMR vaccine and measles immunoglobulin, the baby can receive immediate protection against measles and reduce the risk of developing the infection.

The appropriate investigations for suspected epididymo-orchitis depend on the patient’s age and sexual history. For sexually active younger adults, a nucleic acid amplification test for sexually transmitted infections is the first-line investigation. This is because organisms such as Chlamydia trachomatis and gonorrhoeae are common causes of epididymo-orchitis in this population. On the other hand, older adults with a low-risk sexual history would require a midstream sample of urine for culture to identify organisms such as E coli.

Prescribing levofloxacin without determining the causative organism is not recommended. Antibiotic therapy should be tailored to the specific organism causing the infection. For example, doxycycline is used to treat Chlamydia trachomatis, while ceftriaxone is used to treat gonorrhea. Quinolone antibiotics like ofloxacin or levofloxacin are commonly used to treat E coli infections.

Taking blood for HIV testing is not necessary in this case, as the patient’s symptoms suggest epididymo-orchitis rather than HIV. The focus should be on investigating the cause of the scrotal swelling and discomfort, which can be achieved through a nucleic acid amplification test for sexually transmitted infections.

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.

Cryptococcal meningitis is a serious fungal infection that affects the brain and spinal cord, particularly in individuals with weakened immune systems such as those living with HIV. The recommended treatment for cryptococcal meningitis in this population is combination therapy with amphotericin B and fluconazole.

Amphotericin B is a potent antifungal medication that is effective in treating cryptococcal meningitis. It is typically administered intravenously to achieve high levels in the cerebrospinal fluid where the infection is located. However, amphotericin B can have significant side effects, including kidney toxicity, which is why it is often used in combination with another antifungal medication.

Fluconazole is an oral antifungal medication that is also effective in treating cryptococcal meningitis. When used in combination with amphotericin B, fluconazole helps to enhance the effectiveness of the treatment and reduce the risk of relapse. This combination therapy has been shown to improve outcomes and reduce mortality rates in patients with cryptococcal meningitis.

Overall, combination therapy with amphotericin B and fluconazole is the recommended treatment for cryptococcal meningitis in adults, adolescents, and children living with HIV who test positive for cryptococcal antigen (CrAg) in cerebrospinal fluid (CSF). It is important for healthcare providers to closely monitor patients receiving this treatment to ensure optimal outcomes and manage any potential side effects.

Non-alcoholic steatohepatitis (NASH) is a form of non-alcoholic fatty liver disease (NAFLD) that is characterized by inflammation and liver cell damage, in addition to the presence of fat in the liver. NASH can progress to more serious liver conditions such as cirrhosis or liver cancer.

Out of the options provided, Type 1 diabetes mellitus is not typically associated with NASH. Type 2 diabetes, on the other hand, is a common risk factor for NASH.

Hyperlipidemia, obesity, sudden weight loss or starvation, and jejunoileal bypass are all risk factors for NASH. Hyperlipidemia refers to high levels of fats in the blood, which can contribute to the accumulation of fat in the liver. Obesity is a major risk factor for NASH, as excess body fat can lead to fat accumulation in the liver. Sudden weight loss or starvation can also contribute to the development of NASH, as rapid weight loss can lead to the release of stored fats into the liver. Jejunoileal bypass, a type of weight loss surgery, can also increase the risk of NASH due to changes in the way the body processes fats.

In summary, while Type 1 diabetes mellitus is not associated with NASH, hyperlipidemia, obesity, sudden weight loss or starvation, and jejunoileal bypass are all risk factors for the development of this serious liver condition.

This question is testing the candidate’s knowledge of the management of infants exposed to maternal HIV. In this scenario, the 6-month-old girl has tested positive for HIV, despite being clinically healthy and meeting normal developmental milestones.

The most appropriate next step in this situation is to start co-trimoxazole prophylaxis immediately. Co-trimoxazole is recommended for all infants exposed to maternal HIV, regardless of their CD4 levels, to prevent opportunistic infections. Antiretroviral therapy is also necessary for infants with confirmed HIV infection, but it can wait until further work-up is complete.

Therefore, the correct answer is: Start co-trimoxazole prophylaxis immediately and plan to start antiretrovirals once further work-up is complete. This approach ensures that the infant receives the necessary prophylaxis to prevent infections while allowing time for additional testing and evaluation before starting antiretroviral therapy.

The question presents a scenario where a surgical intern who was prescribed post-exposure prophylaxis following a needlestick injury presents with yellowing of her sclerae one week later. The key to answering this question lies in recognizing the side effects of the drugs listed in the options.

Out of the options provided, Ritonavir is the drug most likely to be implicated in causing the yellowing of the sclerae. Ritonavir is a protease inhibitor commonly used in the treatment of HIV/AIDS. One of the known side effects of Ritonavir is liver toxicity, which can manifest as jaundice (yellowing of the skin and eyes). This is due to the drug’s potential to cause damage to the liver cells, leading to impaired bilirubin metabolism and excretion.

Therefore, in this scenario, the surgical intern presentation of yellowing of the sclerae with no other clinical signs is most likely due to Ritonavir-induced hepatotoxicity. It is important for healthcare providers to be aware of the potential side effects of medications, especially in the context of post-exposure prophylaxis, to promptly recognize and manage any adverse reactions that may occur.

Infants born to mothers diagnosed with TB are at a higher risk of contracting the disease themselves, even if they are asymptomatic at birth. TB preventive therapy (TPT) is recommended for these infants to reduce the risk of developing active TB later in life. BCG vaccination is also recommended as it can provide some protection against severe forms of TB in infants.

Initiating ART immediately is not necessary for asymptomatic infants born to mothers with TB, as they are not yet showing symptoms of the disease. Discontinuing breastfeeding is not recommended, as breastfeeding is important for the overall health and development of the infant. Conducting a sputum culture test is not necessary for asymptomatic infants, as they are not showing any signs of TB. Admitting the infant to the hospital for observation is also not necessary unless there are specific concerns about the infant’s health.

Hepatitis B is a viral infection that affects the liver. When someone is infected with hepatitis B, their immune system will typically clear the virus within a few months. However, in some cases, the virus is not completely eliminated from the body and the infection becomes chronic.

The percentage of patients with hepatitis B that develop chronic infection is about 10%. This means that out of every 100 people infected with hepatitis B, approximately 10 will go on to develop a chronic infection. Chronic hepatitis B can lead to serious complications such as cirrhosis (scarring of the liver) and hepatocellular carcinoma (a type of liver cancer).

On the other hand, about 90% of people who are infected with hepatitis B will develop lifelong immunity after clearing the infection. This means that their immune system will be able to recognize and fight off the virus if they are exposed to it again in the future.

The risk of chronic infection and complications like cirrhosis and hepatocellular carcinoma is higher in individuals who are infected with hepatitis B at birth (congenital infection) compared to healthy adults. In healthy adults, the risk of chronic infection and liver complications is lower, at around 5%.

Overall, it is important for individuals who are at risk of hepatitis B infection to get vaccinated and for those who are already infected to receive appropriate medical care and monitoring to prevent the development of chronic infection and its complications.

Pelvic Inflammatory Disease and its Causes

Pelvic inflammatory disease (PID) is a condition that is consistent with the patient’s history. According to guidelines from the British Association for Sexual Health and HIV (BASHH), triple antibiotic therapy is the recommended treatment for PID. However, in pregnant patients, doxycycline is contraindicated and is substituted with erythromycin.

There are several possible causes of PID, including endogenous vaginal flora, aerobic Streptococci, C. trachomatis, and N. gonorrhoeae. These microorganisms can cause inflammation of the female reproductive organs, leading to PID. It is important to identify the cause of PID to ensure appropriate treatment and prevent complications such as infertility and chronic pelvic pain. By the causes of PID, healthcare providers can take steps to prevent its occurrence and provide effective treatment to those affected.

Diagnosis and Management of HIV Nephropathy

HIV infection is a high possibility in a patient with risk factors and presenting with emaciation, oral ulcers, and lymphopenia. A CD4 count and HIV serological testing should be done urgently. HIV nephropathy is a common complication, with focal and segmental glomerulosclerosis being the most common pathological diagnosis. Other variants include membranoproliferative nephropathy, diffuse proliferative glomerulonephritis, minimal change disease, and IgA nephropathy. Treatment involves ACE inhibitors and antiretroviral therapy, with dialysis being necessary in end-stage disease. Renal biopsy is required to confirm the diagnosis, but HIV testing should be performed first. Serum IgA levels are elevated in IgA nephropathy, while serum complement levels and anti-nuclear factor are needed in SLE-associated nephropathy or other connective tissue diseases or vasculitis. However, the lack of systemic symptoms points away from these diagnoses.

The diagnosis of HIV is predominantly made through the detection of HIV antibodies and p24 antigen. When a person is infected with HIV, their immune system produces antibodies to fight the virus. These antibodies can be detected through various tests, such as ELISA and Western blot. Additionally, the p24 antigen is a protein found on the surface of the HIV virus and can also be detected in the blood.

Viral PCR, or viral load testing, is used to measure the amount of HIV in the blood and is often used to monitor the progression of the disease and the effectiveness of treatment. CD4 count, on the other hand, measures the number of CD4 T-cells in the blood, which are a type of white blood cell that is targeted and destroyed by HIV. A low CD4 count indicates a weakened immune system and progression of the disease.

Thick and thin blood films, viral culture, and electron microscopy are not commonly used for the diagnosis of HIV.

ART initiation is a complex process that requires specialized training and knowledge in HIV treatment and management. NIMART (Nurse-Initiated Management of Antiretroviral Treatment) trained nurses and doctors have received specific training in initiating and managing ART for patients with HIV. They have the necessary skills to assess a patient’s eligibility for ART, prescribe the appropriate medications, monitor treatment progress, and manage any potential side effects or complications.

General physicians, community health workers, pharmacists, and social workers may also play important roles in supporting patients throughout their HIV treatment journey, but the primary responsibility for ART initiation typically falls on NIMART trained nurses or doctors. Their specialized training and expertise make them well-equipped to provide high-quality care and ensure the best possible outcomes for patients starting ART.

Individuals with HIV who also have schizophrenia require careful consideration when selecting psychotropic medications due to potential drug interactions and side effects. In this case, the most suitable treatment option for psychosis in individuals with HIV is risperidone, an atypical antipsychotic with a strong evidence base. Risperidone has been shown to effectively treat psychosis while minimizing the risk of adverse effects and drug interactions in individuals with HIV.

Other atypical antipsychotics such as quetiapine, aripiprazole, and olanzapine are also viable options for treating psychosis in individuals with HIV. However, clozapine may be considered as a last resort due to the need for close monitoring and potential risks associated with its use in this population.

It is important for the physician overseeing the medical care of the 50-year-old man with schizophrenia and HIV to carefully consider the potential benefits and risks of each treatment option before making a decision. Close monitoring and regular follow-up appointments are essential to ensure the safety and effectiveness of the chosen psychotropic medication in managing psychosis in individuals with HIV.

The question asks about an antifungal agent given to a 27-year-old HIV patient that inhibits the biosynthesis of fungal ergosterol. The correct answer is Ketoconazole.

Ketoconazole is a synthetic imidazole antifungal drug that works by inhibiting the biosynthesis of ergosterol in fungi. Ergosterol is an essential component of the fungal cell membrane, and its inhibition disrupts the integrity of the membrane, leading to cell death. Ketoconazole achieves this by blocking demethylation at the C14 site of the ergosterol precursor.

The other options provided in the question are different antifungal agents with varying mechanisms of action. Amphotericin B and Nystatin work by impairing the permeability of the fungal cell membrane. Flucytosine interferes with DNA synthesis in fungi, while Griseofulvin targets the microtubules within the fungal cells.

In summary, Ketoconazole is the correct answer as it inhibits the biosynthesis of fungal ergosterol, making it an effective treatment for fungal infections in patients like the one described in the question.

The 60-year-old male in this scenario developed profuse, watery, green coloured diarrhoea on the fifth day of IV antibiotics for severe pneumonia. This is likely due to pseudomembranous colitis, which is caused by Clostridium difficile. Pseudomembranous colitis is an inflammatory condition of the colon that occurs when the normal balance of gut flora is disrupted by antibiotics, allowing for the overgrowth of C. difficile.

Clostridium difficile is a bacterium that can produce toxins which damage the lining of the colon, leading to symptoms such as severe diarrhoea, abdominal pain, and fever. The risk of developing pseudomembranous colitis is higher with certain antibiotics, including ampicillin, clindamycin, fluoroquinolones, and cephalosporins.

Therefore, in this case, the most likely organism responsible for the profuse, watery, green coloured diarrhoea is Clostridium difficile. It is important to promptly diagnose and treat pseudomembranous colitis to prevent complications and improve the patient’s outcome.

For clients on TLD who have never failed a previous ART regimen and have a viral load ≥ 1000 c/mL, the approach of providing enhanced adherence support without resistance testing as a rule is based on the fact that the TLD regimen contains dolutegravir (DTG), which has a high genetic barrier to resistance. This means that even in cases where the viral load is elevated, there is a lower likelihood of developing resistance to DTG compared to other antiretroviral drugs.

By providing enhanced adherence support, healthcare providers can work with the client to address any barriers to adherence and ensure that the medication is being taken consistently and correctly. This approach allows for the possibility of achieving viral suppression without the need for resistance testing or immediate switching to a third-line regimen.

In cases where adherence support alone is not sufficient to achieve viral suppression, resistance testing may be considered to guide the selection of an appropriate alternative regimen. However, the initial approach of focusing on adherence support is a reasonable first step given the high genetic barrier of DTG and the potential for successful viral suppression with improved adherence.

When a client on TLD (Tenofovir/Lamivudine/Dolutegravir) has a viral load ≥ 1000 c/mL after at least two years on treatment and adherence over 80%, it is important to determine the cause of treatment failure before making any changes to the regimen. Resistance testing is recommended in this situation to identify any mutations in the virus that may be causing the treatment failure.

Switching to a second-line ART regimen immediately without knowing the resistance profile of the virus could lead to further treatment failure and development of drug resistance. Doubling the current ART dose is not recommended as it may increase the risk of side effects without necessarily improving treatment efficacy. Focusing on diet and lifestyle changes may be beneficial for overall health but is not a sufficient strategy for managing treatment failure.

Initiating counseling for treatment adherence is important, but in this case, resistance testing should be prioritized to guide the next steps in treatment. Therefore, the correct answer is to perform resistance testing before any regimen changes.

In this case, the best management for the 6-year-old boy who injured his hand with a metal spike would be to administer Tetanus Ig (immunoglobulin) along with antibiotics. Tetanus Ig provides immediate passive immunity against tetanus, while antibiotics help prevent any potential infection from developing in the wound.

It is important to note that the boy’s immunization schedule is up-to-date, which means he has likely received the tetanus vaccine as part of his routine vaccinations. However, since the wound is considered tetanus-prone due to being a puncture wound and potentially contaminated with debris, it is still recommended to administer Tetanus Ig as an extra precaution.

In summary, the appropriate management for this patient would be Tetanus Ig along with antibiotics to prevent tetanus infection and promote healing of the wound.

The physician is seeking advice on prescribing an antidepressant for a depressed patient with HIV who is taking atazanavir. Atazanavir is an antiretroviral drug used to manage HIV, and it is important to consider potential drug interactions when prescribing other medications. In this case, the antidepressant St John’s Wort should be avoided due to its contraindication with atazanavir. St John’s Wort can reduce the efficacy of antiretroviral drugs, potentially leading to treatment failure and increased risk of HIV progression.

Among the other options provided, paroxetine, citalopram, sertraline, and amitriptyline do not have significant interactions with atazanavir and can be considered for the patient. It is important for the physician to carefully review the patient’s medical history, current medications, and potential drug interactions before prescribing an antidepressant to ensure safe and effective treatment for both depression and HIV.

Dolutegravir (DTG) is an antiretroviral medication used to treat HIV infection. In children from ≥ 3 kg and ≥ 4 weeks of age, the recommended formulation of DTG is 10 mg dispersible tablets. These tablets are specifically designed for pediatric use and are easier for children to take compared to other formulations.

Escherichia coli (also known as E. coli) is a gram-negative, facultatively anaerobic, rod-shaped bacterium commonly found in the lower intestine of warm-blooded organisms. Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in their hosts, and are occasionally responsible for product recalls due to food contamination. The harmless strains are part of the normal flora of the gut, and can benefit their hosts by producing vitamin K2, and preventing colonization of the intestine with pathogenic bacteria. Virulent strains can cause gastroenteritis, urinary tract infections, and neonatal meningitis.
The most common causes of neonatal meningitis is bacterial infection of the blood, known as bacteremia (specifically Group B Streptococci (GBS; Streptococcus agalactiae), Escherichia coli, and Listeria monocytogenes). Although there is a low mortality rate in developed countries, there is a 50% prevalence rate of neurodevelopmental disabilities in E. coli and GBS meningitis

Isoniazid is the drug associated with peripheral neuropathy in this case. This side effect occurs due to a deficiency of biologically active pyridoxine (Vitamin B6). Isoniazid can combine with pyridoxine in the body to form a hydrazone, which is then excreted in the urine, leading to a decrease in the levels of pyridoxine available for normal bodily functions.

To prevent or reduce the risk of peripheral neuropathy associated with isoniazid, pyridoxine supplementation is often recommended. Pyridoxine is essential for nerve function and can help counteract the deficiency caused by isoniazid. Therefore, patients taking isoniazid for the treatment of Pulmonary Tuberculosis may also be prescribed pyridoxine to prevent peripheral neuropathy.

Pregnant women should be tested for HIV regularly throughout pregnancy and breastfeeding because HIV can be transmitted from mother to child during pregnancy, childbirth, and breastfeeding. By testing regularly, healthcare providers can monitor the mother’s HIV status and take appropriate measures to prevent transmission to the baby. Testing at the beginning of pregnancy helps to identify women who are HIV positive and may need treatment to prevent transmission to their baby. Monthly testing throughout pregnancy and at the 10-week EPI visit allows for close monitoring of the mother’s HIV status and ensures that appropriate interventions can be implemented if necessary. Testing at labor/delivery is important to determine the mother’s HIV status at the time of childbirth, and testing every 3 months during breastfeeding helps to monitor the mother’s HIV status and prevent transmission to the baby through breast milk. Overall, regular testing throughout pregnancy and breastfeeding is essential to ensure the health and well-being of both the mother and the baby.

Chickenpox is primarily spread through airborne transmission, meaning that the virus can be spread through respiratory droplets when an infected person coughs or sneezes. This allows the virus to be inhaled by others in close proximity, leading to infection. Close contact with an infected person, such as touching the rash or sharing personal items, can also spread the virus. Additionally, chickenpox can be transmitted through droplets of saliva or mucus, which can contaminate surfaces and objects, leading to indirect transmission through touch. Overall, the main modes of spread for chickenpox are airborne and close contact.

It is important for women who opt not to be tested for HIV during prenatal visits to still have access to information and support regarding their decision. Offering ‘post-refusal’ counseling allows healthcare providers to address any concerns or misconceptions the woman may have about HIV testing, and to provide education on the importance of testing for both her own health and the health of her baby.

Providing the option for re-testing at every subsequent visit ensures that the woman has ongoing opportunities to change her mind and consent to testing if she wishes. This approach respects the woman’s autonomy while also prioritizing the health and well-being of both her and her baby.

Immediate ART initiation without testing, discontinuing prenatal care, or mandatory testing regardless of consent are not recommended approaches as they do not respect the women’s autonomy and may lead to negative outcomes for both the woman and her baby. Offering a one-time test at delivery may not provide enough time for appropriate interventions to be implemented if the woman is found to be HIV positive.

In summary, offering ‘post-refusal’ counseling and re-testing at every subsequent visit is the recommended approach for women who choose not to be tested for HIV during prenatal visits.

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.

Interferon-alpha is a commonly used medication for the treatment of hepatitis C, but it is known to have a variety of side effects. In this case, the most common side effects of interferon-alpha are flu-like symptoms and a transient rise in ALT levels.

Flu-like symptoms such as fever, chills, muscle aches, and fatigue are commonly reported by patients taking interferon-alpha. These symptoms can be quite bothersome and may lead to decreased quality of life during treatment. Additionally, interferon-alpha can cause a temporary increase in liver enzyme levels, specifically ALT, which is a marker of liver inflammation.

Other common side effects of interferon-alpha include nausea, fatigue, and psychiatric issues such as depression and anxiety.

Human papillomavirus (HPV) is a common sexually transmitted infection that can lead to the development of various cancers, including cervical cancer. The onco-proteins associated with HPV infection are E6 and E7. These onco-proteins play a crucial role in the development of cancer by inactivating tumor suppressor proteins.

E6 oncoprotein is responsible for inactivating the p53 tumor suppressor protein, which plays a key role in regulating cell growth and preventing the formation of tumors. By inactivating p53, E6 allows infected cells to continue to divide uncontrollably, leading to the development of cancer.

E7 oncoprotein, on the other hand, inactivates the pRb tumor suppressor protein, which also helps regulate cell growth and division. By inactivating pRb, E7 allows infected cells to bypass normal cell cycle control mechanisms, leading to uncontrolled cell growth and the development of cancer.

Therefore, the correct answer to the question is E6 and E7, as these onco-proteins are directly involved in the development of HPV-related cancers by inactivating important tumor suppressor proteins.

Herpes Simplex Virus (HSV) infection in neonates can be a serious and life-threatening condition, especially when it presents as disseminated infection. In this case, the infant was treated with antivirals upon clinical suspicion, which is crucial in improving outcomes.

The case fatality rate of infants who develop disseminated HSV despite treatment is 0.3, or 30%. This means that even with treatment, there is still a significant risk of mortality for these infants. However, without treatment, the case fatality rate for disseminated HSV infection is much higher at 85%.

It is important for healthcare providers to be vigilant for signs of HSV infection in neonates, especially in cases where the mother has a history of HSV or had a recent outbreak before delivery. Early recognition and prompt treatment with antivirals can greatly improve the chances of survival for these infants.

HIV primarily targets and destroys CD4+ lymphocytes, which are a type of white blood cell that plays a crucial role in the immune system. CD4+ lymphocytes are responsible for coordinating the body’s immune response to infections and diseases. When HIV infects these cells, it replicates inside them and eventually leads to their destruction. As the number of CD4+ lymphocytes decreases, the body becomes more susceptible to infections and is unable to mount an effective immune response.

The destruction of CD4+ lymphocytes by HIV ultimately leads to immunodeficiency, where the body’s immune system is weakened and unable to effectively fight off infections. This is why individuals with HIV are at a higher risk of developing opportunistic infections and certain types of cancers. By targeting and destroying CD4+ lymphocytes, HIV undermines the body’s ability to protect itself, resulting in the development of acquired immunodeficiency syndrome (AIDS) in untreated individuals.