Infection for PLAB 1

A 27 year old man has a fever, a widespread maculopapular rash, a sore throat, mouth ulcers and tender cervical lymphadenopathy for five days. He had unprotected sex with a new partner three weeks ago. His Monospot is negative. He feels systemically unwell but is haemodynamically stable. What is the SINGLE most likely diagnosis?

1. Infectious mononucleosis Fever, sore throat and swollen glands (lymphadenopathy), with unusual-looking white cells (atypical lymphocytes) on the blood film. This is the illness that most often gets mistaken for seroconversion. It does not fit a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot.
2. Cerebral toxoplasmosis A brain infection causing weakness or another localised sign (focal neurology) and headache, with ring-shaped bright spots on the scan, at a CD4 count (immune cell count) below 100. Here, a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot points elsewhere.
3. Human immunodeficiency virus (HIV) correct Correct. An illness that looks like glandular fever, with a rash and mouth ulcers, a negative Monospot test, and a clear recent exposure. Seroconversion (the body's first reaction to the virus) is the diagnosis most often missed because it looks like an ordinary sore throat.
4. Seroconversion illness Fever, a raised spotty rash (maculopapular rash), a sore throat, mouth ulcers and swollen glands (lymphadenopathy), two to four weeks after exposure. That does not match a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot.
5. Pneumocystis pneumonia Breathlessness that gets steadily worse, with a dry cough and a big drop in the oxygen level on exertion that looks far worse than the nearly normal chest X-ray. But a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot does not point to it.

The point: Offer an HIV test much more often than feels needed. Test everyone who registers with a GP or is admitted to hospital in an area where HIV is common, anyone with an indicator condition (an illness that is much more common with HIV and should make you test for it), and anyone who asks for one. The standard test looks for both a piece of the virus and the body's antibody to it (a fourth-generation antigen-antibody test), and it can find infection from about four weeks. After one known exposure, repeat it at twelve weeks to rule the infection out for good. Seroconversion (the short illness the body has when it first meets the virus) looks like glandular fever, with fever, a rash, a sore throat and swollen glands (lymphadenopathy). This is the point where the diagnosis is missed most often, because it looks like an ordinary viral illness. Start treatment (antiretroviral therapy) in everyone, whatever the CD4 count (the blood test that shows how many defence cells are left). The CD4 count then sets the risk of an opportunistic infection (an infection that only takes hold because the immune system is weak): Pneumocystis pneumonia below a CD4 of 200, which is also the point to start preventive antibiotics, and cerebral toxoplasmosis (a brain infection) and cryptococcal disease (a fungal infection) at an even lower count. Give post-exposure prophylaxis (medicine to stop the virus taking hold after a likely exposure) within 72 hours, and offer pre-exposure prophylaxis (medicine taken beforehand to prevent infection) to people at ongoing risk. The choice to test belongs to the patient alone, and the result stays private.

Source: BHIVA — Guidelines for the routine investigation and monitoring of adult HIV-1-positive individuals British HIV Association · tier 2, specialty society or college

A 27 year old man has a fever, a widespread maculopapular rash, a sore throat, mouth ulcers and tender cervical lymphadenopathy for five days. He had unprotected sex with a new partner three weeks ago. His Monospot is negative. He feels systemically unwell but is haemodynamically stable. What is the SINGLE most appropriate initial investigation?

1. Screen for coinfection and other sexually transmitted infections Hepatitis B, hepatitis C, syphilis and the rest, because these infections often occur together and change the treatment plan. Here, a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot points elsewhere.
2. Chest radiograph and induced sputum For breathing symptoms, though the X-ray is often nearly normal in Pneumocystis pneumonia. But a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot does not point to it.
3. CD4 count and HIV viral load The CD4 count (immune cell count) shows how weak the immune system is and predicts the risk of an opportunistic infection. The viral load (how much virus is in the blood) shows how well treatment is working. That does not match a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot.
4. HIV RNA (viral load) in suspected seroconversion correct Correct. At three weeks the antigen-antibody test may still be negative, but the amount of virus in the blood (viral load) is very high in a fresh infection, so this test picks it up before antibodies appear.
5. Repeat the test at 12 weeks after a specific exposure There is a gap (the window period) before the test can pick up a new infection, so a negative test before twelve weeks does not rule out infection after a known exposure. It does not fit a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot.

The point: Offer an HIV test much more often than feels needed. Test everyone who registers with a GP or is admitted to hospital in an area where HIV is common, anyone with an indicator condition (an illness that is much more common with HIV and should make you test for it), and anyone who asks for one. The standard test looks for both a piece of the virus and the body's antibody to it (a fourth-generation antigen-antibody test), and it can find infection from about four weeks. After one known exposure, repeat it at twelve weeks to rule the infection out for good. Seroconversion (the short illness the body has when it first meets the virus) looks like glandular fever, with fever, a rash, a sore throat and swollen glands (lymphadenopathy). This is the point where the diagnosis is missed most often, because it looks like an ordinary viral illness. Start treatment (antiretroviral therapy) in everyone, whatever the CD4 count (the blood test that shows how many defence cells are left). The CD4 count then sets the risk of an opportunistic infection (an infection that only takes hold because the immune system is weak): Pneumocystis pneumonia below a CD4 of 200, which is also the point to start preventive antibiotics, and cerebral toxoplasmosis (a brain infection) and cryptococcal disease (a fungal infection) at an even lower count. Give post-exposure prophylaxis (medicine to stop the virus taking hold after a likely exposure) within 72 hours, and offer pre-exposure prophylaxis (medicine taken beforehand to prevent infection) to people at ongoing risk. The choice to test belongs to the patient alone, and the result stays private.

Source: BHIVA — Guidelines for the routine investigation and monitoring of adult HIV-1-positive individuals British HIV Association · tier 2, specialty society or college

A 27 year old man has a fever, a widespread maculopapular rash, a sore throat, mouth ulcers and tender cervical lymphadenopathy for five days. He had unprotected sex with a new partner three weeks ago. His Monospot is negative. He feels systemically unwell but is haemodynamically stable. What is the SINGLE most appropriate immediate management?

1. Post-exposure prophylaxis within 72 hours Medicine taken for 28 days after a real risk of exposure. The sooner it is started, the better it works. It does not fit a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot.
2. Refer to the HIV specialist service correct Correct. Diagnosis, staging and treatment are led by the specialist team, who also handle telling past partners in confidence.
3. Notify partners with the patient's consent Done through the specialist service, and it is private and only with the patient's agreement, never forced disclosure. But a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot does not point to it.
4. Pre-exposure prophylaxis for those at ongoing risk Tenofovir with emtricitabine, two drugs taken beforehand by people at continuing high risk of catching HIV. That does not match a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot.
5. Co-trimoxazole prophylaxis for a CD4 below 200 An antibiotic that prevents Pneumocystis pneumonia, and it is one of the treatments that saves the most lives in advanced disease. Here, a seroconversion illness (first reaction to the virus) three weeks after unprotected sex with a negative Monospot points elsewhere.

The point: Offer an HIV test much more often than feels needed. Test everyone who registers with a GP or is admitted to hospital in an area where HIV is common, anyone with an indicator condition (an illness that is much more common with HIV and should make you test for it), and anyone who asks for one. The standard test looks for both a piece of the virus and the body's antibody to it (a fourth-generation antigen-antibody test), and it can find infection from about four weeks. After one known exposure, repeat it at twelve weeks to rule the infection out for good. Seroconversion (the short illness the body has when it first meets the virus) looks like glandular fever, with fever, a rash, a sore throat and swollen glands (lymphadenopathy). This is the point where the diagnosis is missed most often, because it looks like an ordinary viral illness. Start treatment (antiretroviral therapy) in everyone, whatever the CD4 count (the blood test that shows how many defence cells are left). The CD4 count then sets the risk of an opportunistic infection (an infection that only takes hold because the immune system is weak): Pneumocystis pneumonia below a CD4 of 200, which is also the point to start preventive antibiotics, and cerebral toxoplasmosis (a brain infection) and cryptococcal disease (a fungal infection) at an even lower count. Give post-exposure prophylaxis (medicine to stop the virus taking hold after a likely exposure) within 72 hours, and offer pre-exposure prophylaxis (medicine taken beforehand to prevent infection) to people at ongoing risk. The choice to test belongs to the patient alone, and the result stays private.

Source: BHIVA — Guidelines for the routine investigation and monitoring of adult HIV-1-positive individuals British HIV Association · tier 2, specialty society or college