Acute HIV Infection

Acute HIV infection is the first weeks after viral transmission, when plasma viral load is high, p24 antigen is detectable, and antibodies are absent or incomplete. A symptomatic seroconversion illness occurs in about 50 to 90 percent of people, 2 to 4 weeks after exposure.

• Transmission risk per exposure is very high during this phase because viral load often exceeds 1 million copies/mL.
• Antibody based rapid tests are frequently negative; delay in recognition causes onward transmission.

Fever, sore throat, malaise, myalgia, arthralgia, headache, lymphadenopathy, maculopapular rash on trunk and face, mucocutaneous ulceration (oral, genital, oesophageal), diarrhoea, weight loss.

• Neurological features: aseptic meningitis, Guillain Barre syndrome, facial palsy, encephalopathy; transient CD4 fall may allow opportunistic infections such as oral candidiasis or pneumocystis pneumonia.
• Differential diagnosis: malaria, dengue, infectious mononucleosis (EBV), cytomegalovirus infection, secondary syphilis, rubella, measles, hepatitis A and B, viral pharyngitis, typhoid, toxoplasmosis, drug reaction, influenza, chikungunya.
• Complications: opportunistic infections, neurological disease, rapid establishment of viral reservoirs, onward transmission, rapid progression in some, transmitted drug resistance.

Test for HIV when features are compatible and exposure is recent (within 2 to 6 weeks).

• Fourth generation antigen and antibody assay; HIV RNA PCR (viral load) if antibody negative or indeterminate; follow with antibody test in 4 weeks and again at 3 months to confirm.
• Baseline CD4 count, viral load, genotypic resistance test if available, full blood count, creatinine, liver enzymes, hepatitis B surface antigen, hepatitis C antibody, syphilis serology, tuberculosis symptom screen, pregnancy test, cryptococcal antigen if CD4 under 200, glucose and lipids.
• Screen for other sexually transmitted infections.

Start antiretroviral therapy on the day of diagnosis (or within 7 days) without waiting for confirmatory results.

• Supportive: counselling, paracetamol 1 g for fever and myalgia, oral hydration, partner notification and testing, condom use, disclosure support, adherence preparation, treat depression.
• Pharmacological: tenofovir disoproxil fumarate 300 mg, lamivudine 300 mg and dolutegravir 50 mg as a once daily fixed dose combination. Start with rifampicin free regimen; if tuberculosis is present, give dolutegravir 50 mg twice daily during rifampicin and for 2 weeks after it stops. Cotrimoxazole 960 mg daily if CD4 under 350 or symptomatic. Hepatitis B coinfection: tenofovir and lamivudine cover both infections; do not interrupt. Pre exposure prophylaxis for partners: tenofovir disoproxil fumarate 300 mg with emtricitabine 200 mg daily, or dapivirine ring, or injectable cabotegravir 600 mg IM at months 0, 1 and then every 2 months.
• Procedures: lumbar puncture when meningitis is suspected; none otherwise.
• Special groups: pregnancy, give tenofovir, lamivudine and dolutegravir at once; infants and children, weight based regimens with dolutegravir (abacavir and lamivudine for under 30 kg per formulation); renal impairment, replace tenofovir with abacavir 600 mg daily if creatinine clearance under 50 mL/min; adolescents, adherence support.
• Red flags: severe headache or confusion (cryptococcal or HIV meningitis), persistent diarrhoea, severe oesophageal symptoms, dyspnoea, pregnancy, CD4 under 200.
• Follow-up: viral load at 3 and 6 months then every 12 months once suppressed; creatinine at 3 months; adherence checks; partner testing.