Synopsis
Confirm and explain a new HIV diagnosis, identify immediate clinical danger, and turn the first specialist encounter into a safe, individualised treatment and prevention plan.
- Screen with a laboratory fourth-generation HIV-1/2 antigen–antibody assay, and submit every reactive result to the national confirmation pathway before calling it a definitive diagnosis.
- Very early infection may precede antigen, antibody or rapid-test reactivity, so request HIV RNA when the exposure and illness suggest acute HIV; hypoxia, neurological change or visual loss also triggers immediate syndrome-directed specialist care.
- Discuss the result privately and without blame, arrange same-day HIV-service linkage, and before or at ART initiation obtain CD4, viral load, genotype, blood count, renal and liver tests, hepatitis B and C, exposure-site STI tests and pregnancy assessment when relevant.
Key red flags
Breathlessness with dry cough and hypoxia in advanced HIV raises concern for Pneumocystis pneumonia and requires urgent oxygenation assessment, blood gas and chest imaging.
Headache, confusion, meningism, a focal deficit or reduced consciousness needs urgent specialist CNS investigation; safe sampling and ART sequencing depend on the syndrome found.
New floaters, reduced acuity or a field defect during severe immune suppression requires same-day HIV and ophthalmology review with dilated retinal examination.
A febrile rash illness with pharyngitis or lymphadenopathy after recent exposure may be primary HIV even when an early antigen–antibody result is negative.
Severe weight loss, prolonged diarrhoea, oesophageal symptoms, oral candidiasis or recurrent infection makes advanced immune deficiency clinically likely before the CD4 result returns.
A person receiving a reactive antenatal or donor screen needs prompt confirmation, privacy, support and specialist linkage before the preliminary result is framed as final.
Fever, diffuse rash, sore throat, lymphadenopathy, diarrhoea, myalgia, headache or aseptic meningitic symptoms after recent risk should prompt RNA testing when serology is early.
Dyspnoea, wasting, chronic diarrhoea, oesophageal pain, neurological features or atypical skin disease suggests major CD4 depletion and demands same-day assessment.
Self-harm thoughts, overwhelming distress, partner violence, coercion, housing insecurity or confidentiality danger need active support during diagnostic care.
Investigation priorities
Detect p24 antigen and antibody as the standard screening step for many established and early infections.
Management branches
A screening laboratory or point-of-care result has returned reactive.
- Clarify that the result is preliminary, protect privacy and assess immediate emotional safety before giving more technical detail.
- Send the required confirmatory samples and check whether recent exposure, PrEP or PEP makes HIV RNA particularly important.