About This Page
This is a clinician-written, evidence-based guide aligned to the MCC Examination Objectives. It is structured by clinical presentation — the way the MCCQE tests and the way patients actually present. Management reflects current Canadian guidelines (CMA, CFPC, CPS). Always cross-reference with institutional protocols and clinical judgment.
The Bottom Line
- HIV can present as acute retroviral syndrome, incidental screening, recurrent infections, STI presentation, pregnancy screening or AIDS-defining illness
- Acute HIV may have a negative or indeterminate antibody test early — order HIV RNA when the syndrome and exposure fit
- Initial staging requires viral load, CD4 count, baseline labs, resistance testing where available and STI/hepatitis/TB screening
- Modern management is rapid linkage to HIV care and early ART for essentially all patients
- The MCCQE1 also tests confidentiality, consent, partner notification, stigma reduction and trauma-informed communication
Approach to the Presentation
HIV is both an infectious-disease and communication presentation. In Canada, HIV is a sexually transmitted and blood-borne infection with important public health, prevention and confidentiality dimensions. Patients may present with acute seroconversion, an STI, pregnancy, abnormal screening, opportunistic infection, weight loss, lymphadenopathy or recurrent infections. The clinical approach is to test appropriately, explain results clearly, confirm diagnosis according to the local laboratory algorithm, stage disease, evaluate co-infections and link rapidly to HIV-experienced care.
Differential Diagnosis
| diagnosis | likelihood | key features | distinguishing test |
|---|---|---|---|
| Acute HIV seroconversion | must-not-miss | Fever, pharyngitis, rash, lymphadenopathy, mucosal ulcers, diarrhoea or aseptic meningitis after sexual/blood exposure | HIV Ag/Ab plus HIV RNA if early infection suspected |
| Advanced HIV/AIDS with opportunistic infection | must-not-miss | Weight loss, chronic diarrhoea, oral candidiasis, recurrent infections, PJP, TB, cryptococcal meningitis, toxoplasmosis or CMV retinitis | HIV test plus CD4 count/viral load and syndrome-specific OI testing |
| HIV-associated tuberculosis | must-not-miss | Fever, night sweats, weight loss, cough or extrapulmonary disease; higher risk with low CD4 | CXR, sputum AFB smear/culture/NAAT or extrapulmonary sampling |
| Mononucleosis (EBV/CMV) | common | Fever, pharyngitis, lymphadenopathy and fatigue; EBV may have splenomegaly | Heterophile/EBV serology; HIV testing if risk or mucosal ulcers |
| Secondary syphilis | common | Rash including palms/soles, mucous patches, condylomata lata and generalized lymphadenopathy | Syphilis serology |
| Viral hepatitis B/C or other STBBI | common | Fatigue, jaundice, transaminitis and risk exposure; coinfections alter management | HBsAg, anti-HBs, anti-HBc, HCV Ab/RNA and liver enzymes |
| HIV stigma/psychosocial crisis | common | Distress, disclosure fears, IPV risk, housing/insurance/employment concerns | Sensitive psychosocial assessment |
| PJP pneumonia | less common | Subacute dry cough, fever, exertional dyspnea and hypoxia with low CD4 risk | CT chest and induced sputum/BAL testing |
| Cryptococcal meningitis | rare | Advanced HIV, headache, fever, raised ICP and cranial nerve palsies; neck stiffness may be absent | Serum/CSF cryptococcal antigen and CSF studies |
Red Flags & Key History
Symptoms
Recent high-risk exposure with fever, rash, pharyngitis, mucosal ulcers or lymphadenopathy
Dyspnea with hypoxia, severe headache, visual symptoms, focal neurological signs or altered mental status
Pregnancy with new HIV diagnosis
Weight loss, chronic diarrhoea, oral candidiasis, shingles, recurrent bacterial infections or TB symptoms
Disclosure safety, intimate partner violence, coercion or severe distress after diagnosis
Ask about PrEP/PEP eligibility, condom use, prior STIs, injection equipment and partners
Signs
Oral candidiasis, hairy leukoplakia, generalized lymphadenopathy, wasting or seborrhoeic dermatitis
Hypoxia, tachypnoea or normal chest exam despite dyspnea
Retinal symptoms, focal neurological deficit, meningism or raised ICP signs
Rash involving palms/soles or mucous lesions suggesting syphilis
Approach to Investigation
First-line
HIV screening test using local laboratory algorithmTypically 4th-generation Ag/Ab screening with confirmatory testing according to provincial lab process
HIV RNA viral loadEssential for staging and when acute HIV is suspected despite negative/indeterminate serology
CD4 countAssesses immune status and opportunistic infection prophylaxis needs
Baseline safety labsCBC, creatinine/eGFR, liver enzymes, bilirubin, glucose/A1c/lipids and urinalysis as regimen-relevant
Co-infection screenSyphilis, gonorrhoea/chlamydia site-specific NAAT, hepatitis A/B/C status, TB risk testing and pregnancy test when relevant
Second-line
HIV resistance testing / genotypeGuides regimen selection; do not delay urgent linkage to care
Regimen-specific testsHLA-B*57:01 if abacavir considered; other tests based on chosen ART
OI-directed testingCXR/CT, cryptococcal antigen, toxoplasma serology, CMV assessment or AFB testing depending on symptoms/CD4
Vaccination reviewHepatitis A/B, HPV, pneumococcal, influenza, COVID-19, meningococcal and others based on age/risk/CD4
Specialist
Rapid HIV-experienced care referralFor ART initiation, resistance interpretation, OI prophylaxis, interactions and psychosocial support
Public health / partner servicesPartner notification and reportable infection processes vary provincially but are integral
Management Principles
PHAC HIV guidance + Canadian HIV primary care guidance1
Communicating the diagnosis
- Confirm understanding, assess immediate safety and supports, and use stigma-free language
- Explain that HIV is treatable and sustained viral suppression prevents sexual transmission
- Protect confidentiality and discuss partner notification supports
2
Initial clinical management
- Link rapidly to HIV-experienced care for ART initiation
- Order viral load, CD4, baseline labs, co-infection screening and resistance testing as locally available
- Assess for opportunistic infections before or at ART start, especially if advanced disease symptoms are present
3
Prevention and public health
- Discuss condoms, U=U, partner testing, PrEP for partners and PEP for recent exposures
- Screen and treat STBBIs; review hepatitis B and HPV vaccination
- Follow provincial reporting and partner-notification requirements
4
Opportunistic infection risk
- Use CD4 count and symptoms to determine need for OI prophylaxis and investigations
- Do not start ART blindly in severe suspected cryptococcal or TB meningitis without specialist input because timing can be complex
Complications & Pitfalls
- Missing acute HIV: A mononucleosis-like illness after exposure needs HIV RNA if early serology may be negative.
- No CD4 count: CD4 guides opportunistic infection risk and prophylaxis.
- Delayed linkage: Modern care emphasises rapid ART linkage.
- Ignoring co-infections: Syphilis, hepatitis, TB and STIs are common co-diagnoses.
- Confidentiality breach: Partner notification should use appropriate consent/public-health pathways.
MCCQE1 Exam Tips
- 1Acute HIV clue: fever + rash + pharyngitis + mucosal ulcers + lymphadenopathy after exposure; order Ag/Ab and HIV RNA
- 2Initial staging after diagnosis: viral load, CD4, baseline labs, resistance testing, STI/hepatitis/TB screening
- 3Opportunistic infection symptoms are red flags; do not simply start routine outpatient ART if cryptococcal or TB meningitis is suspected
- 4HIV questions often test confidentiality, non-judgemental counselling, partner notification and stigma reduction
- 5U=U is relevant counselling: sustained undetectable viral load prevents sexual transmission
- 6Pregnancy with HIV requires urgent specialist linkage
practicetest your knowledge on hiv — diagnosis, staging & initial managementApply what you've learnt with MCCQE1-style questions from the iatroX Q-Bank — infectious disease and beyond.
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