This summary covers two distinct clinical scenarios: acute HIV infection (acute retroviral syndrome) occurring 2–6 weeks after transmission, and late/advanced HIV/AIDS presentation with opportunistic infections (OIs) in patients with previously undiagnosed or untreated HIV. Both are commonly encountered in the ED and primary care.
1. History
- Timing of exposure: Sexual contact (especially condomless), needle sharing, mucous membrane exposure — typically 2–6 weeks before symptom onset for acute retroviral syndrome [1]
- Symptom characterization: "Mono-like" illness — fever, sore throat, lymphadenopathy, rash, myalgias, headache, diarrhea, oral ulcers [1-2]
- Common symptoms in acute infection: fever (93%), fatigue (79%), pharyngitis (67%), headache (64%) in one large cohort [2]
- Median symptom count in ED-diagnosed acute HIV: 5 symptoms (IQR 3–6), with fever often accompanied by ≥3 other symptoms [3]
- For advanced/AIDS presentation: weight loss, chronic diarrhea, night sweats, dyspnea, vision changes, cognitive decline, skin lesions [4-5]
- PrEP history (oral TDF/FTC or injectable cabotegravir) — critical for ART selection [1]
- Important negatives: no cough/rhinorrhea (helps distinguish from typical URI), no heterophile antibody positivity (distinguishes from EBV mono) [1]
2. Alarm Features
- Acute retroviral syndrome with meningismus → consider aseptic meningitis of primary HIV
- CD4 <200: defines AIDS; markedly increased risk of OIs and sepsis mortality [6-7]
- CD4 <100: high risk for cryptococcal meningitis, disseminated MAC, CMV retinitis, toxoplasmosis [8-9]
- Altered mental status, focal neurologic deficits → CNS toxoplasmosis, PML, cryptococcal meningitis, primary CNS lymphoma [10]
- Severe dyspnea with hypoxia → PCP (Pneumocystis jirovecii pneumonia) [7-8]
- New vision loss → CMV retinitis (ophthalmologic emergency)
- Violaceous skin/mucosal lesions → Kaposi sarcoma [4]
- Immune reconstitution inflammatory syndrome (IRIS) in patients recently started on ART [11]
3. Medications
- Recommended initial ART (start within 7 days, including same-day if no active OI): [9][12]
- Bictegravir/tenofovir alafenamide/emtricitabine (Biktarvy) — single tablet, once daily [9][13]
- Dolutegravir + TAF/FTC or TDF/FTC [1][9]
- DTG/3TC (Dovato) only if HIV RNA <500,000, no HBV, and labs available [9]
- If prior cabotegravir PrEP exposure: use boosted darunavir + TXF/XTC pending InSTI genotype (InSTI resistance possible) [1][12]
- OI prophylaxis:
- CD4 <200 → TMP-SMX for PCP prophylaxis [5][14]
- CD4 <100 + Toxoplasma IgG positive → TMP-SMX (covers both PCP and toxoplasmosis) [5]
- Contraindicated: NNRTIs and abacavir should NOT be used for rapid/same-day ART start [14]
- Drug interactions: Cobicistat-boosted regimens have significant CYP3A4 interactions; avoid in pregnancy (lower DRV/cobicistat levels in 2nd/3rd trimester) [1]
4. Diet
- Adequate caloric intake — wasting syndrome is an AIDS-defining condition [8]
- Hydration support, especially with diarrheal illness (acute retroviral syndrome or OI-related)
- Avoid raw/undercooked meats (Toxoplasma, Salmonella risk in immunocompromised)
- Long-term: metabolic syndrome monitoring on ART (lipids, glucose) [9]
5. Review of Systems
Per HIVMA/IDSA 2024 guidelines, a comprehensive ROS with special attention to: [4][15]
- General: unexplained weight loss, night sweats, fever, body habitus changes
- Skin: rash, ulcers, discoloration, lesions
- Lymph nodes: localized or generalized enlargement
- Eyes: vision change or loss (CMV retinitis)
- Oropharynx: oral lesions, dysphagia, odynophagia (candidiasis, HSV, KS)
- Pulmonary: dyspnea, cough, wheezing (PCP, TB, bacterial pneumonia)
- GI: diarrhea, abdominal pain, nausea (MAC, cryptosporidium, CMV colitis)
- Neuropsychiatric: headache, memory loss, cognitive difficulties, seizures, mood changes, paresthesias
- Genitourinary: discharge, dysuria, lesions (concurrent STIs)
- Anorectal: discharge, bleeding, masses
6. Collateral History and Family History
- Partner HIV status and treatment/viral suppression status
- Sexual and substance use history (patients may not disclose or perceive risk) — maintain a low threshold for testing even without reported high-risk behaviors [1][16]
- Prior HIV testing history, PrEP or PEP use
- Social determinants: housing stability, insurance, access to medications (critical for ART adherence and linkage to care) [12]
- Family history is less relevant for HIV acquisition but may inform comorbidity management (cardiovascular, metabolic)
7. Risk Factors
- Condomless sexual intercourse (receptive anal sex highest per-act risk)
- Multiple sexual partners; sex with a partner of unknown HIV status
- Injection drug use / needle sharing [1]
- History of other STIs (syphilis, gonorrhea, chlamydia — mucosal disruption increases transmission) [17]
- Men who have sex with men (MSM), transgender women
- Occupational exposure (needlestick)
- Geographic residence in high-prevalence areas (≥1% HIV prevalence) [16]
- Not on PrEP despite indications
8. Differential Diagnosis
For acute retroviral syndrome (mono-like illness)
- Infectious mononucleosis (EBV) — heterophile antibody positive; ~1.2% of heterophile-negative "mono" cases were acute HIV [1]
- Influenza / COVID-19 — more respiratory symptoms, less rash/lymphadenopathy [1]
- Secondary syphilis — rash (palms/soles), condylomata lata; RPR/VDRL
- CMV mononucleosis — similar presentation, heterophile-negative
- Streptococcal pharyngitis — exudative pharyngitis, rapid strep positive
- Drug reaction — temporal relationship to new medication
- Acute hepatitis (A, B, C) — transaminase elevation, jaundice
For advanced AIDS presentation
- Opportunistic infections (PCP, TB, cryptococcal meningitis, toxoplasmosis, MAC, CMV) [8][18]
- AIDS-defining malignancies (Kaposi sarcoma, primary CNS lymphoma, Burkitt lymphoma) [8]
- IRIS in recently ART-initiated patients [11]
9. Past Medical History
- Prior HIV testing (when, what type, result)
- Previous STIs (syphilis, gonorrhea, chlamydia, hepatitis B/C)
- TB exposure or latent TB treatment
- Prior ART use, adherence history, resistance testing results (for patients re-engaging in care) [4]
- Chronic conditions: renal disease, hepatic disease (affects ART selection — TAF vs TDF) [1]
- Vaccination history (pneumococcal, hepatitis A/B, HPV, influenza)
- Psychiatric history, substance use disorders
10. Physical Exam
Per HIVMA/IDSA 2024 guidelines: [4][15]
- Vitals: fever (most common sign in acute HIV), tachycardia, hypotension (sepsis), hypoxia (PCP)
- General: wasting, lipodystrophy, frailty assessment
- Skin: diffuse maculopapular rash (acute HIV), seborrheic dermatitis, KS lesions (violaceous), molluscum, HSV/VZV, folliculitis
- Lymph nodes: generalized lymphadenopathy (hallmark of acute and chronic HIV)
- Oropharynx: thrush (oral candidiasis), oral hairy leukoplakia, aphthous ulcers, KS, pharyngeal erythema
- Eyes: fundoscopic exam for cotton-wool spots, CMV retinitis (perivascular hemorrhages/"pizza pie" retina)
- Chest: crackles (PCP — often bilateral, diffuse), consolidation (bacterial PNA, TB)
- Abdomen: hepatosplenomegaly (MAC, lymphoma)
- Neurologic: meningismus, focal deficits, cognitive screening, gait abnormalities, vibratory sensation
- Genitourinary/anorectal: ulcers, warts, discharge, KS lesions
11. Lab Studies
HIV-specific: [4][9]
- 4th-generation Ag/Ab combination immunoassay (detects p24 antigen + HIV-1/2 antibodies) — first-line screening
- HIV-1/HIV-2 antibody differentiation assay — if initial Ag/Ab reactive
- Quantitative HIV RNA (viral load) — confirms acute infection if antibody negative/indeterminate; levels typically >100,000 copies/mL in acute infection [1]
- CD4 count with percentage
- Genotypic resistance testing (RT, protease; add integrase if prior CAB-LA PrEP) [1][4]
General baseline labs: [4][9]
- CBC with differential (leukopenia, thrombocytopenia common in acute HIV) [1]
- CMP (renal/hepatic function — guides ART selection)
- Fasting lipids, glucose/HbA1c
- Hepatitis A/B/C serologies
- RPR/VDRL, gonorrhea/chlamydia NAAT
- Toxoplasma IgG
- TB screening (IGRA or PPD)
- Serum cryptococcal antigen if CD4 <100 [9][19]
- Pregnancy test in persons of childbearing potential
- G6PD (if dapsone considered for PCP prophylaxis)
Rapid POC HIV antibody tests miss 100% of acute infections (Fiebig stage 2) — always use lab-based 4th-generation Ag/Ab assay when acute HIV is suspected [20]
12. Imaging
- Chest X-ray: indicated if respiratory symptoms present
- PCP: bilateral diffuse interstitial/ground-glass infiltrates
- TB: upper lobe infiltrates, cavitation, hilar lymphadenopathy
- Bacterial PNA: lobar consolidation
- KS: nodular infiltrates, pleural effusions
- CT chest (HRCT): if CXR normal but PCP suspected (ground-glass opacities)
- CT head with contrast or MRI brain: if focal neurologic deficits, altered mental status, seizures
- Toxoplasmosis: ring-enhancing lesions (basal ganglia)
- PML: non-enhancing white matter lesions
- Primary CNS lymphoma: single enhancing periventricular lesion
- Cryptococcal meningitis: may be normal or show hydrocephalus
- Imaging is unnecessary for uncomplicated acute retroviral syndrome without focal findings
13. Special Tests
- Fiebig staging: classifies stage of acute HIV infection based on sequential appearance of RNA → p24 Ag → IgM → IgG → Western blot [2]
- Lumbar puncture: if meningeal signs, altered mental status, or CD4 <100 with headache
- Opening pressure (elevated in cryptococcal meningitis)
- CSF cryptococcal antigen, India ink, fungal culture
- CSF VDRL (neurosyphilis)
- Toxoplasma PCR, JC virus PCR (PML)
- Induced sputum or BAL with silver stain/DFA for PCP if unable to produce sputum
- Serum LDH: often elevated in PCP
- Beta-D-glucan: elevated in PCP (adjunctive diagnostic)
- Dilated fundoscopic exam: mandatory if CD4 <50 (CMV retinitis screening)
14. ECG
- Not routinely indicated for acute retroviral syndrome
- Obtain if:
- Myocarditis suspected (chest pain, dyspnea, elevated troponin — rare complication of acute HIV)
- Initiating QTc-prolonging medications
- Pericardial disease suspected (low voltage, electrical alternans)
- Sepsis workup
- HIV cardiomyopathy: may show nonspecific ST-T changes, arrhythmias
15. Assessment
Acute retroviral syndrome presents as a mononucleosis-like illness 2–6 weeks post-exposure, with fever, lymphadenopathy, pharyngitis, rash, and myalgias. Approximately 40–90% of acutely infected individuals are symptomatic, but symptoms are nonspecific and transient, peaking around the time of maximum viremia and resolving within days to weeks. [21-22] This is the period of highest infectivity due to extremely elevated viral loads. [17]
Advanced HIV/AIDS (CD4 <200) may present de novo with an OI as the first clinical indicator of HIV. Common presenting OIs include PCP, TB, cryptococcal meningitis, toxoplasmosis, and disseminated MAC. [8][11] IRIS should be considered in patients recently started on ART who develop paradoxical worsening. [11]
The following figure illustrates the transient and modest nature of symptoms and signs during acute HIV infection, highlighting the diagnostic challenge:
16. Treatment Plan
Acute retroviral syndrome (new diagnosis)
- Start ART as soon as possible, ideally same-day or within 7 days [9][12]
- Draw baseline labs (viral load, CD4, genotype, hepatitis serologies, CBC, CMP) but do not delay ART for results [9]
- Preferred regimens: BIC/TAF/FTC (Biktarvy) or DTG + TAF/FTC [1][9]
- Prevention counseling: advise condom use, partner notification; offer PEP to partners if exposure <72 hours [17]
- Screen and treat concurrent STIs [17]
Advanced AIDS with OIs
- Treat the OI first; start ART within 2 weeks for most OIs [9][12]
- Exceptions:
- Cryptococcal meningitis: delay ART 2–4 weeks after antifungal initiation (early ART increases mortality) [9][19]
- TB meningitis: delay ART until clinical improvement, ~2–4 weeks [9]
- OI prophylaxis: [5][14]
- CD4 <200 → TMP-SMX DS daily (PCP prophylaxis)
- CD4 <100 + Toxoplasma IgG+ → TMP-SMX DS daily
- CD4 <50 → azithromycin 1200 mg weekly (MAC prophylaxis) if ART not being started immediately
- Supportive care: IV fluids, antipyretics, nutritional support as needed
17. Disposition
Admit if
- Active OI requiring IV therapy (PCP with hypoxia, cryptococcal meningitis, CMV end-organ disease, disseminated MAC)
- Severe sepsis or hemodynamic instability [6]
- Altered mental status or focal neurologic deficits
- Inability to tolerate oral medications
- CD4 <200 with CAP — consider hospitalization regardless of PSI score [10]
- Severe IRIS with clinical deterioration
Discharge if
- Uncomplicated acute retroviral syndrome (most cases) with confirmed linkage to HIV care
- Stable, ambulatory patient with mild symptoms and reliable follow-up
- Able to tolerate oral ART and has access to medications
Observation
- Diagnostic uncertainty pending HIV RNA results
- Borderline hemodynamic stability
Specialist consultation: Infectious disease/HIV specialist for all new diagnoses; ophthalmology if CD4 <50; neurology/neurosurgery if CNS mass lesion [5]
18. Follow Up / Return Precautions
- Follow-up within 1–2 weeks of ART initiation for adherence assessment, lab review, and tolerability [5]
- Repeat HIV RNA at 4–6 weeks after starting ART to confirm viral load decline [9]
- Viral suppression (HIV RNA <200 copies/mL) expected by 8–24 weeks [5]
- Monitor for IRIS in first weeks to months after ART initiation, especially if baseline CD4 <100 [5][11]
- Return precautions: new or worsening fever, dyspnea, headache with stiff neck, vision changes, confusion, inability to take medications, new rash or skin lesions
- Counsel on transmission risk: highest during acute infection; use condoms until virally suppressed; U=U (Undetectable = Untransmittable) once sustained viral suppression achieved [17]
- Partner notification and testing services
- Linkage to case management, social work, and Ryan White/ADAP programs for medication access [12]
References
1. Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents With HIV. — Roy M. Gulick, Alice K. Pau, Allison Agwu, et al Office of AIDS Research Advisory Council (2024). 2024.
2. Acute Retroviral Syndrome Is Associated With High Viral Burden, CD4 Depletion, and Immune Activation in Systemic and Tissue Compartments. — Crowell TA, Colby DJ, Pinyakorn S, et al. Clinical Infectious Diseases : An Official Publication of the Infectious Diseases Society of America. 2018.
3. Acute HIV Discovered During Routine HIV Screening With HIV Antigen-Antibody Combination Tests in 9 US Emergency Departments. — White DAE, Giordano TP, Pasalar S, et al. Annals of Emergency Medicine. 2018.
4. Primary Care Guidance for Providers of Care for Persons With Human Immunodeficiency Virus: 2024 Update by the HIV Medicine Association of the Infectious Diseases Society of America. — Horberg M, Thompson M, Agwu A, et al. Clinical Infectious Diseases : An Official Publication of the Infectious Diseases Society of America. 2024.
5. HIV Infection in Adults: Initial Management. — Goldschmidt R, Chu C. American Family Physician. 2021.
6. Sepsis in Patients Who Are Immunocompromised: Diagnostic Challenges and Future Therapies. — Deinhardt-Emmer S, Chousterman BG, Schefold JC, et al. The Lancet. Respiratory Medicine. 2025.
7. Immunocompromised Host Pneumonia: Definitions and Diagnostic Criteria: An Official American Thoracic Society Workshop Report. — Cheng GS, Crothers K, Aliberti S, et al. Annals of the American Thoracic Society. 2023.
8. Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection. — Rohan Hazra, Ann J. Melvin, Mary E. Paul, et al Office of AIDS Research Advisory Council (2024). 2024.
9. Antiretroviral Drugs for Treatment and Prevention of HIV in Adults: 2024 Recommendations of the International Antiviral Society–USA Panel. — Gandhi RT, Landovitz RJ, Sax PE, et al. The Journal of the American Medical Association. 2025.
10. Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents With HIV. — Constance Benson, John Brooks, Shireesha Dhanireddy, et al Infectious Diseases Society of America; Office of AIDS Research Advisory Council (2025). 2025.
11. Prevention and Treatment of Opportunistic Infections in HIV-infected Adults and Adolescents: Updated Guidelines From the Centers for Disease Control and Prevention, National Institutes of Health, and HIV Medicine Association of the Infectious Diseases Society of America. — Masur H, Brooks JT, Benson CA, et al. Clinical Infectious Diseases : An Official Publication of the Infectious Diseases Society of America. 2014.
12. Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults: 2022 Recommendations of the International Antiviral Society–USA Panel. — Gandhi RT, Bedimo R, Hoy JF, et al. The Journal of the American Medical Association. 2023.
13. FDA Orange Book. — FDA Orange Book. 2026.
14. Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults: 2018 Recommendations of the International Antiviral Society–USA Panel. — Saag MS, Benson CA, Gandhi RT, et al. The Journal of the American Medical Association. 2018.
15. Primary Care Guidance for Persons With Human Immunodeficiency Virus: 2020 Update by the HIV Medicine Association of the Infectious Diseases Society of America. — Thompson MA, Horberg MA, Agwu AL, et al. Clinical Infectious Diseases : An Official Publication of the Infectious Diseases Society of America. 2021.
16. Adolescents and Young Adults: The Pediatrician's Role in HIV Testing and Pre- And Postexposure HIV Prophylaxis. — Hsu KK, Rakhmanina NY. Pediatrics. 2022.
17. Sexually Transmitted Infections Treatment Guidelines, 2021. — Workowski KA, Bachmann LH, Chan PA, et al. MMWR. Recommendations and Reports : Morbidity and Mortality Weekly Report. Recommendations and Reports. 2021.
18. Fever of Unknown Origin. — Haidar G, Singh N. The New England Journal of Medicine. 2022.
19. Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults: 2020 Recommendations of the International Antiviral Society–USA Panel. — Saag MS, Gandhi RT, Hoy JF, et al. The Journal of the American Medical Association. 2020.
20. Evaluation of a Point-of-Care Rapid HIV Antibody Test With Insights Into Acute HIV Symptomatology in a Population With Low Prevalence. — Bui TI, Farnsworth CW, Anderson NW. Journal of Clinical Microbiology. 2024.
21. Recommendations for the Use of Antiretroviral Drugs During Pregnancy and Interventions to Reduce Perinatal HIV Transmission in the United States. — Martina L. Badell, Brookie M. Best, Kristina M. Brooks, et al Office of AIDS Research Advisory Council (2025). 2025.
22. Prospective Study of Acute HIV-1 Infection in Adults in East Africa and Thailand. — Robb ML, Eller LA, Kibuuka H, et al. The New England Journal of Medicine. 2016.