What screening tests are recommended for diagnosed HIV (Human Immunodeficiency Virus) patients?

Screening Tests in Diagnosed HIV Patients

All newly diagnosed HIV patients require a comprehensive baseline laboratory evaluation including CD4 count, HIV viral load, genotypic resistance testing, HLA-B*5701 testing before abacavir use, hepatitis B and C serology, tuberculosis screening, sexually transmitted infection testing, complete blood count, comprehensive metabolic panel, lipid panel, urinalysis, and pregnancy test in women of childbearing age. 1, 2

Immediate Baseline Laboratory Testing

HIV-Specific Tests

• CD4 cell count with percentage to stage disease, assess immune function, determine need for opportunistic infection prophylaxis, and guide antiretroviral therapy decisions 1
• HIV RNA viral load (quantitative) to establish baseline viremia and monitor treatment response 1
• Genotypic resistance testing for transmitted NRTI and NNRTI resistance before initiating therapy 1, 2
• HLA-B*5701 testing (only needed once) before considering abacavir-containing regimens to prevent hypersensitivity reactions 1, 2
• CCR5 tropism testing if considering maraviroc as part of the regimen 1

Coinfection Screening

• Hepatitis B serology (HBsAg, anti-HBs, anti-HBc) as coinfection affects treatment selection and liver disease progression 1, 2
• Hepatitis C antibody with reflex RNA testing if positive, given high prevalence in HIV populations and impact on morbidity 1, 2
• Tuberculosis screening with either tuberculin skin test (TST) or interferon-gamma release assay (IGRA), as TB is a leading cause of death in HIV patients 1, 2
• Toxoplasma IgG serology to identify patients requiring prophylaxis when CD4 drops below 100 cells/mm³ 1
• Cytomegalovirus (CMV) IgG to assess risk for future CMV disease 1

Sexually Transmitted Infection Screening

• Syphilis serology (RPR or VDRL with confirmatory treponemal testing if positive) at baseline and annually thereafter 1, 2
• Gonorrhea and chlamydia nucleic acid amplification testing from urine, pharynx, and rectum based on sexual practices 1, 2
• Trichomonas testing in women 1

General Health Screening

• Complete blood count with differential to assess for cytopenias that may affect treatment choices 1
• Comprehensive metabolic panel including creatinine (with calculated GFR), transaminases, bilirubin, and glucose to establish baseline organ function 1
• Fasting lipid panel as baseline before starting antiretroviral therapy, which can affect lipid metabolism 1
• Urinalysis to screen for proteinuria and kidney disease, particularly in African American patients and those with diabetes or hypertension 1
• Pregnancy test in all women of childbearing potential before initiating therapy 1

Risk-Based Additional Screening

For African American Patients or Those with Risk Factors

• Annual urinalysis to screen for HIV-associated nephropathy (HIVAN) and other kidney disease, especially if CD4 <200 cells/mm³, HIV RNA >4,000 copies/mL, diabetes, or hypertension present 1
• Quantification of proteinuria with spot urine protein-to-creatinine ratio if dipstick shows ≥1+ protein 1
• Renal ultrasound if proteinuria or declining kidney function detected 1

For Patients with Advanced Disease (CD4 <50 cells/mm³)

• Funduscopic examination by ophthalmologist to screen for CMV retinitis and other ocular manifestations 1
• Cryptococcal antigen testing in serum, particularly in resource-limited settings or symptomatic patients 3
• Histoplasma antigen testing in endemic areas (Ohio and Mississippi River valleys, Central America) as histoplasmosis is a leading opportunistic infection 3

For Men Who Have Sex with Men

• Annual anal Pap smear to screen for anal dysplasia and cancer, given increased HPV-related malignancy risk 1

For Women

• Pap smear at baseline, repeat at 6 months, then annually if normal, as cervical dysplasia progresses more rapidly in HIV-positive women 1
• Pelvic examination with visual inspection for genital ulcers, warts, or other lesions 1

Psychosocial Screening

• Depression screening using validated tools at baseline and periodically, as depression is highly prevalent and affects adherence 1
• Domestic violence screening at initial evaluation and periodic intervals 1
• Substance use assessment to identify barriers to adherence and need for treatment 1

Ongoing Monitoring Schedule

Frequent Monitoring Phase (First Year)

• CD4 count and viral load every 3 months until viral suppression achieved and maintained 1
• Viral load at 4-6 weeks after starting or changing antiretroviral therapy to assess early response 1

Stable Monitoring Phase (After First Year of Suppression)

• Viral load every 6 months once suppressed below 50 copies/mL for at least one year with consistent adherence 1
• CD4 count every 6 months until above 250 cells/mm³ for at least one year with viral suppression, then can be discontinued 1
• Annual STI screening including syphilis, gonorrhea, and chlamydia at anatomically appropriate sites 1, 2
• Annual lipid panel and metabolic monitoring for antiretroviral toxicity 1

Critical Pitfalls to Avoid

Never delay antiretroviral therapy initiation while waiting for all baseline test results—treatment should begin immediately upon confirmed diagnosis, though resistance testing should be sent before starting therapy when possible 1, 2. The evidence shows that immediate treatment initiation improves mortality and reduces transmission risk 1.

Do not skip genotypic resistance testing at baseline—transmitted drug resistance occurs in 10-15% of newly diagnosed patients and significantly impacts treatment success 1, 2. This is a one-time opportunity to detect transmitted resistance before antiretroviral pressure selects for additional mutations.

Avoid using only antibody-based HIV tests for confirmation—always obtain at least one HIV viral load before treatment initiation to confirm active infection, as false-positive screening tests can occur with devastating consequences 2, 4.

Do not overlook opportunistic infection screening in patients presenting with CD4 <350 cells/mm³—screening for tuberculosis, cryptococcosis, and histoplasmosis (in endemic areas) reduces mortality significantly, with one study showing 7% reduction in OI mortality with systematic screening 3.

Never assume patients will disclose all risk factors—routine opt-out screening for STIs at anatomically appropriate sites (pharynx, rectum, urine/cervix) based on sexual practices is essential, as patients are often reluctant to disclose behaviors 1.