HIV & STI Screening — Why Regular Testing Is Part of Preventive Health

HIV (Human Immunodeficiency Virus): attacks CD4+ T-cells — the immune system's key coordinator. Without treatment, HIV progresses to AIDS over 8–10 years.

HIV blood tests::

HIV ELISA (4th generation):: Detects both HIV antibodies and p24 antigen. The standard screening test. **Window period:** 18–45 days after exposure (detects infection much earlier than older tests).

HIV Rapid Test:: Same 4th generation technology in point-of-care format. Results in 30 minutes. Used at collection centres.

HIV Western Blot:: Confirmatory test when ELISA is reactive. More specific — used to rule out false positives.

HIV RNA PCR (Viral Load):: Detects viral RNA directly — earliest possible detection (10–14 days post-exposure). Used for diagnosis in newborns, post-exposure prophylaxis evaluation, and treatment monitoring.

CD4 count:: Measures immune cell level — used to stage disease and guide when to start or modify antiretroviral therapy.

The U=U principle:: People on effective antiretroviral therapy (ART) who achieve an undetectable viral load cannot sexually transmit HIV. This is the global scientific consensus — early detection and treatment saves lives and prevents transmission.

Stages::

• **Primary:** Painless sore (chancre) at infection site — often unnoticed

• **Secondary:** Rash (including palms and soles), fever, lymphadenopathy — can mimic many infections

• **Latent:** No symptoms; remains infectious

• **Tertiary:** Affects heart, brain, blood vessels — potentially fatal decades later

Syphilis tests::

VDRL (Venereal Disease Research Laboratory):: Non-specific screening test. Can be positive in other conditions (lupus, malaria, pregnancy) — 'biological false positive.' Used for initial screen and monitoring treatment response.

TPHA / TPPA (Treponemal tests):: Specific confirmatory tests for syphilis. Remain positive for life even after successful treatment.

RPR (Rapid Plasma Reagin):: Quantitative non-treponemal test — titre falls with successful treatment, useful for monitoring.

Hepatitis B testing::

• **HBsAg (Hepatitis B surface antigen):** Active infection

• **Anti-HBs (surface antibody):** Immunity from vaccination or past infection

• **Anti-HBc (core antibody):** Past or current infection

• **HBV DNA (Viral Load):** Quantifies active replication — guides treatment

Hepatitis C testing::

• **Anti-HCV antibody:** Exposure to HCV (past or present)

• **HCV RNA PCR:** Confirms active infection and quantifies viral load

• Note: Hepatitis C is now **curable** with 8–12 weeks of direct-acting antivirals

Pre-marital screening: for HIV, Hepatitis B, and syphilis is strongly recommended — these tests together cost a fraction of the long-term consequences of late diagnosis.

HIV testing is recommended for::

• All pregnant women (PPTCT — prevention of parent-to-child transmission)

• All sexually active adults annually (regardless of number of partners)

• Anyone with symptoms of opportunistic infections (recurrent oral thrush, weight loss, persistent cough)

• Healthcare workers following needlestick injuries

• Post-exposure prophylaxis (PEP) evaluation

STI panel (HIV + VDRL + Hepatitis B + Hepatitis C) is recommended for::

• Pre-marital health screening

• Anyone planning pregnancy

• New sexual relationships

• Annual routine health check for adults over 25