HIV

HIV

• RNA retrovirus

• HIV-1 most common

• HIV-2 most common in west Africa

• Destroys CD4 T-helper cells

Transmission Of HIV

• Unprotected anal, vaginal or oral sexual activity

• Mother to child at any stage of pregnancy, birth or breastfeeding (called vertical transmission)

• Mucous membrane, blood or open wound exposure to infected blood or bodily fluids

AIDS-Defining Illnesses Caused When CD4 Count Below 200

Examples of AIDS-defining illnesses include:

• Kaposi’s sarcoma

• Pneumocystis jirovecii pneumonia (PCP)

• Cytomegalovirus infection

• Candidiasis (oesophageal or bronchial)

• Lymphomas

• Tuberculosis

Investigations For HIV

Combined antibody and P24 antigen test → 45 day window period for reliability

Normal CD4 Count

500-1200 cells/mm3

Treatment Of HIV

Antiretroviral therapy:

Tenofovir + emtricitabine + bictegravir

Pneumocystis Jirovecci Pneumonia Propylaxis In HIV Patients With CD4 Count <200

Co-trimoxazole

Additional Management Of HIV

• Avoid live vaccines

• Annual cervical smear tests

HIV PEP

PEP involves a combination of ART therapy. The current regime is emtricitabine/tenofovir (Truvada) and raltegravir for 28 days.

HIV PREP

Tenofovir + emtricitabine

Preventing HIV Transmission During Birth

• Viral load under 50→ vaginal

• Viral load over 50→ pre-labour c section

Baby Prophylaxis If Mother Has HIV

• Viral load under 50→ zidovudine for 2-4 weeks

• Viral load over 50→ zidovudine, lamivudine and nevirapine for 4 weeks

Testing In Children To HIV Positive Parents

Babies to HIV positive parents are tested twice for HIV:

• HIV viral load test at 3 months. If this is negative, the child has not contracted HIV during birth and will not develop HIV unless they have further exposure.

• HIV antibody test at 24 months. This is to assess whether they have contracted HIV since their 3 month viral load, for example through breast feeding. If the 3 month test is negative and they are not breastfed, this should be negative.

Note that the antibody test can be positive in infants who do not have HIV for up to 18 months of age. This is due to maternal antibodies that have crossed the placenta during pregnancy.