Post-exposure prophylaxis of HIV infection

Local treatment of the contact area (decontamination)

First-line actions in an emergency depend on where the potentially infected material has landed.

• Skin damage (needle-stick, cut): First, rinse the wound thoroughly with running water. Then treat the wound channel with antiseptics — hydrogen peroxide or 70% ethanol. Smear the wound edges with a 5% alcoholic iodine solution.
• Contact with intact skin: Treat the contact area twice with 70% ethyl alcohol, washing the site with running water and soap between applications.
• Contact with mucous membranes: Immediately rinse the mucous membranes with a 0.05% potassium permanganate solution. If the biological fluid gets into the mouth or pharynx, rinse with the same solution or 70% ethanol.

Risk stratification and selection of the chemoprophylaxis regimen

After local decontamination, the decision on prescribing antiretroviral therapy (ART) is made. The course duration is 4 weeks. The scope of therapy depends on the type of risk:

1. High grade (Type 1): Deep penetrating wounds inflicted by hollow or cutting instruments (needle, scalpel) with visible bleeding. Three-drug therapy is prescribed: two nucleoside reverse transcriptase inhibitors (NRTIs) and one protease inhibitor (PI). For example: zidovudine + lamivudine + indinavir (or saquinavir).
2. Moderate grade (Type 2): Superficial injuries with sparse (droplet) bleeding. A two-drug regimen consisting of two NRTIs is recommended (e.g., zidovudine + lamivudine).
3. Minimum grade (Type 3): Superficial microtraumas of the skin or mucous membranes, as well as simple contact of biological fluids with mucous membranes. Therapy is advisable, using drugs from the NRTI group.

Risk factors and prevention in healthcare settings

The probability of infection for a healthcare worker directly depends on the volume of infected blood that entered the wound. Therefore, an injection (hollow) needle-stick injury presents a much higher risk (about 0.3%) than a surgical (solid) needle injury, because blood remains in the lumen of the hollow needle. The risk of infection from contact with mucous membranes or damaged skin ranges from 0.01% to 0.5%.

The greatest epidemiological threat is posed by blood from HIV-positive patients at the AIDS stage due to the extremely high viral load.

Universal safety measures:

• Any biological material and contaminated linen are considered potentially infected.
• Strict use of gloves, and masks, goggles, and moisture-resistant clothing when there is a risk of splashing.
• Prohibition of removing needles from syringes prior to disinfection.
• The principle of redundancy during invasive procedures: the presence of an assistant who can complete the procedure if the primary specialist sustains an injury (cut, glove tear).

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Ensuring the infectious safety of donor blood components (plasma quarantine, leukoreduction)
• Requirements for sterilization and disinfection of medical instruments
• Physical examination algorithm for a patient with suspected HIV infection
• Laboratory diagnosis of HIV infection: screening and verification (immunoblotting)
• Dynamics of hemogram changes (CBC) depending on the stage of HIV infection

Other topics in the section "Viral Hepatitis and HIV"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.