This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Risk of HIV transmission by exposure type

Authoring team

transmission risk by exposure type

The risk of HIV transmission depends on the exposure and degree of viraemia of the source.

  • needlestick injuries
    • occurs following a needlestick injury with a needle contaminated with blood from a source known to have HIV
    • in healthcare setting source patient (serology) known
      • risk of becoming infected with HIV is thought to be between 0.1% and 0.36%
      • increased risk if large gauge needle, hollow needle, deep injury, visible blood on the device, needle was in patient "s artery/vein, or if the source patient has AIDS (or terminal illness).
    • in healthcare setting source patient unknown or unable to test source
      • risk assessment required of the type of injury and the likely infection status of the source

    • community needle stick
      • risk is more difficult to estimate and the exact incidence of needlestick injuries and the transmission rate is unknown
      • overall low risk and requires a risk assessment of the type of injury, location of the discarded needle (for example if discarded in a location where people who inject drugs are known to inject), likely age of the discarded needle and the background prevalence of HIV in the local population

    • post-exposure prophylaxis (PEP) is thought to reduce seroconversion by up to 81%

  • mucous membrane and non-intact skin exposure to blood - the risk is very low
    • risk for transmission of HIV via mucous membrane exposure is estimated to be 0.09%

  • intact skin exposure to blood - no risk

  • human bites
    • very low risk
    • risk assessment required
    • only risk if blood in the mouth of the biter, and significant injury. No risk if no blood in mouth of biter, and exposure to saliva only
    • if source co-infected with HCV, HCV transmission more likely than HIV transmission

  • sexual exposure
    • risk of transmission of HIV following sexual exposure depends on
      • the type of exposure
      • the viral load of the source the susceptibility of the host
      • the presence of sexually transmitted infections in either the source or the recipient
        • if the index partner also has a genitourinary infection, for instance, the risk of transmission is approximately doubled.
        • if the recipient has a genitourinary infection, the risk of acquiring HIV is also elevated

    • heterosexual exposure (general)
      • if source on antiretroviral therapy with suppressed viral load transmission rate = 0 (if viral load < 400 copies/ml)
      • increased risk if source patient has recently seroconverted, e.g. within 2.5 months of seroconversion risk of transmission is estimated to be 0.0082/coital act

    • receptive vaginal intercourse
      • overall risk is 1 in 1000, which is increased in the presence of cervical ectopy, genital tract trauma, menstruation, genital ulcerative disease (in either partner), infectious syphilis and pregnancy
      • male circumcision reduces HIV acquisition

    • insertive vaginal intercourse
      • overall risk is 1 in 1219

    • men who have sex with men (MSM) unprotected receptive anal intercourse
      • overall risk is 1 in 90
      • increased risk if there is ejaculation within the rectum.
      • the PARTNER study has demonstrated zero transmissions in HIV serodiscordant couples where the HIV positive individual is on effective antiretroviral therapy

    • MSM unprotected insertive anal intercourse
      • overall risk is 1 in 666
      • the PARTNER study has demonstrated zero transmissions in HIV serodiscordant couples where the HIV positive individual is on effective antiretroviral therapy

    • orogenital contact
      • overall very low risk, estimated to be <1 in 10,000 for both receptive and insertive oral sex

Reference:


Create an account to add page annotations

Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.