At the time of the initial test encounter, most individuals should not receive a recommendation to verify an HIV-negative result.
4.1. Situations and settings where re-testing is warranted in all epidemic types
If an individual has previous or ongoing risk for HIV infection (i.e. persons who currently inject drugs, sex workers, or men who have sex with men; having a high-risk or known HIV-positive partner; having clinical indications for re-testing such as newly acquired sexually transmitted infections [STI])
OR
- 2.
If an individual can identify a specific incident of HIV exposure in the three months prior to HIV testing (i.e. history of occupational exposure, unprotected sex with a known HIV-positive person, sharing injecting equipment with a known HIV-positive person).
If an individual receiving an HIV-negative test result fits into either of the above categories, then that individual should be asked to come back for re-testing. The person should be provided with post-test counselling messages appropriate for HIV-negative persons, as per the site's standard protocol for HIV testing and counselling.
HIV-negative persons should be advised that if they have a specific incident of known or suspected HIV exposure in the future then they should return for an HIV test following that exposure. Additionally, if persons begin or resume engaging in HIV risk-related behaviours, they should be recommended to re-test at least annually. Pregnant women in a generalized epidemic setting should be recommended to re-test in their third trimester (see Specific situations). Finally, persons should be told that if they receive health-related services from other facilities, they may be advised to receive another HIV test and counselling in those settings in the future. This is done to ensure correct documentation of HIV status.
SUMMARY
Re-testing is recommended for persons with an HIV-negative test result who:
Have ongoing HIV risk behaviours;
Can identify a specific incident of HIV exposure in the past three months;
Is a pregnant woman in a generalized epidemic setting.
4.2. Specific situations
4.2.1. Based on an indeterminate HIV status
Persons with discordant test results may have acute HIV infection, especially in high-incidence settings.
13,
14 However, discordant test results are more often the result of random or systematic laboratory error, or due to the intrinsic properties of the assay. All HIV testing should be performed in accordance with the HIV test kit package insert and site-developed standard operating procedures to eliminate possible testing errors. In the rare event that the results of an HIV test are discordant, the same assays should be repeated immediately to exclude error while the individual is still at the testing site. The same testing algorithm should be used for the immediate repeat testing, and standard operating procedures should again be followed to minimize error. It may also be necessary to have a more experienced HIV testing and counselling provider at the testing site to perform the repeat testing.
If the results of the tests remain discordant, the individual should be retested after two weeks using the same testing algorithm. It is important to re-test after two weeks as persons who have recently acquired HIV are likely to have detectable antibodies to HIV by then.
4.2.2. Based on population and setting
- 2.
Pregnant women testing HIV negative in their first or second trimesters of pregnancy in settings with generalized epidemics: In order to prevent mother-to-child transmission (MTCT) of HIV, pregnant women should be tested as early as possible in each pregnancy. Women who test HIV negative in their first or second trimesters of pregnancy should be recommended to return for another HIV test in their third trimester of pregnancy, preferably between the 28th and 36th weeks.17 In the event that a woman does not return for testing during her third trimester, she should be recommended to test at labour or, if that is not possible, immediately after delivery. Refer to the Guidance on global scale-up of the prevention of mother-to-child transmission for additional information on maternal and infant testing.18
- 3.
HIV negative persons testing in specific clinical settings (i.e. STI, TB, or outpatient clinics): Individuals seen for a diagnosis or treatment of STIs, for TB patients with a new potential HIV exposure or who are at higher risk of HIV exposure, outpatients with clinical conditions suggestive of HIV infection with an HIV negative test result should be re-tested after four weeks from the time they were initially tested. Individuals with STIs should be recommended to be re-tested for HIV and counselled with each new STI diagnosis.
4.2.3. Based on risk
- 4.
HIV negative persons with ongoing risk behaviours: persons who inject drugs, MSM, sex workers, persons with a known HIV-positive partner, and persons with a partner of unknown HIV status should be tested for HIV at least annually and provided with their respective population-appropriate risk reduction counselling.
- 5.
HIV negative persons who have had a specific incident of known HIV exposure within the past three months: Persons with known HIV exposure who test HIV negative at the first HIV testing encounter following the incident (i.e. sex with a known HIV-positive person, and/ or sharing of injecting equipment with a known HIV-positive person) warrant re-testing after 4 weeks from the time of the initial test to ensure that they are truly HIV negative.
- 6.
HIV negative persons who have had a specific incident of possible HIV exposure within the past 72 hours: Baseline HIV testing and counselling should always be recommended to persons who have experienced sexual violence or an occupational exposure. This should be included as part of a post-exposure prophylaxis (PEP) service package according to national or local protocols, and is meant to establish baseline HIV status of the individual who may have been exposed. For further information about PEP, please see Post-exposure prophylaxis to prevent HIV infection.19
Re-testing: If PEP is not available, persons with a possible HIV exposure who test HIV negative at the first HIV testing encounter following the incident (i.e. sexual violence/rape or occupational exposure) or who have an indeterminate HIV status warrant re-testing after four weeks, and if still negative, at 12 weeks to ensure that they are truly HIV negative as a result of that exposure.
In persons who have been exposed to PEP (i.e. prescribed PEP due to sexual violence/ rape or an occupational exposure), the production of antibodies to HIV may be affected and, in some cases, the time to development of a full antibody profile. For further information on when re-testing should occur in persons receiving PEP, please see Post-exposure prophylaxis to prevent HIV infection.19
SUMMARY FOR SPECIFIC SITUATIONS
Re-testing is recommended for persons who:
Have an indeterminate HIV status;
Are pregnant women in the setting of a generalized epidemic, who have tested HIV negative in the first or second trimester of pregnancy;
Have an STI;
Are outpatients with clinical findings suggestive of HIV;
Have continuing or ongoing risk of acquiring HIV;
Have specific incidents of known HIV exposure within the past three months;
Received an HIV-negative test result on a baseline HIV test for an incident of possible HIV exposure in the past 72 hours; in this case, and if PEP has not been initiated, re-test at 4 weeks after exposure, and if the results are still negative or discordant, the person should be re-tested again at 12 weeks after exposure.
