Rapid HIV testing

Clinical management

Typically, capillary blood is collected using a pipette. The blood is incubated in the testing device for a specified period (usually several minutes), after which a precise amount of buffer is added. The mixture is then incubated again for several minutes. If HIV antibodies are present in the patient‚s blood in sufficient concentrations, a colour reaction occurs along a test strip. Several of these steps are time-sensitive and must be adhered to for accurate results.

As with all HIV testing, the use of rapid HIV test kits requires the specific, informed consent of the person being tested. Given the rapidity of results and the possibility of false-positive outcomes, counselling must be provided for those receiving point-of-care testing. Health Canada has produced a guide for health care professionals that shows how to administer the test and counsel.1

Pretest counselling must include informing patients of the possibility of false-positive results and should stress the importance of confirmatory testing of all equivocal or positive results and advise patients of the cost of point-of-care testing, such as the purchase price of a test kit. Post-test counselling after a positive or equivocal result should include the provision of support and follow-up during the interval required to complete confirmatory testing.

Prevention

HIV infection is reportable under public health legislation in Canada. Health care professionals are required to report identified cases of HIV infection to the public health system to maintain accurate HIV epidemiologic information and to assist in contact tracing. In the event that a patient does not complete confirmatory testing, the health care professional should seek advice from a public health official on reporting requirements. HIV testing may not be reliable in patients who are in the HIV ”window period” during seroconversion. Patients who have engaged in risk activity in the 3 to 6 months before testing should be counselled on the need for appropriate repeat testing.

The faster results and simpler testing technology make it easier to reach high-risk, hard-to-reach populations, such as intravenous drug users who may not use health care services regularly. Despite these benefits, concerns have been raised about the potential for harm.2 Ease of testing might lead to people being tested without their voluntary, specific, informed consent. Prospective situations where this might happen include the testing of pregnant women in labour, the testing of patients before medical care is provided and the testing of patients to avoid the necessity of postexposure prophylaxis.

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