Correspondence (The Lancet 343, 1293, May 21,1994)

Home Testing for HIV

Thiery E. Mertens, George Davey Smith, Eric Van Praag

Surveillance, Evaluation and Forecasting, and Health Care Support Global Programme on AIDS, World Health Organization, Geneva, Switzerland; University of Glasgow, Glasgow G12,BRZ. UK

Sir -- Reading Frerichs' viewpoint (April 16, p 960), we were concerned that an old fallacy -- namely that HIV testing in itself may slow the spread of HIV -- is promoted as a new HlV prevention strategy. What he proposes is that since condoms are either not used or break, and there is no vaccine in sight, home-testing for HIV is an answer to the epidemic. There are several difficulties with this line of reasoning. First, the use of the term personal screening for HIV is inappropriate and misleading. As pointed out by Sackert and Holland, the objective of screening Is "the early detection of those diseases (or conditions) whose treatment is either easier or more effective when undertaken at an earlier point in time. There Is thus an implicit promise that those who volunteer to be screened will benefit... and will receive treatments of proven efficacy".[1] At this time, unfortunately, such promise cannot hold true with respect to HIV testing at home. Although in a health setting HIV testing and counseling can assist in the provision of appropriate care and social support, the only promise offered here is potential rejection of the HIV-positive person. Second, "voluntary home-testing" is said to be a "way to prevent HIV transmission". For this to be the case, it first has to be established that HIV testing and any counseling that precedes and follows it (voluntary testing and counseling, VCT) leads to a reduction in HIV transmission. A comprehensive review of the evidence in 1991 suggested that this is probably not the case.[2] Indeed, if any effect is to be expected from VCT, it is likely to result from the combination of testing with counseling rather than testing alone. In the USA counseling has been made widely available, but in developing countries this is unlikely to be the case because of access and affordability difficulties. The central premise of the personal screening strategy is thus incorrect.

As it is, the unsupported premise is followed by several unrealistic scenarios. The saliva test that Frerichs advocates (and has been involved in developing)[3] needs to be "sent anonymously" to a local laboratory, from where the result returns. With the parlous state of the postal services in many of the "developing countries" in which marketing of the rest is proposed, the wait for the result may be a long one. It Is hard to believe that sexual encounters will be put on hold in the meantime. The frequency with which couples will have to screen each other to be sure that infection has not been contracted or revealed itself since the last test is also a difficulty. A further unlikely scenario has "monogamous" women "quietly" resting their husband. In a world where women are all too often culturally and economically subordinate to men, and cannot control or even negotiate situations to minimize the risk of HIV infection, this suggestion has little grounding in reality. Reality does emerge from amidst the fantasy, however, when it is proposed that "screening test could be widely sold in the private sector": the potential for financial profit for the marketers of testing kits is clearly large if populations are led to believe that testing slows HIV spread.

Finally, ample evidence suggests that people, perhaps including those most vulnerable to HIV infection, are unwilling to undergo testing. In a state of the USA where premarital testing was made compulsory, a large proportion of premarital couples got married elsewhere.[4] This lack of enthusiasm Is unlikely to change because resting is done at home and is less invasive. Like the pregnancy test that has a role in the course of an Individual's life, there is clearly a role for counseling of individuals with HIV and AIDS and their sexual partners, but this role is likely to be marginal in checking the spread of HIV at population level. Because there is a lifelong potential for transmission and there is a possibility of protection, the main challenge for prevention at population level is to act before the HIV test becomes positive and not after. From a public health point of view it has been said that "history says no to the policeman's response to AIDS."[5] The home-policing implicit in the personal testing fantasy is no exception.

1. Sackett DL, Holland W W. Controversy in the detection of disease. Lancet 1975; ii: 357-59.

2. HiggIns DL, Galavotti C, O'Reilly KR et al. Evidence for the effects of HIV antibody counseling and testing on risk behaviors. JAMA 1991; 246: 2419-29.

3. Frerichs RR Htoon MT, Eakes N, Lwin S. Comparison of saliva and serum for HIV surveillance in developing countries. Lancet 1992; 340: 1496_99.

4. Turnock BJ, Kelly CK. Mandatory premarital testing for human immunodeficiency virus. The Illinois experience. JAMA 1989; 261: 3415-18.

5. Porter R. History says no to the policeman's response to AIDS. BMJ 1986: 1589-90.