Letters

Non-sexual transmission of HIV has been overlooked in developing countries

EDITORAccumulating evidence undermines the belief that heterosexual transmission in developing countries has as largeand that unsterile medical equipment has as littlea role as supposed by many HIV experts. In 1983 the World Health Organization identified contaminated sharpsbut not heterosexual promiscuityas a risk factor for HIV in tropical countries.¹ During the next five years, however, high rates of HIV infection were reported in female sex workers and patients at clinics for sexually transmitted diseases.

By the late 1980s a consensus had emerged that more than 90% of adult HIV infections in sub-Saharan Africa were attributable to heterosexual contact, and only about 2% to contaminated sharps. This consensus was forged in the absence of empirical studies controlling for confounding between sexual and medical exposures, and despite the fact that unsafe injections are common in developing countries. ^{2 3} More important, inquiry into iatrogenic transmission all but disappeared from the HIV research agenda, and routine epidemiological reports from developing countriesnot to mention meta-analyses and evaluations of intervention trialshave often been silent about non-sexual transmission. ^{4 5}

The literature indicates that researchers have undervalued data pointing to a significant role for medical transmission. Many studies, particularly from Africa, report unexplained high rates of HIV incidence during antenatal and postpartum periods, implicating nosocomial exposure. They also report that 20-40% of HIV infections can be attributed to injections by univariate population attributable risk calculations; non-trivial rates of HIV in sexually inexperienced adults; and many HIV positive children with HIV negative mothers.^w1-30 In addition, the frequent lack of association between sexual behaviour variables and HIV trends, and the low rate of penovaginal HIV transmission in studies of serodiscordant couples in Africa as elsewhere, suggest a need to reassess the contribution of heterosexual exposure.

Although cofactors such as sexually transmitted diseases and lack of circumcision may boost heterosexual transmission, the levels of such covariates and their known influences on transmission do not seem sufficient to explain Africa's HIV epidemic. In 1999 public and private international health organisations formed the Safe Injection Global Network (SIGN), currently headquartered at WHO, to promote injection safety. Our view, which suggests a pivotal role for contaminated sharps in the global HIV catastrophe, supports the network's efforts to reduce unnecessary and unsterile injections. Adding such interventions to efforts for HIV prevention may bring greater success than has been achieved to date with a narrow focus on condoms and heterosexual transmission.

David Gisselquist, independent consultant. 
29 West Governor Road, Hershey, PA 17033, USA

Richard Rothenberg, professor. 
Department of Family and Preventive Medicine, Emory University School of Medicine, 69 Butler Street SE, Atlanta, GA 30303, USA

John Potterat, independent consultant. 
301 South Union Blvd, Colorado Springs, CO 80910, USA

Ernest Drucker, professor of epidemiology and social medicine. 
Department of Epidemiology and Social Medicine, Montefiore Medical College and Albert Einstein College of Medicine, 111 East 210th Street, Bronx, New York 10467-2490, USA

   References w1-30 are available on bmj.com

1.	World Health Organization. Acquired immunodeficiency syndromean assessment of the present situation in the world: memorandum from a WHO meeting. WHO Bull 1984; 62: 419-432.
2.	Drucker E, Alcabes PG, Marx PA. The injection century: consequences of massive unsterile injecting. Lancet (in press).
3.	Simonsen L, Kane A, Lloyd J, Zaffran M, Kane M. Unsafe injections in the developing world and transmission of bloodborne pathogens. WHO Bull 1999; 77: 789-800.
4.	Rottingen J-A, Cameron DW, Garnett GP. A systematic review of the epidemiologic interactions between classic sexually transmitted diseases and HIV. Sex Transm Dis 2001; 28: 579-597[ISI][Medline].
5.	Grosskurth H, Gray R, Hayes R, Mabey D, Waver M. Control of sexually transmitted diseases for HIV-1 prevention: understanding the implications of the Mwanza and Rakai trials. Lancet 2000; 355: 1981-1987[CrossRef][ISI][Medline].