Reply: Brody and colleagues provide a useful critique of our article1 that questions whether causation can be attributed to the detected association between genital hygiene and HIV-1 status among Kenyan males participating in a study of bacterial vaginosis (BV) in their female partners. They point to a potential confounder, injection treatment for illness, which they argue could possibly explain the associations of “ever treated for serious illness” and the hygiene measure with HIV-1 seropositivity. Previous studies from our group have indeed implicated penicillin injections as risk factors for hepatitis B virus infection2 and for human T-lymphotropic virus type 1 (HTLV-1) infection3 but not for HIV infection in female sex workers in another developing country setting.3 With regard to the issue of causation, we had stated in our results that “the decreased odds of HIV-1 infection associated with large values of hygiene component 2 suggest an inverse association between good hygiene and prevalence of HIV-1.” In the discussion section, we further stressed our unwillingness to assert causation, citing the cross-sectional nature of our study as a limitation. Considering injection for illness as a plausible confounder and source of HIV-1 acquisition, we can provide additional clarification about the variables presented. Twenty-one of 150 male participants had been previously treated for a “serious illness,” a self-described condition, which was further specified by respondents: 8 had had tuberculosis (TB); 2 each had had road accidents and ulcers; and 1 each had had allergies, asthma, arthritis, chronic bronchitis, diabetes, hypertension, phimosis, pneumonia, and typhoid. In Nairobi, injection treatment is often used for some but not all of these conditions. It is plausible that some of the association of treatment for a serious illness could be attributable to iatrogenic transmission. The chronologic relation of HIV-1 infection and these illnesses (as with hygiene practices) is not known; however, it is quite likely that the most common of the serious illnesses reported-TB-and perhaps certain others simply reflect complications of HIV infection. We may not be able to measure accurately whether hygiene, per se, is confounded by injection treatment of genital inflammation or sexually transmitted diseases (STDs). Neither the self-reported measure “number of times treated for an STD” nor “number of times diagnosed for an STD” was significantly associated with HIV-1 status in our cross-sectional study, however, whereas hygiene was. Several other groups have examined the evidence for iatrogenic transmission of HIV through injections in developing countries and have concluded that any role of injections is relatively small compared with the role of sexual transmission.4-6 We agree with Schmidt et al that “though there is a clear need to eliminate all unsafe infections, epidemiologic evidence indicates that sexual transmission continues to be by far the major mode of spread” in sub-Saharan Africa.5 Amalia S. (Meier) Magaret, PhD*† Elizabeth A. Bukusi, MBChB, MMed (Ob/Gyn), MPH, PhD‡§∥ Craig R. Cohen, MD, MPH¶ King K. Holmes, MD, PhD# *Department of Laboratory Medicine University of Washington Seattle, WA †Program in Biostatistics Fred Hutchinson Cancer Research Center Seattle, WA ‡Department of Gynecology University of Washington Seattle, WA §Center for AIDS and STD University of Washington Seattle, WA ∥Center for Microbiology Research Kenya Medical Research Institute Nairobi, Kenya ¶Department of Obstetrics, Gynecology and Reproductive Science University of California San Francisco, CA #Department of Medicine University of Washington Seattle, WA
Read full abstract
Oct 8, 2008
H Moi + 2
Open Access