We commend Becker and colleagues  for assessing one type of potential exposure to HIV, medical injections, rarely examined in HIV epidemiology in India and other developing nations. However, their interpretation of their results is at odds with the evidence they presented, and their research design severely limits the inferences about transmission that can be drawn from the study.
Remarkable proportions of their respondents reported receiving medical injections in the past year (68%) and ever (95%). Becker and colleagues  observed a dose-dependent association between the number of medical injections received and prevalent HIV infection (e.g. adjusted odds ratio for 10+ versus no injections in the past year 2.3, 95% confidence interval 1.2–4.3). Clearly, this is a meaningful relationship, and it is consistent with other research in India [2,3]. However, Becker and colleagues  concluded that ‘… data from this study do not provide evidence for an association between HIV infection and medical injections’ (p. 1335).
Becker and colleagues  dismissed the association by suggesting that it represents HIV-infected individuals seeking more medical care, and thus injections, as a consequence of HIV-related illnesses. Whereas this is possible , Becker and colleagues  presented no data to support the contention. In the absence of identified incident infections and measures of why respondents received injections at particular points in time, there is no empirical basis for interpreting the temporal order of this association.
Given the prevailing assumption that most HIV transmission in India and other poor countries is through penile–vaginal sex, it is important for Becker and colleagues  to show results for analogous analyses of sexual behavior as a correlate of HIV infection. The appropriate benchmark with which to compare their results on medical injections is the association between penile–vaginal sex (ever in lifetime, frequency in the past year, and number of opposite sex partners in the past year) and prevalent HIV infection, including adjustments for the same demographic covariates used in their published analyses and the corresponding measure of medical injections. The measures of penile–vaginal sex should not reflect condom use or partner type, because their measures of medical injections did not capture the riskiness of those exposures or the settings in which they occurred .
As we have noted previously [6,7], many other types of parenteral exposures (e.g. dentistry, tattooing, scarification, injection drug use, surgery, blood transfusion, phlebotomy, etc.) are important to consider for HIV transmission; Becker and colleagues  apparently did not assess any of these. To our knowledge, no study on HIV epidemiology in India has yet included a thorough inventory of both sexual and parenteral exposures. Other barriers to understanding the modes of HIV transmission in India and sub-Saharan Africa are the lack of any systematic analysis of HIV contact tracing or risk networks (especially with respect to incident infections), investigation of the place and time dimensions of transmission, and sequencing of HIV DNA in relation to any of these kinds of data . Without such fundamental evidence on the structure and context of transmission, it is not possible to determine the important modes of transmission with confidence.
1. Becker ML, Reza-Paul S, Ramesh B, Washington R, Moses S, Blanchard JF. Association between medical injections and HIV infection in a community-based study in India. AIDS 2005; 19:1334–1336.
2. Solomon SS, Pulimi S, Rodriguez II, Chaguturu SK, Satish Kumar SK, Mayer KH, Solomon S. Dried blood spots are an acceptable and useful HIV surveillance tool in a remote developing world setting. Int J STD AIDS 2004; 15:658–661.
3. Reynolds SJ, Risbud AR, Shepherd ME, Zenilman JM, Brookmeyer RS, Paranjape RS, et al
. Recent herpes simplex virus type 2 infection and the risk of human immunodeficiency virus type 1 acquisition in India. J Infect Dis 2003; 187:1513–1521.
4. Gisselquist D, Potterat JJ. Review of evidence from risk factor analyses associating HIV infection in African adults with medical injections and multiple sexual partners. Int J STD AIDS 2004; 15:222–233.
5. Brewer DD, Brody S, Drucker E, Gisselquist D, Minkin SF, Potterat JJ, et al
. Mounting anomalies in the epidemiology of HIV in Africa: cry the beloved paradigm. Int J STD AIDS 2003; 14:144–147.
6. Brody S, Potterat JJ. Establishing valid AIDS monitoring and research in countries with generalized epidemics. Int J STD AIDS 2004; 15:1–6.
7. Gisselquist D, Friedman E, Potterat JJ, Minkin SF, Brody S. Four policies to reduce HIV transmission through unsterile health care. Int J STD AIDS 2003; 14:717–722.
8. Brewer DD, Rothenberg RB, Potterat JJ, Brody S, Gisselquist D. HIV epidemiology in sub-Saharan Africa: rich in conjecture, poor in data. Int J STD AIDS 2004; 15:63–65.