Sexually transmitted infection (STI) could be considered a high-risk category for HIV transmission through organ donation. But hemophilia should now be dropped as a risk category, given the low incidence of HIV in that population, according to a study presented at the American Transplant Congress in Philadelphia in May.
The U.S. Centers for Disease Control and Prevention (CDC) issued classifications of high-risk organ donors in 1994, but the epidemiology of certain infections has changed since then. Current evidence shows that STI could now be considered a high-risk category, given the high incidence and prevalence of HIV among this population. But given the very low 1 in 100,000 incidence of HIV among people with hemophilia, it should be dropped as a high-risk category, said Lauren Kucirka, ScM, an epidemiologist in the department of surgery at the Johns Hopkins University School of Medicine in Baltimore.
The CDC currently categorizes potential donors as being at high risk on the basis of seven behaviors or circumstances. These individuals include men who have sex with men, injection drug users, people with hemophilia, commercial sex workers, people who have high-risk sex (that is, with people in any of the foregoing groups), people who have been exposed to HIV through blood, and people who are incarcerated.
By these criteria, about 9 percent of donors from whom at least one organ is recovered are classified as being at high risk, and these organs are 26 percent more likely to be discarded than are those from donors not at high risk. Kucirka noted that the CDC guidelines have several limitations: they were designed in 1994, before the advent of highly active antiretroviral therapy; they were aimed in part at HIV but have been extended to hepatitis C virus (HCV) infection; and although they were designed to identify donors at risk of prevalence infection, the real risk from HIV is from incident infection. In the case of hemophilia, for example, the prevalence of HIV is high among people who received transfusions in the 1980s, but because of tests to screen blood the incidence of new infections is low.
To investigate potential new high-risk categories, Kucirka and colleagues performed a systematic review of the literature on the incidence and prevalence of HIV and HCV from 1995 through 2008, as well as a meta-analysis. They identified 272 eligible abstracts for HIV estimates and 218 for HCV estimates.