Contrasting HCV and HIV seroepidemiology in 11 years of blood donors screening in Brazil

Background: Blood donors are, in principle, healthy individuals who may be revealed as infectious for blood-borne agents by the laboratory screening process, depicting the asymptomatic burden of the disease. Therefore, monitoring hepatitis C virus (HCV)-infected donor and human immunodeficiency virus (HIV)-infected donor and associating to their demographical and behavioural characteristics may shed light on the dynamics and contemporary changes in these viruses' epidemiology.

Methods: Donors presenting repeatedly reactive HCV or HIV serology/nucleic acid testing (NAT) screening results were submitted to confirmatory testing. Confirmed positive donors were invited to return to the blood bank for notification and counselling when a follow-up sample was obtained and an interview performed to eventually disclose potential risks. HCV- or HIV-infected donors identified over 11 years of screening (2004-2015) were evaluated for demographic and behavioural parameters.

Results: In the period, 139 160 donations were screened, and 36 (0.025%) were found positive for HIV, stemming from 29 male and 7 female donors. Among those, eight subjects were repeat donors. A total of 95 donations were found repeatedly reactive for HCV (0.068%), obtained from 60 men and 35 women. Noticeably, in despite of a higher HCV prevalence in the donor population, the incidence of HIV among repeat donors was 10 times that of HCV (18 × 1.6/100 000 persons-year, respectively). On average, HIV-seroreactive men were found to be younger (mean = 34 years old) than women (mean = 40 years old). A total of 10 donors acknowledged sexual behaviours not previously informed, including 2 who were aware of their HIV-positive status and another 2 who admitted to be seeking HIV testing. No window period donation was verified.

Discussion: The majority of the HIV-infected donors are young males who deny risk factors in the interview and also ignore the confidence self-exclusion opportunity. As they may reiterate this behaviour in serial donations, use of the most sensitive laboratory testing is justified in this setting.