Early studies carried out in Glasgow demonstrated that a significant proportion of babies excreting virus particles, 12%, did not exhibit gastrointestinal symptoms; seroprevalence studies carried out in the US have shown that 90% of children have antibody to HastV-1 by age 9, suggesting that (largely asymptomatic) infection is common.
A recent survey found that only 12% of women vendors in Bamako (with an estimated HIV seroprevalence of 6.7%) reported using a condom with their last non-regular partner.