The strengthening case that simuliids play a role in Amazon region Hepatitis-B transmission

Hepatitis B virus (HBV) outbreaks are typically associated with injection drug use and high-risk sexual behavior; however, some cannot be easily explained in these terms. The messy blood-feeding methods of simuliids, provoked Chanteau et al. to investigate the simuliid-facilitated Hepatitis-B transmission (SFHBVT) hypothesis in French Polynesia in the early 1990s. Souto et al. later proposed the hypothesis could explain a HBV outbreak in the Brazilian Amazon which they suggested was driven by the biting of the M. ozzardi vector Simulium oyapockense. A recent Amazon region blood bank survey has provided important further support for the SFHBVT hypothesis playing a role in Amazon region transmission, but the results of this study have hitherto not been discussed in a SFHBVT context. Mansonella ozzardi positive donations were significantly more likely to test positive in anti-HBc and anti-HBc plus HBsAg tests than were M. ozzardi negative donations, suggesting both exposure to the HBV and HBV infections are significantly more common in individuals infected with M. ozzardi. It is argued here that these Amazon region blood bank observations substantially increase the viability of the SFHBVT hypothesis and thus that the hypothesis should be considered more carefully when HBV disease control measures are formulated for the Brazilian Amazon region and indeed beyond.