PRV was also immunogenic among Malian infants, with an anti-RV IgA seroresponse rate at least as high as those detected in the other two study sites in Ghana and Kenya, although lower than has been reported in higher resource settings [4], [15], [16], [17], [18], [19],

[20] and [21]. The assessment of vaccine efficacy in this country-specific analysis was problematic because of the incompatibility of the PP passive, health center-based surveillance system as applied in Mali. During the first year of the trial, 55 cases of RVGE were identified, and 11 (20%) were classified as severe. This is likely Vorinostat chemical structure KPT 330 a combination

of failure to capture cases, as well as underscoring of the RVGE cases that were detected. As the Vesikari scoring system was originally designed for use with daily diary cards in settings of high parental literacy, it is likely that the reliance on passive parental reporting of symptoms and presentation to a health care facility led to underscoring of individual RVGE cases in Mali. A full assessment of the scoring of the clinical severity of diarrhea cases is described elsewhere [22]. In addition, the monthly household visits through the first year of follow-up, mainly intended to ensure very follow up of the families and as a reminder to alert study staff for any cases of gastroenteritis, proved inadequate for case capture and unexpectedly revealed that many infants had experienced episodes of gastroenteritis during the previous month but had not been brought by their parents to the CSCOM. Instead, it was found that the parents had taken the child to be seen by a traditional healer, a common local

practice [23]. Whereas it is known that traditional healers constitute the first line of contact in health care seeking behavior in Mali [23], it had been assumed that the initial enrollment methods and the monthly household visits would suffice to modify this health care seeking preference. However, this turned out not to be true. To the contrary, the respect and role of traditional healers in Malian culture was so ingrained that information provided by the investigator team alone could not modify this behavior. During the second year of follow-up this was addressed by contacting the traditional healers, interacting with them to explain the purpose of the study, demonstrating respect for their important role as providers of primary care and, in return, gaining their confidence.