Donors deferred for self-reported Chagas disease history: does it reduce risk?
In 12 years, only 28 potentially infected donors were identified using the Chagas question. Limited testing data suggest that few of these would have had serologic evidence of prior infection. In contrast, nearly 5 years of anti-T. cruzi screening identified 488 RIPA-positive donors, none of whom answered "yes" to the Chagas question. According to estimates in this study, the value of retaining the questionnaire in addition to testing translates to preventing the collection of 0.4 infected donors per billion. Thus, the Chagas history question has no meaningful value.
Daily stressors seem to be a more reliable trigger of children's headaches than diet or sleep factors.