Screening strategy for Chagas disease in a non-endemic country (Switzerland): a prospective evaluation

The WHO recommends screening of Latin American migrants for Chagas disease to reduce morbidity and mortality and increase the likelihood of eradicating the disease. The objective was to assess the feasibility and acceptability of a screening strategy in one Swiss canton. From February 2011 to September 2012, people attending six healthcare centres of different types were offered a rapid diagnostic test if they or their mother were of Latin American origin (or, at the blood donation centre, if they had travelled for = 1 year in Latin America). In addition, testing was offered during events where Latin Americans gathered. In total, 1,010 people were tested, mainly originating from Brazil (24%), Ecuador (13%) and Chile (10%). 54% were born in Latin America, 15% had a Latin American mother, and 29% were travellers. The prevalence of Chagas disease was 2.3% among migrants (15.5% in the community testing) and 0% among travellers. The prevalence was 18.0%, 0.8%, 0.5% and 0% among Bolivians, Ecuadorians, Brazilians and other countries respectively. Predictors for Chagas disease were: born in Latin America (OR = infinite, p < 0.001), Bolivian origin (OR = 95, 95% CI: 19-482, p < 0.001), being tested in the community (OR = 56, 95% CI: 14-218, p < 0.001), and age > 35 years OR = 3.4, 95% CI: 1.1-10.5, p = 0.03). The prevalence of Chagas disease was much higher in people attending social events than healthcare centres, suggesting that observations based only on health facility data underestimate the real prevalence of Chagas disease. Screening in the community was well accepted and should be promoted to reach the population at highest risk.