Schistosomiasis in Australian travellers to Africa

Objective: To determine the proportion of Australian travellers to Africa at risk of Schistosoma infection, and the proportion of those infected. Design and Participants: Retrospective postal survey of 360 patients who had attended Fairfield Hospital travel clinic in 1994 and stated an intention to travel to Malawi, Zimbabwe or Botswana. Main Outcome Measures: Self-reported risk status for Schistosoma infection. For those at risk, results of an indirect haemagglutination assay (IHA). For those with IHA titres greater than or equal to 1:32, results of enzyme-linked immunosorbent assay, urine microscopy and eosinophil count. Results: 360 letters were sent; 35 were returned to sender. Of the 325 remaining, 250 (77%) either responded or had an IHA test; 19 of these were still overseas or did not travel. 117/231 (51%) returned travellers considered themselves at risk of infection. Significantly fewer older patients reported exposure (chi(2) = 66.6; P < 0.001). 109/117 (93%) of those at risk had IHA tests and 18 had titres greater than or equal to 1:32. Subsequent testing indicated infection in 10/117 travellers (8.5%; 95% CI, 4.2%-15.2%). Conclusion: Our findings indicate that a considerable number of Australian travellers to Africa are at risk of schistosomiasis, and some are infected. As complications can be serious, screening is recommended for individuals with any risk of infection, and treatment should be offered to those infected.