Melioidosis in Hainan, China: a restrospective study.

Background: Melioidosis is a tropical disease caused by infection with Burkholderia pseudomallei. Here, we report an 11 year (2002-2013) retrospective study of melioidosis cases in China.

Methods: A total of 170 culture-confirmed melioidosis cases were included in our analysis, with culture-positive confirmation, biochemical identification and 16S DNA sequencing. A retrospective study design was employed and a correlational analysis of potential risk factors for mortality was carried out with logistic regression.

Results: We observed a year-over-year increasing trend in the incidence of melioidosis in Hainan, particularly after 2007 (annual peak of 64 cases in 2012). Farmers and fishers were the main group susceptible to melioidosis (75/170; 44.1%). Forty-six (27.1%) of the cases were fatal. Pneumonia (58/170; 34.1%) and septicaemia (44/170; 25.9%) were common presentations. Meanwhile, pre-existing diabetes (74/170; 43.5%) and being employed in a job that involves outdoor labour (148/170; 87.1%) emerged as common factors among affected patients. We did not observe a significant effect of seasonal variation on melioidosis mortality, but the greatest number of cases did occur in the rainiest season.

Conclusions: This was the first clinical retrospective study of melioidosis in Hainan, China. The present data will be a useful resource to melioidosis researchers worldwide.