Nonclonal Burkholderia pseudomallei Population in Melioidosis Case Cluster,Sri Lanka

A melioidosis case cluster of 10 blood culture–positive patients occurred in eastern Sri Lanka after an extreme weather event. Four infections were caused by Burkholderia pseudomallei isolates of sequence type 594. Whole-genome analysis showed that the isolates were genetically diverse and the case cluster was nonclonal.     

Phylogeography and Molecular Epidemiology of an Epidemic Strain of Dengue Virus Type 1 in Sri Lanka

In 2009, a severe epidemic of dengue disease occurred in Sri Lanka, with higher mortality and morbidity than any previously recorded epidemic in the country. It corresponded to a shift to dengue virus 1 as the major disease-causing serotype in Sri Lanka. Dengue disease reached epidemic levels in the next 3 years. We report phylogenetic evidence that the 2009 epidemic DENV-1 strain continued to circulate within the population and caused severe disease in the epidemic of 2012. Bayesian phylogeographic analyses suggest that the 2009 Sri Lankan epidemic DENV-1 strain may have traveled directly or indirectly from Thailand through China to Sri Lanka, and after spreading within the Sri Lankan population, it traveled to Pakistan and Singapore. Our findings delineate the dissemination route of a virulent DENV-1 strain in Asia. Understanding such routes will be of particular importance to global control efforts.