Seven Salmonella Typhimurium Outbreaks in Australia Linked by Trace-Back and Whole Genome Sequencing

Salmonella Typhimurium is a common cause of foodborne illness in Australia. We report on seven outbreaks of Salmonella Typhimurium multilocus variable-number tandem-repeat analysis (MLVA) 03-26-13-08-523 (European convention 2-24-12-7-0212) in three Australian states and territories investigated between November 2015 and March 2016. We identified a common egg grading facility in five of the outbreaks. While no Salmonella Typhimurium was detected at the grading facility and eggs could not be traced back to a particular farm, whole genome sequencing (WGS) of isolates from cases from all seven outbreaks indicated a common source. WGS was able to provide higher discriminatory power than MLVA and will likely link more Salmonella Typhimurium cases between states and territories in the future. National harmonization of Salmonella surveillance is important for effective implementation of WGS for Salmonella outbreak investigations.The authors would like to thank ACT Health, NSW Health, Queensland Health, and OzFoodNet. We would also like to thank the laboratories that performed the serotyping, MLVA, and WGS, including the ICPMR, the MDU PHL, and Queensland Health Forensic and Scientific Services. Doherty Applied Microbial Genomics is funded by the Department of Microbiology and Immunology at The University of Melbourne. The National Health and Medical Research Council, Australia, funded a Practitioner Fellowship GNT1105905 to B.P.H. and Project Grant GNT1129770 to B.P.H., D.A.W., and M.D.K. Finally, we would like to thank Milica Stefanovic and Sam McEwen for their contribution to this project. This research is supported by an Australian Government Research Training Program (RTP) Scholarshi

Epidemiology of helminth infections and their relationship to clinical malaria in southwest Uganda.

It has recently been suggested that helminth infections may adversely influence susceptibility to other infections, including malaria. To investigate this hypothesis in a sub-Saharan African setting, surveys of helminth infections were conducted in 2003 among individuals who had been under weekly active case detection for clinical malaria during the preceding 18 months in four villages in Kabale District, southwest Uganda. Overall, 47.3% of individuals had at least one intestinal nematode species infection: hookworm, Ascaris lumbricoides and Trichuris trichiura were detected in 32.1, 17.4 and 8.1% of individuals, respectively. We found evidence of significant household clustering of A. lumbricoides, T. trichiura and hookworm, and clustering of heavy infection of each species. The association between helminth infection and clinical malaria was investigated in two villages and no evidence for an association was observed between the presence of infection or heavy infection and risk of malaria