Strongyloides stercoralis in humans and animals, in particular dogs - is Strongyloidiasis a zoonotic disease
Strongyloidiasis, a human disease caused by mainly Strongyloides stercoralis, is a neglected tropical disease. It is however, not limited to tropical regions. It was long known that human derived S. stercoralis is capable of infecting dogs. However, it is unclear if dogs, and may be other animals, play an important role as a source for S. stercoralis infecting humans. In collaboration with more applied parasitologists we compare S. stercoralis isolated from humans and animals, in particular dogs, using molecular genetic and genomic approaches. Recently we collaborated with the groups of Peter Odermatt at the Swiss Tropical and Publich Health Institute at Basel and with Virak Khieu and Sinuon Muth from the Cambodian National Center for Parasitology, Entomology and Malaria Control at Phnom Penh for work in Cambodia (see Schär, Guo et al. 2014, Jaleta, Zhou et al. 2017), with the group of Dengyu Liu at the Guangxi Medical University at Nanning, China for a study in the Guangxi province, Southern China see (Zhou et al. 2019a) and the group of Atiporn Saeung from the Chiang Mai University for work in Thailand (see Aupalee et al. 2020a). We found that, in the wild, dogs carry human type S. stercoralis, in addition to at least one presumably dog specific species or subspecies. While the S. stercoralis populations in humans on the South East Asian peninsula showed fairly extensive genetic variability, all S. stercoralis we isolated in Guangxi were phylogenetically closely related with each other and appeared to reproduce predominantly, if not exclusively asexually.
As a basis for the further investigation of the differences between poulations observed in the field, we plan to establish a collection of S. stercoralis wild isolates. In addition to collecting ourselves, we hope to encourage people encountering S. stercoralis to contribute their isolates. We plan to culture them in gerbils and freeze them alive. For each isolate we will determine a set of parameters (e.g. life cycle preference, sex ratio) and the whole genome sequence. Selected isolates will be crossed in order to evaluate their species status. The isolates will be made available to the community.
People involved in this project:
- Veroni Amarasinghe
- Dorothee Harbecke
- Sandra Gyarteng
- Xiaoxiao Yin
- Li Guo
- Tegegn Jaleta
- Siyu Zhou
- Kittipatt Aupalee