Background. Fascioliasis is an emerging public health threat in a number of regions worldwide, including Southeast Asia. Up to now, a summary of current knowledge on the occurrence and the distribution in Southeast Asia is lacking. We therefore aim to gather recent information on the distribution and prevalence of and the associated risk factors for Fasciola spp. infections in humans, animals, and plant carriers in Southeast Asia.

Methods. Bibliographic and gray literature databases as well as reference lists of important review articles will be searched for relevant records that are published between January 1, 2000, and the search date. The systematic review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting systematic reviews. The primary outcomes will be both the prevalence of Fasciola spp. in the human and animal hosts, and on plant carriers in Southeast Asia, and the risk factors for occurrence of Fasciola spp. Secondary outcomes are the prevalence of Fasciola spp. in subpopulations (e.g., children and patients visiting clinics), the mapping of different diagnostic tests used, and the occurrence of the different Fasciola spp. in the study region. A descriptive statistical analysis will be conducted, and a meta-analysis will be run to estimate the prevalence of human and animal fascioliasis respectively, in Southeast Asia.

Discussion. This systematic review will summarize the current knowledge on the epidemiology of Fasciola spp. infections in Southeast Asia.

Systematic review registration. This systematic review has been registered with the International Prospective Register of Systematic Reviews (PROSPERO), reference number: CRD42021261104.