Fasciola spp. in Southeast Asia: A systematic review

PLoS Negl Trop Dis. 2024 Jan 17;18(1):e0011904. doi: 10.1371/journal.pntd.0011904. eCollection 2024 Jan.

Abstract

Background: Fasciolosis is an emerging public health threat in a number of regions worldwide. To date, we lack an overview of both its occurrence and distribution in Southeast Asia across all actors involved in the life cycle, which impedes the development of disease control measures. Therefore, our objective was to collect recent information on the distribution and the prevalence of Fasciola spp. and the associated risk factors for infection in humans, animals, snails and plant carriers in Southeast Asia.

Methodology: Bibliographic and grey literature databases as well as reference lists of important review articles were searched for relevant records published between January 1st, 2000, and June 30th, 2022. The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting systematic reviews. A total of 3,887 records were retrieved, of which 100 were included in the final analysis.

Principal findings: The studies focused mainly on one host species (96.0%), with Fasciola spp. infection in animals being the most studied (72.0%), followed by humans (21.0%). Based on the used inclusion and exclusion criteria, reports were retrieved describing the presence of Fasciola spp. infection in seven out of 11 countries in Southeast Asia. Depending on the diagnostic tool applied, the prevalence of Fasciola spp. infection ranged between 0.3% and 66.7% in humans, between 0% and 97.8% in animals, and between 0% and 66.2% in snails. There were no studies reporting the presence of metacercariae on plant carriers.

Conclusions/significance: Our study reconfirms that Fasciola spp. infections are widespread and highly prevalent in Southeast Asia, but it remains difficult to accurately assess the true occurrence of Fasciola spp. in absence of well-designed surveys covering all hosts. As next steps we propose to assess the occurrence of the infection across all actors involved in the transmission, to identify associated risk factors and to estimate the burden of the disease to support national and international decision makers.

Publication types

  • Systematic Review

MeSH terms

  • Animals
  • Asia, Southeastern / epidemiology
  • Databases, Factual
  • Fasciola*
  • Fascioliasis* / epidemiology
  • Humans
  • Snails

Grants and funding

This study was conducted within the context of the EmFaVie project, which is funded by the Flemish Interuniversities Council - University Development Co-operation (VLIR-UOS, https://www.vliruos.be/en; grant number VN2020SIN317A103; granted to BL & DDT) and the FasciCoM project, which is jointly funded by the Research Foundation - Flanders (FWO, https://www.fwo.be/en/; grant number G0E2921N; granted to BL) and the Vietnamese National Foundation for Science and Technology Development (NAFOSTED, https://nafosted.gov.vn/en/; grant number FWO.108.2020.01; granted to DDT). The funders did not have any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.