Advisor(s)
Abstract(s)
Cryptosporidium spp. is an important cause of gastrointestinal disease worldwide, responsible for 69 million cases
of illness in 2016. Information on the sources and transmission pathways of human cryptosporidiosis results
mainly from outbreak investigations.
A systematic review and a meta-analysis of case-control and cohort studies were performed to determine the
main risk factors associated with sporadic cryptosporidiosis. Suitable scientific articles were identified through a
systematic literature search and subjected to a methodological quality assessment. From each study, odds ratio
(OR) measures were extracted or calculated, as well as study characteristics such as population type, design, type
of model and risk factor hierarchy. Mixed-effects meta-analysis models were adjusted by population type to
appropriate data partitions.
From 1985 identified references, the quality assessment stage was passed by 57 cohort and case-control
studies focusing on sporadic cryptosporidiosis. The eligible studies were conducted between 1983 and 2016 and
provided 568 OR categorized for meta-analysis.
This meta-analysis identified travel, immunocompromising conditions, contact with infected humans, waterborne
transmission (contact with recreational waters, wastewater, and consumption of untreated drinking
water), contact with animals and food consumption as the relevant risk factors for sporadic cryptosporidiosis.
With regards to food exposures, consumption of meat, dairy products (raw milk) and dishes consumed outside
home were found significantly associated with cryptosporidiosis. The consumption of poorly washed fruits and
vegetables significantly increases ORs. This meta-analysis reveals that some potential sources of Cryptosporidium
such as shellfish or vegetables are under-investigated.
Future case-control studies for sporadic cryptosporidiosis should include population at risk, and investigate
other potential sources in relation to the genotype and the subtype of Cryptosporidium spp.
Description
Keywords
Case-control studies Cohort studies Cryptosporidium Meta-regression Research synthesis
Pedagogical Context
Citation
Kooh, Pauline; Thébault, Anne; Cadavez, Vasco; Gonzales-Barron, Ursula; Villena, Isabelle (2020). Risk factors for sporadic cryptosporidiosis: a systematic review and meta-analysis. Microbial Risk Analysis. ISSN 352-3522. p. 1-14