Potential Risk Factors Associated with Human Cystic Echinococcosis: Systematic Review and Meta-analysis.
BACKGROUND
Scientific literature on cystic echinococcosis (CE) reporting data on risk factors is limited and to the best of our knowledge, no global evaluation of human CE risk factors has to date been performed. This systematic review (SR) summarizes available data on statistically relevant potential risk factors (PRFs) associated with human CE.


RESULTS
Database searches identified 1,367 papers, of which thirty-seven were eligible for inclusion. Of these, eight and twenty-nine were case-control and cross-sectional studies, respectively. Among the eligible papers, twenty-one were included in the meta-analyses. Pooled odds ratio (OR) were used as a measure of effect and separately analysed for the two study designs. PRFs derived from case-control studies that were significantly associated with higher odds of outcome were "dog free to roam" (OR 5.23; 95% CI 2.45-11.14), "feeding dogs with viscera" (OR 4.69; 95% CI 3.02-7.29), "slaughter at home" (OR 4.67; 95% CI 2.02-10.78) or at "slaughterhouses" (OR 2.7; 95% CI 1.15-6.3), "dog ownership" (OR 3.54; 95% CI 1.27-9.85), "living in rural areas" (OR 1.83; 95% CI 1.16-2.9) and "low income" (OR 1.68; 95% CI 1.02-2.76). Statistically significant PRFs from cross-sectional studies with higher odds of outcome were "age >16 years" (OR 6.08; 95% CI 4.05-9.13), "living in rural areas" (OR 2.26; 95% CI 1.41-3.61), "being female" (OR 1.38; 95% CI 1.06-1.8) and "dog ownership" (OR 1.37; 95% CI 1.01-1.86).


CONCLUSIONS
Living in endemic rural areas, in which free roaming dogs have access to offal and being a dog-owner, seem to be among the most significant PRFs for acquiring this parasitic infection. Results of data analysed here may contribute to our understanding of the PRFs for CE and may potentially be useful in planning community interventions aimed at controlling CE in endemic areas.
Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità (ISS), Rome, Italy.|European Reference Laboratory for Parasites (EURLP), ISS, Rome, Italy.
Alessia
A
Possenti
Instituto de Recursos Naturales y Agrobiologia de Salamanca, IRNASA-CSIC, Salamanca, Spain.
Raúl
R
Manzano-Román
Instituto de Recursos Naturales y Agrobiologia de Salamanca, IRNASA-CSIC, Salamanca, Spain.
Carlos
C
Sánchez-Ovejero
Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità (ISS), Rome, Italy.|European Reference Laboratory for Parasites (EURLP), ISS, Rome, Italy.|World Health Organization Collaborating Centre for the epidemiology, detection and control of cystic and alveolar echinococcosis (in humans and animals), ISS, Rome, Italy.
Belgees
B
Boufana
Sapienza University of Rome, Department of Public health and Infectious Diseases, Rome, Italy.
Giuseppe
G
La Torre
Instituto de Recursos Naturales y Agrobiologia de Salamanca, IRNASA-CSIC, Salamanca, Spain.
Mar
M
Siles-Lucas
Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità (ISS), Rome, Italy.|European Reference Laboratory for Parasites (EURLP), ISS, Rome, Italy.|World Health Organization Collaborating Centre for the epidemiology, detection and control of cystic and alveolar echinococcosis (in humans and animals), ISS, Rome, Italy.
Adriano
A
Casulli
D000367:Age Factors; D000818:Animals; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D016208:Databases, Factual; D004285:Dogs; D004443:Echinococcosis / Q000453:epidemiology* / Q000469:parasitology / Q000517:prevention & control*; D004446:Echinococcus / Q000302:isolation & purification; D005260:Female; D006801:Humans; D012307:Risk Factors; D012737:Sex Factors; D011795:Surveys and Questionnaires