Prevalence of cystic echinococcosis in Iran: a systematic review and meta-analysis

As a significant zoonosis, cystic echinococcosis (CE) is endemic in some parts
of the world, such as the Middle East. There are studies on the prevalence of this
infection in animal and human reservoirs in Iran; hence, we conducted this metaanalysis to elucidate the prevalence of CE in Iran. English (PubMed, Scopus, Web
of Science, Science Direct and Google Scholar) and Persian (Magiran, Iran Medex,
Iran Doc and SID) databases were explored. In the case of definitive, animal and
human intermediate hosts, 37, 90 and 33 studies, respectively, have been included in the current review from January 1990 to December 2015. According
to outcomes of the heterogeneity test, either Der Simonian and Laird’s random-effects method or Mantel–Haenszel’s fixed-effects method were employed
to pool the estimations. The pooled prevalence of Echinococcus granulosus infection in definitive hosts was calculated as 23.6% (95% confidence interval
(CI) = 17.6–30.1%). The weighted prevalence of animal and human hydatidosis
was calculated as 15.6% (95% CI = 14.2–17.1%) and 4.2% (95% CI = 3.0–5.5%), respectively. Meanwhile, most cases of human hydatidosis were in southern Iran,
with a prevalence of 5.8% (3.2–9.2%). In terms of human hydatidosis, more infections were found in rural regions, and mostly in female individuals. Egger’s regression test revealed publication bias, with a remarkable impact on total
prevalence of the infection in animal intermediate hosts (P < 0.001), while it
was not significant in human hosts (P = 0.4) and definitive hosts (P = 0.3).
According to the weighted estimated prevalence of cystic echinococcosis and
its financial burden, implementing appropriate control programmes should be
compulsory to decrease the burden of the disease in Iran