Effects of geographical and climatic factors on cystic echinococcosis in south-western Iran

Abstract

Cystic echinococcosis (CE) is caused by the larval form of Echinococcus granulosus that can cause serious health and economic problems in the endemic foci. CE is globally distributed in various climatic conditions from circumpolar to tropical latitudes. Iran is an important endemic area with a spectrum of weather conditions. The aim of this study was to determine the effects of geo-climatic factors on the distribution of livestock CE in south-western Iran (SWI) in 2016 to 2018. Data of livestock CE were retrieved from veterinary organizations of four provinces of SWI. The geo-climatic factors, including mean annual temperature (MAT), minimum MAT (MinMAT), maximum MAT (MaxMAT), mean annual rainfall (MAR), elevation, mean annual evaporation (MAE), sunny hours, wind speed, mean annual humidity (MAH), slope, frost days and land cover, were analysed using geographical information systems (GIS) approaches. The statistical analysis showed that MAR, frost days, elevation, slope and semi-condensed forest land cover were positively and MAE, MAT, MaxMAT, MinMAT and salt and salinity land cover were negatively correlated with CE occurrence. MAE was shown to be a predictive factor in the stepwise linear logistic regression model. In short, the current GIS-based study found that areas with lower evaporation were the main CE risk zones, though those with lower temperature and higher rainfall, altitude and slope, especially where covered with or in close proximity of semi-condensed forest, should be prioritized for consideration by health professionals and veterinarians for conducting control programmes in SWI.

Risk Mapping and Spatial Modeling of Human Cystic Echinococcosis in Iran from 2009 to 2018: A GIS-Based Survey

“…In the present study, using geographically weighted regression analysis, the correlation between temperature, relative humidity, NDVI and the incidence of human hydatidosis was investigated. In Ilam, Semnan, Hamedan, Qazvin, and Ardabil provinces, the highest correlation was observed between temperature, relative humidity, and NDVI with the incidence of hydatidosis, which is similar to other studies (30)(31)(32). The results of Danson et al study showed the application of GIS in the study of human parasitic infections is very useful and shows a better understanding of parasite transmission.…”

Three cases of brain hydatidosis in North Khorasan, Iran

“…The adult worms are inhabitants in the intestine of dogs and other canid families as the final hosts. 1 , 2 , 3 , 4 …”

“…The World Health Organization (WHO) has classified it as the most prevalent global food‐borne disease. 6 , 7 According to the WHO, Iran is considered one of the hyperendemic areas of the disease due to the high rate of dogs' exposure to livestock ( 3 , 4 ). The prevalence of hydatid cysts in the intermediate host was reported at 11.5%–34.6% and the incidence of 5% in human have been reported from different parts of Iran.…”

“…The disease is caused by the larval stage of tapeworms Echinococcus granulosus ( E. granulosus ). The adult worms are inhabitants in the intestine of dogs and other canid families as the final hosts 1–4 …”

“…The adult worms are inhabitants in the intestine of dogs and other canid families as the final hosts. [1][2][3][4] Dogs are infected by eating contaminated viscera and after a few months, they excrete the eggs with feces. 2,5 The eggs can contaminate foods and water sources and mammalian (including human) infections occur through consumption of contaminated food/water.…”