Epidemiology, Risk Factors and Economics of Echinococcosis in India: A Review

Abstract

Echinococcosis caused by cestode of genus Echinococcus is an important zoonotic disease with worldwide distribution. Two of the important echinococcosis are cystic echinococcosis (CE) and alveolar echinococcosis (AE) caused by metacestodes of Echinococcus granulosus and E. multilocularis, respectively. The definitive hosts for CE or hydatidosis are carnivores and intermediate hosts are herbivores, with humans acquiring the accidental infection from carnivores. The larval stages of E. granulosus can parasitizes internal organs of animals and humans and as a result responsible for substantial morbidity and mortality. Worldwide, India is ranked first in CE cases amounting to 12% of global CE cases. Apart from morbidity and mortality in humans and animals, the economic losses in animals arise from production losses, condemnation of cyst affected carcasses, and losses from poor reproductive performances. The data regarding the losses in animals is often underreported. In humans, 8,71,000 disability- adjusted-life- years (DALY) globally each year points toward the severity of the disease. The various risk factors such as illegal slaughter/ slaughter in uncertified slaughterhouses, large population of stray dogs, dependency of rural population to raise livestock and practice of feeding dogs with offal of home butchered animals facilitate CE transmission in India, which makes it a public health, veterinary and social challenge. Systematic and national level surveillance of disease in rural livestock and human population, awareness programmes about its zoonotic nature, coordinated efforts from veterinary and medical science for epidemiology and diagnosis, and strict legislation in post mortem inspection at abattoirs is needed for prevention and control of the disease.