Incidence, Risk Factors, and Epidemiology of Cystic Echinococcosis: A Complex Socioecological Emerging Infectious Disease in Khyber Pakhtunkhwa, Province of Pakistan.

Cystic echinococcosis is a serious zoonotic disease caused by Echinococcus granulosus species complex. The current study is the first attempt to determine the level of infection in domestic livestock and to explore the CE-related knowledge and awareness among livestock farmers in different districts of Khyber Pakhtunkhwa, province of Pakistan. A total of 1297 animals were examined for hydatid cysts including 538 cows, 428 buffaloes, 208 sheep, and 123 goats, at different slaughter houses in different districts of Khyber Pakhtunkhwa in 2 years from September 2015 to September 2017. For epidemiological investigations, prevalence in association with various factors (climate, age, and gender), organ specificity, types of cysts (fertile, sterile, or calcified), and viability of cysts parameters was recorded. Basing on the results obtained, areas with high prevalence were selected for further follow-ups and administration of questionnaires to the farmers and dog owners, to provide baseline data about this parasitic disease and to identify potential areas of emergence with correspondence animal and of public health significance. The finding of this study revealed the presence of CE in livestock of KP, Pakistan. The prevalence of hydatid cysts was the highest in buffaloes (15.88%) followed by cows (15.79%), sheep (15.38%), and goats (3.25%). Our investigation revealed close relationship between prevalence and animal age and gender in different months of the year. These findings also showed the highest prevalence of hydatid cysts in liver (63.49%), followed by lungs (23.80%) and mesentery (2.64%). Fertile and viable cysts were observed in all animal species except goats. The highest percentage of fertile and viable cysts was reported from the liver and lungs of sheep. For evaluation of risk factors, a total of 384 respondents were investigated. The results of current study revealed that 97.9% of farmers are not familiar with CE and transmission of this infection from dogs to human and livestock. The present study shows that CE will continue to be of medical and veterinary importance in Pakistan.