The epidemiology of paramphistomosis of sheep (Ovis aries L.) in the north west temperate Himalayan region of India.

An epidemiological study with the objective to assess the prevalence of paramphistomosis in association with season, age, sex and breed was carried out in naturally infected sheep over a period of two years from February 2005 to January 2007. Gastrointestinal tract (GIT) and faecal examination were conducted monthly to monitor the seasonal occurrence of paramphistomosis. 793 sheep were examined in the first year, out of which 7.06% were positive for Paramphistomum infection. In the second year, 740 animals were investigated and 7.7% were infected. The overall prevalence of paramphistomosis was 7.3% with a mean of 56.50 +/- 0.50 and 95% confidence interval (CI) (lower bound: 50.1469; upper bound: 62.8531). The prevalence of paramphistomosis through GIT examination (P = 0.593) was 7.6% at 95% CI (lower bound: -19.1186; upper bound: 57.1186) and the prevalence through faecal examination (P = 0.884) was 7.2% at 95% CI (lower bound: 5.7345; upper bound: 69.2655). Generally, season and age were the factors found to have a significant influence on the risk of paramphistomosis in sheep. The highest infection was found in the summer season (P < 0.005); lower age groups (P < 0.005) in males and in migratory (Bhakarwal) breed (P >or= 0.005). Winter, adult animals, females and local breed reported low infection. The present study will be of great significance to understand the epidemiology of gastrointestinal helminthes of sheep initially in the resource poor communities of Himalayan region and will definitely be helpful to devise appropriate control strategies for paramphistomosis.