Epidemiological studies on peste des petits ruminants in sheep and goats
Abstract
During the period from Jan. 2003 to Dec. 2004, 42 outbreaks of PPR involving 111 flocks of sheep and goats were recorded in different districts of Haryana state with overall morbidity, cumulative mortality and case fatality rate (CFR) of 40.03, 23.26 and 58.11%, respectively. Per cent morbidity, cumulative mortality and CFR were significantly more in goats (49.41, 32.61 and 66.00%) than in sheep (38.87, 22.10 and 56.87%). The number of outbreaks were more in the month of March. Per cent CFR in both sheep and goats varied between 28.82 to 82.18% in different months during the period under study. Per cent morbidity and cumulative mortality were significantly more in the rainy season, whereas the case fatality rate was significantly more in the winter season. All the three measurements of disease viz. morbidity, cumulative mortality and CFR were significantly more in young animals than in adults in both sheep and goats. Rainfall had significant correlation with per cent morbidity. The clinical findings in the affected animals comprised of high fever, pneumonia, erosive ulceration in the buccal cavity, nasal and ocular discharges, diarrhoea, abortions and death. Post-mortem changes included dehydrated carcasses, gastroentritis and pneumonia. To know the sero-prevalence , 696 serum amples (499 from Haryana state and 197 from Delhi state) collected from healthy sheep and goats that were not vaccinated against PPR, were examined for PPR antibodies by competitive ELISA. Of these, 44.82% serum samples contained antibodies against PPR. Per cent positivity was more in the samples collected from districts of Western Haryana than those in Eastern Haryana. Per cent positivity for PPR antibodies was more in sheep than in goats. Age-wise analysis of these sample revealed that 51.47% samples from sheep and goats of age more than 2 years contained PPR antibodies followed by 49.37% from animals of age between 1-2 years, and 20.27% from animals of less than one year of age. PPR antigen was detected in 4 nasal swab samples out of 36 samples of nasal swabs, ocular discharges and other tissue specimens examined by sandwich-ELISA.