RESUMEN
AIM: The objective of this study was to screen the prevalence of contagious ecthyma (CE) among the goat population of Assam owing to its high prevalence rate. MATERIALS AND METHODS: In this study, a total of 231 serum samples were collected from 12 districts of Assam during September 2013 to July 2014. The serum samples were tested for the presence of antibodies against Orf virus (ORFV) by indirect enzyme-linked immunosorbent assay (ELISA). Indirect ELISA was standardized using purified Orf reference virus produced in bulk in primary lamb testes cells. RESULTS: Studies on seroprevalence showed 76.62% of goats were seropositive. The total number of animals were divided into different age groups starting from 0-2 months, 2-4 months, 4-6 months, and above 8 months and accordingly highest prevalence of antibodies against ORFV was recorded in the age-group above 8 months of age. Significantly, lower rates of infection were observed in goats of age group 2-4 months. This study recorded that seropositivity from naturally infected animals and in contact apparently healthy animals to be 53.67% and 46.32%, respectively. CONCLUSION: The results indicated that CE is a prevalent infection in goats of Assam, and the healthy population is at increased risk of infection.
RESUMEN
The present study was undertaken to detect the presence of PPRV in the goats of Assam. Competitive ELISA and Sandwich ELISA are used to detect the PPR viral antibody and antigen respectively. In addition, the study also involved the assessment of specific gene targets for detection of PPRV by RT-PCR from the clinical samples. A total of 579 sera samples (68.65 % in outbreak samples and 5.29 % in random samples) collected from different parts of Assam were tested by c-ELISA, indicated overall prevalence of 27.28 in goats. The percentage prevalence of PPRV antibodies in sera samples from goats collected at the time of outbreaks were 79.26, 85.41, 58.82, 6, 29.41 and 36.36 % in Kamrup, Nalbari, Mongoldoi, Jorhat, Darrang and Barpeta respectively. However, high percent prevalence (20.83 %) was observed in district Dhubri in random samples. Among the suspected samples, high percent prevalence (85.41 %) was observed in Nalbari. The competition percentage values (ranges from 35 to 45) obtained in competitive ELISA from tested goat samples found three categories, viz. positive, doubtful and negative. Most of the serum samples (n = 158) with competition percentage less than or equal to 35 % are considered positive for the presence of PPRV antibodies, (n = 9) greater than 35 % and less than or equal to 45 % are considered doubtful and retested, and (n = 423) greater than 45 % are considered negative. The overall sensitivity, specificity, apparent prevalence and true prevalence rate was found to be 68.65, 94.70, 27.28 and 34.69 % respectively. True prevalence rate was calculated based on the sensitivity and specificity of the c-ELISA employed in the study, which has a relative specificity of 94.70 % and sensitivity of 68.65 %.
RESUMEN
The present study describes prevalence of peste des petits ruminants (PPR) virus infection in goats in various parts of North-East (NE) India by screening of suspected serum samples collected during outbreak investigation and random samples during 2013-2014 survey. A total of 391 serum samples (318 random and 73 outbreak/suspected) were collected from 28 districts in 7 states (Meghalaya, Assam, Manipur, Nagaland, Arunachal Pradesh, Tripura and Mizoram) of NE India. Serum samples were screened for PPRV-specific antibodies by using PPR monoclonal-antibody based competitive ELISA. Analysis of 391 serum samples indicates that an overall seroprevalence of 17.90 % [CI 95 % 14.40-22.00] in goats {45.2 % in suspected [CI 95 % 34.32-56.58] and 11.63 % in random [CI 95 % 8.56-15.63] samples} in NE India. As expected prevalence was high in outbreaks vis-à-vis random samples. The random survey results (11.63 %) has specific implication in epidemiological perspectives, since it highlights the exact PPR prevalence under natural situations, where the subclinical, in apparent or nonlethal or recovery of infection was suspected in goats, as samples were collected from unvaccinated animals. It also warrants appropriate control measures against PPR in NE region to prevent spread of infection besides widespread presence of the disease in rest of India.