RESUMO
A cross-sectional study was conducted to determine the seroprevalence of the Peste des Petits Ruminant (PPR) virus (PPRV) in sheep populations and to determine the potential epidemiological risk factors associated with this infection. Between October 2014 and March 2017, 2420 sheep serum samples were collected from ten selected PPR outbreak-prone districts in Bangladesh. The collected sera were analysed by competitive enzyme-linked immunosorbent assay (cELISA) test to detect antibodies against PPR. A previously designed disease report form was used to gather data on important epidemiological risk factors, and a risk analysis was performed to ascertain their association with PPRV infection. By cELISA, 44.3 % (95 % confidence interval:42.4-46.4 %) of sheep sera were positive for PPRV antibodies against PPR. In univariate analysis, the Bagerhat district had significantly higher seropositivity (54.1 %, 156/288) than other districts. Moreover, significantly higher (p < 0.05) seropositivity was found in the Jamuna River Basin (49.1 %, 217/442) compared to other ecological zones, in crossbreeds (60 %; 600/1000) related to native sheep, in males (69.8 %, 289/414) associated with females, in imported sheep (74.3 %, 223/300) compared to other sources, and in winter (57.2 %, 527/920) than in other seasons. In the multivariate logistic regression model, six possible risk factors were identified: study location, ecological zone, breed, sex, source, and season. The high seroprevalence of PPRV is significantly associated with several risk factors, suggesting that PPR is epizootic throughout the country.
RESUMO
OBJECTIVE: This study aimed to explore the seroprevalence of Brucella spp. in goats in some selected areas of Bangladesh. MATERIALS AND METHODS: This study was conducted in different goat-populated regions of Bangladesh from July 2017 to June 2018. A total of 208 serum samples were randomly collected from goats in Jashore (n = 50), Jhenidah (n = 22), Tangail (n = 40), Savar (n = 46), Thakurgaon (n = 18), and Bandarban (n = 32) areas. The samples were subjected to determine the presence of antibodies against Brucella spp. by rose bengal plate test (RBPT) and competitive enzyme-linked immunosorbent assay (c-ELISA). RESULTS: Overall, the seroprevalence of Brucellosis in goats was 4.33% (n = 9/208) by RBPT and 2.40% (n = 5/208) by c-ELISA. The seroprevalence of brucellosis on the basis of RBPT was 6% (buck: 0%, doe: 6%) in Jashore, 4.5% (buck: 0%, doe: 4.5%) in Jhenidah, 2.5% (buck: 0%, doe: 2.5%) in Tangail, 4.35% (buck: 0%, doe: 4.35%) in Savar, 6.25% (buck: 0%, doe: 6.25%) in Bandarban, and 5.56% (buck: 0%, doe: 5.56%) in Thakurgaon. On the other hand, the seroprevalence of brucellosis by c-ELISA was 4% (buck: 0%, doe: 4%) in Jashore, 4.5% (buck: 0%, doe: 4.5%) in Jhenidah, 3.13% (buck: 0%, doe: 3.13%) in Bandarban, and 5.56% (buck: 0%, doe: 5.56%) in Thakurgaon. Brucellosis was more prevalent (p > 0.001) in does aging 3-4 years. CONCLUSION: Goats from different areas of Bangladesh are caring antibodies against Brucella organisms. Further bacteriological investigations are necessary.
RESUMO
OBJECTIVE: The objective of this study was to develop a low-cost kit for the detection of subclinical mastitis (SCM) and to check its validity, reproducibility, and efficacy at the field level. MATERIALS AND METHODS: A total of 550 quarter milk samples from crossbred dairy cows were collected, of which 400 milk samples were used to validate the newly developed BLRI mastitis test (BMT) kit to justify its efficacy as an individual test kit in detecting SCM based on somatic cell count (SCC) by direct microscopic count (DMC). The efficacy of the newly developed BMT was compared with the California Mastitis Test (CMT) kit. Another 150 milk samples were subjected to SCC determined by DMC and DCC (De Laval cell counter®) categorized by CMT and BMT scores. RESULTS: A SCM test kit, namely, BMT kit was successfully developed in this study. The percentage accuracy of CMT and BMT were 76.75% and 75.75%; sensitivity 69.36% and 67.56%; specificity 85.95% and 85.85%; positive predictive value 86.03% and 85.71%; negative predictive value 69.23% and 68%, respectively. A p value of 0.001 was found for both CMT and BMT. However, CMT and BMT had no significant difference in sensitivity (p = 0.778). Average SCCs (cells/ml) determined by DCC and DMC, respectively, were mostly corresponded to the SCC ranges of both CMT and BMT scores. CONCLUSION: The newly developed BMT kit is an independent, cheap, farmer-friendly, first country made, and reliable SCM diagnostic test kit that can be used at field condition.
RESUMO
The true prevalence of brucellosis and diagnostic test characteristics of three conditionally dependent serological tests were estimated using the Bayesian approach in goats and sheep populations of Bangladesh. Serum samples from a random selection of 636 goats and 1044 sheep were tested in parallel by indirect ELISA (iELISA), Rose Bengal Test (RBT) and Slow Agglutination Test (SAT). The true prevalence of brucellosis in goats and sheep were estimated as 1% (95% credibility interval (CrI): 0.7-1.8) and 1.2% (95% CrI: 0.6-2.2) respectively. The sensitivity of iELISA was 92.9% in goats and 92.0% in sheep with corresponding specificities of 96.5% and 99.5% respectively. The sensitivity and specificity estimates of RBT were 80.2% and 99.6% in goats and 82.8% and 98.3% in sheep. The sensitivity and specificity of SAT were 57.1% and 99.3% in goats and 72.0% and 98.6% in sheep. In this study, three conditionally dependent serological tests for the diagnosis of small ruminant brucellosis in Bangladesh were validated. Considerable conditional dependence between IELISA and RBT and between RBT and SAT was observed among sheep. The influence of the priors on the model fit and estimated parameter values was checked using sensitivity analysis. In multiple test validation, conditional dependence should not be ignored when the tests are in fact conditionally dependent.