Risk Factors for Brucella Seroprevalence in Peri-Urban Dairy Farms in Five Indian Cities.

Brucellosis is endemic among dairy animals in India, contributing to production losses and posing a health risk to people, especially farmers and others in close contact with dairy animals or their products. Growing urban populations demand increased milk supplies, resulting in intensifying dairy production at the peri-urban fringe. Peri-urban dairying is under-studied but has implications for disease transmission, both positive and negative. In this cross-sectional study, five Indian cities were selected to represent different geographies and urbanization extent. Around each, we randomly selected 34 peri-urban villages, and in each village three smallholder dairy farms (defined as having a maximum of 10 dairy animals) were randomly selected. The farmers were interviewed, and milk samples were taken from up to three animals. These were tested using a commercial ELISA for antibodies against Brucella abortus, and factors associated with herd seroprevalence were identified. In all, 164 out of 1163 cows (14.1%, 95% CI 12.2-16.2%) were seropositive for Brucella. In total, 91 out of 510 farms (17.8%, 95% CI 14.6-21.4%) had at least one positive animal, and out of these, just seven farmers stated that they had vaccinated against brucellosis. In four cities, the farm-level seroprevalence ranged between 1.4-5.2%, while the fifth city had a seroprevalence of 72.5%. This city had larger, zero-grazing herds, used artificial insemination to a much higher degree, replaced their animals by purchasing from their neighbors, were less likely to contact a veterinarian in case of sick animals, and were also judged to be less clean. Within the high-prevalence city, farms were at higher risk of being infected if they had a young owner and if they were judged less clean. In the low-prevalence cities, no risk factors could be identified. In conclusion, this study has identified that a city can have a high burden of infected animals in the peri-urban areas, but that seroprevalence is strongly influenced by the husbandry system. Increased intensification can be associated with increased risk, and thus the practices associated with this, such as artificial insemination, are also associated with increased risk. These results may be important to identify high-risk areas for prioritizing interventions and for policy decisions influencing the structure and development of the dairy industry.

Quantitative polymerase chain reaction based quantification of Brucella DNA in serum of pre- and post-therapeutic occupationally exposed infected human population.

BACKGROUND: Brucellosis is one of the neglected zoonotic diseases in humans. The serological methods based on antibody detections are unable to detect the effectiveness of treatment in humans as antibodies persist for long time in humans even after therapy. Therefore, we developed qPCR technique to overcome such discrepancy and device a rapid and efficient test for both diagnosis and follow up of the brucellosis affected individuals. METHODS: High risk suspected individuals with positive serology (RBPT, STAT and iELISA) and PCR were mainly analyzed for DNA quantification by qPCR assay. The bcsp-31 gene, a shared gene of Brucella species was amplified by genus specific primers and cloned to pGEMT™ easy vector and the cloned plasmid were used to construct a standard curve (R2=0.99, efficiency=1.98) over 7 orders of magnitude with sensitivity of ≈10 copy number. The assay was found 100% specific. RESULTS: Overall 85 individuals were found positive out of 188. Out of them, 23 serological, PCR and qPCR positive individuals were recommended for 45days therapy according to WHO regimen (Doxycycline and Rifampin) and each case was further followed by qPCR. The mean threshold cycle (Cq) before treatment was 26.05±0.347 (3940.5copies/µl), which increased significantly to 32.7±0.66 (259.13copies/µl) on 4th week during treatment, 35.12±3.12 (38.52copies/µl) at 6th week on day of treatment completion, 35.6±0.66 (34.21copies/µl) on 21st day after treatment depicting a significant reduction in DNA load over the course of treatment. Serological follow up showed that only 3 individuals had decreased STAT titre but no change in RBPT results. Out of 17 symptomatic individuals under therapy, 10 improved clinically, 5 improved clinically with persistent weakness and 2 had no effect of therapy. CONCLUSION: The study suggests that qPCR is more useful and rapid test to follow treated individuals than serology.

Determination of organochlorine pesticide residues in freshwater fish species in Punjab, India.

The levels of organochlorine pesticides residues were determined in five freshwater fish species in Punjab State, India. These species were selected in view of their importance to local human fish consumer. DDTs were the predominant organochlorine contaminants in all species with pp DDT and pp DDE as the main pollutants. Other organochlorines, such as HCH isomers and dieldrin were also found at lower levels in fish species. The alpha-HCH was the dominant isomer of HCH in all fish species followed by gamma-, beta- and delta-HCH. The residues of aldrin, chlordane, heptachlor and endosulphan were not detected in any fish sample. The levels of organochlorines detected in present study were below the tolerance limits recommended at National and International standards.