Seropositivity and risk factors for Brucella in dairy cows in urban and peri-urban small-scale farming in Tajikistan

Abstract

In this cross-sectional study, we assessed and mapped the seroprevalence of brucellosis in small-scale dairy farming in an urban and peri-urban area of Tajikistan and investigated factors associated with seropositivity. As urban and peri-urban farming is both an opportunity to improve the livelihood for small-scale farmers and a potential public health hazard, studies are warranted to reveal possible peculiarities in the epidemiology of brucellosis in this type of dairy farming. In total, 904 cows of breeding age belonging to 443 herds in 32 villages were serologically tested with indirect enzyme-linked immunosorbent assay (ELISA) and positive samples confirmed with competitive ELISA. Two logistic regression models were used to investigate an association between seropositivity and risk factors at herd and individual level. The herd and individual seroprevalences were 4.1 and 2.0 %, respectively. Herds with a history of abortions were found to be associated with seropositivity [odds ratio (OR) = 5.3; 95 % confidence interval (CI), 1.3–21.3]. Large herds with more than eight cattle were more likely to be seropositive compared to smaller herds with one to two cattle (OR = 13.9; 95 % CI, 1.6–119). The number of calves produced per cow (indicating age) was found to be associated with seropositivity. Younger cows with one to two produced calves were less likely to be seropositive compared to older cows with more than six produced calves (OR = 0.24; 95 % CI, 0.06–1.0). Neither introduction of new cattle to the herd nor communal grazing was associated with seropositivity. This study shows that infection with Brucella (1) is present in small-scale urban and peri-urban dairy farming in Tajikistan and (2) has significant negative effects on reproductive performance in this farming system and (3) that some previously known risk factors for seropositivity in rural farming system were absent here.

Detection and characterization of Brucella spp. in bovine milk in small-scale urban and peri-urban farming in Tajikistan

“…The internal inhibition/amplification control was positive in each assay. The apparent individual seroprevalence measured previously with I-ELISA and C-ELISA was 2.1% [25]. All seropositive cows (n = 12) were also positive in the IS 711 qPCR with Ct-values ranging between 26.9 and 31.9.…”

“…The study area and study population have been described in detail previously [25]. In brief, the current study was conducted in the UPU areas of Dushanbe, the capital city of Tajikistan, with a radius of <20 km from the central part of the city (Fig 1).…”

“…This study was carried out simultaneously with a seroprevalence study among dairy cows where the selection of villages, herds and individuals has been described previously in detail [25]. In brief, information of the villages keeping dairy cows with a radius of < 20 km from the central part of Dushanbe was received from the local official veterinarians and the villages were numbered and selected randomly.…”

Bovine brucellosis in Pakistan; an analysis of engagement with risk factors in smallholder farmer settings

“…; Lindahl et al . ). All these factors and practices contribute either to contaminate the environment or act as a source for pathogen transmission.…”

Prevalence and risk factor's analysis of bovine brucellosis in peri-urban areas under intensive system of production in Gujarat, India

“…Such finding is in accordance with the earlier report of Tun [10] who reported significantly higher risk when the herd size is greater than 50 animals as it was 28.6% for herd size above 50 and only 3.1% for herd size less than 50 animals. Likewise, scientists had also reported significant association of herd size with prevalence of brucellosis [11,19,[25][26][27][28][29][30][31][32]. On contrary, non-significant association between herd et al [35].…”