Seroprevalence of brucellosis in sheep and goats in the Arabian Gulf region

Abstract

Background and Aim: Brucellosis is a zoonosis that occurs worldwide. There were more efforts to control brucellosis in all countries. This study was performed to determine the seroprevalence of brucellosis in sheep and goats in some areas in the Arabian Gulf. Materials and Methods: The study analyzed 8500 sera from non-vaccinated sheep and goats. Animals included 6441 sheep (3420 from farms and 3021 from quarantine) and 2059 goats (1580 from farms and 479 from quarantine). Sera were tested using the Rose Bengal Plate Test (RBPT) and confirmed with an indirect enzyme-linked immunosorbent assay (i-ELISA) test. Final confirmation analyzed blood samples from confirmed infected animals (n=30, 23 sheep and seven goats) using polymerase chain reaction (PCR) and culture. Results: The serological examination showed that 62/8500 of animals (0.729%, confidence interval [CI] 95% 0.57-0.94) were seropositive for brucellosis. Thirteen of 5000 (0.26%, CI 95% 0.15-0.45) and 49/3500 (1.4%, CI 95% 1.1-1.8) of animals from farms and quarantine were seropositive, respectively. Out of the 6441, 46 (0.71%) sheep and 16/2059 (0.78%) goats were seropositive. i-ELISA confirmed 41/62 RBPT-positive animals – 41/8500 (0.482%, CI 95% 0.36-0.65). Eight of 5000 of these animals (0.16%, CI 95% 0.08-0.32) and 33/3500 (0.94%, CI 95% 0.67-1.3) were confirmed positive in farms and quarantine, respectively. Thirty of 6441 (0.466%) and 11/2059 (0.534%) cases were positive in sheep and goats, respectively. PCR confirmed 18 of 41 positive animals (0.212% of all sera, CI 95% 0.13-0.34) identified by both RBPT and i-ELISA. Three of 5000 (0.06%, CI 95% 0.019-0.19) and 15/3500 (0.429%, CI 95% 0.26-0.71) from farms and quarantine were confirmed positive. Tissue samples (uterine, supra-mammary, testicular, and accessory glands lymph node) were collected from positive animals, as detected by RBPT and i-ELISA, at culling or slaughtering. Using in vitro culture, 14/30 were confirmed positive – 3/7 from farms (two sheep and one goat) and 11/23 from quarantine (nine sheep and two goats). Biovar 1 was dominant. PCR confirmed 23/30 tissue samples, 4/7 from farms (three sheep and one goat), and 19/23 from quarantine (15 sheep and four goats). Conclusion: The overall brucellosis rate in sheep and goats is 0.48%, with fewer animals from farms testing positive (0.16%) in this area of the Arabian Gulf. The infection appears to be well controlled, and continuous effort is still needed to maintain control and completely eradicate brucellosis. Additional support is needed for testing and slaughterhouse monitoring. In quarantine (imported animals), brucellosis infection in the slaughterhouse (0.94%) could pose a risk for transmission and spread of infection. The effort is needed to monitor this threat, and PCR is a sensitive and time-saving test for brucellosis diagnosis. All 14 confirmed positive samples were Biovar 1 dominant.

The first study on seroprevalence and risk factors for zoonotic transmission of ovine and caprine brucellosis in the Province of Bam, Burkina Faso

“…However, they recommended that vigilance be maintained to maintain its status of being free from this zoonosis in sheep and goats. Our results are also higher than the rate of 0.48% obtained by Ebid et al [37]. Our results are also above 3.2% obtained in China [38].…”

“…Indeed, it is more easily transmitted to humans than bovine brucellosis [22,23]. This zoonotic transmission generally occurs through assisting with births and abortions, handling newborns without gloves, and consuming raw unpasteurized milk [30,35,37].…”

Seroprevalence and Associated Risk Factors of Brucellosis in Livestock and Residents of New Valley Governorate, Egypt

“…Considering sheep, the findings of the current study yield support the results of a study conducted by Samaha (2008) who found that seroprevalence among sheep was 0.00%. In the same vein, Bekele et al (2011) and Ebid and Salib (2020) respectively reported similar estimates of 1.2% and 0.48%, which were lower than the estimated rates of 20% and 15% respectively reported in the studies conducted by Abdel-Razik et al (2007) and Hegazy et al (2009). Similar to the obtained results of the current study concerning goats, (Samaha, 2008) estimated seroprevalence rates as 0.00%, which was almost near to the reported rates of 1.3% and 1.9% mentioned by Tekleye et al (1989) and Megersa et al (2011), respectively.…”

Current state of knowledge regarding bacterially-induced abortion in sheep

“…Recent data from sheep in Wyoming, USA, indicate 0.53% seropositivity in flocks and 22.5% among individual sheep [27]. Elsewhere, 0.71% seropositivity was noted in sheep in the Arabian Gulf [30] and 0% among 213 sheep tested in the Borana pastoral area in Ethiopia [31]. However, no new data has been obtained from other regions of the world, including Europe.…”