Comparative Seroepidemiological Study of Brucellosis in Sheep under Smallholder Farming and Governmental Breeding Ranches of Central and North East Ethiopia

Epidemiology of Brucellosis in Small Ruminants of Rural and Peri-Urban Areas of Multan, Pakistan

Brucellosis is a widespread zoonotic disease of veterinary and public health importance with considerably higher prevalence in developing/underdeveloped countries. This study reports the prevalence and risk determinants of brucellosis in small ruminants of peri-urban and rural areas of district Multan, Southern Punjab, Pakistan. For this purpose, sera samples (n = 392) of small ruminants were collected and subjected to preliminary screening using commercially available RBPT reagents followed by serodetection of brucellosis using multispecies i-ELISA kit (ID.vet, France). All the ELISA positive samples were confirmed by PCR using genus-specific primers, and frequencies of Brucella species in positive samples were enumerated using species-specific primers. Results indicated seropositivity rates of 9.69, 9.95, and 10.20% in study population using RBPT reagents of IDEXX-USA, ID.Vet-France, and VRI-Pakistan, respectively, with a statistically nonsignificant difference (p > 0.05). Results of ELISA showed an overall seroprevalence rate of 7.14% in target population with a slightly higher rate in sheep (7.65%) as compared to goat (6.63%) population (p = 0.695; OR = 1.16, 95% CI = 0.53, 2.57). Results revealed that out of total positive samples, B. abortus was detected in 60.71% of seropositive samples and B. melitensis was detected in 14.28% of positive samples. It was revealed that risk factors including body condition scores, hygienic conditions of the housing facility, farming system, reproductive disorders, educational status of farmers, and awareness of farmers about brucellosis had significant association with brucellosis in small ruminants of study area (p < 0.05). Conversely, farm/herd size, locality, gender, age, weight, and parity showed a nonsignificant association (p > 0.05) with brucellosis. In conclusion, brucellosis is prevalent in small ruminants of Multan, Pakistan. It is recommended to devise and implement effective control strategies with a major focus on raising awareness about brucellosis in farmers for the containment of infection in the region.

Seroprevalence and potential risk factors of brucellosis in sheep from America, Africa and Asia regions: A systematic review and meta-analysis

BACKGROUND

Brucellosis, a neglected and global zoonotic disease, infect a variety of mammals, among which sheep are one of the main hosts. This disease results in huge economic losses and is a widespread concern around the world.

RESULT

Based on the selection criteria, 40 articles from 2010 to 2021 of five databases (CNKI, Wanfang, VIP, PubMed and Science Direct) reported in America, Africa and Asia were included. The data showed that during this period, the overall seroprevalence of sheep brucellosis on these three continents was 6.2%. At the regional level, sheep brucellosis had the highest seroprevalence (8.5%) in Africa and the lowest seroprevalence (1.9%) in the Americas. With regard to the age of the sheep, the seroprevalence was significantly higher in adult sheep (15.5%) than in lambs (8.6%). Further, the seroprevalence was significantly higher in sheep that had abortion (44.3%) than in pregnant (13.0%) and non-pregnant sheep (9.5%). With regard to herd size, herds with >20 sheep (35.4%) had a significantly higher seroprevalence than herds with <20 sheep (16.8%). In terms of farming and grazing mode, free-range rearing (8.4%) was associated with a significantly higher seroprevalence than intensive farming (2.8%), and mixed grazing (37.0%) was associated with a significantly higher seroprevalence than single grazing (5.7%).

CONCLUSION

Sheep brucellosis is widely distributed in sheep-rearing regions of America, Africa and Asia, and sheep are susceptible to brucellosis by themselves or from other infectious sources. Therefore, timely monitoring of ovine brucellosis and improving farming and grazing patterns are critical to reducing the prevalence of brucellosis.

Seroprevalence and assessment of public awareness of Brucella spp., Toxoplasma gondii and Chlamydia abortus in small ruminants from selected smallholder commercial farms of Zimbabwe

Brucella spp., Toxoplasma gondii, and Chlamydia abortus have long been recognized as zoonoses and significant causes of reproductive failure in small ruminants globally. A cross-sectional study was conducted in August 2020 to determine the seroprevalences of Brucella spp., Toxoplasma gondii and Chlamydia abortus in 398 small ruminants from four districts of Zimbabwe (Chivi, Makoni, Zvimba, and Goromonzi) using Indirect-ELISAs. A structured questionnaire was used to assess the knowledge, attitudes, and practices of 103 smallholder farmers towards small ruminant abortions, Brucella spp., T. gondii and C. abortus, and to obtain a general overview of the significance of small ruminant reproductive failure(s) on their livelihoods. The overall seroprevalences were: 9.1% (95% CI: 6.4-12.3) for Brucella spp., 6.8% (95% CI: 4.5-9.7) for T. gondii and 2.0% (95% CI: 0.9-3.9) for C. abortus. Location, age, parity, and abortion history were associated with Brucella spp. seropositivity. Location was also associated with both T. gondii and C. abortus seropositivity. The questionnaire survey established that 44% of respondents had recently faced reproductive disease challenges within their flocks, with 34% correctly identifying abortion causes and only 10%, 6% and 4% having specific knowledge of Brucella spp., C. abortus and T. gondii, respectively. This study provides the first serological evidence of Brucella spp. in small ruminants since 1996 and builds the evidence on small ruminant toxoplasmosis and chlamydiosis in Zimbabwe. Evidence of these zoonoses in small ruminants and the paucity of knowledge shows the need for a coordinated One Health approach to increase public awareness of these diseases, and to establish effective surveillance and control measures. Further studies are required to establish the role these diseases play in small ruminant reproductive failure(s), to identify the Brucella spp. detected here to species/subspecies level, and to assess the socio-economic impact of reproductive failure in livestock among marginalised rural communities.

Study on small ruminant brucellosis and owners awareness in two selected districts of southern region, Ethiopia

INTRODUCTION

Brucellosis is one of the infectious diseases that has the greatest impact on the productivity of sheep and goats. A cross-sectional study followed by a simple random sampling technique was used to investigate the seroprevalence of brucellosis (Rose Bengal plate test; RBPT and complement fixation test; CFT) in small ruminants and its related risk variables from November 2019 to June 2020 in Kolme and Abala Abaya districts. A questionnaire was also given to owners to assess their existing knowledge of the disease.

RESULT

Using the RBPT and CFT, 28 (4.1%) and 23 (3.33%) of the 690 animals were found to be seropositive for brucellosis, respectively. In this study, the seroprevalence of brucellosis detected in the Kolme district (5.3%) was greater when compared to Abala Abaya (1.0%). The odds of Brucella infection were greater for goats (odds ratio [OR] 6.0, 95% confidence interval [CI] 16 0.8-44.9) than for sheep. The odds of adult animals (OR 0.05, 95% CI 0.03-0.07) being positive for brucellosis was higher than young animals. A statistically significant difference in the seropositivity of brucellosis was detected in univariate logistic regression among districts, different age groups, herd size, parity number, and reproductive health problems except for species and sex, but in multivariate logistic regression, only reproductive health problems were revealed a statistically significant difference. Out of 138 families, 100% of respondents were unaware of brucellosis, 94.5% drink raw milk, and 74% handle animals with retained fetal membranes with their bare hands.

CONCLUSION

This study showed that brucellosis was a widely spread disease in the study areas and poses a substantial public health danger. To reduce the spread of the disease in small ruminants, public health risks, and economic losses, stringent vaccination application and awareness of personal hygiene are critical.

Cross-Sectional Study of Seroprevalence and Associated Risk Factors of Bovine Brucellosis in Selected Districts of Jimma Zone, South Western Oromia, Ethiopia

Bovine brucellosis is one of the most widespread but neglected zoonotic diseases in developing countries where it is an endemic and growing problem causing public health impacts. Developing a cost-effective control strategy of the disease can only be guaranteed by knowledge of the disease epidemiology that defines its risk profiles. Hence, this study was designed to evaluate epidemiological aspects of bovine brucellosis in selected districts of Jimma zone. A cross-sectional study with multistage sampling techniques was conducted on 424 cattle to evaluate its seroprevalence. Likewise, 114 households were included for the investigation of risk factors. SPSS version 20 for data analysis and C-ELISA test for antibody detection were used. Moreover, the chi-square test for univariable analysis and logistic regression model for multivariable analysis were employed to assess association between seropositivity and risk factors. From this study, 3.3% (95% CI: 1.82-5.48) and 12.3% (95% CI: 6.88-19.75) seroprevalence of the disease was detected with the highest proportion found at Kersa district (6.5 (95% CI: 1.37-17.90) and (21.4 (95% CI: 4.66-50.80)) followed by Seka Chokorsa (1.76 (95% CI: 0.37-5.07) and (6.7 (95% CI: 1.40-18.27)) and Mana (1.75 (95% CI: 0.21-6.20) and (7.1 (95% CI: 0.88-23.50)) at individual animals and herd levels, respectively. Cattle of poor body condition, pregnant, and cows with history of abortion and repeat breeding were found 4.8 (95% CI: 2.00-22.74), 4.3 (95% CI: 1.43-13.04), 3.3 (95% CI: 1.07-10.21), and 2.7 (95% CI: 1.86-8.15) times more likely seropositive than their counterparts, respectively. Besides these, mixed feeding style was highly associated with seropositive reactors than separate feeding (AOR = 8.3; 95% CI: 1.76-38.99). These findings depicted substantial areas to be addressed in implementation of appropriate and immediate control actions and establishment of intervention mechanisms of bovine brucellosis.

Seroprevalence and risk factors for brucellosis in small ruminant flocks in Karnataka in the Southern Province of India

Background and Aim:

Brucellosis is a zoonotic disease of high economic and public health importance in large and small ruminant populations worldwide. A cross-sectional study was conducted to determine the seroprevalence and risk factors of brucellosis in small ruminants in organized farms in the southern region of India.

Materials and Methods:

Farms exclusively rearing sheep and goats were selected based on the number of animals (small, medium, or large) and the location of the farm (urban, periurban, or rural). A total of 1499 serum samples; 1001 from sheeps and 498 from goats were sourced from six sheep and four goat farms and tested using Rose Bengal Plate and indirect Enzyme-Linked Immunosorbent Assay tests.

Results:

The apparent prevalence of brucellosis was higher in sheep (8.29%, 95% CI 6.7-10.1) than goats (5.82%, 95% CI 4.0-8.2). The true adjusted population level seroprevalence was also higher in sheep, at 7.7% (95% CI 6.0-9.6) than in goats, at 5.1% (95% CI 3.2-7.6). According to bivariate categorical analysis, six highly significant (p<0.001) animal- and farm-level risk factors for sheep were age, breed, number of lambings, history of abortion, rural farms, and presence of dogs on the farm. In goats, five significant risk factors were found: History of abortion, separate sheds, dogs on the farm, weekly veterinary consultation, and lack of brucellosis awareness. In a logistic regression model, abortion (OR _adjusted 10.8, 95% CI 1.2-96.12), rural farms (OR _adjusted 8.5, 95% CI 3.6-20.0), and absence of separate sheds on the farms (OR 1.9, 95% CI 1.1-3.5) were found to be significant risk factors for ovine brucellosis.

Conclusion:

The use of complementary measures to tackle the multiple animal- and farm-level risk factors may help to reduce the disease burden in the absence of a vaccination policy for small ruminants in India.

Assessment of Seroprevalence and the Risk Factors of Sheep Brucellosis in Basrah (Southern Iraq): A Challenge to Prospectively Control Brucellosis

Brucellosis is one of the most important foodborne infectious diseases distributed widely in low- and middle-income countries. The current study was carried out to investigate the prevalence and risk factors that influence the distribution of Brucella in sheep. A structured questionnaire was prepared and introduced to a total of 60 resident owners from five counties, and 400 sheep blood samples were randomly collected from the selected herds. The sera of isolated sheep were tested for Brucella spp. using the Rose Bengal Test (RBT). A univariable and multivariable logistic regression analysis was used to evaluate the risk factors linked to animal management and husbandry practices at the farm level. The overall prevalence estimated for brucellosis was 31% (95% confidence interval [Cl]: 26.5–35.8). The odds of seroprevalence in sheep >1 year were significantly higher than those in sheep ≤1 year (odds ratio [OR]: 2.2, 95% Cl: 1.41–3.44). The logistic regression outcomes revealed that two variables related to the management and practices at the farm level were significantly associated with the seroprevalence of brucellosis. These variables were sheep sheep grazing with other flocks (OR: 5.8, 95 Cl% Cl: 1.53–22.67) and the practice of lending ram among sheep owners (OR: 9.3, 95% Cl: 1.05–83.82). Unconfined domesticated dogs, improper handling of aborted ewes, introduction of new animals in a herd, (purchased), and lack of knowledge about brucellosis among owners were underlined to be further important factors that could influence the spread of brucellosis. This study concluded that brucellosis is an endemic disease in Basrah, and the animal vaccination control program with an integrated health education program for sheep owners are obligatory elements of the prevention measures needed to be established to minimize the risk of brucellosis in Basrah.

Small Ruminant Production in Tanzania, Uganda, and Ethiopia: A Systematic Review of Constraints and Potential Solutions

Sheep and goats are an important commodity for smallholder farmers across East Africa, but severe limitations remain in small ruminant production. This review aimed to identify specific constraints to small ruminant production and identify practical and sustainable solutions. From 54 eligible articles, most were focused in Ethiopia (n = 44) with only 6 studies performed in Tanzania and 4 in Uganda. The most frequently identified constraint in Ethiopia and Tanzania was disease (n = 28 and n = 3, respectively), and in Uganda, it was the lack of access to veterinary services (n = 4). Additionally, access to good breeding stock, lack of animal records, and an established marketing chain were also mentioned in all the three countries. Ectoparasites, gastrointestinal parasites, orf, and sheep/goat pox were the most frequently mentioned disease challenges causing productivity losses. Many articles provided potential solutions as suggested by farmers, including improved access to veterinary services and medicines, improved record keeping, and access to good breeding stock. Farmers highlighted the value of community-based participatory development plans to increase education on disease control, land management, and husbandry. This review also highlighted knowledge gaps, the need for further research, particularly in Tanzania and Uganda, and the importance of addressing multiple challenges holistically due to the links between constraints.

Revisiting Brucellosis in Small Ruminants of Western Border Areas in Pakistan

Brucellosis, globally known bacterial zoonosis, is endemic to Pakistan. B. abortus in bovines, B. melitensis in small ruminants and B. canis in dogs mainly cause this disease. A total of 1821 sera (1196 from sheep and 625 from goats) from animal herds near the Pakistan–Afghanistan border were collected. In parallel testing of sera for anti-Brucella antibodies (B. abortus and B. melitensis) was carried out by RBPT and indirect ELISA. The presence of Brucella DNA in sera was tested by real-time PCR. The overall percentage of seropositive samples was 0.99 (18/1821) by both tests. All positive samples originated from Baluchistan territory which translated into 1.76% (18/1021). None of the positive sera had signals for Brucella DNA and none of sera from goats carried detectable antibodies. Both tests showed an almost perfect agreement with Kappa statistics. The flock size was found to be associated with the presence of anti-Brucella antibodies. The samples of Khyber Pakhtunkhwa (KPK) tested negative in both serological tests and hence were not processed for real-time PCR. The present study shows the presence of anti-Brucella antibodies in sheep in the Baluchistan region of Pakistan. Diagnostic services need to be improved and test and slaughter policies might be implemented for eradication of Brucella infection in these areas. Awareness about the infection is needed at the farmer’s level. Isolation and molecular biology of the isolates could help with understanding the prevailing etiology in a better way.

Spatial sero-prevalence of brucellosis in small ruminants of India: Nationwide cross-sectional study for the year 2017-2018

Brucellosis in small ruminants caused mainly due to Brucella melitensis is an important zoonotic disease characterized by abortion, retained placenta, infertility, orchitis, epididymitis and rarely arthritis. Small ruminants are the main source of economy for the rural and marginally poor farmers and brucellosis is resulting in huge economic losses due to abortions and infertility and causing public health concern among the small ruminant keepers. Bovine brucellosis control programme has been implemented in India and small ruminants are left out of the programme mainly due to paucity of brucellosis status. The present cross-sectional study based on stratified random sampling was undertaken during 2017-18 to provide the nationwide brucellosis sero-prevalence in small ruminants. A total of 24,056 small ruminant serum samples (sheep samples = 8,103 [male-2,440 and female-5,663] and goat samples = 15,953 [male-4,331 and female-11,622]) sourced from 27 out of 29 states and two out of seven union territories (UTs), 350 districts of total 640 districts (54.68% of the Indian districts) and from 1,462 villages out of 6,40,867 villages (43.83% of the Indian villages). The serum samples were tested by indirect ELISA and overall brucellosis apparent and true prevalence of 7.45 (95% CI: 7.13-7.79) and 3.79 (95% CI: 3.44-4.17) was recorded. Significantly higher brucellosis sero-prevalence (p < .0001) was observed in sheep (11.55%) than goats (5.37%). Similarly, brucellosis seropositivity was highly significant in females compared to males in both sheep and goats. Countrywide, greater than 5% brucellosis sero-prevalence in sheep and goats was recorded in 14 and 10 states, respectively, indicating endemicity of the disease. The study provided the latest update on nationwide spatial sero-prevalence of small ruminant brucellosis which will aid government to strengthen regular surveillance and vaccination to reduce the disease burden and public health problems in the country.

Seroprevalence and risk factors for bovine brucellosis in the Chittagong Metropolitan Area of Bangladesh

Brucellosis is a neglected endemic zoonosis in Bangladesh and has a significant impact on public health and animal welfare of dairy farming as well as dairy farm economics. A cross‐sectional study was conducted to evaluate the seroprevalence of and risk factors for brucellosis in dairy cattle in the Chittagong metropolitan area (CMA) of Chittagong, Bangladesh. We collected serum samples (n = 158) from six randomly selected dairy farms in the CMA between February and November, 2015. The Rose Bengal Plate Test (RBPT) and a competitive ELISA (cELISA) were used as the screening and confirmatory tests respectively. Farm level and animal level demographic and risk factor data were collected using a questionnaire. The risk factors were analysed using a multivariable logistic regression with random effects. The overall seroprevalences of antibodies against brucellosis in cattle were 21.5% (34/158) and 7.6% (12/158) based on parallel and serial interpretation of the two tests respectively. Our results revealed that 20.3% (32/158) samples were positive using the RBPT and 8.9% (14/158) were positive using the cELISA. The within‐herd seroprevalence ranged from 10% to 26.3% and 5 to 20.7% using the RBPT and cELISA tests respectively. The odds of seropositivity were significantly higher in lactating cows (OR: 2.59; 95% CI: 1.02–6.55), cows producing less than 2 litres of milk (OR: 29.6; 95% CI: 4.3–353.8), cow producing 2–12 litres of milk (OR: 4.8; 95% CI: 1.1–33.4) and cows with reproductive disorders (OR: 3.2; 95% CI: 1.2–10.1). About 7.6% (12/158) and 1.3% (2/158) of cattle were found to be infected with acute and chronic brucellosis respectively. Based on these results, we suggest that cows that have reproductive disorders and are producing little milk should be prioritized for brucellosis screening in CMA. The screening tests should be used to control brucellosis in cattle in order to protect animal welfare, human health and to minimize the economic losses.

Detection of Brucella antibodies in domestic animals of southern Cameroon: Implications for the control of brucellosis

Brucellosis is one of the world's most widespread bacterial zoonoses caused by Brucella. It leads to considerable economic losses as a result of low productivity of infected animals and the long debilitating illness in humans. Despite its impact on human and animal health, little attention has been paid on Brucella infections in domestic animals. It is in this light that the prevalence of Brucella antibodies was determined in domestic animals with the overarching goal of improving our knowledge on brucellosis in southern Cameroon. During cross-sectional studies conducted from December 2016 to August 2018 in five sites of southern Cameroon, blood samples were collected in cattle, sheep, goat, pig and dog. Plasma was obtained from each blood sample and Brucella antibodies were detected using the Rose Bengal test and the enzyme-linked immunosorbent assay (ELISA). From 1873 animals that were sampled, the overall prevalence of Brucella antibodies using Indirect enzyme-linked immunosorbent assay (i-ELISA) was 6.35% (118/1873): 9.12% (78/855) in cattle; 8.04% (30/373) in sheep; 6.06% (2/33) in dog, 1.87% (3/160) in pig and 1.1% (5/452) in goat. Between animal species (p-value < .0001, x2  = 33.63) as well as sampling sites (p-value = .0001, x2  = 18.97), significant differences were observed in the prevalence of Brucella antibodies. Yoko and Noun localities have shown the highest prevalence of 8.6% (30/348) and 7.2% (78/1070), respectively. This prevalence was significantly higher (p = .03, x2  = 1.25) in female than male cattle. Between adult (16.923%) and young cattle (7.8%), significant difference (p = .04, x2  = 6.42) was observed in the prevalence of Brucella antibodies. This study shows that the prevalence of Brucella antibodies varies between animal species and localities. It also shows several domestic animals of southern Cameroon that have been in contact with Brucella. It enabled to identify villages where investigations on the transmission dynamic must be focused for the final goal of developing control measures for this neglected zoonotic disease.