Herd-level factors for Brucella seropositivity in cattle reared in smallholder dairy farms of Zimbabwe

Brucellosis in camel, small ruminants, and Somali pastoralists in Eastern Ethiopia: a One Health approach

Brucellosis is a neglected bacterial zoonotic disease with economic and public health importance in pastoral communities of sub-Saharan Africa. A cross-sectional study was conducted from December 2021 to April 2022, to estimate the prevalence and identify the associated risk factors causing brucellosis in animals and associated with occupational diseases in humans from three selected districts of "the Somali Pastoral region," Eastern Ethiopia. In this study, 1,000 serum samples were screened for anti-Brucella spp. antibodies using Rose Bengal Plate Test (RBPT) and further confirmed using a competitive enzyme-linked immunosorbent assay (cELISA). A structured questionnaire was used to collect the biodata of tested animals and animal attendants to test the association between explanatory and outcome variables. The overall animal level prevalence was 5% (95% CI, 6.1-7.2.0) in small ruminants, 2.9% (95% CI, 1.5-4.9) in camels, and 2.0% (95% CI, 0.2-3.7) in occupationally linked humans. Herd size and herd history of retained fetal membranes were risk factors associated with Brucella spp. seropositivity in animals (p < 0.05). Disposing of retained fetal membranes was significantly associated (p < 0.05) with Brucella spp. seropositivity in humans. Evidence of brucellosis in various livestock species and associated seropositivity in humans indicates the need for a coordinated One Health approach, considering sociocultural dynamics of pastoral communities in controlling brucellosis to safe guard public health and increase livestock productivity.

Seroprevalence of Coxiella burnetii, Leptospira interrogans serovar hardjo, and Brucella species and associated reproductive disorders in cattle in southwest Ethiopia

In Ethiopia, Coxiella burnetii, Leptospira Hardjo, and Brucella spp are recognized as the primary factors contributing to cattle reproductive issues. A cross-sectional study was conducted in southwest Ethiopia from October 2020 to October 2021 to assess the risk of reproductive disorders associated with L. Hardjo, Coxiella burnetii, and Brucella spp. Moreover, the study aimed to identify the factors associated with reproductive disorders. Using an indirect ELISA, antibodies against these pathogens were observed in serum samples collected from 461 cattle. We employed multivariable random effect logistic regression analysis to identify potential risk factors associated with reproductive disorders in cattle. The study areas showed a prevalence of 25.16 % (95 % CI: 21.20-29.12) for cattle reproductive disorders. The presence of Leptospira Hardjo (OR = 2.9, 95 % CI: 1.17-4.02) and Coxiella burnetii (OR = 3.0, 1.49-5.94) antibodies was associated to the occurrence of cattle reproductive disorders. Seropositivity to pathogens B. abortus, C. burnetii, and L. Hardjo, along with co-infection of all three, showed association with cattle abortion. The presence of L. Hardjo seropositivity and co-infection with C. burnetii were related to dystocia in cattle. Cattle with retained fetal membranes were associated with co-infection seropositivity to these pathogens. Additionally, B. abortus seropositivity was linked to cases of repeated breeding in cattle. Age, breeding practices, and dog access to cattle showed associations with reproductive disorders, with odds ratios of 2.3 (95 % CI: 2.03-4.69), 2.9 (95 % CI: 1.83-4.82), and 6.5 (95 % CI: 1.04-2.53) respectively. This research indicates that Brucella abortus, Coxiella burnetii, and Leptospira Hardjo, which are responsible for severe zoonotic diseases, have a substantial negative impact on cattle production by causing reproductive disorders. To address the transmission of these diseases, it is essential to implement effective mitigation strategies and enhance public awareness. Additional investigation is necessary to identify and understand the factors contributing to cattle reproductive disorders in the specified area.

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.

Herd and animal level seroprevalence and associated risk factors of bovine brucellosis in different agro-ecologies of southwest Ethiopia

Brucellosis is a zoonotic infection that commonly affects cattle in Ethiopia, causing significant negative economic impact. A cross-sectional study was carried out between November 2020 and November 2021 in southwest Ethiopia to determine the seroprevalence of brucellosis and its associated risk factors in cattle herds. Blood samples were taken from 461 randomly selected cattle to test for the presence of Brucella antibodies using the Rose Bengal Plate test, with positive serum confirmed through the complement fixation test. A multivariable random effect logistic regression analysis was used to identify potential risk factors for Brucella seropositivity. The study found 7.14% (95% CI: 4.44-9.01) seroprevalence at the animal level and 12.23% (95% CI: 6.52-16.05) at the herd level based on the complement fixation test. Age (OR = 6.9, 95%CI: 1.83-15.97), herd size (OR = 3.66, 95%CI: 1.39-9.61), introducing new animals (OR = 2.72, 95%CI: 1.17-6.29), management system (OR = 12.2, 95%CI: 1.53-26.80), species composition (OR = 4.24, 95%CI: 1.51-11.91), and abortion (OR = 7.1, 95%CI: 1.93-15.39) were found to be associated with Brucella seropositivity. The analysis also revealed two risk factors for Brucella infection at the herd level, including herd size (OR = 3.4, 95% CI: 1.05-10.68) and species composition (OR = 3.1, 95% CI: 1.20-7.88). The presence of Brucella antibodies in cattle highlights the need for increased awareness and measures to mitigate the identified risk factors of the disease to prevent its spread. Furthermore, further studies are necessary to investigate the zoonotic transmission of brucellosis to humans and its role in cattle reproduction disorders in the study area.

Bovine brucellosis seroprevalence and flow network analysis in slaughterhouses in the state of Ceará

The present study aimed to assess the prevalence and risk factors associated with bovine brucellosis in slaughterhouses in the state of Ceará using spatial distribution and flow network analysis. Four slaughterhouses were sampled in Ceará: two under municipal inspection and two under state inspection. Blood samples were randomly collected from bovine animals, resulting in a total of 964 samples. The collected sera were subjected to the Acidified Buffered Antigen (AAT) test, and the complement fixation test (FC) was performed for positive cases. An epidemiological questionnaire was applied to 38 producers who slaughter animals at the sampled facilities to assess the risk factors for brucellosis. An apparent prevalence of 1.55% (15) was found in the AAT test and 0.2% (n=2) in the FC test. A higher percentage of reactive animals was observed (66.6%) in properties where cattle farming is not the main activity, with OR = 4.75. The absence of contact with neighboring animals is a factor associated with protection, with a lower prevalence of seroreactive animals (23.5%) when animals were raised without contact with others (OR = 0.30). Therefore, bovine brucellosis in herds and animals can be considered low in the studied region and under all production systems. Nevertheless, despite the importance of this disease to the economic and public health aspects and the advances of the PNCEBT Program, brucellosis is still circulating in Ceará.

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.

Knowledge and perception of community about causes of cattle abortion and case-control study of brucellosis as cause of abortion in Jimma zone, Ethiopia

BACKGROUND

Abortion, causes by several infectious and non-infectious factors is one of the most critical health problems of cattle in Ethiopia. Thus, this study aimed to assess knowledge and perception of the community about potential causes of abortion and case-control study of brucellosis as a cause of abortion in cattle of study districts.

METHODS

A cross-sectional study was conducted between October 2016 and October 2017 in selected districts of the Jimma zone using a questionnaire survey. Based on the questionnaire survey, we also carried out a case-control study (141 cases and 282 controls) to confirm whether the most frequently mentioned disease (brucellosis) is associated with abortion. The blood samples were collected from both cases and controls cattle groups and then serum was separated. The presence of antibody against Brucella organism in serum was first tested by Rose Bengal Plate Test (RBPT) and all RBPT positive samples were confirmed using the Complement Fixation Test (CFT).

RESULTS

From a total of 180 randomly selected respondents, the majority (59.4%) of them attributed abortion to infectious diseases. Based on the questionnaire survey, brucellosis, leptospirosis and listeriosis were identified as the major infectious causes of abortion in the areas. Physical injuries, shortage of feed and toxic substances were observed as less important non-infection causes of abortion in the study areas. This study also identified improper disposal of aborted materials and birth products, use of communal bulls, sharing communal grazing areas and water sources which favour disease transmission. Exposure to Brucella organism was higher among cases (6.4%) than controls (2.8%) with a statistically significant difference (p = 0.042).

CONCLUSION

Brucellosis is the most important infectious cause of cattle abortion in this study. Thus, important to conduct appropriate control methods and increasing public awareness of the zoonotic transmission of brucellosis are suggested. This finding also recommended the need for further study to isolate and characterise brucellosis as a cause of abortion in cattle.

Brucellosis in wildlife in Africa: a systematic review and meta-analysis

This study aimed to consolidate current knowledge of wildlife brucellosis in Africa and to analyse available predictors of infection. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Information on species, test used, test results, area, rainfall, livestock and wildlife contact and year of study were extracted. This systematic review revealed 42 prevalence studies, nine disease control articles and six articles on epidemiology. Brucella abortus, Brucella melitensis, Brucella inopinata and Brucella suis were reported in wildlife. The prevalence studies revealed serological evidence of brucellosis in buffalo, antelope (positive in 14/28 species), carnivores (4/12) and other species (7/20) over the last five decades. Buffalo populations were more likely to be infected and had a higher seroprevalence than other species; the pooled seroprevalence was 13.7% (95% CI 10.3-17.3%) in buffalo, 7.1% (95% CI 1.1-15.5%) in carnivores and 2.1% (95% CI 0.1-4.9%) in antelope. Wildlife in high rainfall areas (≥ 800 mm) were more likely to be infected, and infected populations showed higher seroprevalence in high rainfall areas and in studies published after 2000. Domestic animal contact was associated with increased seroprevalence in antelope and carnivore species, but not in buffalo, supporting the hypothesis that buffalo may be a reservoir species.

Seroepidemiology of bovine brucellosis in Colombia's preeminent dairy region, and its potential public health impact

A cross-sectional study was conducted to determine the associated factors of brucellosis in Colombia's preeminent dairy region declared in quarantine. A total of 656 samples were collected from cows ≥ 2-year-old from 40 herds. Samples were screened by the Rose Bengal Plate Test, and the Fluorescence Polarized Assay test and Competitive ELISA were used as confirmatory tests. A cow was classified as positive if the screening and both confirmatory tests were positive. A herd was classified as positive if at least one cow was seropositive. The factors associated to seropositivity were tested using a logistic regression model with explanatory variables regarding cattle management, zootechnical parameters, and sanitary practices. The seroprevalence at the animal level was 6.6% (43/656) and at herd level 27.5% (11/40). In the model, five variables explained the animal cases: purchase or animal transfer between owner's farms (OR = 2.79, 95% CI 1.42, 5.49), history of abortion (OR = 4.22, 95% CI 1.91, 9.33), birth of weak calves (OR = 13.77, 95% CI 2.75, 68.91), use of a bull for mating (OR = 9.69, 95% CI 2.23, 42.18), and the vaccination in adulthood (OR = 3.03, 95% CI 1.04.8.78). In the model at the herd level, two variables explained the cases: birth of weak calves (OR = 9.60, 95% CI 1.54, 59.76) and purchase or animal transfer between owner's farms (OR = 7.22, 95% CI 1.03, 50.62). These results justify the need for a quarantine declaration in the region and the implementation of epidemiological studies as a public health measures used to combat outbreak.

Abortion and various associated risk factors in dairy cow and sheep in Ili, China

We studied livestock abortion and various associated risk factors in the Ili region of northwest China. Livestock abortion prevalence was estimated and correlated with infections (Brucellosis, Salmonellosis, Mycoplasma and Chlamydia seropositivity) and management (farming type and contact with other herds/flocks) risk factors. A total of 2996 serum samples (1406 cow, 1590 sheep) were identified by RBPT (Rose Bengal Plate Test) and c-ELISA (competitive-enzyme linked immunosorbent assay), and they showed the overall seroprevalence of brucellosis in the study area was cow 6.76%, sheep 9.50%. The seroprevalence of brucellosis in X county was cow 7.06%, sheep 9.12%; in H county was cow 11.70%, sheep 10.80%; and in Q county was cow 4.22%, sheep 9.11%. The overall seroprevalence of Mycoplasma in the study area was cow 3.20%, sheep 6.42%. The seroprevalence of Mycoplasma in X county was cow 3.39%, sheep 7.98%; in H county was cow 5.26%, sheep 9.97%; and in Q county was cow 2.11%, sheep 4.33%. The Odds ratio of brucellosis for cow and sheep, respectively, were 45.909 [95% CI 26.912-78.317, P<0.001] and 70.507 [95% CI 43.783-113.544, P<0.001] times higher than other abortion-related factors including mixed farming, contact with other flocks and Mycoplasma infection. A total of 54 samples, including aborted cow (22), sheep (30) fetuses and milk samples (2), were identified as Brucella melitensis (B. melitensis) positive. A total of 38 Brucella were isolated from 16 aborted cow, 20 sheep fetuses and 2 milk samples. All of these isolates were identified, and confirmed, as B. melitensis. A phylogenetic tree showed that the Brucella isolates closely matched the B. melitensis biovar 3 isolated in Inner Mongolia, China, and B. melitensis isolated from Norway and India. These results suggest that B. melitensis biovar 3 is the main pathogen responsible for cow and sheep abortion and also pose a human health risk. Additionally, livestock reproduction can also be influenced by Mycoplasma infection and managerial factors (farming type and contact with other herds/flocks), especially in remote areas.

Brucellosis in ruminants and pastoralists in Borena, Southern Ethiopia

Brucellosis is a bacterial zoonotic disease that has important veterinary and public health consequences as well as economic impact in sub Saharan Africa including Ethiopia. A cross-sectional study was conducted in four selected districts of Borena Pastoral setting in Southern Ethiopia from October 2017 to February 2018 to estimate the prevalence of brucellosis and assess associated risk factors in cattle, sheep, goats and occupationally associated humans. A total of 750 cattle, 882 sheep and goats and 341 human subjects were screened for evidence of brucellosis using the Rose Bengal Test (RBT) with positive results confirmed by Competitive-ELISA(c-ELISA). Structured questionnaires were used for collection of metadata from individual animals, herders and animal attendants to test the association between explanatory and outcome variables. The overall animal level prevalence was 2.4% (95% confidence interval, CI: 1.4-3.7) in cattle, 3.2% (95% CI: 2.1-4.6) in sheep and goats, and 2.6% (95% CI: 1.2-5) in humans occupationally linked to livestock production systems. Herd size, parity, and history of abortion were risk factors associated with Brucella seropositivity (P<0.05) in cattle whereas in sheep and goats the results showed that district, age group, flock size, and history of abortion were significantly associated risk factors with Brucella seropositivity (P<0.05). Assisting calving and presence of seropositive animals in a household (P<0.05) were significantly associated with Brucella seropositivity in humans. Evidence of brucellosis in various animal species and the associated human population illustrates the need for a coordinated One Health approach to controlling brucellosis so as to improve public health and livestock productivity.

Evaluation of the sensitivity and specificity of the lateral flow assay, Rose Bengal test and the complement fixation test for the diagnosis of brucellosis in cattle using Bayesian latent class analysis

This study was conducted to evaluate the sensitivity (Se) and specificity (Sp) of the Rose Bengal test (RBT), complement fixation test (CFT), the serum lateral flow assay (LFA_serum) and the blood lateral flow assay (LFA_blood) for the detection of antibodies to Brucella spp. using Bayesian latent class models (BLCMs). Sera and whole blood were collected from naturally infected cattle reared in smallholder, small-scale commercial and large-scale commercial farms in Zimbabwe (n = 1022) and Botswana (n = 770). The BLCMs were fitted under the assumption that conditional dependences existed between the tests. Based on the conditional dependence model, the RBT had the highest Se of 0.897 (95 % Probability Intervals: 0.854; 0.932) compared to 0.827 (0.773; 0.872), 0.812 (0.76; 0.858) and 0.809 (0.785; 0.832) for the LFA_serum, LFA_blood and CFT, respectively. The CFT recorded a higher Sp of 0.999 (0.995; 1.000) than the LFA_serum 0.996 (0.99; 1.000), the LFA_blood 0.984 (0.976; 0.991) and the RBT 0.969 (0.959; 0.978). The data indicated that both the Se and Sp of RBT and CFT and the Sp of LFA_serum and LFA_blood were conditionally independent, while the Se appeared to be conditionally dependent. These results indicated that none of the evaluated tests had perfect Se and Sp and consequently could not be used alone for the diagnosis of brucellosis in cattle from the studied farming sectors. Thus, based on high Se and Sp, respectively, a brucellosis testing regimen using the RBT (screening) and the LFA (confirmatory) may be considered.

Epidemiological investigation of brucellosis in breeding female cattle under the traditional production system of Jimma zone in Ethiopia

Bovine brucellosis is a serious zoonotic infectious disease with widespread occurrence in developing countries like Ethiopia. A cross-sectional study was conducted from November 2017 to November 2018 to investigate the prevalence and associated risk factors of brucellosis in breeding female cattle under the traditional production system of the Jimma zone in Ethiopia. Blood samples were collected from a total of 423 breeding female cattle to test the presence of Brucella antibody. The presence of antibody against Brucella spp. was serially tested first by the Rose Bengal Plate test, then positive sera were confirmed using the complement fixation test. Potential risk factors for Brucella seropositivity were analyzed using multivariable logistic regression analysis. An overall 11.6% (95%CI: 6.25-16.94) and 4.3% (95%CI: 2.15-5.89) seroprevalence of brucellosis was recorded at herd and animal level, respectively in study areas. We identified age (OR=9.6, 95% CI: 2.08-44.07), breed (OR=4.5, 95%CI: 1.54-12.99), herd size (OR=10.4, 95%CI: 1.27-85.04) and species composition (OR=4.4, 95%CI: 1.31-14.89) as risk factors for Brucella infection. Herd level analysis of risk factor shows that herds kept with sheep and/goats was at higher risk (OR=3.7, 95% CI: 1.25-11.17) of acquired Brucella infection. This result showed that brucellosis was a widely spread disease in the study areas. Thus, important to carry out appropriate control methods and creating awareness on public zoonotic transmissions of brucellosis are recommended. Moreover, further investigation should be carried out to isolate and characterized brucellosis as a cause of reproduction problems in the study areas.

Seroprevalence and risk factors of brucellosis among slaughtered indigenous cattle, abattoir personnel and pregnant women in Ngaoundéré, Cameroon

BACKGROUND

Brucellosis is a neglected debilitating zoonosis with a high prevalence in many developing countries. Bovine brucellosis is widespread in Cameroon but the epidemiological situation of human brucellosis is not known. A cross sectional study was carried to determine the seroprevalence and factors associated with bovine and human Brucellosis among abattoir personnel and pregnant women in Ngaoundéré, Cameroon.

METHODS

Serum sample from 590 abattoir cattle and 816 plausible occupational risk and vulnerable humans to brucellosis (107 abattoir personnel and 709 pregnant women) were collected and screened for anti-brucella antibodies using Rose Bengal Plate Test (RBPT) and ELISA tests. Structured questionnaires were used to collect data on socio-demographics and risk-factors. The differences in proportions between seropositive and seronegative reactors were tested using odds-ratio and χ2tests.

RESULTS

Bovine brucellosis seroprevalence was at 3.40% (n = 590; 3.4% for RBPT, 5.93% for i-ELISA). Human Brucella seroprevalence was at 5.6% among abattoir personnel (n = 107; 5.6% for RBPT, 12.15% for Brucella IgG ELISA) and 0.28% in pregnant women (n = 709; both tests). Breed (P < 0.00001) was associated with increased risk of brucellosis in cattle and the seroprevalence was highest among the Djafoun (OR = 16.67, 95%CI: 4.49-28.85) and Akou (OR = 16.96, 95% CI: 0.10-23.91) cattle compared to the other breeds. There was a moderate positive correlation (R2 = 0.5025) of Brucella IgG concentrations (> 200 U/ml) and clinical data for Brucella IgG ELISA seropositive humans. Several potential factors were associated (P > 0.05) with increased risk of human brucellosis seroprevalence among the abattoir personnel. The abattoir personnel were essentially males; the seropositive respondents were male and did not use protective equipment at work. Handling of foetus and uterine contents (OR = 13.00, 95%CI: 1.51-111.88) was associated with increased risk of human brucellosis.

CONCLUSIONS

Antibrucella antibodies are prevalent in cattle (3.40%), among abattoir personnel (5.60%) and in pregnant women (0.28%) in Ngaoundéré, Cameroon. The study reports the first evidence of human brucellosis in Cameroon and therefore, an indication of a real public health problem. Public awareness campaigns and health education especially among livestock professional and in agropastoral communities should be highlighted to disseminate knowledge, associated risk factors and control measures of brucellosis.

Seroprevalence and Associated Risk Factors of Brucellosis among Indigenous Cattle in the Adamawa and North Regions of Cameroon

A cross-sectional seroprevalence study was conducted on cattle in the North and Adamawa Regions of Cameroon to investigate the status of bovine brucellosis and identify potential risk factors. The diagnosis was carried out using the Rose Bengal Plate test (RBPT) and indirect ELISA (i-ELISA), while questionnaires were used to evaluate risk factors for bovine brucellosis in cattle. The Bayesian approach was used to evaluate the diagnostic tests' sensitivity and specificity. The overall individual level (n = 1031) and herd level (n = 82) seroprevalence were 5.4% (0.4-10.5) and 25.6% (16.2-35.0), respectively. Bayesian analysis revealed sensitivity of 58.3% (26.4-92.7) and 89.6% (80.4-99.4) and specificity of 92.1% (88.7-95.2) and 95.7% (91.1-99.7) for RBPT and i-ELISA, respectively. Management related factors such as region, locality, herd size, and knowledge of brucellosis and animal related factors such as sex and age were significantly associated with seropositivity of brucellosis. Zoonotic brucellosis is a neglected disease in Cameroon. The study highlights the need for control measures and the need to raise public awareness of the zoonotic occurrence and transmission of bovine brucellosis in the country. An integrated disease control strategy mimicking the one health approach involving medical personnel, veterinarians, related stakeholders, and affected communities cannot be overemphasized.

Association of farmers' socio-economics with bovine brucellosis epidemiology in the dry zone of Sri Lanka

The aim of the study was to investigate the farmers' socio-economic factors and their association with Brucella prevalence in the dry zone of Sri Lanka. A cross-sectional survey was planned and a total of 1,153 blood samples were collected from milking and dry animals of 155 farms from three selected veterinary ranges of Kalmunai, Navithanveli, and Mahaoya in the Ampara district, which is a multi-ethnic area. The 　Rose Bengal Test (RBT) and competitive enzyme-linked immunosorbent assay (c-ELISA) were used for the Brucella screening and confirmation, respectively. Socio-economic attributes such as family income, poverty, education, main job, ethnicity, parent farmer, farming experience, and training in animal husbandry were determined as potential farmer-level risk factors. Meanwhile, herd size, grazing practice, breeding method, animal brought-in to the farm, and abortions were considered as herd factors. The results revealed that the overall animal level sero-prevalence of brucellosis was 2.7% (35/1153; 95% confidence interval [CI]: 1.7, 3.7%) and the herd prevalence was 9.6% (15/155; 95% CI: 5.7, 15.7%) in the area of study. Brucellosis prevalence varies significantly (p<0.001) among the selected veterinary ranges with the highest herd prevalence in Kalmunai (20.0%) followed by Navithanveli (11.9%) and Mahaoya (2.7%). Disease prevalence showed variability (p<0.001) among ethnicities with the highest in Muslims (27.3%) followed by Tamils (8.1%) and Sinhalese (2.7%). Poverty was highly associated (OR=3.75; 95% CI: 1.43-10.00) with the disease. Free movement grazing practices (p<0.01) with OR=7.2 and animal brought-in from outside (p<0.06) with OR=3.06 were positively related to brucellosis. It was revealed that farmers' socio-economics, such as ethnicity and poverty, and animal movement patterns, such as grazing practices are significantly associated with epidemiology of brucellosis in the dry zone of Sri Lanka. Therefore, the "farmer factor" should be carefully considered in veterinary epidemiological studies and animal disease control plans in the future.　.

Seroprevalence of brucellosis in cattle and selected wildlife species at selected livestock/wildlife interface areas of the Gonarezhou National Park, Zimbabwe

A study was conducted to investigate seroprevalence and risk factors for Brucella species infection in cattle and some wildlife species in communities living at the periphery of the Great Limpopo Transfrontier Conservation Area in south eastern Zimbabwe. Three study sites were selected based on the type of livestock-wildlife interface: porous livestock-wildlife interface (unrestricted); non-porous livestock-wildlife interface (restricted by fencing); and livestock-wildlife non-interface (totally absent or control). Sera were collected from cattle aged≥2years representing both female and intact male animals. Sera were also collected from selected wild ungulates from Mabalauta (porous interface) and Chipinda (non-interface) areas of the Gonarezhou National Park. Samples were screened for Brucellaantibodies using the Rose Bengal plate test and confirmed by the complement fixation test. Data were analysed by descriptive statistics and multivariate logistic regression modelling. In cattle, brucellosis seroprevalence from all areas was 16.7% (169/1011; 95% CI: 14.5-19.2%). The porous interface recorded a significantly (p=0.03) higher seroprevalence (19.5%; 95% CI: 16.1-23.4%) compared to the non-interface area (13.0%; 95% CI: 9.2-19.9%).The odds of Brucellaseropositivity increased progressively with parity of animals and were also three times higher (OR=3.0, 2.0<OR<4.6, p<0.0001) in cows with history of abortion compared to those without.Brucella antibodies were detected in buffaloes; 20.7% (95% CI: 13.9-29.7%) form both study sites, but no antibodies were detected from impalas and kudus. These results highlight the importance of porous interface in the interspecies transmission of Brucella species and that independent infections may be maintained in buffalo populations. Thus, brucellosis control aimed at limiting animal inter-species mixing may help reduce the risk of human brucellosis in interface areas. Further studies should aim at establishing subspecies identity and direction of possible transmission of brucellosis between wildlife and livestock.

Assessment of community awareness and risk perceptions of zoonotic causes of abortion in cattle at three selected livestock–wildlife interface areas of Zimbabwe

A study was conducted to assess the awareness of cattle abortions due to brucellosis, Rift Valley fever (RVF) and leptospirosis, and to compare frequencies of reported abortions in communities living at the periphery of the Great Limpopo Transfrontier Conservation Area in southeastern Zimbabwe. Three study sites were selected based on the type of livestock–wildlife interface: porous livestock–wildlife interface (unrestricted); non-porous livestock–wildlife interface (restricted by fencing); and livestock–wildlife non-interface (totally absent or control). Respondents randomly selected from a list of potential cattle farmers (N = 379) distributed at porous (40·1%), non-interface (35·5%) and non-porous (26·4%), were interviewed using a combined close- and open-ended questionnaire. Focus group discussions were conducted with 10–12 members of each community. More abortions in the last 5 years were reported from the porous interface (52%) and a significantly higher per cent of respondents from the porous interface (P < 0·05) perceived wildlife as playing a role in livestock abortions compared with the other interface types. The odds of reporting abortions in cattle were higher in large herd sizes (odds ratio (OR) = 2·6; 95% confidence interval (CI) 1·5–4·3), porous (OR = 1·9; 95% CI 1·0–3·5) and non-porous interface (OR = 2·2; 95% CI 1·1–4·3) compared with livestock–wildlife non-interface areas. About 21·6% of the respondents knew brucellosis as a cause of abortion, compared with RVF (9·8%) and leptospirosis (3·7%). These results explain to some extent, the existence of human/wildlife conflict in the studied livestock–wildlife interface areas of Zimbabwe, which militates against biodiversity conservation efforts. The low awareness of zoonoses means the public is at risk of contracting some of these infections. Thus, further studies should focus on livestock–wildlife interface areas to assess if the increased rates of abortions reported in cattle may be due to exposure to wildlife or other factors. The government of Zimbabwe needs to launch educational programmes on public health awareness in these remote areas at the periphery of transfrontier conservation areas where livestock–wildlife interface exists to help mitigate the morbidity and mortality of people from some of the known zoonotic diseases.

Review of brucellosis in Nepal

Brucellosis is an abortifacient zoonotic disease that remains prominent in third world countries like Nepal. Brucellosis poses a public health concern, because its incidence in livestock can present substantial economic and health burdens for herders and health professionals. Several cases of bovine and human brucellosis have been reported and the prevalence is higher among livestock than among humans in Nepal. Lack of awareness, unhealthy food habit, traditional husbandry practices, and a lack of surveillance and immunization have been the major factors in maintaining a vicious cycle of propagation of the disease in human and animals. The aim of this paper is to evaluate the current status of the disease, the mechanism of infection, and pathogenesis, its zoonotic potential, diagnostic advances, treatment regimens, and the preventive measures that can be adopted in managing human brucellosis in under-developed countries such as Nepal.

Large-scale study of herd-level risk factors for bovine brucellosis in Brazil

Bovine brucellosis is an important zoonosis caused by Brucella abortus that negatively impacts livestock productivity. In 2001, Brazil launched a new national program aimed at eradicating animal brucellosis that included large-scale studies of the prevalence and risk factors to support strategic decision-making. These studies were implemented by the animal health authorities and were underpinned by the scientific coordination of the University of São Paulo and the University of Brasília. The state-level results were published and revealed important differences in herd prevalence among regions. The risk factors varied across states and did not clearly explain the observed spatial disease spread. This study used a consolidated herd-level database of 14 states and 17,100 herds, from the prevalence surveys' data, to gain insights into herd profiles and cattle production practices that might be associated with the risk of brucellosis. At the time of data collection, the study area comprised just over 56 million bovine females aged over 24 months and approximately 1.8 million herds. After an exploratory univariable analysis, all factors with p≤0.20 were included in a multiple logistic regression model, using the design-based method in order to take herd sampling weights into account. The number of females in the herd markedly increased the risk of infection; compared with smaller herds (less than 30 females), the odds ratio was 3.42 [CI 95% 2.98-3.91] for herds with 31 to 100 females, 5.68 [4.92-6.55] for herds with 101 to 400 females, and 13.14 [10.94-15.78] for herds with more than 400 females. The risk was higher for extensive cattle production farms (OR=1.23 [1.07-1.42]) and for farms that purchased replacement stock from cattle traders (OR=1.27 [1.08-1.47]) or directly from other farms (OR=1.19 [1.07-1.32]). The exclusive use of artificial insemination (OR=0.57 [0.4-0.81]) and regular veterinary support (OR=0.68 [0.6-0.77]) appeared to be protective factors. These findings are consistent with the regional prevalence trends observed in the study and provide key guidance for the planning of the national effort to control and eradicate brucellosis. High vaccination coverage of heifers is recommended, especially when targeted to areas where large-scale extensive cattle production predominates. The smaller, more intensive herds, are good candidates for disease accreditation schemes.

Long-term changes in the spatial distribution of lumpy skin disease hotspots in Zimbabwe

Outbreaks of lumpy skin disease (LSD) are reported almost every year in Zimbabwe but not much is known regarding whether the pattern of the disease is changing in response to major socio-economic programmes such as the land reform launched in 2000. In this paper, geo-referenced data of LSD cases was used to detect and map significant LSD hotspots over a 20-year period (1995-2014). The hotspots were then overlaid on top of a land tenure map to explore whether hotspots have spread or persist in some land tenure types. The main results are that LSD outbreaks are on the rise and the disease is spreading throughout the country with areas formerly large-scale commercial farms now experiencing more outbreaks. These results suggest that regular vaccination should be now recommended in most districts in the country.

Review of Brucellosis in Nepal

OBJECTIVES

The aim of this paper is to evaluate the current status of the disease, the mechanism of infection, and pathogenesis, its zoonotic potential, diagnostic advances, treatment regimens, and the preventive measures that can be adopted in managing human brucellosis in under-developed countries such as Nepal.

METHODS

We performed a systematic review of all the available literture through Google Scholar, PubMed, Gideon Informatics, World Health Organization and other legitimate sources. Other secondary informations were collected from the government agencies such as department of livestock services and Ministry of Health. The obtained information was then re-analysed and summarized.

RESULTS

Few publications have addressed brucellosis in Nepal and most of those publications have focused on bovine brucellosis with sparse information available on brucellosis in humans and small ruminants. Brucella abortus is the most predominant causative agent followed by B. suis. B. abortus is predominant in cattle accounting for a substantial portion of bovine abortion in the country. Lack of awareness, unhealthy food habit, traditional husbandry practices, and a lack of surveillance and immunization have been the major factors in maintaining a vicious cycle of propagation of the disease in human and animals. Unfortunately, nothing has been done to identify the species of Brucella at the biovar level.

CONCLUSIONS

Although brucellosis has been reported to be endemic in Nepal, neither the distribution nor the economic and public health impact of this disease is well characterized. Robust and well-designed nationwide survey is warranted to assess the prevalence and distribution of disease in livestock and humans. Such data would facilitate the design of appropriate control programmes.

Brucellosis in Nepal - A Potential Threat to Public Health Professionals

Brucellosis is a prominent zoonotic disease affecting humans and animals which with the lack of proper diagnosis and treatment remains dangerous in third world countries like Nepal. Currently, Brucellosis poses a public health concern, whose incidences among entire herds of animals can present substantial economic and health burdens for herders and health professionals. Additionally, factors such as close contact with animals, poor animal husbandry, and unhygienic feeding habits can exacerbate the spread of Brucella and related zoonotic agents. In Nepal, serious cases of bovine and even human brucellosis have been reported, although the topic is yet to be extensively reviewed. This paper evaluates the literatures on human and animal brucellosis in Nepal and other countries, with an emphasis on the impact of Brucella outbreaks on public health professionals. Herein, we summarize the current status of the disease, the mechanism of infection, pathogenesis, zoonotic potential, diagnostic advances, treatment regimens, and the preventive measures that can be adopted in managing human brucellosis in under-developed countries such as Nepal.

Bovine and Caprine Brucellosis in Bangladesh: Bayesian evaluation of four serological tests, true prevalence, and associated risk factors in household animals

A cross-sectional study was carried out to estimate the true prevalence of Brucella spp. and identify allied risk factors/indicators associated with brucellosis in the Dinajpur and Mymensingh districts of Bangladesh. A total 320 stratified random blood samples were collected and tested in parallel for Brucella antibodies using Rose Bengal (RBT), slow agglutination (SAT), and indirect and competitive ELISA. In addition, a structured questionnaire was administered to each household herd owner to gather information regarding potential risk factors. Both univariate and multivariate logistic regression analyses were used to identify potential risk factors or indicators at animal level. A Bayesian approach was used to estimate the true prevalence of brucellosis along with the test performances (Se and Sp). The estimated animal level true prevalence in cattle was 9.70 % (95 % CPI 5.0-16 %) and in goat 6.3 % (95 % CPI 2.8-11.0 %). The highest sensitivity was achieved by SAT ranges from 69.6 to 78.9 %, and iELISA was found to be more specific (97.4 to 98.8 %) in comparison with other tests. On the other hand, a significant level of (P < 0.05) Brucella seropositivity was found in cattle that breed naturally compared with those that undergo artificial insemination. In goats, exotic breeds were significantly associated (P < 0.05) with Brucella seroprevalence compared with indigenous breeds. Goats with a previous records of abortion and/or retained placenta were also found to have significant levels (P < 0.05). Cows with previous abortion records showed higher odds (18 times) of being seropositive. None of the evaluated tests can be recommended to apply alone for the diagnosis of bovine and caprine brucellosis.

THE PREVALENCE OF BRUCELLOSIS IN CATTLE AND THEIR HANDLERS IN NORTH TONGU DISTRICT OF VOLTA REGION, GHANA

BACKGROUND

Brucellosis is a zoonotic pathogen responsible for great economic losses in most sub-Saharan nations. Although Ghana has successfully implemented the "One Health" initiative for the control of some emerging infectious zoonotic diseases with pandemic potential like Avian Influenza, there is very limited data available on brucellosis especially human brucellosis prevalence. He objective of his study is to determine the seroprevalence of human and bovine brucellosis as well as the predisposing factors at the community level in the North Tongu District of Ghana.

MATERIALS AND METHODS

Rose Bengal Plate test (RBPT) was used to analyze blood samples from 178 cattle farmers, and 315 cattle. The positive samples were further confirmed with cELISA. Predisposing factors were determined by questionnaires administered to cattle farmers. All sample sites were geo-referenced.

RESULTS

Human and bovine brucellosis seroprevalence using RBPT were 10.1% and 22.9% respectively. Eighty six percent (62/72) of bovine cases were confirmed with ELISA. Delivery assistants were more likely to be infected (p=0.043) with odds ratio of 2.7. Out of the human cases (18), males constituted 88.9%. Ages 11-20 years recorded 77.7% seropositivity whilst cattle drovers represented 44.5% (8/18) of positives. Significant risk factors in cattle were herd size (p=0.037), history of retained placenta (0.000) and abortion (0.005).

CONCLUSION

Bovine and human brucellosis is prevalent in North Tongu district, Ghana. Close contact with parturient cows was a major predisposing factor for human infection. Early referral of positive persons to the Hospital for confirmation and treatment is required to comply with the "One Health" initiative on brucellosis and other zoonoses.

Serological survey of bovine brucellosis in Fulani nomadic cattle breeds (Bos indicus) of North-central Nigeria: Potential risk factors and zoonotic implications

A cross sectional study was conducted to investigate seroprevalence and associated risk factors of bovine brucellosis in Fulani nomadic herds in the 3 agro-ecological zones of Niger State, North-central Nigeria between January and August 2013. A total of 672 cattle in 113 herds were screened for Brucella antibodies using Rose Bengal Plate Test (RBPT) and confirmed by Lateral flow Assay (LFA). Data on herd characteristics and zoonotic factors were collected using structured questionnaire administered on Fulani herd owners. Factors associated with Brucella infection were tested using Chi-square test and multivariable logistic model. The overall cattle-level seroprevalence was 1.9% (95% CI: 1.1-3.2) with highest in agro-zone C (3.2%). Herd-level seroprevalence was 9.7% (95% CI: 5.23-16.29) and highest in agro-zone C (13.5%). Sex and agro-ecological zones were significantly (P<0.006 and P<0.01, respectively) associated with Brucella abortus seropositivity. Herd composition, abortion in herd, exchange of bulls for mating, introduction of new cattle, and socio-cultural practices were significantly associated with brucellosis occurrence. Inhalation of droplets from milk of infected cows, and drinking raw milk were less likely [OR 0.27; 95% CI: 0.09-0.82 and OR 0.27; 95% CI: 0.08-0.99, respectively] not to predisposed to brucellosis in humans. Eating infected raw meat, and contact with infected placenta were more likely [OR 7.49; 95% CI: 2.06-28.32 and OR 5.74; 95% CI: 1.78-18.47, respectively] to be risks for the disease in humans. These results highlighted the important risk factors for bovine brucellosis in Fulani herds. Thus, brucellosis control programs which take these factors into consideration will be beneficial.

The prevalence and distribution of Brucella melitensis in goats in Malaysia from 2000 to 2009

A study was conducted to describe the prevalence and distribution of zoonotic Brucella melitensis in goats in Peninsular Malaysia. Using serosurveillance data of the last decade (2000-2009) involving 119,799 goats and 3555 farms, the seroprevalence of brucellosis among goats was 0.91% (95% CI=0.86-0.96) and among farms was 7.09% (95% CI=6.27-7.98). The odds of brucellosis was significantly (P<0.05) higher in the later part of the decade, in larger herd size and among the states located in the peninsula as compared to eastern Malaysia. The infection was detected throughout Malaysia but at generally low seroprevalences with states like Perlis that border neighbouring countries having higher seroprevalence of brucellosis than other non-border states.

Spatial predictors of bovine tuberculosis infection and Brucella spp. exposure in pastoralist and agropastoralist livestock herds in the Ruaha ecosystem of Tanzania

While many studies investigate animal-related risk factors for disease, few have considered environmental or spatial risk factors in the dynamics of bovine tuberculosis (bTB) and brucellosis. In the Ruaha ecosystem of Tanzania, we investigated the role of household location as a predictor for infection with Mycobacterium bovis and exposure to Brucella in pastoralist and agropastoralist cattle herds in a typical African wildlife-livestock-human interface. ArcGIS was utilized to calculate Euclidian distances between households and the nearest river, village center, protected area, and other infected households, followed by multivariate logistic regression to assess the association between risk factors and herd-level bTB and Brucella outcomes. Global and local spatial clustering of bTB-infected and Brucella-exposed herds was explored using the Cuzick-Edward’s test and SaTScan spatial scan statistics. Households located farther from rivers and closer to village centers and herds belonging to agropastoralists were more likely to have bTB-positive cattle. Risk of Brucella exposure increased with proximity to protected areas. One spatial cluster of households with Brucella spp. seropositive cattle was identified. Spatial factors may be useful for assessing disease risk and for formulating intervention and control strategies for households that manage cattle in ecosystems characterized by seasonally limited resources and intense wildlife-livestock interfaces.

Seroprevalence and potential risk factors for Brucella spp. infection in traditional cattle, sheep and goats reared in urban, periurban and rural areas of Niger

INTRODUCTION

In Niamey, Niger, interactions within the interface between animals, humans and the environment induce a potential risk of brucellosis transmission between animals and from animals to humans. Currently, little is known about the transmission of Brucella in this context.

RESULTS

5,192 animals from 681 herds were included in the study. Serum samples and hygroma fluids were collected. A household survey enabled to identify the risk factors for transmission of brucellosis. The true adjusted herd-level prevalence of brucellosis ranged between 11.2% and 17.2% and the true adjusted animal-population level prevalence was 1.3% (95% CI: 0.9-1.8%) based on indirect ELISA test for Brucella antibodies. Animals aged of 1-4 years were found to be more susceptible than animals less than 1 year old (Odds ratio [OR] of 2.7; 95% CI: 1.43-5.28). For cattle, the odds of brucellosis seropositivity were higher in rural compared to the periurban areas (OR of 2.8; 95% CI: 1.48-5.17) whereas for small ruminants the risk of seropositivity appeared to be higher in urban compared to periurban areas (OR of 5.5; 95% CI: 1.48-20.38). At herd level, the risk of transmission was increased by transhumance (OR of 5.4; 95% CI: 2.84-10.41), the occurrence of abortions (OR of 3.0; 95% CI: 1.40-6.41), and for herds having more than 50 animals (OR of 11.0; 95% CI: 3.75-32.46). Brucella abortus biovar 3 was isolated from the hygromas.

CONCLUSION

brucellosis in Niger is a serious problem among cattle especially in the rural areas around Niamey and among sheep in the urban areas of Niamey. The seroprevalence varies across strata and animal species with important risk factors including herd size, abortion and transhumance at herd level and age at animal population level. For effective control of brucellosis, an integrated approach seems appropriate involving all stakeholders working in public and animal health.

Herd-level risk factors for Campylobacter fetus infection, Brucella seropositivity and within-herd seroprevalence of brucellosis in cattle in northern Nigeria

Brucellosis and campylobacteriosis are economically important diseases affecting bovine reproductive efficiency in Nigeria. A questionnaire-based survey was conducted in 271 cattle herds in Adamawa, Kaduna and Kano states of northern Nigeria using multistage cluster sampling. Serum from 4745 mature animals was tested for Brucella antibodies using the Rose-Bengal plate test and positives were confirmed in series-testing protocol using competitive enzyme-linked immunosorbent assay. Preputial scrapings from 602 bulls were tested using culture and identification for Campylobacter fetus. For each disease, a herd was classified as positive if one or more animals tested positive. For each herd, information on potential managemental and environmental risk factors was collected through a questionnaire administered during an interview with the manager, owner or herdsman. Multiple logistic regression models were used to model the odds of herd infection for each disease. A zero-inflated Poisson model was used to model the count of Brucella-positive animals within herds, with the number tested as an exposure variable. The presence of small ruminants (sheep and/or goats) on the same farm, and buying-in of >3 new animals in the previous year or failure to practice quarantine were associated with increased odds of herd-level campylobacteriosis and brucellosis, as well as increased within-herd counts of Brucella-positive animals. In addition, high rainfall, initial acquisition of animals from markets, practice of gynaecological examination and failure to practice herd prophylactic measures were positively associated with the odds of C. fetus infection in the herd. Herd size of >15, pastoral management system and presence of handling facility on the farm were associated with increased odds, and gynaecological examination with reduced odds of herd-level Brucella seropositivity. Furthermore, the zero-inflated Poisson model showed that borrowing or sharing of bulls was associated with higher counts, and provision of mineral supplement with lower counts of Brucella-positive cattle within herds. Identification of risk factors for bovine campylobacteriosis and brucellosis can help to identify appropriate control measures, and the use of zero-inflated count model can provide more specific information on these risk factors.

Herd and individual animal prevalence of bovine brucellosis with associated risk factors on dairy farms in Haryana and Punjab in India

Herd and individual animal prevalence along with associated risk factors of bovine brucellosis was assessed on dairy farms located in 22 districts in Haryana and Punjab of India. Examination of 4,580 female animals of 119 dairy farms by Rose Bengal test and enzyme-linked immunosorbent assay revealed that an overall herd prevalence was 65.54% (78/119) and individual animal prevalence was 26.50 % (1,214/4,580). Herd prevalence in Haryana was 62.79% which was not significantly different (P = 0.4208) from Punjab (72.72%). Individual animal prevalence was 34.15% in Punjab which was significantly higher (P < 0.0001) than Haryana (22.34%). Prevalence of brucellosis on dairy farms was detected in 20 of the 22 districts, of which 12 districts were in Haryana and 8 in Punjab. Risk factors such as species of animals, age of animals, herd size, awareness of dairymen for brucellosis, entry of a purchased animals on the farm, abortion on farm, use of calving pens, type of breeding, and type of farming were analyzed. The study indicated that the odds ratio (OR) was significant with risk factors of species (OR = 1.63; 95 %CI = 1.40-1.90; P < 0.0001), age (OR = 0.22; 95%CI = 0.17-0.29; P < 0.0001), awareness of brucellosis among dairymen (OR = 21.65; 95%CI = 2.63-178.04; P = 0.0042), entry of purchased animal on the farm (OR = 9.16; 95%CI = 2.38-35.18; P = 0.0012), abortion in animals (OR = 5.57; 95%CI = 1.92-16.10; P = 0.0015) and on cow farm (OR = 3.43; 95 %CI = 1.33-8.82; P = 0.0105). While the OR was insignificant (P > 0.05) with risk factors of herd size, use of calving pen on farms, type of breeding and on buffalo and mixed type of farms.

Detection of Brucella abortus in Chiredzi district in Zimbabwe

Brucellosis is an endemic disease in Zimbabwe caused by the genus Brucella. Brucella seroprevalence was recently reported to be high in the wildlife-livestock interface in the Chiredzi district and the neighbouring Gonarezhou National Park (GNP) in Zimbabwe, and higher amongst communal cattle with an abortion history and access to grazing in GNP than amongst communal cattle with no abortion history or access to grazing in GNP. The aim of this study was to investigate Brucella species in brucellosis seropositive cattle in the Chiredzi district with access to GNP using isolation and identification. Isolation of Brucella species from whole blood (n = 18) and milk samples (n = 10) from seropositive animals with an abortion history was based on the rose Bengal test (RBT) and enzyme-linked immunoassays (enzyme- linked immunosorbent assay [ELISA]; indirect ELISA and complement ELISA), using microbiology and polymerase chain reaction (PCR) methods. Brucella abortus was cultured and identified from blood and milk collected from seropositive cows in both communal areas. The Brucella-specific 16-23S intergenic spacer (ITS) PCR and multiplex AMOS-PCR assays verified the identification of the cultures. Our results confirmed that B. abortus is present in cattle on communal farms in the Chiredzi district in Zimbabwe and might cause cattle abortions. The need for implementing control measures and raising public awareness on zoonotic transmission of brucellosis are recommended.

Temporal and spatial distribution of cattle anthrax outbreaks in Zimbabwe between 1967 and 2006

This retrospective study aimed to assess the spatial and temporal distribution of anthrax and to identify risk areas in Zimbabwe. The data were extracted from the monthly and annual reports of the Division of Livestock Production and Veterinary Services for the period 1967 to 2006. The data were analyzed in relation to temporal and spatial factors. The hot-dry season was found to be significantly (X (2)=847.8, P<0.001) associated with the occurrence of anthrax in cattle, and the disease was found to be approximately three times more likely to occur during this season compared to other seasons. Anthrax outbreaks demonstrated a gradual temporal increase from an annual mean of three outbreaks for the 5-year period (1967-1971) to 42 for the 5-year period (2002-2006). Similarly, the data demonstrated a spatial increase in the number of districts affected by anthrax between 1967 and 2006, with 12 districts affected for the 10-year period (1967-1976) that expanded to 42 districts for the 10-year period (1997-2006). The majority of outbreaks (83.7%) were recorded in rural areas, and 11 districts were found to be at a higher risk than others. There is need to develop differential vaccination strategy, other control strategies and preventive recommendations to reduce anthrax in high-risk districts. In the medium- to low-risk districts, maintenance of effective surveillance systems and improvement of awareness is very important to detect and contain outbreaks early.

Survey of brucellosis at the wildlife-livestock interface on the Zimbabwean side of the Great Limpopo Transfrontier Conservation Area

A cross-sectional study was conducted to determine the seroprevalence of bovine brucellosis in communal cattle and wildlife at a wildlife-livestock interface in the southeast lowveld of Zimbabwe, part of the Great Limpopo Transfrontier Conservation Area. RBT and c-Elisa were used in serial for detection of antibodies against Brucella spp. Between July 2007 and October 2009, a total of 1,158 cattle were tested and the overall seroprevalence of brucellosis was 9.9%. A total of 97 wild animals (African buffaloes (n=47), impala (n=33), kudu (n=16), and giraffe (n=1)) were tested and only one animal (giraffe) was seropositive for brucellosis (1.03%). Brucella seroprevalence showed an increasing trend with age, with adult cattle (>6 years) recording the highest seroprevalence (11.1%), but the differences were not statistically significant. Similarly, female cattle recorded a relatively higher seroprevalence (10.8%) compared to males (7.9%), but the difference was not significant. However, a significant (P<0.001) association between Brucella seropositivity and abortion history was recorded in female cattle. Similarly, Brucella seropositivity was significantly (P<0.01) associated with a history of grazing in the park for female cattle. Overall, from the interface area, cattle with a history of grazing in the park recorded a significantly (P<0.01) higher Brucella seroprevalence (13.5%) compared to those with no history of grazing in the park (4.9%). The significant association between abortion history and seropositivity observed in this study illustrates the potential economic significance of Brucella in cattle in this area. Hence, public awareness and further epidemiological studies of the disease in wildlife, livestock, and humans in the study area are of great importance.

Brucellosis at the animal/ecosystem/human interface at the beginning of the 21st century

Following the recent discovery of new Brucella strains from different animal species and from the environment, ten Brucella species are nowadays included in the genus Brucella. Although the intracellular trafficking of Brucella is well described, the strategies developed by Brucella to survive and multiply in phagocytic and non-phagocytic cells, particularly to access nutriments during its intracellular journey, are still largely unknown. Metabolism and virulence of Brucella are now considered to be two sides of the same coin. Mechanisms presiding to the colonization of the pregnant uterus in different animal species are not known. Vaccination is the cornerstone of control programs in livestock and although the S19, RB51 (both in cattle) and Rev 1 (in sheep and goats) vaccines have been successfully used worldwide, they have drawbacks and thus the ideal brucellosis vaccine is still very much awaited. There is no vaccine available for pigs and wildlife. Animal brucellosis control strategies differ in the developed and the developing world. Most emphasis is put on eradication and on risk analysis to avoid the re-introduction of Brucella in the developed world. Information related to the prevalence of brucellosis is still scarce in the developing world and control programs are rarely implemented. Since there is no vaccine available for humans, prevention of human brucellosis relies on its control in the animal reservoir. Brucella is also considered to be an agent to be used in bio- and agroterrorism attacks. At the animal/ecosystem/human interface it is critical to reduce opportunities for Brucella to jump host species as already seen in livestock, wildlife and humans. This task is a challenge for the future in terms of veterinary public health, as for wildlife and ecosystem managers and will need a "One Health" approach to be successful.

Seroprevalence of brucellosis and its associated risk factors in cattle from smallholder dairy farms in Zimbabwe

A cross-sectional study was conducted to investigate seroprevalence of brucellosis and the associated risk factors in cattle from smallholder dairy farms in Gokwe, Marirangwe, Mushagashe, Nharira, Rusitu and Wedza areas of Zimbabwe. A total of 1,440 cattle from 203 herds were tested serially for Brucella antibodies using Rose Bengal test and the competitive ELISA. Weighted seroprevalence estimates were calculated and risk factors in individual cattle investigated using logistic regression analysis. The overall individual animal brucellosis seroprevalence was low, with mean of 5.6% (95% confidence interval (CI), 4.4%, 6.8%). Gokwe had the highest individual (12.6%; 95% CI, 3.9%, 21.4%) and herd-level (40.0%; 95% CI, 22.1%, 58.0%), while Wedza had the lowest individual (2.3%; 95% CI, 0%, 5.3%) and herd-level (8.0%; 95% CI, 0.0%, 18.9%) brucellosis seroprevalence, respectively. In individual cattle, the area of origin, age and history of abortion were independently associated with brucellosis seroprevalence. While the seroprevalence was independent of sex, it decreased with increasing age. Cattle 2-4 years old had higher odds (odds ratio (OR) = 3.2; 95% CI, 1.1%, 9.1%) of being seropositive compared to those >7 years. Cows with a history of abortion were more likely to be seropositive (OR = 7.9; 95% CI, 3.1, 20.1) than controls. In conclusion, the area-to-area variation of brucellosis may be linked to ecological factors and differences in management practices. The implementation of stamping out policy, bleeding and testing animals before movement and promoting the use self-contained units are likely to significantly reduce the public health risks associated with Brucella infections in cattle.

Risk factors for Brucella spp. infection in smallholder household herds

Risk factors for Brucella infection, the association and impact of Brucella seropositivity on abortions were investigated in cattle (n=1291) reared in smallholder household herds (n=203) from six geographical areas of Zimbabwe between September 2004 and 2005. Data on management, abortion and herd structure were collected. Sera were tested for Brucella antibodies using the Rose Bengal test and a competitive enzyme-linked immunosorbent assay. Data were analysed by generalized estimating equation and logistic regression models. Brucella antibodies were estimated at 5·5% and 22·9% for individual cattle and herds, respectively. Abortions were reported in 3·2% of cows and 22·0% herds. The age of cows and Brucella seropositivity predicted abortion. For herds, Brucella seropositivity, geographical area, purchase of cattle and large herd size were independently associated with increased odds of abortion. Exposure to Brucella had a significant impact on abortion. These results highlight the important risk factors for Brucella spp. infection in smallholder herds. Thus, brucellosis control programmes which take these factors into consideration will be beneficial.