Seroprevalence and risk factors associated with brucellosis as a professional hazard in Pakistan

Human Brucellosis in the Rural and Urban Population of Pakistan: Seroprevalence, Risk Factors, and Clinical Manifestations

Brucella spp. is the bacterium responsible for brucellosis, a zoonotic infection that affects humans. This disease poses significant health challenges and contributes to poverty, particularly in developing countries. This study aimed to assess the seroprevalence, risk factors, and clinical symptoms of human brucellosis within the general population of Multan and Muzaffargarh, Pakistan. A total of 307 blood samples were collected from patients visiting local hospitals in Multan and Muzaffargarh between August 2015 and January 2016. Demographic information, risk factors, and clinical outcomes were documented. Serum samples were initially screened for anti-Brucella antibodies using the Rose Bengal Plate Test, and positive cases were subsequently confirmed through RT-PCR. The chi-square test assessed the link between Brucella positivity and the identified risk factors. The study recorded an overall seroprevalence of 6.8%, with 8.9% in Multan and 4.3% in Muzaffargarh. Genus-specific Brucella detection through RT-PCR confirmed that 20 out of 21 samples were positive. Significant associations with human brucellosis were found for contact with aborted animals (p = 0.032) and consumption of raw milk (p = 0.031), while factors such as age, gender, occupation, urbanicity, and geographical region did not show a significant impact on seropositivity (p > 0.05). Non-specific clinical symptoms were commonly observed among seropositive patients. The findings highlight the significance of close human interaction with infected animals, especially concerning livestock practices and dairy product consumption. The results also emphasize the importance of focusing efforts on raising awareness in risky occupations and developing control programs by healthcare authorities.

Seroprevalence of brucellosis and associated risk factors in camels and its herders in selected districts of Somali Pastoral Region, Eastern Ethiopia

Brucellosis poses a major public and animal health problem in many parts of the world, particularly in pastoral settings, however, seroepidemological studies are scarce. A cross-sectional study was conducted from December 2021 to April 2022 to estimate the prevalence of brucellosis and to identify the associated risk factors for camels and occupational individuals from three purposively selected districts of the Somali pastoral region in Eastern Ethiopia. Serum samples were serially diluted using the Rose Bengal Plate Test (RBPT) as a screening test and a competitive Enzyme-Linked Immunosorbent Assay (cELISA) test as a confirmatory test. From a total of 450 camels and 250 human serum samples tested, the overall seroprevalence was confirmed to be 2.9 % (95 % CI, 1.5-4.9) in camels and 2.0 % (95 % CI, 0.2-3.7) in humans. In camels, abortion and retained fetal membrane (RFM) were significant risk factors for Brucella seropositivity (p<0.05). However, in humans, RFM disposal differed significantly (p<0.05). The fact that brucellosis is found in both camels and humans highlights the importance of implementing a coordinated One Health approach to control and eliminate the disease. This would ensure improved public health and increased livestock productivity.

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.

Prevalence, diagnosis, and manifestations of brucellosis: A systematic review and meta-analysis

Objectives

Brucellosis is one of the most prevalent zoonotic diseases common between humans and animals. Despite eradication efforts, the burden of the disease is well-known in endemic countries and in countries where brucellosis has not been an important health issue until recently. The aim of this study was to evaluate the prevalence, diagnosis, and manifestations of brucellosis.

Methods

In this study, PubMed, Web of Science, Scopus, Embase, and Google scholar databases were systematically searched to find studies published from 2011 to 2021. The search was conducted using text words and Medical Subject Headings (MeSH) Terms on the prevalence of brucellosis. Stata software 14.0 was used for all analyses.

Results

Based on the results, the pooled prevalence of brucellosis was 15.27% (95% CI: 9.68-21.86; heterogeneity I 2 index: 97.43; p < 0.001) for man and 15.33% (95% CI: 7.19-25.75; heterogeneity I 2 index: 98.19; p < 0.001) for woman. Age (coefficient: 0.240; p = 0.480), gender (coefficient: -0.017; p = 0.800), and publication year (coefficient: 0.114; p = 0.861) showed no significant effect on heterogeneity among studies. Egger's test indicated a significant publication bias for the prevalence of brucellosis (coefficient 3.894; p < 0.001). Moreover, the trim-and-fill method exhibited that the adjusted prevalence of brucellosis (18.30%, 95% CI: 14.10-22.52) was not significantly different from the original prevalence of brucellosis.

Conclusion

The pooled estimate for brucellosis prevalence was estimated as 15.53%. To better understand the epidemiology of brucellosis globally, more extensive studies are needed to be conducted throughout the world, especially in developing and low-income countries.

Evaluation of Hematological, Oxidative Stress, and Antioxidant Profile in Cattle Infected with Brucellosis in Southern Punjab, Pakistan

Brucellosis is a well-known and harmful zoonotic disease that poses a severe threat to public health and wild and dairy animals. Due to a lack of monitoring and awareness, disease incidence has increased. Therefore, this study was conducted for the first time to ascertain the status of seroprevalence of brucellosis, hematological, oxidative stress, and antioxidant enzymes in different breeds of cattle reared under tropical-desert conditions in Pakistan. This study comprised 570 cattle of different breeds. We recorded some epidemiological traits, including age and gender. The blood samples were obtained from all the cattle, screened with RBPT, and then confirmed by ELISA and PCR. The results recorded an overall 11.75%, 10.7%, and 9.64% prevalence of brucellosis based on RBPT, ELISA, and PCR. We obtained nonsignificant results in different age and sex groups of cattle. The results showed significantly (P ≤ 0.05) lower values of erythrocyte counts, hemoglobin quantity, hematocrit, lymphocytes, and monocytes in infected cases. The results showed that the total leukocyte and neutrophil cells significantly (P ≤ 0.05) increased. The lipid peroxidation parameters (MDA- and NO-scavenging activity of erythrocyte) increased significantly (P ≤ 0.05) in infected cattle, whereas significantly reduced antioxidant enzymes like SOD, RGSH, and CAT were. Similarly, significantly lower serum albumin levels and total serum proteins were recorded in infected cattle.

Risk Factors for Acute Brucellosis in Patients on the Day of Admission at Selected Hospitals of Abbottabad, Pakistan

Brucellosis is a neglected zoonotic disease of ruminants. It causes severe health problems in humans and significant economic loss. Only a limited number of studies have been conducted in Pakistan to determine the prevalence of human brucellosis and related risk factors. The objectives of the current cross-sectional study were to determine the prevalence of anti-Brucella antibodies in sera collected from symptomatic patients at three hospitals of Abbottabad using a commercial slide agglutination test (SAT) and to determine risk factors for brucellosis for these patients. Five hundred blood samples were collected. A questionnaire was filled in for each patient to obtain information on age, gender, living area, brucellosis associated symptoms, associated risk factors, pregnancy and abortion history. A total of 13.6% (n = 68) patients were found to be SAT positive and in 83.3% (n = 57) of these samples Brucella DNA was detected by genus specific RT-PCR for BCSP-31 gene. Statistical analysis was performed to determine odd ratios, risk ratios, 95% confidence intervals, and p-values. The prevalence of brucellosis by SAT was reported to be higher in women (14.6%, n = 44) than in men (12.1%, n = 24). The age group 25–50 years was found to be at higher risk for brucellosis (14.5%, n = 50) “animal contact” was reported as the main risk factor followed by “consumption of raw animal products.” Out of 131 pregnant women and 21 patients had abortion, the seropositivity of Brucellosis was 9.9% and 23.8%, respectively. The present study reports a striking prevalence of brucellosis among patients including pregnant women at three hospitals of Abbottabad. These findings may foster strategies for controlling human brucellosis at household level, raising of awareness about brucellosis in hospital and family doctors, and finally in setting up an eradication program in the dairy industry.

Brucella Seroprevalence and Associated Risk Factors in Occupationally Exposed Humans in Selected Districts of Southern Province, Zambia

Background: Brucellosis is a neglected debilitating zoonosis widely recognized as an occupational health hazard. The seroprevalence of human anti-Brucella antibodies in high-risk populations, as well as their risk factors, have not been well-documented in Zambia. This study aimed at estimating the Brucella seroprevalence in herdsmen and abattoir workers and assess the associated risk factors. Methods: A cross-sectional seroepidemiological study was carried out between May and December 2020 among abattoir workers and herdsmen in Namwala, Monze and Choma districts of Southern Province in Zambia. Seroprevalence was assessed by indirect enzyme-linked immunosorbent assay (i-ELISA) or competitive enzyme-linked immunosorbent assay (c-ELISA) while a questionnaire was administered to obtain epidemiological data. Results: A total of 153 individuals were recruited in the study. The overall Brucella seroprevalence was 20.3% (95% CI: 14.6-27.5). Seropositivity among herdsmen and abattoir workers was 14.4% (95% CI: 9.2-21.8) and 46.4%, (95% CI: 28.8-65.0), respectively. Comparable seropositive results among districts showed Namwala with 26.9%, which was the highest, seconded by Monze 19.0%, and the least was Choma with 11.36%, seropositivity. The multivariate logistic regression model showed that occupation, age category, and district of residence were predictors of being seropositive to Brucella spp. antibodies. The odds of abattoir workers being seropositive to Brucella antibodies were 8.6 (95% CI: 2.6-28.2) higher than that of herdsmen being the reference group. The odds of age category 17-50 years being seropositive to Brucella antibodies were 7.0 (95% CI: 0.7-72.2) higher than being <16 years as the reference group. The odds of one having attained primary level of education being seropositive to Brucella were 1.3 (95% CI: 0.1-14.7) or secondary level of education were 6.2 (95% CI: 0.5-72.6) or tertiary level of education were 5.1 (95% CI: 0.2, 113.3) higher than that of no level of education as the reference group. Furthermore, the odds of a respondent being seropositive to Brucella antibodies were 4.5 (95% CI: 1.3-15.7) for Namwala and 4.9 (95% CI: 1.1-21.7) for Monze higher than that of Choma as the reference group. Conclusion: Anti-Brucella antibodies are prevalent among herdsmen and abattoir workers in the study areas of Zambia (20.26%), a sign of exposure to Brucella pathogens. Type of profession, age and level of education seem to influence the exposure to Brucella pathogens. This zoonosis should be considered as one of the differential diagnosis in humans presenting intermittent fever, malaria-like signs and general pain in humans.

Knowledge of Brucellosis, Health-Seeking Behaviour, and Risk Factors for Brucella Infection amongst Workers on Cattle Farms in Gauteng, South Africa

Brucellosis in humans is under-detected and underreported in sub-Saharan Africa. Risk factors associated with Brucella infection and health seeking behaviour in response to brucellosis-like symptoms, amongst cattle farm workers and veterinary officials in South Africa, are unknown. Farm workers and veterinary officials (N = 230) were screened for brucellosis using commercial Rose Bengal Test (RBT^®), IgM Enzyme-linked Immunoassay (ELISA)^®, IgG ELISA^® and the BrucellaCapt^® test. Knowledge of brucellosis and risk factors for exposure to Brucella were also investigated. Seroprevalence varied according to test used: 10.1% (RBT^®), 20.9% (IgG ELISA^®) and 6.5% (BrucellaCapt^®). Only 22.2% (6/27) of veterinary officials opt to visit a clinic, doctor, or hospital in response to self-experienced brucellosis-like symptoms, compared to 74.9% (152/203) of farm workers (p < 0.001). Of the BrucellaCapt^® seropositive participants, 53% (7/15) did not visit a clinic in response to brucellosis-like symptoms. Weak evidence of an association between the handling of afterbirth or placenta and infection of a short evolution (RBT^®, IgM ELISA^® and IgG ELISA^® seropositive) was found (OR = 8.9, 95% CI: 1.0–81.1, p = 0.052), and strong evidence of an association between this outcome and the slaughter of cattle (OR = 5.3, 95% CI: 1.4–19.6, p = 0.013). There was strong evidence of a positive association between inactive/resolved infection and veterinary officials vs. farm workers exposed to seropositive herds (OR = 7.0, 95% CI: 2.4–20.2, p < 0.001), with a simultaneous negative association with the handling of afterbirth or placenta (OR = 3.9, 95% CI: 1.3–11.3, p = 0.012). Findings suggest a proportion of undetected clinical cases of brucellosis amongst workers on cattle farms in Gauteng.

Seroepidemiological survey of brucellosis and Q fever among high-risk occupations in northeast of Iran for first time

Background and Objectives:

Brucellosis and Q fever are considered as occupational hazards to people in contact with domestic animals or their carcasses. The present cross-sectional study was carried out to determine the seroprevalence of brucellosis and Q fever among professions at risk in the North Khorasan Province, northeastern Iran during 2020.

Materials and Methods:

In this study, 185 sera samples were collected from butchers, slaughterhouse workers, farmers, and veterinarians in different counties of the province. The collected sera were tested by ELISA test for the detection of IgG antibodies against Coxiella burnetii and Brucella spp. A questionnaire was filled for each participant to investigate demographic characteristics information (i.e., age, gender, educational status, occupation, years of occupational experience, and location), and any exposure to risk factors (animals Keeping, consumption of unpasteurized dairy products, exposure to ill or dead animals, tick bite, splashing animal fluids, travel history, and use of personal protective equipment) that could be associated with these infections.

Results:

The seroprevalence of antibodies against C. burnetii and Brucella spp. were 17.2% and 19.4%, respectively. Twelve participants also had Q fever and brucellosis co-infection, with a prevalence of 6.4%.

Conclusion:

Based on the results, it is concluded that brucellosis and Q fever occur among the high-risk populations in this area and it needs more surveillance to control the diseases by public health and veterinary authorities.

Animal and Human Brucellosis in Pakistan

Brucellosis is a bacterial zoonotic disease that affects many animal species and can be transmitted to humans via direct contact or via contaminated food. Although brucellosis is a serious health hazard, its public health concern has been neglected in many countries. In some developing countries, such as Pakistan, where brucellosis is endemic, this disease continues to be of importance. A literature search for the past 11 years (2011–2021) provided a comprehensive insight into brucellosis in Pakistan. In this review, particular emphasis was placed on occurrence, diagnostic tests used, and prevention, treatment, and control in the context of the “One Health” approach.

Sexual Dimorphism and Gender in Infectious Diseases

Epidemiological studies and clinical observations show evidence of sexual dimorphism in infectious diseases. Women are at less risk than men when it comes to developing most infectious diseases. However, understanding these observations requires a gender approach that takes into account an analysis of both biological and social factors. The host’s response to infection differs in males and females because sex differences have an impact on hormonal and chromosomal control of immunity. Estradiol appears to confer protective immunity, while progesterone and testosterone suppress anti-infectious responses. In addition, genetic factors, including those associated with sex chromosomes, also affect susceptibility to infections. Finally, differences in occupational activities, lifestyle, and comorbidities play major roles in exposure to pathogens and management of diseases. Hence, considering sexual dimorphism as a critical variable for infectious diseases should be one of the steps taken toward developing personalized therapeutic approaches.

Serosurvey and Risk Factors Associated with Brucella Infection in High Risk Occupations from District Lahore and Kasur of Punjab, Pakistan

Brucellosis is a neglected zoonotic disease, and occupations with a high risk of infection exist. Limited information is available on brucellosis for these employees at high risk in Pakistan. A total of 459 persons with high-risk occupations, i.e., 211 abattoir workers, 63 milkers, 52 dung cake makers, 44 veterinarians, 44 shepherds, and 45 veterinary students of the districts Kasur and Lahore, Pakistan, were tested in this study. Blood samples and information on place of residence, gender, age, urbanicity, type of occupation, socioeconomic status, contact with animals, consumption of raw milk, contact to women who had a miscarriage, contact to aborted animal fetus or abortion material, pregnancy, miscarriage history, or intrauterine fetal death were collected. Serum samples were examined using Rose Bengal tests for anti-Brucella antibodies and seropositive samples were subjected to genus-specific qPCR for the detection of DNA. Data were analyzed using chi-squared and binary regression. Twenty (4.35%) persons were seropositive for anti-Brucella antibodies. Out of these, 18 (90%) were tested positive by Brucella genus-specific qPCR. Positive sera were more often found in Lahore district (8.3%) than in Kasur district (3.1%). Persons older than 36 years were more often seropositive. Persons involved in the handing of milk and in contact with animals were more often seropositive. Contact with women who had had a miscarriage was also a significant factor for seropositivity for brucellosis. Place of residence, gender, age, urbanicity, and contact with animals were identified as potential risk factors in the present study. The present study confirmed that brucellosis is an occupation hazard for abattoir workers, milkers, dung cake makers, and veterinarians in the districts of Lahore and Kasur of Punjab, Pakistan. The study shows the need for strategies for safety at work to minimize the risk of infection. Raising awareness for the prevention and use of proper personal protection equipment during the slaughtering and treatment of animal is highly needed.

Seroprevalence and Molecular Detection of Brucellosis in Hospitalized Patients in Lahore Hospitals, Pakistan

Brucellosis is one of the most notorious zoonoses worldwide. The disease is common and endemic in humans and animals of Pakistan, but lack of awareness and lack of research have resulted in an increased incidence in the human population. The present study aimed to determine the seroprevalence and at molecular detection of brucellosis in patients with clinical symptoms in six different hospitals from Lahore, which is the capital city of Punjab province. A total of 218 blood samples were collected from hospitalized patients. The samples were initially screened by the Rose Bengal Plate Test (RBPT), and then quantitative real-time PCR (qRT-PCR) was applied. An overall seroprevalence of 17% (37/218) was found. The highest prevalence was found at the Lady Health center (36.53%), which was followed by the Lady Willingdon Hospital (28.6%). Female patients showed a higher seroprevalence than males and peaked at 34% (n = 32) for women who suffered from abortion. In total, 16.8% of patients younger than 30 years showed seropositive reactions, while the prevalence was 19% in patients between 31 and 50. Thirty-three DNA samples from 24 seropositive and nine seronegative patients tested positive, 32 samples were found positive for B. abortus DNA, and one sample failed to be identified at the species level. Almost all positive cases had direct contact with animals and consumed unpasteurized dairy products. Research on human brucellosis is still scarce in Pakistan. For the diagnosis of brucellosis, serology and molecular tools should be combined if isolation by culture is not possible. Nationwide control activities and increasing awareness for zoonotic brucellosis are needed.

Systematic review and meta-analysis of veterinary-related occupational exposures to hazards

Understanding hazards within the veterinary profession is critical for developing strategies to ensure the health and safety of personnel in the work environment. This study was conducted to systematically review and synthesize data on reported risks within veterinary workplaces. A systematic review of published data on occupational hazards and associated risk factors were searched within three database platforms namely PubMed, Ebscohost, and Google scholar. To determine the proportion estimates of hazards and pooled odds ratio, two random-effects meta-analysis were performed. For the biological, chemical and physical hazards, the pooled proportion estimates were 17% (95% CI: 15.0-19.0, p < 0.001), 7.0% (95% CI: 6.0-9.0%, p < 0.001) and 65.0% (95% CI: 39.0-91.0%, p < 0.001) respectively. A pooled odds ratio indicated the risk of exposures to physical (OR=1.012, 95% CI: 1.008-1.017, p < 0.001) and biological hazards (OR=2.07, 95% CI: 1.70-2.52, p <0.001) increased when working or in contact with animals. The review has provided a better understanding of occupational health and safety status of veterinarians and gaps within the developing countries. This evidence calls for policy formulation and implementation to reduce the risks of exposures to all forms of occupational-related hazards in veterinary workplaces.

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.

Epidemiology and Associated Risk Factors for Brucellosis in Small Ruminants Kept at Institutional Livestock Farms in Punjab, Pakistan

Brucellosis is reportedly endemic in ruminants in Pakistan. Both Brucella abortus and B. melitensis infections have been decumented in domestic animals and humans in the country. This study aimed to identify the burden of anti-Brucella antibodies in small ruminants as well as associated potential risk factors with its occurrence at nine institutional livestock farms in Punjab, Pakistan. The sera collected from equal number of sheep and goats (500 from each species) were screened by indirect-ELISA for anti-smooth-Brucella antibodies followed by a serial detection by real-time PCR. Overall, 5.1% (51/1000) seropositivity was registered corresponding to 5% (25/500) prevalence in goats and 5.2% (26/500) in sheep. Brucella-DNA could not be detected in any of the tested sera by real-time PCR. Multiple logistic regression model indicated that farm location (OR 34.05), >4 years of age (OR 2.88), with history of reproductive disorders (OR 2.69), and with BCS of ≤ 3 (OR 12.37) were more likely to test positive for brucellosis at these farms. A routine screening, stringent biosecurity, and quarantine measures are warranted for monitoring and eradication of the infection. Similarly, isolation and molecular investigation of the etiologic agent(s) are needed to understand the relationship of epidemiology and out-breaks of brucellosis in the country.

Serological and Molecular Investigation of Brucellosis in Breeding Equids in Pakistani Punjab

Brucellosis is an important zoonosis worldwide. Equines are susceptible to the infection when in close contact with infected animals. The objective of our study was to update the existing knowledge and detect and differentiate the causative agent of brucellosis in breeding equines in Punjab, Pakistan. A cross-sectional study was designed to evaluate the occurrence and etiology of the infection in the equine population in three districts. A total of 448 equine sera were collected from three prefectures viz. Sahiwal, Khanewal, and Okara of the Punjab Province of Pakistan. Ninety-six (21.4%) samples were found positive by RBPT, 3.56% (16/448) by iELISA, and 4.24% (19/448) by CFT. Real-time PCR demonstrated the presence of Brucella abortus-DNA in sero-positive samples. Age and location were found as risk factors. The study concludes equine brucellosis seroprevalence in the country where Brucella abortus as the main etiology. Fistulous withers and poll evil cases should be treated with care as they could be hazardous and a source of zoonotic transmission. Routine screening at an early age, vaccination in ruminants, and consumption of pasteurized dairy milk in humans is recommended for prevention of the infection. Specific tests need to be standardized and validated.

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.

Serological and Molecular Detection of Bovine Brucellosis at Institutional Livestock Farms in Punjab, Pakistan

Bovine brucellosis remains a persistent infection in ruminants in Pakistan. A total of 828 (409 buffaloes and 419 cattle) sera were collected from 11 institutional-owned livestock farms in Punjab, Pakistan. The samples were tested by rose bengal plate agglutination test (RBPT) and indirect enzyme-linked immunosorbent assay (iELISA). The seroprevalence along with 95% confidence interval (CI) was determined. Univariable and multivariable analysis of the epidemiological background data was conducted and odds ratio (OR) was calculated to understand any association between the risk factors and the seroprevalence. An overall seroprevalence of 3.9% (Positive/Tested = 32/828) and 3.3% (27/828) was detected by RBPT and iELISA, respectively. The seroprevalence of 5.6% (CI 3.6-8.3) and 4.7%, (CI 2.8-7.2) and the odds ratio of 2.63 (CI 1.20-5.77) and 2.50 (CI 1.08-5.78) for testing positive by RBPT and iELISA, respectively were significantly higher (p < 0.05) in buffaloes than in cattle. Breed, sex, history of abortion and retention of fetal membranes (RFM) in the animals were not found statistically significantly associated with the infection. RBPT and iELISA based results agreed almost perfect (k = 0.877). In total, Brucella abortus-DNA (9/27) was amplified from seropositive samples by real-time polymerase chain reaction. This study identified for the first time the etiological agents of brucellosis at a molecular level at institutional-owned livestock farms in Pakistan.

Serological and Molecular Investigation of Brucella Species in Dogs in Pakistan

Brucellosis is an important bacterial zoonosis caused by B. abortus and B. melitensis in Pakistan. The status of canine brucellosis caused by B. canis remains obscure. In total, 181 serum samples were collected from stray and working dogs in two different prefectures viz. Faisalabad (n = 87) and Bahawalpur (n = 94). Presence of antibodies against B. canis and B. abortus/B. melitensis was determined using the slow agglutination test (SAT) and ELISA, respectively. Real-time PCR was performed to detect and differentiate Brucella DNA at the species level. In Faisalabad, the serological prevalence was found to be 9.2% (8/87) and 10.3% (9/87) by SAT and ELISA, respectively. Only one of the ELISA positive samples (1.15%) yielded amplification for B. abortus DNA. In Bahawalpur, 63.8% (60/94) samples were found positive by SAT; however, none of the samples was positive by ELISA or by real-time PCR. Location, age (≥1 year) and body condition (weak) were found to be associated with B. canis infection, whereas presence of wounds was found to be associated with B. abortus infection only. These findings point towards a risk of transmission from dog to livestock and humans and vice versa. The study expects to draw the attention of concerned authorities towards infection prevention and animal welfare. This study warrants further epidemiological investigation on brucellosis in pet dogs and their owners. To the best of our knowledge, this is first ever report on B. canis and B. abortus in dogs in Pakistan.

Acute Febrile Illness Caused by Brucella abortus Infection in Humans in Pakistan

Brucellosis is a zoonosis of great and worldwide public health concern that can cause a severe febrile illness in humans. In Pakistan, brucellosis is a critical problem in both animals and humans. This study aimed to gain insight into its prevalence and to analyze the potential risk factors of patients with acute febrile illness (AFI) of an unknown cause, at the hospitals of Rawalpindi and Islamabad in Pakistan. In total, 446 blood samples were collected from patients and screened for brucellosis using the Rose Bengal Plat Test (RBPT). All the serum samples were investigated for Brucella DNA using specific real-time PCR. Age, sex, occupation, urbanicity, socioeconomic status and history of animal contact were recorded and assessed as potential risk factors. The proportion of acute febrile illness patients for whom brucellosis could be suspected was 10.1% by the RBPT. Brucella DNA was detected in 26 (5.8%) cases and identified as B. abortus. Contact with infected animals, consumption of raw milk and socioeconomic status showed a highly significant (p < 0.05) correlation with seropositivity. Elderly patients (19.7% RBPT and 12.1% PCR) and females (13% RBPT and 9.3% PCR) were of high risk of brucellosis. Patients suffering from brucellosis-related manifestations should be screened for brucellosis, especially those in contact with animals or those consuming their unprocessed products, given the increased risk. The results of this study, which highlight that Brucella abortus as an important cause of acute febrile illnesses in humans, aid the development of effective control strategies for human brucellosis in Pakistan.

Brucellosis in India: results of a collaborative workshop to define One Health priorities

Brucellosis is an important zoonosis worldwide. In livestock, it frequently causes chronic disease with reproductive failures that contribute to production losses, and in humans, it causes an often-chronic febrile illness that is frequently underdiagnosed in many low- and middle-income countries, including India. India has one of the largest ruminant populations in the world, and brucellosis is endemic in the country in both humans and animals. In November 2017, the International Livestock Research Institute invited experts from government, national research institutes, universities, and different international organizations to a one-day meeting to set priorities towards a "One Health" control strategy for brucellosis in India. Using a risk prioritization exercise followed by discussions, the meeting agreed on the following priorities: collaboration (transboundary and transdisciplinary); collection of more epidemiological evidence in humans, cattle, and in small ruminants (which have been neglected in past research); Economic impact studies, including cost effectiveness of control programmes; livestock vaccination, including national facilities for securing vaccines for the cattle population; management of infected animals (with the ban on bovine slaughter, alternatives such as sanctuaries must be explored); laboratory capacities and diagnostics (quality must be assured and better rapid tests developed); and increased awareness, making farmers, health workers, and the general public more aware of risks of brucellosis and zoonoses in general. Overall, the meeting participants agreed that brucellosis control will be challenging in India, but with collaboration to address the priority areas listed here, it could be possible.

Seroepidemiology and the Molecular Detection of Animal Brucellosis in Punjab, Pakistan

Brucellosis is an infectious disease caused by bacteria of the genus Brucella (B.), affecting both animals and humans, causing severe economic loses and severe illness, respectively. The objective of the present study was to determine the seroprevalence and the risk factors associated with caprine, ovine, and bovine brucellosis in selected districts of Punjab, Pakistan. A total of 1083 blood samples were randomly collected from animals (goats = 440, sheep = 203, cows = 206, and buffaloes = 234). Questionnaires were used to collect data on risk factors associated with brucellosis on the sampling day. All samples were initially screened for anti-Brucella antibodies using the rose bengal plate test (RBPT). The seropositive serum samples were confirmed by a quantitative real-time polymerase chain reaction (PCR) assay for the detection of the Brucella genus- and Brucella species-specific DNA (B. abortus and B. melitensis). Univariant and binary logistic regression were used to identify important risk factors of brucellosis. Anti-Brucella antibodies and DNA were detected in 35 (3.23%) serum samples. Thirty-four (97.1%) DNA samples were confirmed as B. melitensis by qRT-PCR. Abortion history and natural mating were found to be potential risk factors. Brucella melitensis was identified as the causative agent of caprine, ovine, and bovine brucellosis in the selected districts of Punjab, Pakistan. Diseased animals may act as a source of infection for other animals. The elimination of positive seroreactors, development of control strategies for brucellosis, and education programs regarding the control of zoonotic disease are highly needed in developing countries like Pakistan.

Seroreactivity and Risk Factors Associated with Human Brucellosis among Cattle Slaughterhouse Workers in South Korea

The prevalence rate of human brucellosis in high-risk populations, as well as their risk factors, have not been well understood in South Korea. In this cross-sectional study, we investigated the seroreactivity and risk factors associated with human brucellosis among South Korean cattle slaughterhouse workers. We enrolled 922 subjects working in 71 slaughterhouses across the country in 2012. A structured questionnaire was used to obtain data from the subjects, following which blood samples were collected and tested using the microagglutination test; serum titers ≥ 1:20 were considered reactive. Independent risk factors were identified using multivariate logistic regression analysis with backward elimination. Overall, 62 of 922 participants (6.7%) exhibited seroreactivity for brucellosis, and 0.4% had a seroprevalence at a dilution of 1:160. Multivariate analysis revealed that the risk factors for human brucellosis seroreactivity included large-scale slaughtering (≥100 cattle per day; odds ratio (OR), 5.41; 95% confidence interval (CI), 2.95–9.91) and medium-scale slaughtering (50–99 cattle per day; OR, 2.53; 95% CI, 1.16–5.51). Moreover, the risk of brucellosis infection was significantly lower among slaughterhouse workers who always wear protective glasses (OR, 0.27; 95% CI, 0.11–0.69) than in those who sometimes or rarely wore such glasses. Regular and consistent use of personal protective equipment, especially protective glasses, should be encouraged among cattle slaughterhouse workers to reduce brucellosis infection.

Serological evidence of Francisella tularensis in febrile patients seeking treatment at remote hospitals, northeastern Kenya, 2014-2015

Tularaemia is a highly contagious infectious zoonosis caused by the bacterial agent Francisella tularensis. The aim of this study was to investigate the presence of antibodies to F. tularensis in febrile patients in northeastern Kenya. During 2014-2015, 730 patients were screened for anti-F. tularensis antibodies using a combination of ELISA and Western blot. Twenty-seven (3.7%) individuals were positive for F. tularensis. Tularaemia was not suspected by the treating clinicians in any of them. Our results suggest that tularaemia may be present in Kenya but remain unreported, and emphasizes the need for local clinicians to broaden their diagnostic repertoire when evaluating patients with undifferentiated febrile illness.

Knowledge, attitudes and practices (KAP) relating to brucellosis in smallholder dairy farmers in two provinces in Pakistan

The present study aimed to assess the extent of knowledge and understanding of brucellosis in smallholder dairy farmers and identify practices at the farm and household level that might pose a risk for humans contracting brucellosis. Between February and June 2015 a cross-sectional study was conducted among smallholder farms (n = 420) in five districts of Punjab and two districts of Sindh province. Farmers were interviewed using a questionnaire to obtain information on farmers' knowledge about brucellosis and the potential risks for contracting the disease that are present for dairy farmers and their families. Logistic regression and ordinal logistic models were used to investigate potential predictors for risky behaviours. The results show almost all farmers (97%) were not aware of the modes of transmission of brucellosis. Relating to risk, the majority (66%) of the farmers' families were reported to consume raw milk and its products, live in shared housing with animals (49%) and not cover hand cuts during contact with animals (74%). All farmers performed at least one risky practice on a regular basis for brucellosis transmission from animal to human. A multivariable analysis highlighted that the respondents with no formal education and those who had not heard of the disease displayed greater risky behaviour. Poor understanding of the disease, presence of multiple risky practices on farm and at the household, and incorrect perception supports the need for an educational awareness program in order to ensure uptake of improved practices.

Trend of human brucellosis over a decade at tertiary care centre in North Karnataka

BACKGROUND

Brucellosis is an important zoonotic disease. India having a major agrarian population is expected to have a higher prevalence. However, due to lack of laboratory facility or awareness among clinicians, the disease is largely underreported. The aim of this study was to know the prevalence and trend of human brucellosis over a decade, in patients attending a teaching hospital in North Karnataka, and to understand their geographical distribution.

MATERIALS AND METHODS

The study was conducted from January 2006 to December 2015 at a tertiary care teaching hospital in North Karnataka. A total of 3610 serum samples were evaluated from suspected cases of brucellosis. All serum samples were initially screened by Rose Bengal plate test, and positive samples were further analysed by Serum agglutination test (SAT) using standard Brucella abortus antigen from Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India. A titre above or equal to 1:80 IU/ml was considered as positive. Demographic data such as age, sex and native place of these patients were also analysed.

RESULTS

We observed that human brucellosis is present in North Karnataka. The overall seropositivity of brucellosis in suspected cases was 5.1%. The positive titres ranged from 1:80 to 163,840 IU/ml. The majority of the patients were from Gadag, Koppal and Haveri districts of North Karnataka.

CONCLUSION

Our study confirms the presence of human brucellosis in the northern part of Karnataka. Further studies to understand the prevalence of animal brucellosis in these areas will help in implementing prevention measures.

Seroprevalence and risk factors associated with bovine brucellosis in the Potohar Plateau, Pakistan

Background

The seroprevalence and risk factors of bovine brucellosis were studied at animal and herd level using a combination of culture, serological and molecular methods. The study was conducted in 253 randomly selected cattle herds of the Potohar plateau, Pakistan from which a total of 2709 serum (1462 cattle and 1247 buffaloes) and 2330 milk (1168 cattle and 1162 buffaloes) samples were collected. Data on risk factors associated with seroprevalence of brucellosis were collected through interviews using questionnaires. Univariable and multivariable random effects logistic regression models were used for identifying important risk factors at animal and herd levels.

Results

One hundred and seventy (6.3%) samples and 47 (18.6%) herds were seropositive for brucellosis by Rose Bengal Plate test. Variations in seroprevalence were observed across the different sampling sites. At animal level, sex, species and stock replacement were found to be potential risk factors for brucellosis. At herd level, herd size (≥9 animals) and insemination method used were important risk factors. The presence of Brucella DNA was confirmed with a real-time polymerase chain reaction assay (qRT-PCR) in 52.4% out of 170 serological positive samples. In total, 156 (6.7%) milk samples were positive by milk ring test. B. abortus biovar 1 was cultured from 5 positive milk samples.

Conclusion

This study shows that the seroprevalence of bovine brucellosis is high in some regions in Pakistan. Prevalence was associated with herd size, abortion history, insemination methods used, age, sex and stock replacement methods. The infected animal may act as source of infection for other animals and for humans. The development of control strategies for bovine brucellosis through implementation of continuous surveillance and education programs in Pakistan is warranted.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2394-2) contains supplementary material, which is available to authorized users.

Brucellosis in pregnant women from Pakistan: an observational study

BACKGROUND

Brucella species occasionally cause spontaneous human abortion. Brucella can be transmitted commonly through the ingestion of raw milk or milk products. The objective of this study was to determine the sero-prevalence of and to identify potential risk factors for brucellosis in pregnant women from Rawalpindi, Pakistan.

METHODS

We conducted a cross-sectional study at the Gynecology Outdoor Patient department of the Benazir Bhutto Hospital, Rawalpindi, Pakistan from March to June 2013. Data related to potential risk factors and clinical history was collected by individual interviews on the blood sampling day. The 429 serum samples collected were initially screened by Rose Bengal Plate Agglutination test for the detection of Brucella antibodies. We applied standard descriptive statistics and logistic regression analyses.

RESULTS

Twenty five (5.8 %; 95 % confidence interval (CI): 3.8 % -8.5 %) serum samples were found to be seropositive. Brucellosis-related clinical symptoms were recorded in various seropositive cases. Animal contact, raw milk consumption, having an abortion history and the experience of an intrauterine fetal death were associated with seropositivity for brucellosis in univariate analyses (all p <0.05). In multiple logistic regression models only the contact with animals remained as independent and robust risk factor (odds ratio 5.21; 95 % CI: 1.88-13.75; p = 0.001) for seropositivity.

CONCLUSION

Brucellosis is a serious threat for pregnant women and their unborn children in Pakistan. Pregnant women having brucellosis-related symptoms or previous history of abortions, miscarriages, intrauterine fetal death and other brucellosis-related manifestations should be screened for brucellosis - especially those exposed to animals given the increased risk - and medication should be administered according to state of the art.

Cases of human brucellosis in Sweden linked to Middle East and Africa

BACKGROUND

Human brucellosis cases are still reported each year in Sweden despite eradication of the disease in animals. Epidemiological investigation has never been conducted to trace back the source of human infection in the country. The purpose of the study was to identify the source of infection for 16 human brucellosis cases that occurred in Sweden, during the period 2008-2012.

RESULTS

The isolates were identified as Brucella melitensis and MLVA-16 genotyping revealed 14 different genotypes of East Mediterranean and Africa lineages. We also reported one case of laboratory-acquired brucellosis (LAB) that was shown to be epidemiological linked to one of the cases in the current study.

CONCLUSIONS

Brucella melitensis was the only species diagnosed, confirming its highest zoonotic potential in the genus Brucella, and MLVA-16 results demonstrated that the cases of brucellosis in Sweden herein investigated, are imported and linked to travel in the Middle East and Africa. Due to its zoonotic concerns, any acute febrile illness linked to recent travel within those regions should be investigated for brucellosis and samples should be processed according to biosafety level 3 regulations.

Risk factors for human brucellosis in agro-pastoralist communities of south western Uganda: a case-control study

BACKGROUND

Brucellosis is a zoonosis of veterinary, public health and economic significance in most developing countries. The disease can result in permanent and disabling sequelae and considerable medical expenses in addition to loss of income due to loss of working hours. A case-control study was conducted in Nyabushozi, Kiruhura district, Uganda, so as to determine the risk factors for transmission of brucellosis to humans in these communities.

METHODS

We conducted a matched case-control study among participants in a previous study who were positive by the standard Serum Agglutination Test with titres ≥1:160. Controls were two neighbors for each case, matched by sex and age. A structured interviewer administered questionnaire was used to collect data on potential risk factors for brucellosis. Categorical variables were presented as proportions and their associations determined by Chi-square test. Bivariate analysis was performed to explore associations between the disease and the risk factors of brucellosis. Conditional logistic regression models were fitted to estimate independent associations between the disease and the risk factors using Odds Ratios and 95% confidence intervals.

RESULTS

A total of 45 cases and 90 controls were interviewed. Of the 45 cases, 21 (46.7%) were male while 44/90 (48.9%) of the controls were female. The most significant risk factors for infection being an agro-pastoralist (P = 0.05), consumption of raw cow ghee (P = 0.03) and consumption of unpasteurized milk (P = 0.02).

CONCLUSION

The greatest risk factors for acquiring brucellosis in the study area were being an agro-pastoralist, consumption of raw cow ghee and consumption of unboiled milk. We recommend dissemination of health education packages regarding risks and prevention measures for brucellosis in these communities.

Prevalence of Brucella antibodies on a previously acute brucellosis infected population: sensitivity, specificity and predictive values of Rose Bengal and Wright standard tube agglutination tests

PURPOSE

Brucellosis is a zoonosis with worldwide distribution. The presence of antibodies after acute infection and the prevalence of positive serology in endemic area are not well documented.

METHODS

Patients hospitalized with acute brucellosis were relocated 3-13 years after the initial infection. Hospital records of the initial infection were retrieved, and examination of Brucella antibodies using Rose Bengal test (RBT) and Wright standard tube agglutination (STA) test was performed.

RESULTS

Eighty-three patients were hospitalized from 2000 to 2010; 50.6 % were farmers and 37.4 % livestock farmers. All had febrile illness and various focal complications. All had positive serology, and 82.2 % had positive blood cultures; 91.5 % were treated with streptomycin plus doxycycline. Seventy-two (86.7 %) were relocated on follow-up. Nine (12.5 %) had positive RBT and STA up to 1/320. Occupational history was associated with positive serology (p = 0.0172), and 8/9 of the positive individuals were livestock farmers (38.0 % of the livestock farmers checked). Residence, years after the infection, clinical presentation of brucellosis and treatment were not associated with serology results. Both tests had excellent sensitivity (nearly 100 %), specificity 87.5 % and excellent negative predictive value (nearly 100 %); however, positive predictive value was only 11.4 %.

CONCLUSIONS

Rapid and low-cost tests as RBT and STA are still very useful in diagnosing acute brucellosis; however, every positive test must be examined together with clinical symptoms and occupational history. The tests can be used as screening tests in endemic populations to rule out acute brucellosis.

Seroprevalence survey of brucellosis among rural people in Mongolia

BACKGROUND

After the transition from socialism to a market economy in 1990, human brucellosis re-emerged in Mongolia. The aim of our study was to estimate a representative seroprevalence of Brucella spp. and to determine risk factors for brucellosis seropositivity among rural people.

METHODS

A cross-sectional study with multistage random selection was conducted in eight provinces of Mongolia. Study participants were interviewed using a questionnaire to obtain their brucellosis history, current symptoms and likely risk factors. Blood samples were drawn to determine brucellosis seroprevalence.

RESULTS

A total of 2856 randomly selected rural people aged four to 90 years were enrolled in the study. The seroprevalence of Brucella spp. was 11.1% (95% confidence interval [CI]: 10.0-12.1), ranging between 2.3% and 22.6% in the eight provinces; 39.2% (n = 609) of nomadic camps had at least one seropositive participant. Risk factors associated with brucellosis seropositivity were being older than 45 years (adjusted odds ratio [AOR] = 6.9, 95% CI = 5.1-8.7) and being a veterinarian (AOR = 2.8, 95% CI = 1.5-5.0).

CONCLUSION

Our study confirms that human brucellosis seroprevalence among rural people in Mongolia is high. Human brucellosis can be effectively controlled if high-coverage livestock mass vaccination is implemented with a coverage survey after the vaccinations to ensure completeness. This mass vaccination should be accompanied by public awareness and educational programmes.

Human brucellosis among pyrexia of unknown origin cases and occupationally exposed individuals in Goa Region, India

Background

Brucellosis is a widespread zoonotic infection. This disease is endemic in many parts of Asia, including India. Brucellosis is a major cause of pyrexia of unknown origin (PUO). Persons exposed to infected animals or contaminated animal products are at high risk. Seropositivity among animal handlers, veterinarians and dairy workers has been documented in India. Thus, the present study was aimed to determine prevalence of brucellosis among PUO cases and occupationally exposed individuals.

Methods

In this study, serum samples (n=282) from cases of pyrexia of unknown origin (PUO) (n=243), and occupationally exposed individuals (n=39) were collected and tested for brucellosis by Rose Bengal plate test (RBPT), serum agglutination test (SAT), indirect ELISA, IgG and IgM ELISA. Blood culture for isolation of Brucella was performed for 10 serologically positive patients using BACTEC 9050 automated blood culture system. Biochemical tests and PCR techniques were used for confirmation of the isolates.

Results

Of the samples tested, 4.25%, 3.54%, 6.02% and 4.96% samples were positive by RBPT, SAT, indirect ELISA and IgG ELISA, respectively. None of the sample was positive for IgM ELISA. Of the 10 blood samples cultured bacteriologically, one Brucella isolate was recovered. The isolate was confirmed as Brucella abortus. Amplification of the bcsp31 and IS711 genes was also observed.

Conclusion

Seropositivity for brucellosis was observed among PUO cases, animal handlers and dairy workers in Goa, India. The serological tests showed variable results. One Brucella isolate was obtained by performing blood culture. Confirmation of the case was done rapidly using molecular tools. General awareness about clinical symptoms should be increased which will improve proper diagnosis within short time frame.