Risk Factors For Human Brucellosis Research Articles

Seroprevalence of brucellosis among high-risk individuals in Madinah, Saudi Arabia.

Brucellosis is a highly contagious, neglected zoonotic disease of major importance worldwide. The disease is endemic in many countries, burdening healthcare systems and the livestock industry and representing a persistent public health concern in these countries. Brucellosis is considered an important occupational hazard for livestock workers. Limited studies have investigated human brucellosis in Saudi Arabia. Therefore, this study aimed to estimate the prevalence of brucellosis among employees of high-risk brucellosis professions, including veterinarians, animal herders, and abattoir workers in Madinah, Saudi Arabia, and to determine the associated risk factors. A cross-sectional study was conducted in Madinah, Saudi Arabia, during the period of January-March 2023. Ninety blood samples were collected from individuals occupationally at risk of exposure to Brucella infections. Serum samples were examined for immunoglobulins (Ig)M and IgG antibodies against Brucella using an indirect enzyme-linked immunosorbent assay. Before sample collection, a predesigned online questionnaire was used to collect the participants' sociodemographic characteristics and the probable risk factors for human brucellosis. A Chi-square test was used to compare the differences among groups; p < 0.05 were considered statistically significant. Among the 90 participants among the high-risk individuals, Brucella IgM and IgG seropositivity were found in 8 (8.8%) and 11 (12.12%) cases, respectively. IgM mono antibody positivity was observed in 4 (4.44%) and 7 (7.77%) of the study population who tested positive for IgG only. Dual positivity for IgM and IgG antibodies was observed in 4 (4.44%) participants. No significant association was determined between seropositivity and age, urbanicity, education, occupation, and duration of exposure (p > 0.05). Brucellosis is a high-risk occupational disease among workers with close contact with livestock. This study demonstrates that the seroprevalence of brucellosis among occupationally high-risk individuals in Madinah, Saudi Arabia, is relatively low compared to other countries in the region. Nevertheless, educational programs should be implemented to improve knowledge regarding brucellosis, particularly among high-risk individuals.

Knowledge, Attitude, and Practice on Brucellosis among the Rural Population in Nagpur, Maharashtra, India

Abstract Introduction: Brucellosis is a disease that can have severe consequences for both humans and animals, resulting in considerable economic losses due to its impact on human health and animal productivity. To prevent the transmission of this disease from animals to humans, it is essential to improve the community’s knowledge, attitude, and practice (KAP). This study aimed to evaluate the KAP and associated risk factors for human brucellosis among rural populations in Nagpur, Maharashtra, India. Materials and Methods: Using closed-ended questionnaires, a cross-sectional study was conducted to collect data on demographics and risk exposure variables from 382 participants. The collected data were entered into Microsoft Excel and analyzed using SPSS. Descriptive statistics were used to evaluate demographic features and KAP. Results: 78.5% were male, and 21.5% were female. Their ages ranged from 18 to 90 years, and 92.1% were married. Only 4.5% of respondents had heard of brucellosis, 21.5% consumed unpasteurized milk, 3.9% used protective gloves while assisting during calving, and 15.4% milked the animal. Furthermore, 21.2% buried animal birth products, 10.9% burned animal birth products, and 13.6% threw animal birth products in the dustbin. Overall, the respondents’ attitude was average to poor. Conclusion: This study revealed that the rural population has poor knowledge and high-risk self-reported practices and behaviors for brucellosis. Therefore, enhancing public health education and local organizational involvement is imperative to increase the community’s capacity to prevent brucellosis as an integral part of the National Control Program on Brucellosis in India.

Sero-prevalence and risk factors for human brucellosis in Marsabit county, Kenya (2014)

Introduction: brucellosis is among the world's most widespread zoonotic diseases which is recognized as a public health concern in both developed and developing countries. It is endemic in Kenya's pastoral communities where it is associated with significant economic losses due to decreased animal productivity and high burden in humans. The objectives of this study were: i) To estimate the sero-prevalence and determine the risk factors of brucellosis in humans ii) To assess the knowledge attitude and practices (KAP) of a pastoral community in relation to brucellosis transmission and control.

Human and Animal Brucellosis: A Comprehensive Review of Biology, Pathogenesis, Epidemiology, Risk Factors, Clinical Signs, Laboratory Diagnosis, Public Health Significance, Economic Importance, Prevention and Control

Brucellosis is a highly infectious anthropozoonotic disease caused by the bacterial genus Brucella and is prevalent throughout the world. It has a wide host range, and this makes brucellosis an important public health problem causing a negative impact on the economy of the affected country. The disease is endemic in the bovine population, resulting in an estimated economic loss of US dollars 344 billion to the livestock industry. Poor management, irrational animal movement, wide ranges of hosts, large herd size, and commingling of different animal species are risk factors for animal brucellosis. Globally, brucellosis is estimated to account for 500,000 cases in humans every year. The possible risk factors for human brucellosis are eating infected animal products, occupational exposure, and contact with diseased animals or their products and discharges. Human brucellosis is characterized by a variable incubation period and has many clinical manifestations. In humans, undulating fever is the most frequently observed clinical sign with infections reported during the early trimesters of pregnancy. The common measures of preventing animal brucellosis include proper hygiene, control of animal movement, and testing and slaughtering infected animals. Successful prevention of the disease can only be achieved when extension services emphasize addressing the impacts of risk factors for the occurrence of brucellosis. Generally, there is no single prevention strategy that inhibits the transmission of brucellosis amongst animals and humans. Therefore, public education on the transmission, source of infection, public health and economic importance of the disease needs to be undertaken. The control of human and animal brucellosis is multidisciplinary, requiring the efforts of all professionals, and farmers.

Epidemiology of human brucellosis in Nahavand county, Hamadan Province, western Iran: an 8-year (2010-2017) registry-based analysis.

Brucellosis is an infectious zoonosis, which greatly afflicts human health and animal productivity. To describe the trends and epidemiological characteristics of human brucellosis in Nahavand county, Hamadan Province, western Iran over 8 years (2010-2017). In this registry-based longitudinal study, we analyzed all reported cases of human brucellosis, including 1,130 patients from 2010 to 2017. A checklist including demographic and clinical characteristics of patients with reported cases of brucellosis had been used to gather data. We calculated annual percent changes (APCs) and average annual percent changes (AAPCs) using Joinpoint software to determine the trend of brucellosis using a segmented regression model. Among the patients, 60.9% were male and 87.3% lived in rural areas. The mean age of the patients was 35.9 ± 18.34 years. Compared with male patients, female patients were more affected when they were elderly (15.6% men vs. 24.2% women for those aged ≥55 years) (P = 0.001). Of patients with brucellosis, 65.2% had consumed unpasteurized dairy products and 82.3% had a history of contact with animals. The incidence of human brucellosis in Nahavand county increased between 2010 and 2014, then decreased in 2015, and thereafter remained steady. Per 100,000 population, the AAPC pertaining to the incidence was 17.4 in the male population (95% CI: 4.4, 31.9), 13.8 in the female population (95% CI: 0.2, 29.3), and 16.1 in rural dwellers (95% CI: 2.2, 31.8) indicating an increasing trend from 2010 to 2017 (P < 0.05). The incidence of brucellosis in the western part of Iran is high and remains a challenging health problem. In the present study, age, job, sex, and seasonal changes are important risk factors for human brucellosis.

Seroprevalence and risk factors for human brucellosis in agro-pastoral areas in Tanzania

Background: Brucellosis is an endemic zoonosis in Tanzania. This study was conducted to investigate the seroprevalence of human brucellosis and its risk factors in agro-pastoral areas in Morogoro Region, Tanzania.&#x0D; Methods: Questionnaire survey and blood sampling were conducted from January to February 2018 at four villages. Anyone living in the villages and wished to participate were involved. Competitive ELISA was used for diagnosis. Risk factor analysis for sero-positivity in human and analysis for the association of sero-positivity between cattle and human within each farm were conducted, using the data of farm-level bovine brucellosis status from our bovine brucellosis research performed in 2016.&#x0D; Results: The seroprevalence was 33.3% (44/132). In univariable analysis, the Maasai were significantly more sero-positive (56.5%) than other tribes (28.4%) (OR = 3.23, 95% CI: 1.28–8.41). Drinking raw milk was a risk factor in both univariable and multivariable analyses (OR = 3.97, 95% CI: 1.61–10.20). A negative association between sero-positivity in cattle and human within each farm was found (p&lt;0.01). The Maasai performed more risk-taking behaviours for human infection than other tribes: drinking raw milk (p&lt;0.01) or blood (p&lt;0.01) and helping delivery of cattle with bare hands (p=0.03).&#x0D; Conclusions: The Maasai were at high risk of human brucellosis. More detailed survey and educational interventions are urgently needed.

Risk Factors for Human Brucellosis in Northern Tanzania.

.Little is known about the epidemiology of human brucellosis in sub-Saharan Africa. This hampers prevention and control efforts at the individual and population levels. To evaluate risk factors for brucellosis in northern Tanzania, we conducted a study of patients presenting with fever to two hospitals in Moshi, Tanzania. Serum taken at enrollment and at 4–6 week follow-up was tested by Brucella microagglutination test. Among participants with a clinically compatible illness, confirmed brucellosis cases were defined as having a ≥ 4-fold rise in agglutination titer between paired sera or a blood culture positive for Brucella spp., and probable brucellosis cases were defined as having a single reciprocal titer ≥ 160. Controls had reciprocal titers < 20 in paired sera. We collected demographic and clinical information and administered a risk factor questionnaire. Of 562 participants in the analysis, 50 (8.9%) had confirmed or probable brucellosis. Multivariable analysis showed that risk factors for brucellosis included assisting goat or sheep births (Odds ratio [OR] 5.9, 95% confidence interval [CI] 1.4, 24.6) and having contact with cattle (OR 1.2, 95% CI 1.0, 1.4). Consuming boiled or pasteurized dairy products was protective against brucellosis (OR 0.12, 95% CI 0.02, 0.93). No participants received a clinical diagnosis of brucellosis from their healthcare providers. The under-recognition of brucellosis by healthcare workers could be addressed with clinician education and better access to brucellosis diagnostic tests. Interventions focused on protecting livestock keepers, especially those who assist goat or sheep births, are needed.

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

BackgroundBrucellosis 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.MethodsWe 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.ResultsA 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).ConclusionThe 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-015-1361-z) contains supplementary material, which is available to authorized users.

Serological, Clinical, and Epidemiological Profile of Human Brucellosis in Rural India.

Background:Brucellosis is an important but neglected zoonotic disease in India. Due to frequent animal contact, high prevalence of this disease, though expected in rural population, has not been much studied.Aim:The study was carried out to determine serological, clinical, and epidemiological profile including associated risk factors for human brucellosis in rural India.Materials and Methods:In this cross-sectional study, serum samples from 1,733 individuals residing in rural areas were screened for the presence of anti-brucellar antibodies by Rose Bengal Plate test (RBPT), Serum Agglutination test (SAT), and 2-Mercaptoethanol test (2-ME). Clinical symptoms, epidemiological data including risk factors and knowledge about brucellosis were evaluated by personal interview using a structured questionnaire.Results:Of the 1,733 individuals, 998 had direct contact with animals, whereas 735 had no direct contact. The overall positivity rates by RBPT, SAT, and 2-ME test were 10.50% (182), 7.32% (127), and 5.88% (102), respectively. Clinical symptoms resembling brucellosis were seen in 151 (8.71%) subjects. Animal contact especially during milking, parturition/abortion was the major risk factor, followed by raw milk ingestion. None of the participant knew about brucellosis.Conclusion:Regular surveillance of the disease with awareness programs emphasizing prevention and control are needed.

Risk factors for human brucellosis in northern Jordan

Little is known about the risk factors of human brucellosis in Jordan. A case-control study was conducted involving 56 Jordanians who had been treated for brucellosis and at least 3 matched controls for each case (n = 247). Matching was for sex, age, locality (the same village) and socioeconomic standard. Univariate and multivariate logistic regression analyses were used. In all, 17 risk factors were examined related to: contact with various livestock, milk and milk product consumption, drinking-water treatment and disease awareness. Most variables were associated with brucellosis in the univariate analysis but the final logistic model included only 4: milking sheep and goats (OR 3.5), consumption of raw feta cheese made from sheep and goat milk (OR 2.8) and consumption of cows' milk (OR 0.4) and boiled feta cheese (OR 0.4). Small ruminant farmers need to be trained in safer milking practices and feta cheese making procedures.

Risk factors associated with human brucellosis in the country of Georgia: a case-control study

Human brucellosis occurs when humans ingest or contact Brucella spp. from shedding animals or contaminated environments and food. In Georgia animal and human brucellosis is endemic, but the epidemiology has not been fully characterized. A case-control study was conducted in 2010 to identify risk factors for human brucellosis. Using multivariable logistic regression, the following risk factors were identified: animal-related work [odds ratio (OR) 77·8, 90% confidence interval (CI) 4·7-1278], non-animal-related work (OR 12·7, 90% CI 1·1-149), being unemployed or a pensioner (OR 13·1, 90% CI 1·7, 101), sheep ownership (OR 19·3, 90% CI 5·1-72·6), making dairy products (OR 12·4, 90% CI 1·4-113), living in eastern Georgia (Kakheti) (OR 278·1, 90% CI 9·5-8100), and being aged >44 years (OR 9·3, 90% CI 1·02-84·4). Education of at-risk groups about risk factors and control of disease in sheep may reduce the human disease risk. This is the first study of its kind in Georgia since the collapse of the Soviet Union.

Spatial epidemiology of hospital-diagnosed brucellosis in Kampala, Uganda

BackgroundA retrospective case-control study was undertaken to examine the spatial risk factors for human brucellosis in Kampala, Uganda.MethodsInformation on age, sex and month of diagnosis was derived from records from plate agglutination tests undertaken at Mulago Hospital, Kampala. Information on Parishes (LC2s) where patients reside was sourced from the outpatient registration book. In-patient fracture cases were selected for use as controls using 1:1 matching based on the age, sex and month of diagnosis. The locations of cases and controls were obtained by calculating Cartesian coordinates of the centroids of Parish level (LC2) polygons and a spatial scan statistic was applied to test for disease clustering. Parishes were classified according to the level of urbanization as urban, peri-urban or rural.ResultsSignificantly more females than males were found to show sero-positivity for brucellosis when compared with the sex ratio of total outpatients, in addition female brucellosis patients were found to be significantly older than the male patients. Spatial clustering of brucellosis cases was observed including around Mulago Hospital (radius = 6.8 km, p = 0.001). The influence of proximity to the hospital that was observed for brucellosis cases was not significantly different from that observed in the controls. The disease cluster was confounded by the different catchment areas between cases and controls. The level of urbanization was not associated with the incidence of brucellosis but living in a slum area was a significant risk factor among urban dwellers (odds ratio 1.97, 95% CI: 1.10-3.61).ConclusionsBeing female was observed to be a risk factor for brucellosis sero-positvity and among urban dwellers, living in slum areas was also a risk factor although the overall risk was not different among urban, peri-urban and rural areas of the Kampala economic zone.

Quantifying risk factors for human brucellosis in rural northern Tanzania.

BackgroundBrucellosis is a zoonosis of veterinary, public health and economic significance in most developing countries. Human brucellosis is a severely debilitating disease that requires prolonged treatment with a combination of antibiotics. The disease can result in permanent and disabling sequel, and results in considerable medical expenses in addition to loss of income due to loss of working hours. A study was conducted in Northern Tanzania to determine the risk factors for transmission of brucellosis to humans in Tanzania.MethodsThis was a matched case-control study. Any patient with a positive result by a competitive ELISA (c-ELISA) test for brucellosis, and presenting to selected hospitals with at least two clinical features suggestive of brucellosis such as headache, recurrent or continuous fever, sweating, joint pain, joint swelling, general body malaise or backache, was defined as a case. For every case in a district, a corresponding control was traced and matched by sex using multistage cluster sampling. Other criteria for inclusion as a control included a negative c-ELISA test result and that the matched individual would present to hospital if falls sick.ResultsMultivariable analysis showed that brucellosis was associated with assisted parturition during abortion in cattle, sheep or goat. It was shown that individuals living in close proximity to other households had a higher risk of brucellosis. People who were of Christian religion were found to have a higher risk of brucellosis compared to other religions. The study concludes that assisting an aborting animal, proximity to neighborhoods, and Christianity were associated with brucellosis infection. There was no association between human brucellosis and Human Immunodeficiency Virus (HIV) serostatus. Protecting humans against contact with fluids and tissues during assisted parturition of livestock may be an important means of reducing the risk of transferring brucellosis from livestock to humans. These can be achieved through health education to the communities where brucellosis is common.

Quantifying Risk Factors for Human Brucellosis in Tanzania

Setting: Arusha and Manyara regions, Tanzania. Objective: To determine the risk factors for transmission of brucellosis to humans in Tanzania Study design: A matched case-control study Methodology: Any person with a positive result by competitive ELISA test (c-ELISA) for brucellosis, and presenting to the selected hospitals with at least two signs or symptoms suggestive of brucellosis such as headache, fever which is recurrent or continuous, sweating, joint pain, joint swelling, general body malaise or backache, was defined as a case. For every case in a district, a corresponding control was traced and matched by sex using multistage sampling. Other criteria for inclusion as a control included that the matched individual had a negative c-ELISA result and would present to hospital if sick. Using risk sets as a matching variable, and cases and controls as outcome variables, models were fitted to test their significance and the likelihood ratio was used to identify risk factors for human brucellosis. Results: Brucellosis was found to be associated with assisting cattle, sheep or goat during abortion. The closer the distance between households, the higher was the risk of brucellosis. People belonging to one religion group were found to have a higher risk of brucellosis compared to others. No association was established between brucellosis serostatus in humans and brucellosis serostatus of their own livestock. In humans, there was no association between brucellosis serostatus and HIV serostatus. Conclusion: Protecting humans against contact with fluids and tissues during assisted parturition of livestock may be an important means of reducing the risk of transferring brucellosis from livestock to humans. The possibility of contracting brucellosis from neighbours should also be considered. These can be achieved through health education to the communities where brucellosis is common. Interestingly there was no association between HIV serostatus and brucellosis serostatus, indicating that unlike other infectious diseases brucellosis is not more likely to occur in patients immune compromised by HIV in these areas.

Risk factors for human brucellosis in Iran: a case–control study

Brucellosis is a zoonotic disease of worldwide distribution. Despite its control in many countries, it remains endemic in Iran. The aim of this study was to determine the risk factors for brucellosis acquisition in the central province of Iran. A matched case-control study was conducted in the central part of Iran. A total of 300 subjects (150 cases and 150 controls) were enrolled in the investigation. Brucellosis cases were defined on the basis of epidemiologic, clinical, and laboratory criteria. Subjects were interviewed using a questionnaire to obtain risk factor information. We used odds ratios and conditional logistic regression models to explore the association between the disease and the variables studied. Significant risk factors for infection were related to the existence of another case of brucellosis in the home (OR=7.55, p=0.0001) and consumption of unpasteurized dairy products (OR=3.7, p=0.014). Keeping cattle and cattle vaccination were also important risk factors. Pasteurization of dairy products and education regarding fresh cheese must be pursued for eradication of brucellosis. A major risk factor for acquiring brucellosis is the existence of another infected family member. Therefore screening family members of an index case of brucellosis may lead to the detection of additional cases.

Seroprevalences and local variation of human and livestock brucellosis in two villages in Gharbia Governorate, Egypt

This study aimed at assessing the epidemiology of brucellosis among both human and livestock populations in an endemic area in Egypt. A cross-sectional survey was conducted in two villages, where 616 inhabitants (aged 3-75 years) and 350 livestock of 97 households were enrolled. Sera were tested for Brucella spp. antibodies by tube agglutination test for both populations. Proportions of seropositive sera were 0.0 and 1.7% among the inhabitants, and 0.0 and 16% among livestock of villages I and II, respectively. Calculated seroprevalences considering the clustering of brucellosis within households were 0.03 for people and 5.2 for livestock in village II. The village variable (P=0.07) and keeping sheep in the household (P=0.01) were significant risk factors for human brucellosis, whereas only the village was significant for livestock (P<0.001). Sheep showed the highest seropositive proportions of brucellosis among livestock. No association could be detected between human and livestock brucellosis. In conclusion, we found local variation of seroprevalences of brucellosis among human and livestock in the two surveyed villages. Further epidemiological studies have to be conducted in randomly selected governorates, not only to confirm the low seroprevelance of human brucellosis, but also to assess the risk factors of livestock infection for terms of prophylaxis.

P1230 Risk factors for human brucellosis in Iran: a case-control study

P1230 Risk factors for human brucellosis in Iran: a case-control study

Risk factors for human brucellosis in Yemen: a case control study.

Brucellosis is known to occur in Yemen but its epidemiology has not been extensively studied. The present investigation examined risk factors for human brucellosis in Yemen using a hospital-based case-control study. A total of 235 consecutive patients with brucellosis attending the Central Health Laboratory in Sana'a, Yemen, were matched in respect of age, sex, and place of residence, rural or urban, with 234 controls selected from individuals attending the Central Health Laboratory for unrelated health problems. Clinical information on patients and controls was supplemented with occupational and socio-economic data obtained by interview of cases and controls using a standard questionnaire. After controlling for confounding factors significant risk factors for infection related to occupation as a farmer (OR 2.5 (95% CI 1.4-4.5, P < 0.0001)), shepherd (OR 7.8 (95% CI 1.0-61, P 0.05)) or microbiologist (OR 24.5 (95% CI 2.9-204, P 0.003)); and drinking fresh milk (OR 2.0 (95% CI 1.3-4.3, P 0.001)) and laban (OR 22.7 (95% CI 1.7-4.2 P < 0.0001)). Taking other milk products and offal were not risk factors. Socio-economic and educational factors were also independent risk factors. Occupational, food and socio-economic risk factors significantly confounded one another. Yemen shares some but not all of the risk factors of neighbouring countries. The interrelation between the various factors is complex and studying any one in isolation may give a false impression of its public health significance. Control through education of the population to minimize exposure to, and contact with, animals and their milk and milk products and to boil milk before drinking it or using it to make buttermilk, would be difficult as these would represent such fundamental changes to established patterns of behaviour of this society. Ideally there would be a campaign to control the infection by animal vaccination but the costs and logistic difficulty would be great. Presently there is a clear need for doctors in Yemen to be made aware of the frequency of this infection, the means available for clinical and laboratory diagnosis and effective treatment, while strategies to control the disease in Yemen are formulated and field tested.