The prevalence and risk factors for human Brucella species infection in a cross-sectional survey of a rural population in Punjab, India

Seroprevalence of brucellosis among animal handlers in West Bengal, India: an occupational health study

Brucellosis is a highly contagious zoonotic disease and a major human health problem worldwide. Due to its ways of transmission, direct or indirect contact with infected animals or their contaminated biological products, the disease exhibits strong occupational association with animal handlers comprising a significant population at risk. This study was undertaken to estimate the seroprevalence of brucellosis in animal handlers and to understand the epidemiological and serological aspects of the same. The animal handlers from the state of West Bengal, India were included in this study. It was a prospective and observational cohort study from November 2021 to March 2022. A total of 669 sera samples were collected from animal handlers and tested using various serological tests for Brucella antibodies. All serum samples were tested using the Rose Bengal plate test (RBPT), standard tube agglutination test (STAT), and enzyme-linked immunosorbent assay (ELISA). 106 (15.8%) patients were diagnosed with brucellosis among the total number of patients tested. Most of the patients affected with brucellosis belonged to the age group 51-60 years (23.5%). The seropositivity rate in male animal handlers was higher than female animal handlers in this study. More studies are needed to understand the occupational association of this disease. Awareness programs, safe livestock practices, and prevention of the disease by timely diagnosis must be implemented in order to control human brucellosis.

Situation Analysis and Recommendations for the Biosecurity Status of Dairy Farms in Punjab, India: A Cross-Sectional Survey

Farm biosecurity is an important herd management strategy to assure infection prevention and animal health. The present study aimed to evaluate the implementation of biosecurity measures on dairy farms in Punjab, India, using the standardized Biocheck.UGent™ scoring system. Convenience sampling was used to select 94 dairy farms, comprising both cattle and buffaloes, with a mean herd size of 74.8 animals. The study found that the mean external and internal biosecurity scores for the selected dairy farms were 45.4% and 43.7%, respectively. Among the subcategories, the highest external biosecurity score was observed for 'vermin control and other animals' (63%), and the highest internal biosecurity score was observed for 'adult cattle management' (76.6%). Whereas the lowest score for external biosecurity was observed for 'purchase and reproduction' (30.6%), and the lowest score for internal biosecurity was observed for 'health management' (33.6%). The overall mean biosecurity score of the present study was 44.8%, which was lower than the overall mean global score of 52%. The correlation analysis indicated a positive correlation between herd size and overall biosecurity scores, indicating that larger farms had, on average, higher biosecurity scores. Based on these results, it can be concluded that the implementation of biosecurity measures on dairy farms in Punjab needs improvement, especially in the subcategories of 'purchase and reproduction' and 'health management'. Further research to identify the factors influencing the implementation of biosecurity measures on dairy farms in the region is recommended.

Brucellae as resilient intracellular pathogens: epidemiology, host-pathogen interaction, recent genomics and proteomics approaches, and future perspectives

Brucellosis is considered one of the most hazardous zoonotic diseases all over the world. It causes formidable economic losses in developed and developing countries. Despite the significant attempts to get rid of Brucella pathogens in many parts of the world, the disease continues to spread widely. Recently, many attempts proved to be effective for the prevention and control of highly contagious bovine brucellosis, which could be followed by others to achieve a prosperous future without rampant Brucella pathogens. In this study, the updated view for worldwide Brucella distribution, possible predisposing factors for emerging Brucella pathogens, immune response and different types of Brucella vaccines, genomics and proteomics approaches incorporated recently in the field of brucellosis, and future perspectives for prevention and control of bovine brucellosis have been discussed comprehensively. So, the current study will be used as a guide for researchers in planning their future work, which will pave the way for a new world without these highly contagious pathogens that have been infecting and threatening the health of humans and terrestrial animals.

Assessing and Prioritizing Zoonotic Diseases in Punjab, India: A One Health Approach

Zoonotic diseases have a significant impact on both human and animal health globally. The present study was planned to prioritize the zoonoses in Punjab state of India. To develop a zoonotic disease prioritization scoring system, a comprehensive approach has been taken, including literature review, key person interviews with animal health experts (n = 12) and medical professionals (n = 7), and nine focus group discussions (FGDs) with veterinary academicians, medical professionals, and field veterinary doctors. The scoring system comprises of seven major criteria, each assigned a weightage score (ws): prevalence/incidence of the disease (ws = 0.20), severity of illnesses in humans (ws = 0.18), epidemic potential (ws = 0.16), socio-economic burden (ws = 0.16), availability of effective control and prevention measures (ws = 0.15), inter-sectoral collaborations (ws = 0.1), and bioterrorism potential (ws = 0.05). The finalized scoring system, accompanied by a list of 15 selected zoonotic diseases, was implemented among a group of 23 professionals engaged in zoonoses research (n = 7), animal health (n = 10), and medical health (n = 6) to determine their prioritization. The zoonotic diseases prioritized for the Punjab (India) included, Brucellosis (0.70) > Rabies (0.69) > Anthrax (0.64) > Leptospirosis (0.62) = Toxoplasmosis (0.62) = Highly Pathogenic Avian Influenza (HPAI) (0.62) > Bovine tuberculosis (0.61) > Q fever (0.60) > Cysticercosis (0.59) > Listeriosis (0.58) > Crimean-Congo haemorrhagic fever (CCHF) (0.57) > Japanese encephalitis (0.56) = Echinococcosis (0.56) > Dermatophytosis (0.53) > and Scrub typhus (0.48), respectively. Higher priority is suggested for endemic zoonoses (e.g., brucellosis and rabies) as compared to those with epidemic potential (e.g., CCHF, HPAI etc.) in Punjab. Results of the current study will help in the development of targeted control and prevention strategies for zoonotic diseases in Punjab and other geographical regions facing similar challenges.

Serological and molecular prevalence of Brucella spp. among livestock species in Rajasthan, India

A seroprevalence and molecular study was carried out in six districts of the state of Rajasthan, India to detect brucellosis in major livestock species. This study involves the testing of 3,245 livestock samples using the Rose Bengal Plate Test (RBPT), Indirect Enzyme-Linked Immunosorbent Assay (i-ELISA), and genus-specific polymerase chain reaction (PCR) markers for molecular diagnosis of the disease. In the tested samples, seroprevalence was 5.06% (CI: 1.96-8.15) using the RBPT test and 6.88% (CI: 1.98-11.78) using the i-ELISA test, while the cumulative seroprevalence (RBPT and i-ELISA) was 3.63% (CI: 0.44-6.83). The prevalence of the disease was 1.27% (CI: 0.56-3.11) when tested using molecular markers. The highest prevalence of brucellosis was detected in Cattle (7.00, 3.22%), followed by camels (5.50, 2.50%), buffalo (2.66, 0.00%), sheep (2.43, 0.41%), and goats (0.58, 0.23%) when serological (cumulative) and molecular diagnosis were considered preferred methods of detection. Cattle (3.22%) and camels (2.50%) also showed a high prevalence of disease when tested using molecular markers. The results of this study reveal that cattle, camel, and sheep brucellosis is prevalent in the study areas.

Modelling the control of bovine brucellosis in India

Brucellosis imposes substantial impacts on livestock production and public health worldwide. A stochastic, age-structured model incorporating herd demographics was developed describing within- and between-herd transmission of Brucella abortus in dairy cattle herds. The model was fitted to data from a cross-sectional study conducted in Punjab State of India and used to evaluate the effectiveness of control strategies under consideration. Based on model results, stakeholder acceptance and constraints regarding vaccine supply, vaccination of replacement calves in large farms should be prioritized. Test and removal applied at early stages of the control programme where seroprevalence is high would not constitute an effective or acceptable use of resources because significant numbers of animals would be 'removed' (culled or not used for breeding) based on false positive results. To achieve sustained reductions in brucellosis, policymakers must commit to maintaining vaccination in the long term, which may eventually reduce frequency of infection in the livestock reservoir to a low enough level for elimination to be a realistic objective. This work provides key strategic insights into the control of brucellosis in India, which has the largest cattle population globally, and a general modelling framework for evaluating control strategies in endemic settings.

Seroprevalence of human brucellosis among the tribal and non-tribal population residing in an eastern state of India: Findings from the state-wide serosurvey

BACKGROUND

Brucellosis is a neglected zoonotic disease found predominantly in lower- and middle-income countries (LMICs), causing significant public health concern in India. The objective of this study was to assess the prevalence of human brucellosis in Odisha, India among community members involved in animal husbandry as a common practice.

METHOD

This cross-sectional study included 817 adult participants from 11 districts in Odisha. Four districts from the Northern division, four districts from the Central division, and three districts from the Southern division were selected for the study. Blood samples were collected during a COVID-19 serosurvey in Odisha conducted from 1st to 17th September 2021. Immunoglobulin-G (IgG) antibodies were measured against Brucella using a commercial ELISA kit. Point estimates at 95% confidence intervals (CIs) and adjusted odds ratio were calculated.

RESULTS

The overall prevalence of anti-Brucella IgG antibodies was calculated at 16.65% (95% CI: 14.19-19.42). The highest seropositivity was found in Sambalpur district (29.73%; 95% CI: 16.43-47.16) and the lowest was determined in Mayurbhanj district (4.44%; 95% CI: 0.99-15.60). Compared to males, females were more prone to contracting the disease (AOR: 1.13; 95% CI: 1.05-1.67). Participants from rural settings had higher prevalence of anti-Brucella IgG antibodies than urban dwellers (AOR: 4.53; 95% CI: 1.73-11.86).

CONCLUSION

This study revealed that human brucellosis was associated with sociodemographic factors like gender, living settings, and household numbers. To prevent brucellosis, screening should be initiated, infected humans should be treated early, and the public should be educated about risk factors and preventive measures.

Seroprevalence and Risk Factors for Brucella Infections in Jordan

Brucellosis is a significant zoonotic disease and is endemic in several regions of the world. This study is aimed to determine the nationwide spatial distribution, seroprevalence, and risk factors for Brucella infections in Jordan. Serum samples of 938 individuals from 11 governorates were tested for Brucella spp. antibodies using Rose Bengal and Brucellacapt® tests. A validated questionnaire was used to collect demographic, animal ownership, and food consumption data. The seroprevalence of Brucella infection in Jordan’s population was 6.7% (95% CI, 5.2–8.5%). The multivariate model showed that location of residence, consuming raw milk/milk products, and owning small ruminants (goat and/or sheep) were significantly associated with seropositivity after controlling for age and gender. Individuals living in the northern Badia region had 8.82 greater odds (95% CI, 4.56–17.03) of seropositivity than individuals living in the Middle region of the country. Individuals who reported consumption of raw milk/milk products had 3.7 higher odds (95% CI, 2.01–6. 81) of seropositivity compared with individuals not consuming raw milk/milk products. In addition, individuals who own small ruminants (goat and/or sheep) had 2.14 higher odds (95% CI, 1.11–4.12) of seropositivity compared with individuals who do not own small ruminants. The identified geographic hotspots and small ruminants’ ownership, risk of raw milk products highlight the need for tailored training, education campaigns, and resources for controlling brucellosis in Jordan.

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.

Importance of brucellosis control programs of livestock on the improvement of one health

Brucellosis not only represents an important health restraint on livestock but also causes high economic losses in many developing countries worldwide. Despite considerable efforts made for the control of brucellosis, the disease is still spreading in many regions (such as the Middle East) where it represents one of the most important health hazards impacting both animals and humans. The present review aims to investigate the efficacy of veterinary control programs regarding brucellosis, with a special focus on current prevention, control, and eradication approaches. The reasons for unsuccessful control programs such as the absence of highly effective vaccines and non-certified bulls are also debated, to understand why the prevalence of brucellosis in livestock is not decreasing in many areas despite considerable efforts taken to date. The importance of governmental and regional investment in brucellosis control remains one of the main limiting factors owing to the limited budget allocated to tackle this disease. In this context, one health concept has generated novel comprehensive approaches with multiple economic implications across the livestock industry and public health. However, the implementation of such global preventive strategies appears to be a key issue for many endemic and low-income countries. According to the collected data, epidemiological contexts including management and trade systems along with well-defined agro-ecological zones should be evaluated in brucellosis endemic countries to improve milk production and to enhance the sustainability of the livestock sector at both national and regional levels.

Epidemiology of bovine brucellosis in Hisar, India: identification of risk factors and assessment of knowledge, attitudes, and practices among livestock owners

Brucellosis caused by facultative intracellular bacteria, Brucella, remains a global threat to both animal and human health. In this study we aimed to identify potential risk factors of bovine brucellosis and to assess the knowledge, attitudes, and practices (KAPs) of livestock keepers in Hisar, India. A standardized questionnaire was used to collate information regarding potential risk factors of bovine brucellosis and livestock owners' KAPs. A total of 127 livestock keepers were involved. Serum samples from their animals (n = 635) were tested for the presence of antibodies against Brucella by Rose Bengal Plate Test (RBPT) and indirect enzyme-linked immunosorbent assay (iELISA). Out of these, 78 (61.4%) of the herds had at least one seropositive animal, and 302 (47.6%) of the cattle were seropositive. Univariate and multivariate analysis revealed significant associations between intensive farm type (OR = 4.6; 95% CI, 1.6-16.7; P = 0.009), hygienic disposal of aborted fetuses (OR = 0.3; 95% CI, 0.08-0.9; P = 0.04) and herd seropositivity for brucellosis. The majority, 96 (75.6%) of the respondents, were males aged 18-50, and 82 (64.6%) owned a small-backyard farm. Only 51 (40.2%) of the participants knew about brucellosis; out of them, 54.9% (28/51) could not identify clinical signs of brucellosis. Six (11.8%) participants indicated abortion as the most noticeable clinical sign, and 45.1% indicated that consumption of raw milk is associated with high risk of contracting brucellosis. A large proportion of respondents confirmed that milk from their animals was regularly consumed (86.6%) and sold (59.8%) to other people. These results suggest that bovine brucellosis is endemic in Haryana, where Brucella-contaminated milk is likely being regularly sold. Brucellosis control efforts in Haryana should include education programs to raise awareness of the disease and means to control it in cattle and to prevent zoonotic transmission.

Bovine brucellosis - a comprehensive review

Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as well as transmission of brucellosis from wild and domestic animals is of great significance in terms of new epidemiological dimensions. Brucellosis poses a major public health threat by the consumption of non-pasteurized milk and milk products produced by unhygienic dairy farms in endemic areas. Regular and meticulous surveillance is essentially required to determine the true picture of brucellosis especially in areas with continuous high prevalence. Additionally, international migration of humans, animals and trade of animal products has created a challenge for disease spread and diagnosis in non-endemic areas. Isolation and identification remain the gold standard test, which requires expertise. The advancement in diagnostic strategies coupled with screening of newly introduced animals is warranted to control the disease. Of note, the diagnostic value of miRNAs for appropriate detection of B. abortus infection has been shown. The most widely used vaccine strains to protect against Brucella infection and related abortions in cattle are strain 19 and RB51. Moreover, it is very important to note that no vaccine, which is highly protective, safe and effective is available either for bovines or human beings. Research results encourage the use of bacteriophage lysates in treatment of bovine brucellosis. One Health approach can aid in control of this disease, both in animals and man.

Epidemiology of brucellosis in cattle and dairy farmers of rural Ludhiana, Punjab

Brucellosis is a zoonotic disease imposing significant impacts on livestock production and public health worldwide. India is the world's leading milk producer and Punjab is the state which produces the most cattle and buffalo milk per capita. The aim of this study was to investigate the epidemiology of bovine brucellosis to provide evidence for control of the disease in Punjab State, India. A cross-sectional study of dairy farms was conducted in humans and livestock in rural Ludhiana district using a multi-stage sampling strategy. The study suggests that brucellosis is endemic at high levels in cattle and buffalo in the study area with 15.1% of large ruminants testing seropositive and approximately a third of dairy farms having at least one animal test seropositive. In total, 9.7% of those in direct contact with livestock tested seropositive for Brucella spp. Persons that assisted with calving and/or abortion within the last year on a farm with seronegative livestock and people which did not assist with calving/abortion had 0.35 (95% CI: 0.17 to 7.1) and 0.21 (0.09 to 0.46) times the odds of testing seropositive compared to persons assisting with calving/abortion in a seropositive farm, respectively. The study demonstrated that persons in direct contact with cattle and buffalo in the study area have high risk of exposure to Brucella spp. Control of the disease in livestock is likely to result in benefits to both animal and public health sectors.

Brucellosis risk factors and milk hygiene handling practices in pastoral communities in Isiolo county, Kenya

The study was conducted from June to August 2014 in Isiolo Central division of Isiolo Sub‐County and Sericho division of Garbatulla Sub‐County and comprised two components: (i) a cross‐sectional study on the milk‐handling hygiene practices, where milk traders’ households were the study units and (ii) a case‐control study on the risk factors for Brucella spp. infection in humans. Results of the cross‐sectional study showed that 26.74% of the respondents never washed their hands before milking, 60.47% never washed the udder before milking and 54.65% never withhold consumption of milk from animals under treatment with antibiotics. The case–control study included household units with previous cases of brucellosis (53.33%) and those without (46.67%) over the previous 5 years and identified drinking of raw milk as the main risk factor for infection (OR = 26.44; 95% CI: 8.04–86.99). Pastoralists’ unhygienic handling of milk from production to market is suboptimal and this is due to poor knowledge on hygienic practices, poor knowledge on the risks associated with poor milk hygiene and lack of sufficient and potable water for cleaning of milk containers. Many pastoralists still consume milk raw and this is a major public health risk for milk‐borne diseases.

Seroprevalence and Molecular Identification of Brucella spp. in Bovines in Pakistan-Investigating Association With Risk Factors Using Machine Learning

Bovine brucellosis is a global zoonosis of public health importance. It is an endemic disease in many developing countries including Pakistan. This study aimed to estimate the seroprevalence and molecular detection of bovine brucellosis and to assess the association of potential risk factors with test results. A total of 176 milk and 402 serum samples were collected from cattle and buffaloes in three districts of upper Punjab, Pakistan. Milk samples were investigated using milk ring test (MRT), while sera were tested by Rose–Bengal plate agglutination test (RBPT) and indirect enzyme-linked immunosorbent assay (i-ELISA). Real-time PCR was used for detection of Brucella DNA in investigated samples. Anti-Brucella antibodies were detected in 37 (21.02%) bovine milk samples using MRT and in 66 (16.4%) and 71 (17.7%) bovine sera using RBPT and i-ELISA, respectively. Real-time PCR detected Brucella DNA in 31 (7.71%) from a total of 402 bovine sera and identified as Brucella abortus. Seroprevalence and molecular identification of bovine brucellosis varied in some regions in Pakistan. With the use of machine learning, the association of test results with risk factors including age, animal species/type, herd size, history of abortion, pregnancy status, lactation status, and geographical location was analyzed. Machine learning confirmed a real observation that lactation status was found to be the highest significant factor, while abortion, age, and pregnancy came second in terms of significance. To the authors' best knowledge, this is the first time to use machine learning to assess brucellosis in Pakistan; this is a model that can be applied for other developing countries in the future. The development of control strategies for bovine brucellosis through the implementation of uninterrupted surveillance and interactive extension programs in Pakistan is highly recommended.