Seroprevalence of human brucellosis in and around Jammu, India, using different serological tests

Seroprevalence of Human Brucellosis among Syrian Refugees in Jordan, 2022

Introduction

Brucellosis is prevalent in Mediterranean countries. The aim of this study was to determine the seroprevalence of brucellosis and associated factors among Syrian refugees in Jordan.

Methods

A cross-sectional study was conducted among adult Syrian refugees who attended the Public Health Lab (PHL) in Al Mafraq governorate, during the period of May-June 2022 to obtain a health certificate, which is legally required to receive governmental authorization for employment in Jordan. Blood samples were obtained from participants and a serum specimen was tested for the presence of IgG antibodies against Brucella using enzyme-linked immunosorbent assay (ELISA) IgG kits (Vircell Microbiologists, Granada, Spain).

Results

A total of 1562 Syrian refugees were enrolled in the study. Their ages ranged between 18 and 74 years, with a median age of 30 years at presentation. The majority were males (75.9%, n = 1186) and 24.1% (n = 376) were females. The Brucella ELISA IgG results were positive for 149 persons, with an overall seroprevalence rate of 9.5% (95% confidence interval: 8.0%-11.0%). Having animal-related occupations, residing outside refugee camps, consuming unpasteurized milk, handling animals or their tissues, and slaughtering animals within 6 months of study inclusion were significantly higher among the seropositive group. In the multivariate analysis, IgG-positive persons were 13 times more likely to report being diagnosed with brucellosis (OR = 13.1, 95% CI: 6.1-28.3; p ≤ 0.001). In addition, they were more likely to reside in the city of Al Mafraq, as opposed to a refugee camp (OR = 1.9, 95% CI: 1.1-3.2; p = 0.025) and to have handled animals within 6 months of study inclusion (OR = 3.1, 95% CI: 1.1-8.9; p = 0.035).

Conclusions

In conclusion, one-tenth of adult Syrian refugees were tested positive for Brucella ELISA IgG. Being diagnosed with brucellosis, residing in the city of Al Mafraq, as opposed to a refugee camp, and handling animals within 6 months of study inclusion were significantly associated with being positive for Brucella ELISA IgG. This study illustrates the need for improved brucellosis control measures via comprehensive vaccination of animals and enhanced laboratory detection and surveillance capacities, in addition to emphasizing the need for increased awareness sessions among Syrian refugees on the safe use and preparation of dairy products and safety practices of handling animals and their tissues.

Brucellosis, a diagnostic dilemma, presenting atypically in a child with terminal ileitis: A case report

BACKGROUND

Brucellosis is endemic in India with seropositivity rates as high as 10% in children in the eastern states, yet the disease is not on the radar when a differential diagnosis of pyrexia of unknown origin (PUO) is being considered, especially in children in urban set-up. This may be because of the non-specific multitude of systemic symptoms seen in this disease and the lack of awareness among clinicians.

CASE SUMMARY

We present a case of a 13-year-old boy, who came with a history of undulating fever for the past three and a half months, loss of appetite, and abdominal pain. The child had visited several pediatricians and was even admitted to a tertiary care hospital for PUO evaluation, but to no avail. He presented to us after three and half months of suffering and weight loss of more than 10% of body weight. His ultrasonography revealed thickening of the terminal ileum. His blood culture grew Brucella melitensis. A diagnosis of Brucellosis with terminal ileitis was made. Brucella serology by enzyme-linked immunoassay (ELISA) was positive for both IgG and IgM. He was treated with doxycycline and Rifampicin along with syrup multivitamin and zinc, for 6 wk. There was remarkable improvement with gain in 4 kg body weight within 2 mo of completing treatment. History revealed consumption of unpasteurized milk and contact with cattle.

CONCLUSION

Clinical suspicion, detailed history, appropriate laboratory investigations are the three pillars for diagnosing Brucellosis in patients presenting with vague symptoms.

Human Brucellosis: An Observational Study From a Tertiary Care Centre in North India

AIM

The main aim/objective of this study was to detect and characterize the Brucella species from patients having complaints of joint pain and also to know the potential causes of human brucellosis. In our study, we focused on joint pain symptoms that may be due to arthralgia or arthritis.  Introduction: Brucellosis is a neglected zoonotic disease that affects both humans and animals. In humans, brucellosis begins with chronic illness leading to great financial losses from not being able to work well and continued treatment costs, but few such studies have come from northern India. Joint pain is the common presentation of brucellosis and there are several risk factors associated with brucellosis.

METHODS

A total of 200 blood samples were collected from the participants having joints pain from September 2019 to September 2021 at Gandhi Memorial & Associated Hospitals of King George's Medical University, Lucknow, India, and tested by serology for anti-Brucella IgM and IgG enzyme-linked immunosorbent assay (ELISA), molecular tests byreverse transcriptase-polymerase chain reaction (RT-PCR), conventional polymerase chain reaction (PCR), and automated blood culture system. The anti-Brucella IgM and IgG ELISA were performed using the kit from NovaTec Immundiagnostica GmbH (Dietzenbach, Germany). Isolation of DNA was carried out using the QIAamp DNA Mini kit (QIAGEN, Hilden, Germany), and the primers and probes specific for targeted regions (BCSP31 and IS711 gene) in the Brucella genome were procured from Eurofins Scientific SE (Luxembourg, France), and for internal control from CDC.

RESULT

The study showed 19 (9.5%) and 23 (11.5%) positive results by anti-Brucella IgM ELISA and anti-Brucella IgG, respectively, and of these, one (0.5%) was positive for both anti-Brucella IgM and anti-Brucella IgG ELISA. Out of 19 anti-Brucella IgM ELISA positive, eight (4%) samples were positive for PCR/RT-PCR and that was negative for anti-Brucella IgG ELISA. All blood culture reports of all patients were negative.  Conclusion: Anti-Brucella IgM ELISA was more accurate than anti-Brucella IgG ELISA in detecting human brucellosis. Consumption of animal products (i.e. milk, a dairy product of cow, buffalo, goat, and meat of goat) and contact with animals were the main risk factors that were identified for Brucella disease.

Seroprevalence of Brucellosis in Patients Having Complained of Joint Pain: A Case Control

BACKGROUND

Brucellosis is a neglected zoonotic disease affecting humans and animals.

OBJECTIVES

This study aimed to estimate the seroprevalence of brucellosis in patients with joint pain.

METHODS

A total of 200 participants aged from 7 to 86 years were involved in this study. Blood samples were collected from all the participants for two years, from September 2019 to September 2021, and screened for Brucella using anti-brucella IgM ELISA and anti-brucella IgG ELISA antibodies. A questionnaire was used to collect data on socio-demographic characteristics and human brucellosis-related risk factors.

RESULTS

Human Brucella seroprevalence was 19 (9.5%) for Brucella IgM ELISA and 23 (11.5%) for Brucella IgG ELISA. The sensitivity for Brucella IgM ELISA and Brucella IgG ELISA was 65.2% and 31.6%, respectively, while the specificity was 44.1% for Brucella IgM ELISA and 77.9% for Brucella IgG ELISA. All blood culture reports of all patients were negative. The principal presentation was the observable symptoms of human brucellosis: fever, headache, chills, myalgia, and Joint pain.

CONCLUSION

Risk factors like consumption of raw milk or their products were found to be the most important for Brucella infection, so the awareness or information of risk factors and the modes of transmission is much more important in control and prevention programs. General awareness about clinical symptoms should be increased, which will improve proper diagnosis and will be helpful in early treatment. An ELISA test should be considered for diagnosing brucellosis in both acute and chronic phases.

Development of multiple reaction monitoring (MRM) assays to identify Brucella abortus proteins in the serum of humans and livestock

In the present study, a targeted multiple reaction monitoring-mass spectrometry (MRM-MS) approach was developed to screen and identify protein biomarkers for brucellosis in humans and livestock. The selection of proteotypic peptides was carried out by generating in silico tryptic peptides of the Brucella proteome. Using bioinformatics analysis, 30 synthetic peptides corresponding to 10 immunodominant Brucella abortus proteins were generated. MRM-MS assays for the accurate detection of these peptides were optimized using 117 serum samples of human and livestock stratified as clinically confirmed (45), suspected (62), and control (10). Using high throughput MRM assays, transitions for four peptides were identified in several clinically confirmed and suspected human and livestock serum samples. Of these, peptide NAIYDVVTR corresponding to B. abortus proteins: BruAb2_0537 was consistently detected in the clinically confirmed serum samples of both humans and livestock with 100% specificity. To conclude, a high throughput MRM-MS-based protocol for detecting endogenous B. abortus peptides in serum samples of humans and livestock was developed. The developed protocol will help design sensitive assays to accurately diagnose brucellosis in humans and livestock. The data associated with this study are deposited in Panorama Public (https://panoramaweb.org/rNOZCy.url with ProteomeXchange ID: PXD034407).

Brucellosis in Camels and Humans: Seroprevalence and Associated Risk Factors in Amibara District of Afar Region, Ethiopia

Brucellosis is an important neglected zoonotic disease caused by infection with bacteria of the genus Brucella affecting different mammalian species including humans. A cross-sectional study was conducted to estimate the seroprevalence of brucellosis in camels and humans and its associated risk factors in Amibara District of Afar Region in Northeast Ethiopia, from October 2019 to May 2020. A total of 250 camel and 120 human sera were serially tested using the Rose Bengal plate test (RBPT) and complement fixation test (CFT). The overall seroprevalence of camel brucellosis in this study was 7.6% (95% CI: 4.9-11.56) by RBPT and 3.2% (95% CI: 1.63-6.2) by combined RBPT and CFT. In humans, twelve (10%) of the collected sera were positive by RBPT among which only four of them (3.33%) were positive by CFT. The risk factor analysis indicated that age, body condition, number of parity, and abortion history were significantly associated with Brucella seropositivity in camel (P ≤ 0.05). In humans, occupation and nonprotective handling of dystocia cases showed an apparent association with Brucella seropositivity. The results of this study indicated that brucellosis is a common health problem in camels and humans in Amibara District of Afar Region. The public health importance of this disease is associated with raw milk consumption and close contact with the animals having history of recent abortion. Therefore, controlling the risk factors, establishing Brucella diagnostic service in human clinics and hospitals, continuous social training with feedback assessments, and overall implementing of One Health approach framework to attain optimal health for people and domestic animals in area are recommended to safeguard the health of society.

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.

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

BACKGROUND

Brucellosis is an important neglected zoonosis. Effective cattle vaccines are available but are infrequently used in India, where rural households commonly own one or two cattle as sources of protein and income. We assessed the prevalence of infection and risk factors in humans.

METHODS

We conducted a cross-sectional sero-survey in randomly selected individuals in 60 villages in Punjab. Infection prevalence was assessed by positive Rose Bengal testing or immunoglobulin G enzyme-linked immunosorbent assay. Risk factors were adjusted for potential confounding using multivariable analyses.

RESULTS

Of the 1927 subjects who were approached, 93% agreed to participate. Age-standardised prevalence for Brucella infection was 2.24% (95% confidence interval [CI] 1.61 to 3.11). More than 60% of households kept cattle and 10% assisted with calving or abortions. Nearly all individuals consumed boiled cow/buffalo milk from their own or neighbours' cattle and 3.3% consumed goat's milk. There was a 2.18 times increased odds (95% CI 0.96 to 4.95) of infection with calving/abortions and a 4.26 times increased odds (95% CI 1.33 to 13.6) with goat's milk but not bovine milk consumption.

CONCLUSIONS

An association with calving/abortions and goat's milk consumption was seen. Brucella vaccination of household livestock would reduce the risk to humans in such settings. Additional measures include biosecurity training around calving/abortions, education to boil all milk and for healthcare workers to test for brucellosis.

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.

Sero-prevalence of brucellosis, Q-fever and Rift Valley fever in humans and livestock in Somali Region, Ethiopia

Information on zoonotic diseases in humans and livestock are limited in pastoral/agro-pastoral communities in Ethiopia. A multi-stage cross sectional cluster design study was implemented with the aim to establish the seroprevalence of zoonotic diseases including brucellosis, Q-fever and Rift Valley fever (RVF) in humans and livestock in Adadle Woreda of the Somali Region, Ethiopia. Blood samples were collected from humans and livestock and tested by relevant serological tests. For brucellosis, Rose Bengal test (RBT) and indirect ELISA was used for screening and confirmatory diagnosis respectively. Indirect and competitive ELISA were also used for Q-fever and RVF respectively. The individual seropositivity of Q-fever in livestock was 9.6% (95% CI 5.9-15.1) in cattle, 55.7% (95% CI 46.0-65.0) in camels, 48.8% (95% CI 42.5-55.0) in goats, and 28.9% (95% CI 25.0-33.2) in sheep. In humans, seropositivity of Q-fever was 27.0% (95% CI 20.4-34.0), with prevalence in males of 28.9% vs 24.2% in females (OR = 1.3; 95% CI 0.6-2.5). Camel seropositivity of Q-fever was significantly associated with age (OR = 8.1; 95% CI 2.8-23.7). The individual apparent seroprevalence of RVF was 13.2% (95% CI 8.7-18.8) in humans, 17.9% (95% CI 11.0-27.8) in cattle, 42.6% (95% CI 34.8-50.7) in camels, 6.3% (95% CI 3.3-11.6) in goats and 7.4% (95% CI 4.7-11.5) in sheep. Camels had the highest seropositivity of both Q-fever and RVF. Only a weak correlation was observed between human and livestock seropositivity for both Q-fever and RVF. Only cattle and camels were seropositive for brucellosis by iELISA. The individual seroprevalence of brucellosis was 2.8(0.9-6.4) in humans, 1.5% (95% CI 0.2-5.2) in cattle and 0.6% (95% CI 0.0-3.2) in camels. This study showed the importance of zoonoses in Somali Region and is the first published study to describe RVF exposure in humans and livestock in the country. Even though human exposure to RVF virus was reported, public health sector of Somali Region has not given attention to such zoonoses. Collaboration between public and animal health sectors for further investigation on these zoonoses using the One Health concept is indispensable.

Brucella Seroprevalence in a High-Risk Population in Greece: A Cross-Sectional Study

Introduction

Brucellosis is a zoonosis with high occupational risk. However, seroprevalence of Brucella antibodies among occupational groups is not known, since studies in endemic countries are rare.

Methods

A cross-sectional seroprevalence study was conducted among livestock farmers in an endemic region in Greece. A low-risk group of individuals that just moved in the region was used as controls. Rose Bengal, Wright standard tube agglutination (STA) tests, and specific IgG and IgM antibodies using ELISA were evaluated; differences and odds ratios were calculated. Results were compared with studies from other endemic regions.

Results

100 livestock farmers and family members and 34 first-year students were enrolled. Rose Bengal results were 18% positive versus 0% (p=0.007); Wright STAs for Brucella melitensis were 8% versus 2.9% (p=0.448) and for Brucella abortus they were 2% versus 2.9% (p=0.588). ELISA IgG was positive in 8% of farmers versus 2.9% of students (p=0.448). Parallel testing with Rose Bengal and ELISA IgG was positive in 3% versus 0% (p=0.571). No significant odds ratios were calculated for Wright STAs and ELISA IgG.

Conclusions

Healthy livestock farmers may present with positive Rose Bengal test but this translates to true seroprevalence in only a small proportion. Livestock farmers have no significant seroprevalence that may obscure diagnosis of acute brucellosis in clinical settings.