Systematic review of brucellosis in Kenya: disease frequency in humans and animals and risk factors for human infection

Serum changes in pyridinoline, type II collagen cleavage neoepitope and osteocalcin in early stage male brucellosis patients

Musculoskeletal changes are the most common clinical manifestation of brucellosis. The main objective of this study was to provide a better understanding of this disease, while also attempting to identify potential markers that can identify the early stage musculoskeletal changes associated with human brucellosis. In this case–control study, 41 male early-stage brucellosis patients (within 6 months of diagnosis) who had not received drug therapy and 44 matched controls were examined. Venous blood samples were collected and serum pyridinoline (PYD), type II collagen cleavage neoepitope (C2C) and osteocalcin (OC) levels were quantified using an enzyme-linked immunosorbent assay (ELISA). In the brucellosis group, the median serum levels of PYD (278.53 µg/L), C2C (82.23 µg/L) and OC (8.41 µg/L) were significantly elevated relative to the control group (Z = 5.686, 3.997, 3.579; P = 0.000). Serum PYD, C2C, and OC levels were increased in early-stage male brucellosis patients, and these factors appear to have promise as potential indicator biomarkers that can reflect the osteoarticular changes that occur in the early stage of human brucellosis.

Serological detection of brucellosis among febrile, malaria-negative children and domesticated dogs in an urban African setting

Background

Childhood brucellosis and malaria are co-endemic febrile illnesses in some sub-Saharan African countries. Malaria and brucellosis co-infection or brucellosis sole infections are often missed due to an over emphasis on malaria and the lack of appropriate diagnostic infrastructure. Brucellosis in dogs is usually overlooked and yet there is extensive contact between humans and their pets.

Objective

This study investigated brucellosis in children and dogs using a confirmatory serological testing series that screens for three Brucella sp.

Methods

Residual blood samples from malaria smear-negative febrile children were collected and tested for Brucella sp and malaria parasite. During the same period, residual blood samples presented to a veterinary microbiology laboratory in the same area were tested for brucellosis using the same approach.

Results

A total of 105 human and 80 canine blood samples were tested for brucellosis antibodies. The seroprevalence of brucellosis was 22.86% (25/105) in children and 1.3% (1/80) in dogs using the Card, buffered acidified plate antigen, and standard plate agglutination tests but was 0% using the rivanol precipitation plate agglutination test.

Conclusion

Given that brucellosis can be caused by both smooth and rough colony strains, there is a need to modify the current serological surveillance strategy (targeted at only Brucella abortus and other smooth colony Brucella strains) to figure out the relative contribution of rough colony Brucella strains (B. ovis and B. canis). Since Uganda is endemic for brucellosis there is a need to modify the brucellosis surveillance strategy.

Detection of Brucella spp. in raw milk from various livestock species raised under pastoral production systems in Isiolo and Marsabit Counties, northern Kenya

Introduction

Brucellosis is an important zoonotic disease in Kenya, and identifying the bacteria in milk is important in assessing the risk of exposure in people.

Methods

A cross-sectional study that involved 175 households was implemented in the pastoral counties of Marsabit and Isiolo in Kenya. Pooled milk samples (n = 164) were collected at the household level, and another 372 were collected from domesticated lactating animals (312 goats, 7 sheep, 50 cattle and 3 camels). Real-time polymerase chain reaction (qPCR) testing of the milk samples was performed to identify Brucella species. Brucella anti-LPS IgG antibodies were also detected in bovine milk samples using an indirect enzyme-linked immunosorbent assay (ELISA).

Results

Based on the qPCR, the prevalence of the pathogen at the animal level (considering samples from individual animals) was 2.4% (95% confidence interval (CI) 1.1–4.5) and 3.0% (CI: 1.0–7.0) in pooled samples. All 14 samples found positive by qPCR were from goats, with 10 contaminated with B. abortus and 4 with B. melitensis. The Brucella spp. antibody prevalence in bovine milk using the milk ELISA was 26.0% (95% CI: 14.6–40.3) in individual animal samples and 46.3% (95% CI: 30.7–62.6) in pooled samples.

Conclusion

The study is the first in Kenya to test for Brucella spp. directly from milk using qPCR without culturing for the bacteria. It also detected B. abortus in goats, suggesting transmission of brucellosis between cattle and goats. The high prevalence of Brucella spp. is a significant public health risk, and there is a need for intervention strategies necessary in the study area.

Electronic supplementary material

The online version of this article (10.1007/s11250-020-02389-1) contains supplementary material, which is available to authorized users.

Zoonotic Pathogens of Dromedary Camels in Kenya: A Systematised Review

Kenya is home to Africa’s third largest population of dromedary camels, and production at commercial and local levels are increasingly important. In pastoral and nomadic communities in the arid and semi-arid lands (ASALs), camels play a vital role in food security, while commercial milk production and formalized export markets are rapidly emerging as camel populations expand into non-traditional areas. Until recently, little focus was placed on camels as hosts of zoonotic disease, but the emergence of Middle Eastern respiratory coronavirus (MERS-CoV) in 2012, and the discovery of exposure to the virus in Kenyan camels, highlighted the need for further understanding of this area. This systematised review utilised a robust search strategy to assess the occurrence of camel-associated zoonoses in Kenya and to evaluate the quality of the published literature. Seventy-four studies were identified, covering sixteen pathogens, with an increasing number of good quality studies in recent years. Despite this, the area remains under-researched and there is a lack of robust, high-quality research. Trypanosome spp., Echinococcus granulosus and Brucella spp. appeared most frequently in the literature. Pathogens with the highest reported prevalence were MERS-CoV (0–100%), Echinococcus granulosa (7–60%) and Rift Valley fever virus (7–57%). Exposure to Brucella spp., Coxiella burnetii and Crimean-Congo haemorrhagic fever virus showed higher levels in camel or camel-associated vectors than other livestock species, although brucellosis was the only disease for which there was robust evidence linking camel and human exposure. Zoonotic agents with less severe human health outcomes, such as Dermatophilosus congolensis and contagious ecthyma, were also represented in the literature. This review provides an important summary of the scope and quality of current knowledge. It demonstrates that further research, and improved adherence to robust study design and reporting are essential if the zoonotic risk from camels in Kenya, and elsewhere, is to be better understood.

Molecular characterization of Brucella species detected in humans and domestic ruminants of pastoral areas in Kagera ecosystem, Tanzania

Brucellosis is a zoonotic disease of importance to both public health and the livestock industry. The disease is likely to be endemic in Tanzania and little is reported on molecular characterization of Brucella species in pastoral settings. This study aimed at characterizing Brucella species (targeting genus Brucella) infecting humans, cattle and goat in Kagera region (Ngara and Karagwe districts) using real-time PCR, PCR amplification of 16S rRNA genes and Sanger sequencing. Brucella spp. were detected in 47 samples (19 sera and 28 milk) out of 125 samples (77 sera, 35 milk and 13 aborted materials) using real-time PCR. All aborted materials (13 samples) were negative to real-time PCR. Out of the 47 real-time PCR positive samples (28 milk and 19 sera), 20 samples (10 milk and 10 sera) showed an expected 16S rRNA gene PCR product. Sequence analysis and blasting confirmed the presence of Brucella spp. in pastoral areas of Kagera region. The Brucella spp. from Kagera were phylogenetically grouped in two clades and three branches all closer to B. melitensis, B. abortus and B. suis from USA, Sudan and Iran. However, they were distinct from other species isolated also in USA, New Zealand, Germany and Egypt. This was expected based on the distance between the geographical regions from which the data (nucleotides sequences from 16S gene sequencing) for the phylogeny reconstruction were obtained. This is the first study to report Brucella species identified using 16S rRNA gene sequencing in East and Central Africa. A livestock vaccination program re-inforced with a high index of Brucella diagnosis is needed to eradicate brucellosis in animals and minimize suffering from Brucella infections in humans in Tanzania.

Serological and molecular evidence of Brucella species in the rapidly growing pig sector in Kenya

BACKGROUND

Brucellosis is an emerging yet neglected zoonosis that has been reported in Kenya. Epidemiological data on brucellosis in ruminants is readily accessible; however, reports on brucellosis in pigs remain limited. This study sought to detect Brucella infection in pig serum by both serological and molecular techniques. Serum from 700 pigs randomly collected at a centralized abattoir in Nairobi region, Kenya were screened in parallel, using both Rose Bengal Test (RBT) and competitive Enzyme-Linked Immuno-sorbent Assay (cELISA) for antibodies against Brucella spp. All sera positive by RBT and 16 randomly selected negative samples were further tested using conventional PCR targeting bcsp31 gene and real-time PCR (RT-PCR) assays targeting IS711 and bcsp31 genes.

RESULTS

A prevalence of 0.57% (n = 4/700) was estimated using RBT; none of these samples was positive on cELISA. All RBT positive sera were also positive by both PCRs, while two sero-negative samples also tested positive on RT-PCR (n = 6/20). Brucella abortus was detected in four out of the six PCR positive samples through a real-time multiplex PCR.

CONCLUSION

The detection of antibodies against Brucella spp. and DNA in serum from slaughterhouse pigs confirm the presence of Brucella in pigs. Therefore, investigation of the epidemiology and role of pigs in the transmission of brucellosis in Kenya is needed. Further targeted studies would be useful to systematically quantify and identify the spp. of Brucella in pigs.

Prevalence and speciation of brucellosis in febrile patients from a pastoralist community of Tanzania

Brucellosis is an endemic zoonosis in sub-Saharan Africa. Pastoralists are at high risk of infection but data on brucellosis from these communities are scarce. The study objectives were to: estimate the prevalence of human brucellosis, identify the Brucella spp. causing illness, describe non-Brucella bloodstream infections, and identify risk factors for brucellosis in febrile patients from a pastoralist community of Tanzania. Fourteen (6.1%) of 230 participants enrolled between August 2016 and October 2017 met study criteria for confirmed (febrile illness and culture positivity or ≥four-fold rise in SAT titre) or probable (febrile illness and single SAT titre ≥160) brucellosis. Brucella spp. was the most common bloodstream infection, with B. melitensis isolated from seven participants and B. abortus from one. Enterococcus spp., Escherichia coli, Salmonella enterica, Staphylococcus aureus and Streptococcus pneumoniae were also isolated. Risk factors identified for brucellosis included age and herding, with a greater probability of brucellosis in individuals with lower age and who herded cattle, sheep or goats in the previous 12 months. Disease prevention activities targeting young herders have potential to reduce the impacts of human brucellosis in Tanzania. Livestock vaccination strategies for the region should include both B. melitensis and B. abortus.

Risk factors for acute human brucellosis in Ijara, north-eastern Kenya

Brucellosis is an important zoonotic disease globally, with particularly high burdens in pastoral settings. While the zoonotic transmission routes for Brucella spp. are well known, the relative importance of animal contact, food-handling and consumption practices can vary. Understanding the local epidemiology of human brucellosis is important for directing veterinary and public health interventions, as well as for informing clinical diagnostic decision making. We conducted a cross-sectional study in Ijara District Hospital, north-eastern Kenya. A total of 386 individuals seeking care and reporting symptoms of febrile illness were recruited in 2011. Samples were tested for the presence of Brucella spp. using a real-time PCR (RT-PCR) and results compared to those from the test for brucellosis used at Ijara District Hospital, the febrile Brucella plate agglutination test (FBAT). A questionnaire was administered to all participants and risk factors for brucellosis identified using logistic regression with an information theoretic (IT) approach and least absolute shrinkage and selection (LASSO). Sixty individuals were RT-PCR positive, resulting in a prevalence of probable brucellosis of 15.4% (95% CI 12.0-19.5). The IT and LASSO approaches both identified consuming purchased milk as strongly associated with elevated risk and boiling milk before consumption strongly associated with reduced risk. There was no evidence that livestock keepers were at different risk of brucellosis than non-livestock keepers. The FBAT had poor diagnostic performance when compared to RT-PCR, with an estimated sensitivity of 36.6% (95% CI 24.6-50.1) and specificity of 69.3% (95% CI 64.0-74.3). Brucellosis is an important cause of febrile illness in north-eastern Kenya. Promotion of pasteurisation of milk in the marketing chain and health messages encouraging the boiling of raw milk before consumption could be expected to lead to large reductions in the incidence of brucellosis in Ijara. This study supports the growing evidence that the FBAT performs very poorly in the diagnosis of brucellosis.

Relationship of meteorological factors and human brucellosis in Hebei province, China

BACKGROUND

Brucellosis has always been one of the major public health problems in China. Investigating the influencing factors of brucellosis is conducive to its prevention and control. The incidence trend of brucellosis shows an obvious seasonality, suggesting that there may be a correlation between brucellosis and meteorological factors, but related studies were few. We aimed to use the autoregressive integrated moving average (ARIMA) model to analyze the relationship between meteorological factors and brucellosis.

METHODS

The data of monthly incidence of brucellosis and meteorological factors in Hebei province from January 2004 to December 2015 were collected from the Chinese Public Health Science Data Center and Chinese meteorological data website. An ARIMA model incorporated with covariables was conducted to estimate the effects of meteorological variables on brucellosis.

RESULTS

There was a highest peak from May to July every year and an upward trend during the study period. Atmospheric pressure, wind speed, mean temperature, and relative humidity had significant effects on brucellosis. The ARIMA(1,0,0)(1,1,0)₁₂ model with the covariates of atmospheric pressure, wind speed and mean temperature was the optimal model. The results showed that the atmospheric pressure with a 2-month lag (β = -0.004, p = 0.037), the wind speed with a 1-month lag (β = 0.030, p = 0.035), and the mean temperature with a 2-month lag (β = -0.003, p = 0.034) were significant predictors.

CONCLUSION

Our study suggests that atmospheric pressure, wind speed, mean temperature, and relative humidity have a significant impact on brucellosis. Further understanding of its mechanism would help facilitate the monitoring and early warning of brucellosis.

Investigation of the Sensitivity and Specificity of Laboratory Tests Used in Differential Diagnosis of Childhood Brucellosis

Objectives 

Childhood brucellosis is a common public health problem in developing countries. The diagnosis of brucellosis based on nonspecific symptoms is an ongoing problem for physicians, especially in endemic areas. In this study, it is aimed to discuss the efficacy of frequently used test methods in the differential diagnosis of brucellosis.

Methods

The records of 332 patients admitted to pediatric clinic on suspicion of brucellosis were retrospectively analyzed. Patients with brucellosis were included in the positive group (n = 262) and those without brucellosis were included in the negative group (n = 70).

Results

 As a result of biochemical analysis of the cases, median alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), erythrocyte sedimentation rate (ESR), and C reactive protein (CRP) values were significantly higher in the positive group than that in the negative group (p<0.05). There was no significant difference between median white blood cell, neutrophil, lymphocyte, neutrophil to lymphocyte ratio, hemoglobin, and platelet values between groups (p>0.05). Receiver operating curves were plotted to compare predictive values of CRP (area under curve (AUC): 0.635, p= 0.001), ESR(AUC:0.701, p<0.001), AST(AUC: 0.595, p=0.015), ALT(AUC:0.604, p=0.007), and GGT(AUC:0.593, p=0.016) in 332 patients with suspected brucellosis.

Conclusions

Increased levels of AST, ALT, GGT, CRP, and ESR may have a complementary role in the differential diagnosis of childhood brucellosis. However, all of these markers should be evaluated with clinical findings due to their low specificity and sensitivity. 

Serological Evidence of Yersiniosis, Tick-Borne Encephalitis, West Nile, Hepatitis E, Crimean-Congo Hemorrhagic Fever, Lyme Borreliosis, and Brucellosis in Febrile Patients Presenting at Diverse Hospitals in Kenya

Data on pathogen prevalence is crucial for informing exposure and disease risk. We evaluated serological evidence of tick-borne encephalitis (TBE), West Nile (WN), Hepatitis E virus (HEV), Crimean-Congo Hemorrhagic Fever (CCHF), Yersiniosis, Lyme Disease (LD), and brucellosis in 1033 patients presenting with acute febrile illness at 9 health care facilities from diverse ecological zones of Kenya: arid and semiarid (Garissa District Hospital, Lodwar District Hospital, Marigat District Hospital, Gilgil District Hospital), Lake Victoria basin (Kisumu District Hospital, Alupe District Hospital, Kombewa Sub-County Hospital), Kisii highland (Kisii District Hospital), and coastal (Malindi District Hospital). Epidemiological information of the patients such as geography, age, gender, and keeping animals were analyzed as potential risk factors. Of the 1033 samples, 619 (59.9%) were seropositive to at least one pathogen by IgM (current exposure), IgG/IgM (recent exposure), and IgG (past exposure). Collective seroprevalence for current, recent, and past to the pathogens was 9.4%, 5.1%, and 21.1% for LD; 3.6%, 0.5%, and 12.4% for WN; 0.9%, 0.5%, and 16.9% for HEV; 5.8%, 1.3%, and 3.9% for brucellosis; 5.7%, 0.2%, and 2.3% for yersiniosis; 1.7%, 0%, and 6.2% for TBE; and 0.4%, 0%, and 1.9% for CCHF. Brucellosis risk was higher in patients recruited at Garissa District Hospital (odds ratio [OR] = 3.41), HEV (OR = 2.45) and CCHF (OR = 5.46) in Lodwar District Hospital, LD in Alupe District Hospital (OR = 5.73), Kombewa Sub-district hospital (OR = 8.17), and Malindi District hospital (OR = 3.3). Exposure to LD was highest in the younger age group, whereas yersiniosis did not vary with age. Age was a significant risk for WN, brucellosis, CCHF, TBE, and HEV and in those aged >14 years there was an increased risk to WN (OR = 2.30, p < 0.0001), brucellosis (OR = 1.84, p = 0.005), CCHF (OR = 4.35, p = 0.001), TBE (OR = 2.78, p < 0.0001), and HEV (OR = 1.94, p = 0.0001). We conclude that LD is pervasive and constitutes a significant health burden to the study population, whereas yersiniosis and CCHF are not significant threats. Going forward, community-based studies will be needed to capture the true seroprevalence rates and the associated risk factors.

Zoonotic Pathogen Seroprevalence in Cattle in a Wildlife-Livestock Interface, Kenya

A cross-sectional study was conducted to determine the seroprevalence of Brucella spp. and Leptospira spp. and risk factors of exposure in cattle in three zones with varying land use types and wildlife-livestock interactions. Five villages were selected purposively; two in areas with intensive livestock-wildlife interactions (zone 1), another two in areas with moderate livestock-wildlife interactions (zone 2) and one in areas where wildlife-livestock interactions are rarer (zone 3). Sera samples were collected from 1170 cattle belonging to 390 herds in all the zones and tested for antibodies against Brucella abortus and Leptospira interrogans serovar hardjo using ELISA kits. Data on putative risk factors for seropositivity of these pathogens in cattle were collected using a questionnaire. The overall apparent animal-level seroprevalence of brucellosis and leptospirosis was, respectively, 36.9% (95% CI 34.1-39.8) and 23.5% (95% CI 21.1-26.0). Brucella spp. seroprevalence was higher in zone 1 than in zones 2 and 3 (χ2 = 25.1, df = 2, P < 0.001). Zones 1 and 2 had significantly higher Leptospira spp. seroprevalence than zone 3 (χ2 = 7.0, df = 2, P = 0.029). Results of multivariable analyses identified animal sex (female) and zones (high interface area) as significant predictors (P < 0.05) of animal-level seropositivity of Brucella spp. For Leptospira spp., important predictors of animal-level seropositivity were animal sex (female), zones (moderate interface area) and herds utilizing a communal grazing reserve. The seroprevalences of Brucella spp. and Leptospira spp. in cattle were higher in areas with moderate to high wildlife-livestock interactions than those with rare interactions.

Occupational Animal Contact in Southern and Central Vietnam

Despite the global zoonotic disease burden, the underlying exposures that drive zoonotic disease emergence are not understood. Here, we aimed to assess exposures to potential sources of zoonotic disease and investigate the demographics, attitudes, and behavior of individuals with sustained occupational animal contact in Vietnam. We recruited 581 animal workers (animal-raising farmers, slaughterers, animal health workers, and rat traders) and their families in southern and central Vietnam into a cohort. Cohort members were followed for 3 years and interviewed annually regarding (1) demography and attitudes regarding zoonotic disease, (2) medical history, (3) specific exposures to potential zoonotic infection sources, and (4) socioeconomic status. Interview information over the 3 years was combined and analyzed as cross-sectional data. Of the 297 cohort members interviewed, the majority (79.8%; 237/297) reported raising livestock; almost all (99.6%; 236/237) reported being routinely exposed to domestic animals, and more than a quarter (28.7%; 68/237) were exposed to exotic animals. Overall, 70% (208/297) reported slaughtering exotic animals; almost all (99.5%; 207/208) reported consuming such animals. The consumption of raw blood and meat was common (24.6%; 73/297 and 37%; 110/297, respectively). Over half (58.6%; 174/297) reported recent occupational animal-induced injuries that caused bleeding; the use of personal protective equipment (PPE) was limited. Our work demonstrates that individuals working with animals in Vietnam are exposed to a wide range of species, and there are limited procedures for reducing potential zoonotic disease exposures. We advocate better education, improved animal security, and enforced legislation of PPE for those with occupational animal exposure in Vietnam.

Knowledge of pastoralists on livestock diseases and exposure assessment to brucellosis within rural and peri-urban areas in Kajiado, Kenya

Background: Livestock diseases impact the livelihoods of pastoralists. Brucellosis, a neglected zoonotic disease is highly prevalent in this system with an estimated 16% of livestock population in sub-Saharan Africa infected with the disease. The objective of this study was to assess knowledge of livestock diseases and the risk of exposure to brucellosis among pastoralists living in Kajiado County of Kenya. Methods: The study sites included pastoralist communities living in rural and peri-urban areas within the County. Both primary and secondary data were collected using participatory methods including pairwise ranking, proportional piling and probing and a review of the published literature. Exposure risk assessment was conducted according to the CODEX Alimentarius framework: Hazard identification, hazard characterization, exposure assessment and risk estimation. Results: According to pastoralists, livestock diseases that frequently occurred in their flocks and herds were contagious caprine pleuropneumonia, lumpy skin disease and foot and mouth disease; but zoonoses, including anthrax and brucellosis, were also mentioned during focus group discussions. Potential pathways of exposure to brucellosis and other zoonoses included consumption of unpasteurized milk, handling infected aborted materials without protective measures and consumption of raw meat and raw blood. Consumption of unpasteurized milk and handling infected aborted materials without protectives were linked with high risk of exposure to household members living in rural areas, with the risk level within the peri-urban areas ranked very low to low for most of these risk practices. Conclusions: The results call for enhanced public education targeting vulnerable groups to mitigate risks of disease spread and other impacts of brucellosis within the affected pastoralist production systems.

Positive association between Brucella spp. seroprevalences in livestock and humans from a cross-sectional study in Garissa and Tana River Counties, Kenya

BACKGROUND

Brucella spp. is a zoonotic bacterial agent of high public health and socio-economic importance. It infects many species of animals including wildlife, and people may get exposed through direct contact with an infected animal or consumption of raw or undercooked animal products. A linked livestock-human cross-sectional study to determine seroprevalences and risk factors of brucellosis in livestock and humans was designed. Estimates were made for intra-cluster correlation coefficients (ICCs) for these observations at the household and village levels.

METHODOLOGY

The study was implemented in Garissa (specifically Ijara and Sangailu areas) and Tana River (Bura and Hola) counties. A household was the unit of analysis and the sample size was derived using the standard procedures. Serum samples were obtained from selected livestock and people from randomly selected households. Humans were sampled in both counties, while livestock could be sampled only in Tana River County. Samples obtained were screened for anti-Brucella IgG antibodies using ELISA kits. Data were analyzed using generalized linear mixed effects logistic regression models with the household (herd) and village being used as random effects.

RESULTS

The overall Brucella spp. seroprevalences were 3.47% (95% confidence interval [CI]: 2.72-4.36%) and 35.81% (95% CI: 32.87-38.84) in livestock and humans, respectively. In livestock, older animals and those sampled in Hola had significantly higher seroprevalences than younger ones or those sampled in Bura. Herd and village random effects were significant and ICC estimates associated with these variables were 0.40 (95% CI: 0.22-0.60) and 0.24 (95% CI: 0.08-0.52), respectively. In humans, Brucella spp. seroprevalence was significantly higher in older people, males, and people who lived in pastoral areas than younger ones, females or those who lived in irrigated or riverine areas. People from households that had at least one seropositive animal were 3.35 (95% CI: 1.51-7.41) times more likely to be seropositive compared to those that did not. Human exposures significantly clustered at the household level; the ICC estimate obtained was 0.21 (95% CI: 0.06-0.52).

CONCLUSION

The presence of a Brucella spp.-seropositive animal in a household significantly increased the odds of Brucella spp. seropositivity in humans in that household. Exposure to Brucella spp. of both livestock and humans clustered significantly at the household level. This suggests that risk-based surveillance measures, guided by locations of primary cases reported, either in humans or livestock, can be used to detect Brucella spp. infections in livestock or humans, respectively.

Connected diagnostics: linking digital rapid diagnostic tests and mobile health wallets to diagnose and treat brucellosis in Samburu, Kenya

BACKGROUND

Despite WHO guidelines for testing all suspected cases of malaria before initiating treatment, presumptive malaria treatment remains common practice among some clinicians and in certain low-resource settings the capacity for microscopic testing is limited. This can lead to misdiagnosis, resulting in increased morbidity due to lack of treatment for undetected conditions, increased healthcare costs, and potential for drug resistance. This is particularly an issue as multiple conditions share the similar etiologies to malaria, including brucellosis, a rare, under-detected zoonosis. Linking rapid diagnostic tests (RDTs) and digital test readers for the detection of febrile illnesses can mitigate this risk and improve case management of febrile illness.

METHODS

This technical advance study examines Connected Diagnostics, an approach that combines the use of point-of-care RDTs for malaria and brucellosis, digitally interpreted by a rapid diagnostic test reader (Deki Reader) and connected to mobile payment mechanisms to facilitate the diagnosis and treatment of febrile illness in nomadic populations in Samburu County, Kenya. Consenting febrile patients were tested with RDTs and patient diagnosis and risk information were uploaded to a cloud database via the Deki Reader. Patients with positive diagnoses were provided digital vouchers for transportation to the clinic and treatment via their health wallet on their mobile phones.

RESULTS

In total, 288 patients were tested during outreach visits, with 9% testing positive for brucellosis and 0.6% testing positive for malaria. All patients, regardless of diagnosis were provided with a mobile health wallet on their cellular phones to facilitate their transport to the clinic, and for patients testing positive for brucellosis or malaria, the wallet funded their treatment. The use of the Deki Reader in addition to quality diagnostics at point of care also facilitated geographic mapping of patient diagnoses in relation to key risk areas for brucellosis transmission.

CONCLUSIONS

This study demonstrates that the Connected Dx approach can be effective even when addressing a remote, nomadic population and a rare disease, indicating that this approach to diagnosing, treatment, and payment for healthcare costs is feasible and can be scaled to address more prevalent diseases and conditions in more populous contexts.

Sero-prevalence and community awareness on the risks associated with Livestock and Human brucellosis in selected districts of Fafan Zone of Ethiopian-Somali National Regional State

A cross-sectional study was conducted to estimate the sero-prevalence, potential risk factors for transmission and spread of brucellosis in livestock and human in Jigjiga and Gursum Woredas of Fafan Zone in Ethiopian-Somali. Two Kebeles were purposively selected from each Worada based on accessibility and willingness of livestock owners. For serology, a total of 268 cattle, 108 sheep, 172 goats, 183 camels, 211 humans were included. For questionnaire, 99 volunteers were recruited. Blood samples were collected from livestock and human. The serum was subjected to Rose Bengal Plate Test (RBPT) and Complement Fixation Test (CFT) to detect Brucella antibody. Out of the total 731 livestock examined, 3.0% were positive for Brucella antibodies using RBPT. Highest sero-prevalence was recorded in camels (4.9%) followed by goat (2.9%), cattle (2.6%), and sheep (0.9%). Using CFT, 0.4% of animals were found positive for brucellosis. A sero-prevalence of 1.7% was recorded in goats using CFT but no in other animal species. From the 211 human serum samples, 5 (2.4%) were positive for Brucella infection using RBPT. One (0.4%) was confirmed by CFT. Questioner survey revealed, almost all respondents (98%) were not aware about zoonotic risks of brucellosis. Cattle and camel milking were mainly performed by housewives. Although 97-99% of respondent had habits of cooked meat consumption, the majorities (99%) consume raw milk. In the pastoral community, the observed sero-prevalence of human brucellosis along with the practices of animal husbandry and animal food consumption habits, might give an insight that brucellosis could pose a public health hazard.

Risk factors for human brucellosis among a pastoralist community in South-West Kenya, 2015

Objective

Brucellosis is one of the top five priority zoonosis in Kenya because of the socio-economic burden of the disease, especially among traditional, livestock keeping communities. We conducted a 1 year, hospital based, unmatched case–control study to determine risk factors for brucellosis among Maasai pastoralists of Kajiado County in 2016. A case was defined by a clinical criteria; fever or history of fever and two clinical signs suggestive of brucellosis and a positive competitive enzyme-linked immunosorbent assay test (c-ELISA). A control was defined as patients visiting the study facility with negative c-ELISA. Unconditional logistic regression was used to study association between exposure variables and brucellosis using odds ratios (OR) and 95% confidence intervals (CI).

Results

Forty-three cases and 86 controls were recruited from a population of 4792 individuals in 801 households. The mean age for the cases was 48.7 years while that of the controls was 37.6 years. The dominant gender for both cases (62.7%) and controls (58.1%) groups was female. Regular consumption of un-boiled raw milk and assisting animals in delivery were significantly associated with brucellosis by OR 7.7 (95% CI 1.5–40.1) and OR 3.7 (95% CI 1.1–13.5), respectively.

Spatio-temporal cluster and distribution of human brucellosis in Shanxi Province of China between 2011 and 2016

In recent years, the incidence of human brucellosis (HB) in the Shanxi province has ranked to be the top five among the 31 China provinces. HB data in Shanxi province between 2011 and 2016 were collected from the Centers for Disease Control and Prevention. Spatial and temporal distribution of HB was evaluated using spatial autocorrelation analysis and space-time scan analysis. The global Moran's I index ranged from 0.37 to 0.50 between 2011 and 2016 (all P < 0.05), and the "high-high" clusters of HB were located at the northern Shanxi, while the "low-low" clusters in the central and southeastern Shanxi. The high-incidence time interval was between March and July with a 2-fold higher risk of HB compared to the other months in the same year. One most likely cluster and three secondary clusters were identified. The radius of the most likely cluster region was 158.03 km containing 10,051 HB cases. Compared to the remaining regions, people dwelling in the most likely region were reported 4.50-fold ascended risk of incident HB. HB cases during the high-risk time interval of each year were more likely to be younger, to be males or to be farmers or herdsman than that during the low-risk time interval. The HB incidence had a significantly high correlation with the number of the cattle or sheep especially in the northern Shanxi. HB in Shanxi showed unique spatio-temporal clustering. Public health concern for HB in Shanxi should give priority to the northern region especially between the late spring and early summer.

Prevalence and risk factors of brucellosis among febrile patients attending a community hospital in south western Uganda

Human brucellosis, a chronic disease contracted through contact with animals and consuption of unpasteurized dairy products is underreported in limited-resource countries. This cross-sectional study aimed to determine the prevalence and risk factors of brucellosis among febrile patients attending a community hospital in South western Uganda. A questionnaire that captured socio-demographic, occupational and clinical data was administered. Blood samples were tested for Brucella antibodies using Rose Bengal Plate Test (RBPT) and blood culture with standard aerobic BACTEC bottle was done. Of 235 patients enrolled, prevalence of brucellosis (RBPT or culture confirmed) was 14.9% (95% CI 10.6-20.1) with a culture confrmation in 4.3% of the participants. The factors independently associated with brucellosis were consumption of raw milk (aOR 406.15, 95% CI 47.67-3461.69); history of brucellosis in the family (aOR 9.19, 95% CI 1.98-42.54); and selling hides and skins (aOR 162.56, 95% CI 2.86-9256.31). Hepatomegaly (p < 0.001), splenomegaly (p = 0.018) and low body mass index (p = 0.032) were more common in patients with brucellosis compared to others. Our findings reveal a high prevalence of brucellosis among febrile patients and highlight a need for implementing appropiate tests, public awareness activities and vaccination of animals to control and eliminate the disease.

Animal pathogens and their impact on animal health, the economy, food security, food safety and public health

Animal pathogens attract attention in both the livestock and public health sectors for their impacts on socio-economics, food safety and security, and human health. These impacts are felt at the household, national, regional and global levels. Whereas the World Organisation for Animal Health (OIE) has identified 118 animal diseases as notifiable, based on their potential for impact on trade, there is a selected subset that have been classified as posing a greater threat to countries due to unique characteristics, such as being highly transmissible, spreading rapidly within and between countries, and requiring cooperation between several countries to control their spread or exclude them. While these 'transboundary diseases' are endemic in much of the world, particularly the developing nations, many countries are classified as disease free. Following the terrorist events of 11 September 2001 in the United States, a small group of zoonotic pathogens and a group of animal-specific pathogens (those that cause what are referred to as `high-consequence foreign animal diseases'), were classified as high-risk, biothreat 'select agents'. Rather than providing a comprehensive review of all animal pathogens, the authors briefly review the impact of these high-risk biothreat agents on animal health, the economy, food security and safety, and public health, using highly pathogenic avian influenza, foot and mouth disease and brucellosis as examples. They focus on the impact of these diseases in the context of high-income countries and low- and middle-income countries, comparing and contrasting their impact at the national and individual household levels.

An overview of animal health and communication constraints in smallholder farming systems of Machakos County, Kenya

Information sharing is an important pillar for any strategy that aims to control infectious diseases especially in farms and systems that are connected. A study was designed to analyze practices related to sharing of animal health information and identify health constraints affecting livestock keeping in smallholder farming systems of Mwala in Machakos County. Data were collected through focus group discussions (number of groups = 3) and one-on-one questionnaire interviews (n = 172). These were analyzed using both descriptive and thematic approaches. The most (33%; n = 158) feared animal disease was pneumonia which was also the most (62%) frequently reported health problem. Rabies, Newcastle disease, and east coast fever were ranked high by the farmer groups. Current animal management practices, for example, failure to confine dogs, predispose the community to a number of health risks including bites from rabid animals. Smallholder farmers in Mwala utilize a number of options to communicate animal health problems; such sharing is, however, constrained by a number of factors including bad roads, poor coverage of mobile networks, and bad relationships between animal health providers and the farmers themselves. Some of the reasons why farmers delay the reporting of disease problems included the tendency for one to first try local herbal formulations, the bad times when cases are observed, and the unavailability of reliable animal health providers at the time when the farmers need them. This study has provided useful baseline data that can then be used to (1) design a village-based animal disease reporting system which is currently lacking in the surveyed villages and (2) support the county government's efforts to manage animal diseases including zoonoses, through better reporting, for improved health, nutrition, and livelihoods.

Real-time PCR assays for diagnosing brucellar spondylitis using formalin-fixed paraffin-embedded tissues

It is difficult to diagnose brucellar spondylitis because of its nonspecific clinical, radiological, and histological characteristics. This study aimed to determine whether real-time polymerase chain reaction (PCR) using formalin-fixed paraffin-embedded (FFPE) tissues was superior to conventional serum-based methods for diagnosing brucellar spondylitis.This retrospective study included 31 patients with brucellosis and a control group of 20 people with no history of brucellosis or exposure to Brucella spp. Samples from all patients with brucellar spondylitis were evaluated using Giemsa staining, the standard tube agglutination (STA) test, blood culture, and real-time PCR.The brucellar spondylitis was acute in 7 patients (22.6%), subacute in 15 patients (48.4%), and chronic in 9 patients (29%). Serological assays provided positive results for 25 patients (80.1%), real-time PCR provided positive results for 29 patients (93.5%), and blood cultures provided positive results for 11 patients (35.5%). The real-time PCR provided sensitivity of 93.5%, specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 100%. The corresponding values for the STA test were 80.1%, 100%, 100%, and 76.9%, respectively. Real-time PCR provided better sensitivity than Giemsa staining, the STA test, and blood culture, although the difference between PCR and STA was not statistically significant (P = .22). B melitensis was the only pathogen that was detected in patient with brucellar spondylitis using real-time PCR.These results suggest that real-time PCR provides a high sensitivity for diagnosing brucellar spondylitis. Furthermore, the real-time PCR results indicate that B melitensis was the causative pathogen in these cases.

Brucellosis in West and Central Africa: A review of the current situation in a changing landscape of dairy cattle systems

Brucellosis is a neglected endemic zoonosis in West and Central Africa. In this narrative review, evidence of livestock and human infection is presented along with details of past and current control strategies in 14 selected countries. Data from available literature is combined with expert opinion elicited during a regional workshop on brucellosis diagnostics. Demographic changes that affect both the epidemiology of brucellosis and the success of control or surveillance are also considered. The evidence suggests that brucellosis prevalence in emerging peri-urban dairy cattle systems may be higher than that found in traditional transhumant extensive systems. Accurate microbiological and epidemiological evidence across the region is lacking but it appears there is inherent interest in controlling the disease. There are many data gaps which require collaborative future research to evaluate fully the social and economic impact of the disease in an evolving livestock sector heavily influenced by high rates of urbanisation and regional population growth.

Detection of Brucella abortus B19 strain DNA in seminal plasma by polymerase chain reaction in Brazil

A total of 27 seminal plasma samples from cattle-breeding farms or semen centres located in Minas Gerais, Brazil, previously negative by serological and tested positive for Brucella spp. with primer specific for the amplification of the gene virb5 by polymerase chain reaction (PCR) were analysed for the detection of Brucella abortus DNA by PCR. It was found that nine samples (33.33%) contained B. abortus B19 strain DNA, two (7.40%) contained B. abortus DNA and five (18.51%) contained both DNA. The larger number of samples with B. abortus B19 strain DNA would explained by the environmental contamination by vaccinated females with persistent excretion or some illegal vaccination process. It is first reported of male bovines detected with both DNA.

Pathogen Exposure in Cattle at the Livestock-Wildlife Interface

Land use is an important driver of variation in human infectious disease risk, but less is known about how land use affects disease risk in livestock. To understand how land use is associated with disease risk in livestock, we examined patterns of pathogen exposure in cattle across two livestock ranching systems in rural Kenya: private ranches with low- to medium-intensity cattle production and high wildlife densities, and group ranches with high-intensity cattle production and low wildlife densities. We surveyed cattle from six ranches for three pathogens: Brucella spp., bovine viral diarrhea virus (BVDV) and Leptospira serovar Hardjo. We found that exposure risk for Leptospira was higher on private ranches than on group ranches, but there was no difference in exposure by ranch type for Brucella or BVDV. We hypothesize that variation in livestock and wildlife contact patterns between ranch types may be driving the pattern observed for Leptospira exposure and that the different relationships we found between exposure risk and ranch type by pathogen may be explained by differences in transmission mode. Overall, our results suggest that wildlife-livestock contact patterns may play a key role in shaping pathogen transmission to livestock and that the magnitude of such effects likely depend on characteristics of the pathogen in question.

Incidence and knowledge of bovine brucellosis in Kahuro district, Murang'a County, Kenya

Brucellosis in cattle is a zoonosis mainly caused by Brucella abortus. In Kenya, the disease is widespread, but its prevalence is largely unknown. The objective of this study was to investigate incidence rates of brucellosis and farmers' knowledge on the disease in Kahuro district, Murang'a County. In this study, 150 pooled milk samples were collected from 75 milk collection centers and tested. Subsequently, 230 milk samples were collected from farmers in 16 collection centers in Wangu and Mugoiri divisions whose pooled samples gave positive results. Five cow owners in each of the 16 collection centers were interviewed using a questionnaire to assess their knowledge levels. Wangu division had the highest incidence rate 19% with positive samples observed from 14 collection centers. Mugoiri division recorded 3% with two collection centers having positive samples, while Murarandia had none. All respondents with no formal education were unaware of the causative agent of brucellosis. There was a significant difference in incidence between Mugoiri and Wangu divisions (p < 0.05). Knowledge levels were high in the young and educated farmers compared to the old and uneducated. Frequent screening for brucellosis to identify infected animals should be initiated thus prevent transmission to other animals and humans.