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

Effect of awareness training to frontline health workers and the use of e-based technology on reporting of brucellosis cases in selected pastoral communities, Tanzania: a quasi-experimental study

INTRODUCTION

Brucellosis is a serious community health problem and endemic disease in Tanzania in both humans and animals. Frontline health workers (FHWs) play a vital role in reporting and hence prevent and control brucellosis in rural settings. This study aims to evaluate the effect of awareness training to frontline health workers and use of electronic technology (e- technology) on reporting of brucellosis cases.

METHODS

A quasi-experimental design was implemented in two pastoral communities in eastern part of Tanzania with one as control and another as treatment involving 64 FHWs who were purposively selected from May 2020 to December 2020. A total of 32 FHWs from treatment pastoral community were purposively selected for awareness training, rapid diagnosis using Rose Bengal test (RBT) and use of electronic technology (AfyaData app) for brucellosis reporting while nothing was done in control community. Before and after training information about their knowledge, attitude and practices were collected from all participants using a structured questionnaires uploaded in the mobile phone powered by AfyaData application. Blood samples were collected from 141 febrile patients attending the selected facilities in treatment community. Serum obtained from collected blood were analyzed using RBT and Competitive Enzyme Linked Immunosorbent Assay (c-ELISA) for brucellosis screening and confirmatory, respectively. Results from this analysis were reported back to the health facility using AfyaData app. Chi-square was used to analyze categorical variables and t-test and/Anova test was used to assess the effectiveness of the intervention.

RESULTS

Results revealed that before the training majority of the participants were ignorant about brucellosis, although they had good attitude towards brucellosis prevention. Participant's awareness, practice and attitude increased significantly (p = 0.003, p = 0.001, p = 0.032) respectively, after the intervention. Total of 17(12.1%) patients were positive on RBT and four (2.8%) were confirmed by c-ELISA. AfyaData app was proven to provide quick reports regarding brucellosis in the study area.

CONCLUSION

The training program was effective in increasing the level of knowledge and practice about brucellosis. Electronic based technology (AfyaData app) improved the reporting of brucellosis cases. There is a need for the use of electronic based technology to improve timely management of brucellosis in pastoral communities. Also, continuous training on FHWs regarding the disease is needed to improved their awareness and practices.

Brucellosis and One Health: Inherited and Future Challenges

One Health is the collaborative efforts of multiple disciplines to attain optimal health for people, animals and the environment, a concept that historically owes much to the study of brucellosis, including recent political and ethical considerations. Brucellosis One Health actors include Public Health and Veterinary Services, microbiologists, medical and veterinary practitioners and breeders. Brucellosis awareness, and the correct use of diagnostic, epidemiological and prophylactic tools is essential. In brucellosis, One Health implementation faces inherited and new challenges, some aggravated by global warming and the intensification of breeding to meet growing food demands. In endemic scenarios, disease awareness, stakeholder sensitization/engagement and the need to build breeder trust are unresolved issues, all made difficult by the protean characteristics of this zoonosis. Extended infrastructural weaknesses, often accentuated by geography and climate, are critically important. Capacity-building faces misconceptions derived from an uncritical adoption of control/eradication strategies applied in countries with suitable means, and requires additional reference laboratories in endemic areas. Challenges for One Health implementation include the lack of research in species other than cattle and small ruminants, the need for a safer small ruminant vaccine, the need to fill in the infrastructure gap, the need for realistic capacity-building, the creation of reference laboratories in critical areas, and the stepwise implementation of measures not directly transposed from the so-called developed countries.

Seroprevalence and Associated Risk Factors of Brucellosis Among Human Population in Duhok City, Iraq

Purpose

Brucellosis is a zoonotic disease that contributes to severe global health and economic issues. In this study, the Rose Bengal Test (RBT), a crucial diagnostic tool for brucellosis in Duhok city, was evaluated in order to offer updated epidemiological data on this disease.

Patients and Methods

A total of 339 patients suffered from fever and seeking medical attention in the private medical health center in Duhok city, Iraq, were enrolled after taking ethical approval from committee at Faculty of Sciences, University of Zakho and a verbal consent from each enrolled patient for using his/her blood and data. The blood specimens were tested for Brucella spp. Antibodies using the RBT and blood cultures, followed by spp. determination. A questionnaire form was designed to detect the associated risk factors.

Results

Prevalence of brucellosis was 12.6% among participants with a probable diagnosis and 10.3% among those with a confirmed diagnosis (positive blood culture). Most of the positive cases were between the ages of 20 to 40 years. A highly significant (P < 0.0001) association was found between brucellosis with both consuming raw milk and having contact with cattle. The most common species identified were Brucella melitensis (57.1%) and Brucella abortus (42.7%).

Conclusion

Brucellosis is a significant cause of fever in the current study and can be detected using the RBT. Human brucellosis can be reduced by minimizing the chances of contact with cattle and consuming boiled or pasteurized milk.

Sero - epidemiology of brucellosis in people and their livestock: A linked human - animal cross-sectional study in a pastoralist community in Kenya

BACKGROUND

Brucellosis is associated with massive livestock production losses and human morbidity worldwide. Efforts to control brucellosis among pastoralist communities are limited by scarce data on the prevalence and risk factors for exposure despite the high human-animal interactions in these communities. This study simultaneously assessed the seroprevalence of brucellosis and associated factors of exposure among pastoralists and their livestock in same households.

METHODS

We conducted a cross-sectional study in pastoralist communities in Marsabit County - Kenya. A total of 1,074 women and 225 children participated and provided blood samples. Blood was also drawn from 1,876 goats, 322 sheep and 189 camels. Blood samples were collected to be screened for the presence of anti-Brucella IgG antibodies using indirect IgG Enzyme-Linked Immunosorbent Assay (ELISA) kits. Further, Individual, household and herd-level epidemiological information were captured using a structured questionnaire. Group differences were compared using the Pearson's Chi-square test, and p-values < 0.05 considered statistically significant. Generalized mixed-effects multivariable logistic human and animal models using administrative ward as the random effect was used to determine variables correlated to the outcome.

RESULTS

Household-level seropositivity was 12.7% (95% CI: 10.7-14.8). The individual human seroprevalence was 10.8% (9.1-12.6) with higher seroprevalence among women than children (12.4 vs. 3.1%, p < 0.001). Herd-level seroprevalence was 26.1% (23.7-28.7) and 19.2% (17.6-20.8) among individual animals. Goats had the highest seroprevalence 23.1% (21.2 - 25.1), followed by sheep 6.8% (4.3-10.2) and camels 1.1% (0.1-3.8). Goats and sheep had a higher risk of exposure OR = 3.8 (95% CI 2.4-6.7, p < 0.001) and 2.8 (1.2-5.6, p < 0.007), respectively relative to camels. Human and animal seroprevalence were significantly associated (OR = 1.8, [95%CI: 1.23-2.58], p = 0.002). Herd seroprevalence varied by household head education (OR = 2.45, [1.67-3.61, p < 0.001]) and herd size (1.01, [1.00-1.01], p < 0.001).

CONCLUSIONS

The current study showed evidence that brucellosis is endemic in this pastoralist setting and there is a significant association between animal and human brucellosis seropositivity at household level representing a potential occupational risk. Public health sensitization and sustained human and animal brucellosis screening are required.

Artificial Intelligence Models for Zoonotic Pathogens: A Survey

Zoonotic diseases or zoonoses are infections due to the natural transmission of pathogens between species (animals and humans). More than 70% of emerging infectious diseases are attributed to animal origin. Artificial Intelligence (AI) models have been used for studying zoonotic pathogens and the factors that contribute to their spread. The aim of this literature survey is to synthesize and analyze machine learning, and deep learning approaches applied to study zoonotic diseases to understand predictive models to help researchers identify the risk factors, and develop mitigation strategies. Based on our survey findings, machine learning and deep learning are commonly used for the prediction of both foodborne and zoonotic pathogens as well as the factors associated with the presence of the pathogens.

Human brucellosis: Widespread information deficiency hinders an understanding of global disease frequency

Background

For decades, human brucellosis has been recognized worldwide as a significant cause of morbidity, yet the annual incidence of this disease remains unknown. We analyzed this frequency, using international reports (2005–2019), identifying information gaps, and distinguishing a possible path forward.

Methodology/Principal findings

A novel approach to estimating the incidence of this disease was explored. We utilized annual health data extracted from the World Organization for Animal Health (OIE)–World Animal Health Information System (WAHIS) database, assessing the dataset completeness and representativeness of the data for the world population. Additionally, we assessed the reported country level human brucellosis case counts and the factors that influenced the observed changes over time. Our analysis revealed incomplete and unrepresentative information, preventing the estimation of annual human brucellosis case incidence at the global level. In the OIE-WAHIS database, only 48.4% of the required reports have been submitted as of 2019, with approximately 47.3% of the world population represented. Additionally, geographic regions were disproportionate in completeness, representativeness, and actual reported case counts. Africa and Asia constituted the majority of reported cases, while simultaneously submitting the lowest percentage of reports as well as covering the lowest percentage of their populations within those reports, when compared to the rest of the world.

Conclusions/Significance

The global annual frequency of human brucellosis cases remains elusive. Furthermore, there exists great heterogeneity in diagnostic, surveillance, and reporting systems worldwide, calling into question the validity of available information. This study reveals that the Neglected Zoonotic Disease priority status for brucellosis should be restored.

Despite brucellosis being a major concern worldwide, particularly for populations residing within resource-limited settings, a suitable estimate of annual incidence is currently nonexistent for human disease. To our knowledge, this is the first study to characterize global human brucellosis frequency by utilizing nationally reported case data supplied to the global intergovernmental public health authorities. The combined records demonstrate that within currently available and established international reporting systems, there are insufficient data to calculate the annual global frequency of human brucellosis. Furthermore, the regional differences in populations represented within reports, as well as actual reported case counts, bias the correct interpretation of the overall human brucellosis disease frequency. This suggests that broadcasting a specific global quantity of new cases each year is misleading and, accordingly, there is presently no way to assess the global public health impact of this disease. In past years, disease prioritization by individual countries, including the reallocation of funds to national surveillance, have been demonstrated to positively impact the completeness and representativeness of the data. In the future, the international community must similarly reallocate resources to understand and fill gaps within the available information. Application of this information can be directed towards effectively pinpointing disease burden and efficient control strategies. The reinstatement of human brucellosis as a priority Neglected Zoonotic Disease by the WHO would substantially facilitate this process.

Knowledge, attitude and practices of frontline health workers in relation to detection of brucellosis in rural settings of Tanzania: a cross-sectional study

BACKGROUND

Brucellosis an important zoonotic disease worldwide, which frequently presents as an undifferentiated febrile illness with otherwise varied and non-specific clinical manifestations. Despite its importance, there are few reports on its awareness among frontline health workers. This study aimed at assessing the baseline knowledge, attitude and practice (KAP) related to detection and management of brucellosis among frontline health workers (FHWs) namely; healthcare workers (HWs) and community health workers (CHWs).

METHODS

A cross-sectional study was conducted from December 2019 to January 2020 in Kilosa and Chalinze districts of Tanzania. Data on demographic characteristics, knowledge, attitude and practices regarding brucellosis were collected from the study participants using a structured questionnaire. Interviews were conducted with 32 HWs and 32 CHWs who were systematically selected in study districts. Chi square/fisher Exact was used to assess the association between sociodemographic variables and those related to knowledge, attitude and practices.

RESULTS

Overall, a total of 30 (93.8%) HWs and nine (28.1%) CHWs from the study districts heard about brucellosis, with (34.4%) of HWs having knowledge about the causative organism. Overall, knowledge showed almost half (46.9%) HWs and (28.1%) CHWs were aware of the symptoms, clinical signs, diagnosis and control regarding brucellosis. Knowledge difference was statistically significant with HWs' age (p = 0.016). Almost half (46.9%) HWs and less than quarter (12.5%) CHWs had good practices regarding brucellosis control. Almost three quarters (71.9%) of HWs and (21.9%) CHWs had positive attitude regarding brucellosis control; overall attitude was statistically significant with CHWs age (p = 0.028) and education level (p = 0.024). Lack of awareness and unavailability of diagnostic tools were the main challenges faced by FHWs in the two districts.

CONCLUSION

The majority of participants were not aware of human brucellosis. Moreover, their overall knowledge was inadequate and the common practices were diagnostic tools, and adequate knowledge to manage brucellosis cases. These findings highlight the need to strengthen frontline health workers knowledge, practices and diagnostic capacities related to brucellosis.

Assessment of Milk Quality and Food Safety Challenges in the Complex Nairobi Dairy Value Chain

Food networks present varying food safety concerns because of the complexity of interactions, production, and handling practices. We investigated total bacteria counts (TBCs) and total coliform counts (TCCs) in various nodes of a Nairobi dairy value chain and identified practices that influence food safety. A value chain analysis framework facilitated qualitative data collection through 23 key informant interviews and 20 focus group discussions. Content thematic analysis identified food safety challenges. Cow milk products (N = 290) were collected from farms (N = 63), collection centers (N = 5), shops/kiosks (N = 37), milk bars (N = 17), roadside vendors (N = 14), restaurants (N = 3), milk vending machines (N = 2), mobile traders (N = 2) and a supermarket (N = 1). Mean values of colony-forming units for TBC and TCC were referenced to East African Standards (EAS). Logistic regression analysis assessed differences in milk acceptability based on EAS. The raw milk from farms and collection centers was relatively within acceptable EAS limits in terms of TBC (3.5 × 10⁵ and 1.4 × 10⁶ respectively) but TCC in the milk from farms was 3 times higher than EAS limits (1.5 × 10⁵). Compared to farms, the odds ratio of milk acceptability based on TBC was lower on milk bars (0.02), restaurants (0.02), roadside vendors (0.03), shops/kiosks (0.07), and supermarkets (0.17). For TCC, the odds that milk samples from collection centers, milk bars, restaurants, roadside vendors, and shops/kiosks were acceptable was less than the odds of samples collected from farms (0.18, 0.03, 0.06, 0.02, and 0.12, respectively). Comparison of raw milk across the nodes showed that the odds of milk samples from restaurants, roadside vendors, and shops/kiosks being acceptable were less than the odds of samples collected the farm for TBC (0.03, 0.04, and 0.04, respectively). For TCC, the odds of raw milk from collection centers, restaurants, roadside vendors, milk bars, and shops/kiosks being acceptable were lower than the odds of acceptability for the farm samples (0.18, 0.12, 0.02, 0.04, and 0.05, respectively). Practices with possible influence on milk bacterial quality included muddy cowsheds, unconventional animal feed sources, re-use of spoilt raw milk, milk adulteration, acceptance of low-quality milk for processing, and lack of cold chain. Therefore, milk contamination occurs at various points, and the designing of interventions should focus on every node.

Using a One Health Case-Based Investigation for Improved Control of Brucellosis in Isiolo, Kenya

Brucella is a highly pathogenic bacteria endemic in Kenya, and in spite of its severity in humans, the highly inadequate Febrile Antigen Brucella Agglutination Test (FBAT) remains a primary tool for its diagnosis. Blood samples were collected from febrile patients in Kinna health center and screened by the local routine. Milk samples were purchased from local milk hawkers and analyzed for Brucella antibodies using the milk ring test (MRT). The MRT-positive milk was traced to farms, and lactating cattle were sampled for milk and blood. Milk was MRT-tested and the serum was analyzed using the Rose Bengal test (RBT) and iELISA. Available patient and farm samples were stored on FTA cards for qPCR analyses. Despite a limited sample size, our study, in line with previous reports, shows a low diagnostic sensitivity (67%) and specificity (40%) of FBAT when compared to qPCR. As many as 48% of the raw bulk cattle milk samples were MRT-positive for Brucella antibodies and 60% of cattle on three visited farms were IS711 qPCR-positive. This case-based One Health investigation confirms the suspected Brucella presence, suggesting a targeted vaccination at high-prevalence farms, urgent interventions on milk safety, and a re-evaluation of the diagnostic and treatment regimen.

Tokpa K, Fokou G, Shilabukha K, Ezekiel M, Bonfoh B, Kazwala R, Kreppel K. Lay attitudes and misconceptions and their implications for the control of brucellosis in an agro-pastoral community in Kilombero district, Tanzania

Brucellosis is a priority zoonotic disease in Tanzania that causes ill-health in people and affects livestock productivity. Inadequate awareness and behavior risking transmission can impede control efforts. We conducted a cross-sectional survey of 333 livestock owners in three villages in the Kilombero district, Tanzania, to understand their awareness, knowledge and behavior associated with brucellosis. Six Focus Group Discussions (FGDs), two in each village, were conducted, as well as an additional FGD with male herders from one of the villages. Factors associated with knowledge on brucellosis, food consumption and animal husbandry behavior risking transmission of this disease, were identified using generalized linear models. Predictors for knowledge of brucellosis were being male and having a higher educational level, while age was positively associated with a higher level of knowledge. Faith and ethnicity were associated with the performance of practices risking transmission. Following traditional religion and belonging to the Wamaasai ethnicity significantly increased the odds of carrying out these practices. Qualitative analysis gave insight into risk practices and reasoning. Of the 333 respondents, 29% reported that they had experienced abortions in their herds, 14% witnessed retained placentas, and 8% had seen still-births in their cattle within the previous year. However, survey results also showed that only 7.2% of participants had heard about brucellosis as a disease in livestock. Of those who had heard about brucellosis in livestock, 91% associated abortions with it and 71% knew that humans can get infected through raw milk consumption. People overwhelmingly attributed symptoms and transmission of brucellosis in livestock to infection with trypanosomiasis and to supernatural reasons instead. In the community, consumption of raw milk was valued and handling of aborted material was not considered a risk for infection. This agro-pastoralist community holds on to long-held beliefs and practices and lacks understanding of the biomedical concept of brucellosis. Transmission routes and symptoms of brucellosis in humans and livestock are completely unknown. The disparity between risk perception and actual transmission risk related to animal handling and consumption of animal products presents a challenge for disease awareness communication. This study recommends focused community engagement and sensitization to address the limited awareness and misconceptions among agro-pastoralists.

Molecular epidemiology of Brucella species in mixed livestock-human ecosystems in Kenya

Brucellosis, caused by several species of the genus Brucella, is a zoonotic disease that affects humans and animal species worldwide. Information on the Brucella species circulating in different hosts in Kenya is largely unknown, thus limiting the adoption of targeted control strategies. This study was conducted in multi-host livestock populations in Kenya to detect the circulating Brucella species and assess evidence of host-pathogen associations. Serum samples were collected from 228 cattle, 162 goats, 158 sheep, 49 camels, and 257 humans from Narok and Marsabit counties in Kenya. Information on age, location and history of abortion or retained placenta were obtained for sampled livestock. Data on age, gender and location of residence were also collected for human participants. All samples were tested using genus level real-time PCR assays with primers specific for IS711 and bcsp31 targets for the detection of Brucella. All genus positive samples (positive for both targets) were further tested with a speciation assay for AlkB and BMEI1162 targets, specific for B. abortus and B. melitensis, respectively. Samples with adequate quantities aggregating to 577 were also tested with the Rose Bengal Test (RBT). A total of 199 (33.3%) livestock and 99 (38.5%) human samples tested positive for genus Brucella. Animal Brucella PCR positive status was positively predicted by RBT positive results (OR = 8.3, 95% CI 4.0-17.1). Humans aged 21-40 years had higher odds (OR = 2.8, 95% CI 1.2-6.6) of being Brucella PCR positive compared to the other age categories. The data on detection of different Brucella species indicates that B. abortus was detected more often in cattle (OR = 2.3, 95% CI 1.1-4.6) and camels (OR = 2.9, 95% CI 1.3-6.3), while B. melitensis was detected more in sheep (OR = 3.6, 95% CI 2.0-6.7) and goats (OR = 1.7, 95% CI 1.0-3.1). Both B. abortus and B. melitensis DNA were detected in humans and in multiple livestock host species, suggesting cross-transmission of these species among the different hosts. The detection of these two zoonotic Brucella species in humans further underpins the importance of One Health prevention strategies that target multiple host species, especially in the multi-host livestock populations.

Performance characteristics and costs of serological tests for brucellosis in a pastoralist community of northern Tanzania

The control of brucellosis across sub-Saharan Africa is hampered by the lack of standardized testing and the use of tests with poor performance. This study evaluated the performance and costs of serological assays for human brucellosis in a pastoralist community in northern Tanzania. Serum collected from 218 febrile hospital patients was used to evaluate the performance of seven index tests, selected based on international recommendation or current use. We evaluated the Rose Bengal test (RBT) using two protocols, four commercial agglutination tests and a competitive enzyme-linked immunosorbent assay (cELISA). The sensitivity, specificity, positive predictive value, negative predictive value, Youden's index, diagnostic accuracy, and per-sample cost of each index test were estimated. The diagnostic accuracy estimates ranged from 95.9 to 97.7% for the RBT, 55.0 to 72.0% for the commercial plate tests, and 89.4% for the cELISA. The per-sample cost range was $0.69-$0.79 for the RBT, $1.03-$1.14 for the commercial plate tests, and $2.51 for the cELISA. The widely used commercial plate tests performed poorly and cost more than the RBT. These findings provide evidence for the public health value of discontinuing the use of commercial agglutination tests for human brucellosis in Tanzania.

The intersection of land use and human behavior as risk factors for zoonotic pathogen exposure in Laikipia County, Kenya

A majority of emerging infectious diseases (EIDs) are zoonotic, mainly caused through spillover events linked to human-animal interactions. We conducted a survey-based human behavioral study in Laikipia County, Kenya, which is characterized by a dynamic human-wildlife-livestock interface. Questionnaires that assessed human-animal interactions, sanitation, and illnesses experienced within the past year were distributed to 327 participants among five communities in Laikipia. This study aimed to 1) describe variation in reported high-risk behaviors by community type and 2) assess the relationship between specific behaviors and self-reported illnesses. Behavioral trends were assessed in R via Fisher’s exact tests. A generalized linear mixed model with Lasso penalization (GLMMLasso) was used to assess correlations between behaviors and participants’ self-reported illness within the past year, with reported behaviors as independent variables and reported priority symptoms as the outcome. Reported behaviors varied significantly among the study communities. Participants from one community (Pastoralist-1) were significantly more likely to report eating a sick animal in the past year (p< 0.001), collecting an animal found dead to sell in the past year (p<0.0001), and not having a designated location for human waste (p<0.0001) when compared to participants from other communities. The GLMMLasso revealed that reports of an ill person in the household in the past year was significantly associated with self-reported illness. Sixty-eight percent of participants reported that bushmeat is available within the communities. Our study demonstrates community-level variation in behaviors that may influence zoonotic pathogen exposure. We further recommend development of targeted studies that explore behavioral variations among land use systems in animal production contexts.

Many infectious diseases, such as H1N1, Ebola, and COVID-19, can be spread to humas from animals. In order to reduce the risk of disease “spillover” (disease transmission from an animal to a person), it is important to understand how interactions between humans and animals can influence spread. Certain behaviors, such as eating raw meat, hunting, or sharing drinking water with animals can put people at greater risk of contacting bacteria and viruses that can cause these diseases. Globally, communities that depend on animal production are at heightened risk due to increased contact with animals. In this study, the authors conducted human behavioral surveys among different communities in Kenya that raise livestock. Results show that reported behaviors varied greatly by community. One of the communities reported a significantly higher proportion of behaviors, such as eating raw meat or eating animals found dead. Communities that show high prevalence of these behaviors may be at greater risk for contracting diseases from animals. Understanding this variation is important for developing plans for community outreach and addressing behaviors that can influence risk of disease spread.

Hospital-based evidence on cost-effectiveness of brucellosis diagnostic tests and treatment in Kenyan hospitals

Hospitals in Kenya continue to use the Febrile Antigen Brucella Agglutination Test (FBAT) to diagnose brucellosis, despite reports showing its inadequacy. This study generated hospital-based evidence on the performance and cost-effectiveness of the FBAT, compared to the Rose Bengal Test (RBT).Twelve hospitals in western Kenya stored patient serum samples that were tested for brucellosis using the FBAT, and these were later re-tested using the RBT. Data on the running time and cost of the FBAT, and the treatment prescribed for brucellosis, were collected. The cost-effectiveness of the two tests, defined as the cost in US Dollars ($) per Disability Adjusted Life Year (DALY) averted, was determined, and a basic sensitivity analysis was run to identify the most influential parameters. Over a 6-month period, 180 patient serum samples that were tested with FBAT at the hospitals were later re-tested with RBT at the field laboratory. Of these 24 (13.3%) and 3 (1.7%) tested positive with FBAT and RBT, respectively. The agreement between the FBAT and RBT was slight (Kappa = 0.12). Treatment prescribed following FBAT positivity varied between hospitals, and only one hospital prescribed a standardized therapy regimen. The mean $/DALY averted when using the FBAT and RBT were $2,065 (95% CI $481-$6,736) and $304 (95% CI $126-$604), respectively. Brucellosis prevalence was the most influential parameter in the cost-effectiveness of both tests. Extrapolation to the national level suggested that an estimated $338,891 (95% CI $47,000-$1,149,000) per year is currently spent unnecessarily treating those falsely testing positive by FBAT. These findings highlight the potential for misdiagnosis using the FBAT. Furthermore, the RBT is cost-effective, and could be considered as the mainstay screening test for human brucellosis in this setting. Lastly, the treatment regimens must be harmonized to ensure the appropriate use of antibiotics for treatment.

Brucellosis is the most common bacterial zoonosis globally, with a higher burden in low-resource settings. In humans, the disease manifests itself with non-specific clinical signs, and current international guidelines recommend the use of two serological diagnostic tests to make a confirmatory diagnosis. Many hospitals in Kenya and some neighbouring countries have been using the Febrile Antigen Brucella Agglutination Test (FBAT) for diagnosis, despite reports showing its poor performance. In this study we compared the diagnostic performance and cost-effectiveness of the FBAT with that of the Rose Bengal Test (RBT), a serological assay recommended by international guidelines. Our results showed that, compared to the RBT, the FBAT incorrectly diagnosed a number of patients. This is of concern as it leads to unnecessary antibiotic treatments, increasing the economic burden of the disease and exacerbating the risk of antibiotic resistance. We also highlight the discrepancies in brucellosis treatment regimens currently being prescribed by various hospitals. Finally, we showed that the RBT is a more cost-effective diagnostic test. Our recommendation, therefore, is for the RBT to be considered as the mainstay diagnostic test for human brucellosis in all Kenyan hospitals, and for the harmonization of treatment guidelines.