Seroprevalence of Brucella spp. and Rift Valley fever virus among slaughterhouse workers in Isiolo County, northern Kenya

Brucella spp. and Rift Valley fever virus (RVFV) are classified as priority zoonotic agents in Kenya, based on their public health and socioeconomic impact on the country. Data on the pathogen-specific and co-exposure levels is scarce due to limited active surveillance. This study investigated seroprevalence and co-exposure of Brucella spp. and RVFV and associated risk factors among slaughterhouse workers in Isiolo County, northern Kenya. A cross-sectional serosurvey was done in all 19 slaughterhouses in Isiolo County, enrolling 378 participants into the study. The overall seroprevalences for Brucella spp. and RVFV were 40.2% (95% CI: 35.2–45.4) and 18.3% (95% CI: 14.5–22.5), respectively while 10.3% (95% CI 7.4%-13.8%) of individuals were positive for antibodies against both Brucella spp. and RVFV. Virus neutralisation tests (VNT) confirmed anti-RVFV antibodies in 85% of ELISA-positive samples. Our seroprevalence results were comparable to community-level seroprevalences previously reported in the area. Since most of the study participants were not from livestock-keeping households, our findings attribute most of the detected infections to occupational exposure. The high exposure levels indicate slaughterhouse workers are the most at-risk population and there is need for infection, prevention, and control programs among this high-risk group. This is the first VNT confirmation of virus-neutralising antibodies among slaughterhouse workers in Isiolo County and corroborates reports of the area being a high-risk RVFV area as occasioned by previously reported outbreaks. This necessitates sensitization campaigns to enhance awareness of the risks involved and appropriate mitigation measures

Data that underlies this paper.

Brucella spp. and Rift Valley fever virus (RVFV) are classified as priority zoonotic agents in Kenya, based on their public health and socioeconomic impact on the country. Data on the pathogen-specific and co-exposure levels is scarce due to limited active surveillance. This study investigated seroprevalence and co-exposure of Brucella spp. and RVFV and associated risk factors among slaughterhouse workers in Isiolo County, northern Kenya. A cross-sectional serosurvey was done in all 19 slaughterhouses in Isiolo County, enrolling 378 participants into the study. The overall seroprevalences for Brucella spp. and RVFV were 40.2% (95% CI: 35.2–45.4) and 18.3% (95% CI: 14.5–22.5), respectively while 10.3% (95% CI 7.4%-13.8%) of individuals were positive for antibodies against both Brucella spp. and RVFV. Virus neutralisation tests (VNT) confirmed anti-RVFV antibodies in 85% of ELISA-positive samples. Our seroprevalence results were comparable to community-level seroprevalences previously reported in the area. Since most of the study participants were not from livestock-keeping households, our findings attribute most of the detected infections to occupational exposure. The high exposure levels indicate slaughterhouse workers are the most at-risk population and there is need for infection, prevention, and control programs among this high-risk group. This is the first VNT confirmation of virus-neutralising antibodies among slaughterhouse workers in Isiolo County and corroborates reports of the area being a high-risk RVFV area as occasioned by previously reported outbreaks. This necessitates sensitization campaigns to enhance awareness of the risks involved and appropriate mitigation measures.</div

Sample demographics and descriptive analysis for <i>Brucella</i> spp. and RVFV seroprevalence estimates amongst slaughterhouse workers in Isiolo county.

The test for statistical significance was done at α = 0.05.</p

A continental map of Africa highlighting the location of Kenya (Orange) with a blown-up map of Kenya showing the location of Isiolo County (orange) and a magnified map of Isiolo County (grey) showing the locations of slaughterhouses that were used in the study (blue dots).

The base map of Africa was created in R using the function ’wrld_simpl’ (Region 2) in the maptools package [36]. The base map shapefile for Africa was downloaded from: Natural Earth (http://www.naturalearthdata.com/). The Kenya counties shapefile was downloaded from: https://data.amerigeoss.org/dataset/47-counties-of-kenya/resource/11e8697c-48a9-4af5-85f9-f5a2b0625d2c. This work is licensed under a Creative Commons Attribution [4.0] License. The wards shapefile was downloaded from: https://data.amerigeoss.org/dataset/kenya-admin-level-3-wards/resource/2fe6fcaa-58af-4d5d-a17d-81c73574ae2a. This work is licensed under a Creative Commons Attribution [4.0] License.</p

If You're Not Confused, You're Not Paying Attention: Ochrobactrum Is Not Brucella

Bacteria of the genus Brucella are facultative intracellular parasites that cause brucellosis, a severe animal and human disease. Recently, a group of taxonomists merged the brucellae with the primarily free-living, phylogenetically related Ochrobactrum spp. in the genus Brucella. This change, founded only on global genomic analysis and the fortuitous isolation of some opportunistic Ochrobactrum spp. from medically compromised patients, has been automatically included in culture collections and databases. We argue that clinical and environmental microbiologists should not accept this nomenclature, and we advise against its use because (i) it was presented without in-depth phylogenetic analyses and did not consider alternative taxonomic solutions; (ii) it was launched without the input of experts in brucellosis or Ochrobactrum; (iii) it applies a non-consensus genus concept that disregards taxonomically relevant differences in structure, physiology, population structure, core-pangenome assemblies, genome structure, genomic traits, clinical features, treatment, prevention, diagnosis, genus description rules, and, above all, pathogenicity; and (iv) placing these two bacterial groups in the same genus creates risks for veterinarians, medical doctors, clinical laboratories, health authorities, and legislators who deal with brucellosis, a disease that is particularly relevant in low- and middle-income countries. Based on all this information, we urge microbiologists, bacterial collections, genomic databases, journals, and public health boards to keep the Brucella and Ochrobactrum genera separate to avoid further bewilderment and harm.Las bacterias del género Brucella son parásitos intracelulares facultativos causantes de la brucelosis, una grave enfermedad animal y humana. Recientemente, un grupo de taxónomos fusionó las brucelas con las Ochrobactrum spp., principalmente de vida libre y filogenéticamente emparentadas, en el género Brucella. Este cambio, fundado únicamente en análisis genómicos globales y en el aislamiento fortuito de algunas Ochrobactrum spp. oportunistas de pacientes médicamente comprometidos, se ha incluido automáticamente en colecciones de cultivos y bases de datos. Sostenemos que los microbiólogos clínicos y ambientales no deberían aceptar esta nomenclatura, y desaconsejamos su uso porque (i) se presentó sin análisis filogenéticos en profundidad y no consideró soluciones taxonómicas alternativas; (ii) se lanzó sin la aportación de expertos en brucelosis u Ochrobactrum; (iii) aplica un concepto de género no consensuado que ignora las diferencias taxonómicamente relevantes en estructura, fisiología, estructura poblacional, ensamblajes del núcleo-pangenoma, estructura genómica, rasgos genómicos, características clínicas, tratamiento, prevención, diagnóstico, reglas de descripción del género y, sobre todo, patogenicidad; y (iv) colocar estos dos grupos bacterianos en el mismo género crea riesgos para veterinarios, médicos, laboratorios clínicos, autoridades sanitarias y legisladores que se ocupan de la brucelosis, una enfermedad especialmente relevante en países de renta baja y media. Basándonos en toda esta información, instamos a los microbiólogos, las colecciones bacterianas, las bases de datos genómicos, las revistas y los consejos de salud pública a mantener separados los géneros Brucella y Ochrobactrum para evitar más desconcierto y perjuicios.Universidad Nacional, Costa RicaEscuela de Medicina Veterinari