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Alinaitwe L, Aturinda CJ, Lubega A, Kivali V, Bugeza J, Wainaina M, Richter MH, Hoona JJ, Roesel K, Mayer-Scholl A, Cook EAJ, Kankya C, Dürr S. Cross-sectional serosurvey of Leptospira species among slaughter pigs, goats, and sheep in Uganda. PLoS Negl Trop Dis 2024; 18:e0012055. [PMID: 38489377 PMCID: PMC10971767 DOI: 10.1371/journal.pntd.0012055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 03/27/2024] [Accepted: 03/07/2024] [Indexed: 03/17/2024] Open
Abstract
INTRODUCTION Leptospira are a group of bacteria, including pathogenic types that cause leptospirosis. In Uganda, Leptospira exposure has been reported in humans, with domesticated animals being speculated as the source. However, comparable evidence of Leptospira prevalence and circulating serovars/serogroups in animals is only documented for cattle, and dogs. Our study determined Leptospira seroprevalence, associated risk factors and serogroups circulating among slaughtered pigs, goats, and sheep in Uganda. METHODS During an 11-month cross-sectional survey in selected slaughter facilities in three regions of Uganda, we collected blood from 926 pigs, 347 goats, and 116 sheep. The age, sex, breed, and origin of each sampled animal were noted. The samples were tested for anti-Leptospira antibodies using the microscopic agglutination test, based on a panel of 12 serovars belonging to 12 serogroups. RESULTS Leptospira seroprevalence was 26.67% (247/926, 95%CI 23.92-29.61) among pigs, and 21.81% (101/463, 95%CI 18.29-25.80) in goats and sheep (small ruminants). L. interrogans Australis and L. kirschneri Grippotyphosa were the commonest serovars among pigs, as was L. borgpetersenii Tarassovi in small ruminants. Pigs sourced from the Eastern (Odds Ratio [OR] = 2.82, 95%CI 1.84-4.30) and Northern (OR = 3.56, 95%CI 2.52-5.02) regions were more likely to be seropositive, compared to those from the Central region. For small ruminants, being female (OR 2.74, 95% CI 1.69-4.57) and adult (OR 4.47, 95% CI 1.57-18.80) was significantly more associated with Leptospira seropositivity. Conclusion/significance: Detection of a moderate seroprevalence, and several Leptospira serogroups among pigs, sheep, and goats from all regions of Uganda, supports existing reports in cattle and dogs, and implies widespread Leptospira exposure in domestic animals in Uganda. These findings may inform future programs for the control of leptospirosis in livestock in Uganda.
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Affiliation(s)
- Lordrick Alinaitwe
- Human and Animal Health Program, International Livestock Research Institute, Nairobi, Kenya
- Veterinary Public Health Institute, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
- College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB), Makerere University, Kampala, Uganda
| | - Christopher Joshua Aturinda
- College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB), Makerere University, Kampala, Uganda
| | - Ashiraf Lubega
- College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB), Makerere University, Kampala, Uganda
| | - Velma Kivali
- Human and Animal Health Program, International Livestock Research Institute, Nairobi, Kenya
| | - James Bugeza
- Human and Animal Health Program, International Livestock Research Institute, Nairobi, Kenya
- Vaccinology Research Program, National Livestock Resources Research Institute, Kampala, Uganda
| | - Martin Wainaina
- Department of Biological Safety, Federal Institute for Risk Assessment, Berlin, Germany
| | - Martin H. Richter
- Department of Biological Safety, Federal Institute for Risk Assessment, Berlin, Germany
| | - Jolly Justine Hoona
- Department of Animal Production, Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), Entebbe, Uganda
| | - Kristina Roesel
- Human and Animal Health Program, International Livestock Research Institute, Nairobi, Kenya
| | - Anne Mayer-Scholl
- Department of Biological Safety, Federal Institute for Risk Assessment, Berlin, Germany
| | | | - Clovice Kankya
- College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB), Makerere University, Kampala, Uganda
| | - Salome Dürr
- Veterinary Public Health Institute, University of Bern, Bern, Switzerland
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Wainaina M, Lindahl JF, Dohoo I, Mayer-Scholl A, Roesel K, Mbotha D, Roesler U, Grace D, Bett B, Al Dahouk S. Longitudinal Study of Selected Bacterial Zoonoses in Small Ruminants in Tana River County, Kenya. Microorganisms 2022; 10:microorganisms10081546. [PMID: 36013964 PMCID: PMC9414833 DOI: 10.3390/microorganisms10081546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 11/19/2022] Open
Abstract
Brucellosis, Q fever, and leptospirosis are priority zoonoses worldwide, yet their epidemiology is understudied, and studies investigating multiple pathogens are scarce. Therefore, we selected 316 small ruminants in irrigated, pastoral, and riverine settings in Tana River County and conducted repeated sampling for animals that were initially seronegative between September 2014 and June 2015. We carried out serological and polymerase chain reaction tests and determined risk factors for exposure. The survey-weighted serological incidence rates were 1.8 (95% confidence intervals [CI]: 1.3–2.5) and 1.3 (95% CI: 0.7–2.3) cases per 100 animal-months at risk for Leptospira spp. and C. burnetii, respectively. We observed no seroconversions for Brucella spp. Animals from the irrigated setting had 6.83 (95% CI: 2.58–18.06, p-value = 0.01) higher odds of seropositivity to C. burnetii than those from riverine settings. Considerable co-exposure of animals to more than one zoonosis was also observed, with animals exposed to one zoonosis generally having 2.5 times higher odds of exposure to a second zoonosis. The higher incidence of C. burnetii and Leptospira spp. infections, which are understudied zoonoses in Kenya compared to Brucella spp., demonstrate the need for systematic prioritization of animal diseases to enable the appropriate allocation of resources.
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Affiliation(s)
- Martin Wainaina
- Department of Biological Safety, German Federal Institute for Risk Assessment, 12277 Berlin, Germany; (A.M.-S.); (S.A.D.)
- Department of Veterinary Medicine, Freie Universität Berlin, 14163 Berlin, Germany; (K.R.); (D.M.)
- Animal & Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya; (J.F.L.); (D.G.); (B.B.)
- Correspondence:
| | - Johanna F. Lindahl
- Animal & Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya; (J.F.L.); (D.G.); (B.B.)
- Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, 75237 Uppsala, Sweden
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
| | - Ian Dohoo
- Centre for Veterinary Epidemiologic Research, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada;
| | - Anne Mayer-Scholl
- Department of Biological Safety, German Federal Institute for Risk Assessment, 12277 Berlin, Germany; (A.M.-S.); (S.A.D.)
| | - Kristina Roesel
- Department of Veterinary Medicine, Freie Universität Berlin, 14163 Berlin, Germany; (K.R.); (D.M.)
- Animal & Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya; (J.F.L.); (D.G.); (B.B.)
| | - Deborah Mbotha
- Department of Veterinary Medicine, Freie Universität Berlin, 14163 Berlin, Germany; (K.R.); (D.M.)
- Animal & Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya; (J.F.L.); (D.G.); (B.B.)
| | - Uwe Roesler
- Institute for Animal Hygiene and Environmental Health, Freie Universität Berlin, 14163 Berlin, Germany;
| | - Delia Grace
- Animal & Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya; (J.F.L.); (D.G.); (B.B.)
- Natural Resources Institute, University of Greenwich, Kent ME4 4TB, UK
| | - Bernard Bett
- Animal & Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya; (J.F.L.); (D.G.); (B.B.)
| | - Sascha Al Dahouk
- Department of Biological Safety, German Federal Institute for Risk Assessment, 12277 Berlin, Germany; (A.M.-S.); (S.A.D.)
- Department of Internal Medicine, RWTH Aachen University Hospital, 52074 Aachen, Germany
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Mwololo D, Nthiwa D, Kitala P, Abuom T, Wainaina M, Kairu-Wanyoike S, Lindahl JF, Ontiri E, Bukachi S, Njeru I, Karanja J, Sang R, Grace D, Bett B. Sero-epidemiological survey of Coxiella burnetii in livestock and humans in Tana River and Garissa counties in Kenya. PLoS Negl Trop Dis 2022; 16:e0010214. [PMID: 35239658 PMCID: PMC8923444 DOI: 10.1371/journal.pntd.0010214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 03/15/2022] [Accepted: 01/28/2022] [Indexed: 01/17/2023] Open
Abstract
Background Coxiella burnetii is a widely distributed pathogen, but data on its epidemiology in livestock, and human populations remain scanty, especially in developing countries such as Kenya. We used the One Health approach to estimate the seroprevalance of C. burnetii in cattle, sheep, goats and human populations in Tana River county, and in humans in Garissa county, Kenya. We also identified potential determinants of exposure among these hosts. Methods Data were collected through a cross-sectional study. Serum samples were taken from 2,727 animals (466 cattle, 1,333 goats, and 928 sheep) and 974 humans and screened for Phase I/II IgG antibodies against C. burnetii using enzyme-linked immunosorbent assay (ELISA). Data on potential factors associated with animal and human exposure were collected using a structured questionnaire. Multivariable analyses were performed with households as a random effect to adjust for the within-household correlation of C. burnetii exposure among animals and humans, respectively. Results The overall apparent seroprevalence estimates of C. burnetii in livestock and humans were 12.80% (95% confidence interval [CI]: 11.57–14.11) and 24.44% (95% CI: 21.77–27.26), respectively. In livestock, the seroprevalence differed significantly by species (p < 0.01). The highest seroprevalence estimates were observed in goats (15.22%, 95% CI: 13.34-17.27) and sheep (14.22%, 95% CI: 12.04–16.64) while cattle (3.00%, 95% CI: 1.65–4.99) had the lowest seroprevalence. Herd-level seropositivity of C. burnetii in livestock was not positively associated with human exposure. Multivariable results showed that female animals had higher odds of seropositivity for C. burnetii than males, while for animal age groups, adult animals had higher odds of seropositivity than calves, kids or lambs. For livestock species, both sheep and goats had significantly higher odds of seropositivity than cattle. In human populations, men had a significantly higher odds of testing positive for C. burnetii than women. Conclusions This study provides evidence of livestock and human exposure to C. burnetii which could have serious economic implications on livestock production and impact on human health. These results also highlight the need to establish active surveillance in the study area to reduce the disease burden associated with this pathogen. Q fever caused by Coxiella burnetii is a significant zoonotic disease that affects wildlife, domestic animals and humans. This study determined the prevalence of antibodies to C. burnetii in livestock (cattle, sheep, and goats) and human populations in arid and semi-arid areas of Kenya between December 2013 and February 2014. We also identified potential factors that were associated with exposure among the above-targeted hosts. Results from this study showed considerable exposure in both livestock and human populations. However, human exposure to this pathogen at the household level was not correlated with herd-level seropositivity. Further studies are needed to elucidate the transmission routes of this pathogen among humans.
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Affiliation(s)
- Damaris Mwololo
- Directorate of Veterinary Services, Ministry of Agriculture, Livestock, Fisheries and Cooperatives, Nairobi, Kenya
| | - Daniel Nthiwa
- Department of Biological Sciences, University of Embu, Embu, Kenya
- International Livestock Research Institute, Nairobi, Kenya
- * E-mail:
| | - Philip Kitala
- Department of Public Health, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | - Tequiero Abuom
- Department of Clinical Medicine, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | | | - Salome Kairu-Wanyoike
- Department of Veterinary Services, Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
| | - Johanna F. Lindahl
- International Livestock Research Institute, Nairobi, Kenya
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Enoch Ontiri
- International Livestock Research Institute, Nairobi, Kenya
| | - Salome Bukachi
- Institute of Anthropology, University of Nairobi, Nairobi, Kenya
| | - Ian Njeru
- Division of Disease Surveillance and Response, Ministry of Public Health and Sanitation, Kenyatta National Hospital, Nairobi, Kenya
| | - Joan Karanja
- Division of Disease Surveillance and Response, Ministry of Public Health and Sanitation, Kenyatta National Hospital, Nairobi, Kenya
| | | | - Delia Grace
- International Livestock Research Institute, Nairobi, Kenya
- Natural Resources Institute, University of Greenwich, Kent, United Kingdom
| | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
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Wainaina M, Vey da Silva DA, Dohoo I, Mayer-Scholl A, Roesel K, Hofreuter D, Roesler U, Lindahl J, Bett B, Al Dahouk S. A systematic review and meta-analysis of the aetiological agents of non-malarial febrile illnesses in Africa. PLoS Negl Trop Dis 2022; 16:e0010144. [PMID: 35073309 PMCID: PMC8812962 DOI: 10.1371/journal.pntd.0010144] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 02/03/2022] [Accepted: 01/04/2022] [Indexed: 12/16/2022] Open
Abstract
Background The awareness of non-malarial febrile illnesses (NMFIs) has been on the rise over the last decades. Therefore, we undertook a systematic literature review and meta-analysis of causative agents of non-malarial fevers on the African continent. Methodology We searched for literature in African Journals Online, EMBASE, PubMed, Scopus, and Web of Science databases to identify aetiologic agents that had been reported and to determine summary estimates of the proportional morbidity rates (PMr) associated with these pathogens among fever patients. Findings A total of 133 studies comprising 391,835 patients from 25 of the 54 African countries were eligible. A wide array of aetiologic agents were described with considerable regional differences among the leading agents. Overall, bacterial pathogens tested from blood samples accounted for the largest proportion. The summary estimates from the meta-analysis were low for most of the agents. This may have resulted from a true low prevalence of the agents, the failure to test for many agents or the low sensitivity of the diagnostic methods applied. Our meta-regression analysis of study and population variables showed that diagnostic methods determined the PMr estimates of typhoidal Salmonella and Dengue virus. An increase in the PMr of Klebsiella spp. infections was observed over time. Furthermore, the status of patients as either inpatient or outpatient predicted the PMr of Haemophilus spp. infections. Conclusion The small number of epidemiological studies and the variety of NMFI agents on the African continent emphasizes the need for harmonized studies with larger sample sizes. In particular, diagnostic procedures for NMFIs should be standardized to facilitate comparability of study results and to improve future meta-analyses. Reliable NMFI burden estimates will inform regional public health strategies. Previous systematic reviews have highlighted the research priorities of causative agents for non-malarial febrile illnesses by counting the number of publications attributed to an agent. However, proportional morbidity rates are calculated by dividing the number of cases with a specific disease (numerator) by the total number of diagnosed fever cases (denominator) and are better indicators of the relative importance of aetiological agents in a population. Therefore, we present the leading causes of non-malarial febrile illnesses in African patients in both healthcare and community settings. Preference is given to HIV-negative patients when data could be found. We also determined summary estimates of Brucella spp., Chikungunya virus, Dengue virus, Haemophilus spp., Klebsiella spp., Leptospira spp., non-typhoidal Salmonella spp., typhoidal Salmonella spp., Staphylococcus spp., and Streptococcus spp. The wide array of aetiological agents causing febrile illnesses on the African continent does not only complicate malaria control programs but may also hamper response to epidemic and pandemic illnesses such as Ebola and COVID-19. The harmonisation of diagnostics and study designs will reduce between-study differences, which may result in better estimates of disease burden on the continent and in the different African regions. This information is important for Pan-African surveillance and control efforts.
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Affiliation(s)
- Martin Wainaina
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
- Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- International Livestock Research Institute, Nairobi, Kenya
- * E-mail:
| | - David Attuy Vey da Silva
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
- Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Ian Dohoo
- University of Prince Edward Island, Charlottetown, Canada
| | - Anne Mayer-Scholl
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Kristina Roesel
- Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- International Livestock Research Institute, Nairobi, Kenya
| | - Dirk Hofreuter
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Uwe Roesler
- Institute for Animal Hygiene and Environmental Health, Freie Universität Berlin, Berlin, Germany
| | - Johanna Lindahl
- International Livestock Research Institute, Nairobi, Kenya
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
| | - Sascha Al Dahouk
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
- Department of Internal Medicine, RWTH Aachen University Hospital, Aachen, Germany
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Omwenga I, Aboge GO, Mitema ES, Obiero G, Ngaywa C, Ngwili N, Wamwere G, Wainaina M, Bett B. Antimicrobial Usage and Detection of Multidrug-Resistant Staphylococcus aureus, Including Methicillin-Resistant Strains in Raw Milk of Livestock from Northern Kenya. Microb Drug Resist 2020; 27:843-854. [PMID: 33185504 DOI: 10.1089/mdr.2020.0252] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The association of antimicrobial usage (AMU) with prevalence of antimicrobial-resistant (AMR) Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA) in livestock raw milk consumed by pastoralists in Kenya remains unclear. We investigated the relationship between AMU and emergence of multidrug-resistant (MDR) S. aureus, including MRSA in raw milk of livestock. AMU data were obtained using sales records from veterinary pharmacies. S. aureus was isolated from 603 milk samples from various livestock species, including sheep, goat, cow, and camel reared in Isiolo and Marsabit counties in Kenya. Resistant phenotypes and genotypes were determined by disc diffusion and molecular methods, respectively. Correlation between AMU and occurrence of resistance was determined by Pearson's correlation coefficient (r) method. The consumption of various antimicrobial classes were as follows; 4,168 kg of oxytetracycline, 70 kg of sulfonamides, 49.7 kg of aminoglycosides, 46 kg of beta-lactams, 39.4 kg of macrolides, and 0.52 kg for trimethoprim. The S. aureus isolates were mainly resistant to tetracycline (79%), ampicillin (58%), and oxacillin (33%), respectively. A few isolates (5-18%) were resistant to clindamycin, cephalexin, erythromycin, kanamycin, and ciprofloxacin. Most of the MDR-S. aureus isolates were MRSA (94%). The genetic determinants found in the AMR isolates included tetK/tetM (96.5%/19%) for tetracycline, blaZ (79%) for penicillin, aac (6')/aph (2'')/aph (3')-IIIa (53%) for aminoglycosides, mecA (41%) for oxacillin, and msrA/ermA (24%/7%) for macrolides. Oxytetracycline usage was correlated to tetK/tetM (r = 0.62/1) detection, penicillins to mecA/blaZ (r = 0.86/0.98), aminoglycoside to aac (6')/aph (2'')/aph (3')-IIIa (r = 0.76/-13), and macrolide usages for detection of ermA/msrA (r = 0.94/0.77). AMU appeared to be associated with occurrence of MDR-SA and the tetM detection. Consumption of raw milk contaminated with MRSA could pose a serious public health risk in pastoral communities in northern Kenya.
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Affiliation(s)
- Isaac Omwenga
- International Livestock Research Institute, Nairobi, Kenya.,Department of Public Health Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | - Gabriel O Aboge
- Department of Public Health Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya.,Center for Biotechnology and Bioinformatics, College of Biological and Physical Sciences, University of Nairobi, Nairobi, Kenya
| | - Eric S Mitema
- Department of Public Health Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | - George Obiero
- Center for Biotechnology and Bioinformatics, College of Biological and Physical Sciences, University of Nairobi, Nairobi, Kenya
| | - Catherine Ngaywa
- International Livestock Research Institute, Nairobi, Kenya.,Center for Biotechnology and Bioinformatics, College of Biological and Physical Sciences, University of Nairobi, Nairobi, Kenya
| | | | - George Wamwere
- International Livestock Research Institute, Nairobi, Kenya
| | | | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
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Wainaina M, Aboge GO, Omwenga I, Ngaywa C, Ngwili N, Kiara H, Wamwere-Njoroge G, Bett B. Detection of Brucella spp. in raw milk from various livestock species raised under pastoral production systems in Isiolo and Marsabit Counties, northern Kenya. Trop Anim Health Prod 2020; 52:3537-3544. [PMID: 32948966 PMCID: PMC7606284 DOI: 10.1007/s11250-020-02389-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 09/10/2020] [Indexed: 11/26/2022]
Abstract
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.
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Affiliation(s)
| | - Gabriel O Aboge
- Department of Public Health Pharmacology and Toxicology, College of Agriculture and Veterinary Sciences, University of Nairobi, Nairobi, Kenya
- Centre for Biotechnology and Bioinformatics, College of Biological and Physical Sciences, University of Nairobi, Nairobi, Kenya
| | - Isaac Omwenga
- International Livestock Research Institute, Nairobi, Kenya
- Department of Public Health Pharmacology and Toxicology, College of Agriculture and Veterinary Sciences, University of Nairobi, Nairobi, Kenya
| | - Catherine Ngaywa
- International Livestock Research Institute, Nairobi, Kenya
- Centre for Biotechnology and Bioinformatics, College of Biological and Physical Sciences, University of Nairobi, Nairobi, Kenya
| | | | - Henry Kiara
- International Livestock Research Institute, Nairobi, Kenya
| | | | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
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Kairu-Wanyoike S, Nyamwaya D, Wainaina M, Lindahl J, Ontiri E, Bukachi S, Njeru I, Karanja J, Sang R, Grace D, Bett B. Positive association between Brucella spp. seroprevalences in livestock and humans from a cross-sectional study in Garissa and Tana River Counties, Kenya. PLoS Negl Trop Dis 2019; 13:e0007506. [PMID: 31622339 PMCID: PMC6818805 DOI: 10.1371/journal.pntd.0007506] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 10/29/2019] [Accepted: 09/23/2019] [Indexed: 11/17/2022] Open
Abstract
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.
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Affiliation(s)
- Salome Kairu-Wanyoike
- Department of Veterinary Services, Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
| | - Doris Nyamwaya
- International Livestock Research Institute, Nairobi, Kenya
| | | | | | - Enoch Ontiri
- International Livestock Research Institute, Nairobi, Kenya
| | - Salome Bukachi
- Institute of Anthropology, University of Nairobi, Nairobi, Kenya
| | - Ian Njeru
- Division of Disease Surveillance and Response, Ministry of Public Health and Sanitation, Kenyatta National Hospital, Nairobi, Kenya
| | - Joan Karanja
- Division of Disease Surveillance and Response, Ministry of Public Health and Sanitation, Kenyatta National Hospital, Nairobi, Kenya
| | | | - Delia Grace
- International Livestock Research Institute, Nairobi, Kenya
| | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
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8
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Lindahl JF, Ragan IK, Rowland RR, Wainaina M, Mbotha D, Wilson W. A multiplex fluorescence microsphere immunoassay for increased understanding of Rift Valley fever immune responses in ruminants in Kenya. J Virol Methods 2019; 269:70-76. [PMID: 30974177 DOI: 10.1016/j.jviromet.2019.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/07/2019] [Accepted: 04/07/2019] [Indexed: 10/27/2022]
Abstract
Rift Valley fever virus (RVFV) is an important mosquito-borne pathogen with devastating impacts on agriculture and public health. With outbreaks being reported beyond the continent of Africa to the Middle East, there is great concern that RVFV will continue to spread to non-endemic areas such as the Americas and Europe. There is a need for safe and high throughput serological assays for rapid detection of RVFV during outbreaks and for surveillance. We evaluated a multiplexing fluorescence microsphere immunoassay (FMIA) for the detection of IgG and IgM antibodies in ruminant sera against the RVFV nucleocapsid Np, glycoprotein Gn, and non-structural protein NSs. Sheep and cattle sera from a region in Kenya with previous outbreaks were tested by FMIA and two commercially available competitive ELISAs (BDSL and IDvet). Our results revealed strong detection of RVFV antibodies against the Np, Gn and NSs antigen targets. Additionally, testing of samples with FMIA Np and Gn had 100% agreement with the IDvet ELISA. The targets developed in the FMIA assay provided a basis for a larger ruminant disease panel that can simultaneously screen several abortive and zoonotic pathogens.
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Affiliation(s)
- Johanna F Lindahl
- International Livestock Research Institute, Nairobi, Kenya; Zoonosis Science Center, Uppsala University, Uppsala, Sweden; Swedish University of Agricultural Research, Uppsala, Sweden.
| | - Izabela K Ragan
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA; Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - R R Rowland
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | | | - Deborah Mbotha
- International Livestock Research Institute, Nairobi, Kenya; Institute for Parasitology and Tropical Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany
| | - William Wilson
- Arthropod-Borne Animal Diseases Research Unit, USDA, ARS, Manhattan, KS, USA
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9
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Wainaina M, Bett B, Ontiri E, Picozzi K, Agwanda B, Strand T, Grace D, Lundkvist Å, Lindahl J. Leptospira bacteria detected in rodents in Tana River and Garissa counties of Kenya. Infect Ecol Epidemiol 2018. [DOI: 10.1080/20008686.2018.1547093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Affiliation(s)
- Martin Wainaina
- International Livestock Research Institute, Nairobi, Kenya
- The University of Edinburgh, Edinburgh, UK
| | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
| | - Enoch Ontiri
- International Livestock Research Institute, Nairobi, Kenya
| | | | | | - Tanja Strand
- Zoonosis Science Center, Uppsala University, Uppsala, Sweden
- Swedish University of Agriculture, Uppsala, Sweden
| | - Delia Grace
- International Livestock Research Institute, Nairobi, Kenya
| | - Åke Lundkvist
- Zoonosis Science Center, Uppsala University, Uppsala, Sweden
| | - Johanna Lindahl
- International Livestock Research Institute, Nairobi, Kenya
- Zoonosis Science Center, Uppsala University, Uppsala, Sweden
- Swedish University of Agriculture, Uppsala, Sweden
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10
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Mbotha D, Bett B, Kairu-Wanyoike S, Grace D, Kihara A, Wainaina M, Hoppenheit A, Clausen PH, Lindahl J. Inter-epidemic Rift Valley fever virus seroconversions in an irrigation scheme in Bura, south-east Kenya. Transbound Emerg Dis 2017; 65:e55-e62. [PMID: 28710814 DOI: 10.1111/tbed.12674] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Indexed: 11/30/2022]
Abstract
Rift Valley fever (RVF) is an acute mosquito-borne viral zoonosis whose outbreaks are often associated with prolonged rainfall and flooding, during which large numbers of vectors emerge. Recent studies into the inter-epidemic maintenance of RVF virus (RVFV) suggest that both vertical transmission in vectors and direct transmission between hosts act in combination with predisposing factors for persistence of the virus. A comparative longitudinal survey was carried out in Tana River County, Kenya, in irrigated, riverine and pastoral ecosystems from September 2014-June 2015. The objectives were to investigate the possibility of low-level RVFV transmission in these ecosystems during an inter-epidemic period (IEP), examine variations in RVFV seroprevalence in sheep and goats and determine the risk factors for transmission. Three hundred and sixteen small ruminants were selected and tested for immunoglobulin G antibodies against RVFV nucleoprotein using a competitive ELISA during six visits. Data on potential risk factors were also captured. Inter-epidemic RVFV transmission was evidenced by 15 seroconversions within the irrigated and riverine villages. The number of seroconversions was not significantly different (OR = 0.66, CI = 0.19-2.17, p = .59) between irrigated and riverine areas. No seroconversions were detected in the pastoral ecosystem. This study highlights the increased risk of inter-epidemic RVFV transmission posed by irrigation, through provision of necessary environmental conditions that enable vectors access to more breeding grounds, resting places and shade, which favour their breeding and survival.
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Affiliation(s)
- D Mbotha
- International Livestock Research Institute, Nairobi, Kenya.,Institute for Parasitology and Tropical Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany
| | - B Bett
- International Livestock Research Institute, Nairobi, Kenya
| | | | - D Grace
- International Livestock Research Institute, Nairobi, Kenya
| | - A Kihara
- International Livestock Research Institute, Nairobi, Kenya
| | - M Wainaina
- International Livestock Research Institute, Nairobi, Kenya
| | - A Hoppenheit
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany
| | - P-H Clausen
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universitaet Berlin, Berlin, Germany
| | - J Lindahl
- International Livestock Research Institute, Nairobi, Kenya.,Swedish University of Agricultural Sciences, Uppsala, Sweden.,Uppsala University, Uppsala, Sweden
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