Q Fever

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

Coxiella burnetii, the causative agent of Query fever (Q fever), is among the most highly infectious zoonotic pathogens transmitted among livestock, with chronic effects challenging to veterinary and medical detection and care systems. Transmission among domestic livestock species can vary regionally due to herd management practices that determine which livestock species are raised, whether or not livestock are in contact with wildlife, and the susceptibility of these livestock to infection. To explore how different livestock management practices are associated with the risk of infection in multispecies environments, we carried out a comparative study of three types of herd management systems in the central Kenyan county of Laikipia: agro-commercial, mixed conservancy/commercial, and smallholder ranches. We tested C. burnetii antibody seroprevalence in four common livestock species. Across all management types, the highest seroprevalence was in camels (20%), followed by goats (18%), sheep (13%), and cattle (6%). We observed a lower odds of testing seropositive for young compared to adult animals (adjusted OR = 0.44 [95% CI 0.24, 0.76]), and for males compared to females (adjusted OR = 0.52 [95% CI 0.33, 0.80]). Animals from mixed conservancy/commercial and smallholder operations had a higher odds of testing seropositive compared to animals from agro-commercial ranches (adjusted OR = 5.17 [95% CI 2.71, 10.44] and adjusted OR = 2.21 [95% CI 1.17, 4.43] respectively). These data suggest that herd management practices might affect the transmission dynamics of C. burnetiiin arid African ecosystems like those seen in Kenya where several transmission modes are possible, risk of drought has promoted new livestock species such as camels, and multiple wildlife species may co-occur with livestock on the landscape. Further longitudinal studies are needed to disentangle the mechanisms underlying these patterns, and further explore transmission patterns between wildlife, domestic animal, and human populations.

Q fever is a worldwide zoonosis caused by Coxiella burnetii (Cb). From January 2018 to November 2019, plasma samples from 2,382 patients with acute fever of unknown cause at a hospital in Zhuhai city of China were tested using metagenomic next-generation sequencing (mNGS). Of those tested, 138 patients (5.8%) were diagnosed with Q fever based on the presence of Cb genomic DNA detected by mNGS. Among these, 78 cases (56.5%) presented from Nov 2018 to Mar 2019, suggesting an outbreak of Q fever. 55 cases with detailed clinical information that occurred during the outbreak period were used for further analysis. The vast majority of plasma samples from those Cb-mNGS-positive patients were positive in a Cb-specific quantitative polymerase chain reaction (n = 38) and/or indirect immunofluorescence assay (n = 26). Mobile phone tracing data was used to define the area of infection during the outbreak. This suggested the probable infection source was Cb-infected goats and cattle at the only official authorized slaughterhouse in Zhuhai city. Phylogenic analysis based on genomic sequences indicated Cb strains identified in the patients, goat and cattle were formed a single branch, most closely related to the genomic group of Cb dominated by strains isolated from goats. Our study demonstrates Q fever was epidemic in 2018-2019 in Zhuhai city, and this is the first confirmed epidemic of Q fever in a contemporary city in China.

BackgroundBrucella species and Coxiella burnetii have been detected in livestock populations in Togo. Populations exposed to livestock ruminants through their occupation may be at increased risk of infection.Methods/principal findingsA cross-sectional serosurvey was conducted in 108 abattoir and 81 dairy farm workers (from 52 dairy farms) in peri-urban Lomé, Togo in 2019-2020. Structured questionnaires were used to collect data on participant livestock contact and dairy product consumption. Sera were tested using the Rose Bengal plate agglutination test (RBT) and the indirect Brucella IgG Enzyme-Linked Immunosorbent Assay (ELISA) for Brucella, and the IgG ELISA for Coxiella burnetii in Phase 1 and in Phase 2. Fresh bulk milk samples from farms were tested using an indirect milk ELISA for Brucella IgG. The association between seropositivity and exposure variables was examined using logistic regression with robust standard errors to account for site-level clustering. Eighteen workers (9.5%, 95% CI 5.5-16.0) were Brucella seropositive. Twenty-eight percent (95% CI 22.5-34.3) of workers were seropositive for C. burnetii. Twenty of fifty-one farms which gave milk samples tested positive for Brucella antibodies (39.2%, 95% CI 26.6 - 53.4%). Farmworkers had nearly twice the crude odds of being Brucella seropositive compared to abattoir workers (OR 1.93, 95% CI: 0.94-3.93, p = 0.07). After adjusting for age, working on farms with animal ill health, a positive milk test, participating in small ruminant husbandry and assisting with cattle abortion were all associated with increased odds of seropositivity. Farm and abattoir workers who consumed raw milk at least every month were more likely to be seropositive for Brucella species (OR 3.79, 95% CI: 2.34-6.13, p ConclusionsLivestock workers in peri-urban Lomé have been exposed to both Brucella and Coxiella burnetii bacteria. The widespread consumption of raw dairy products and lack of personal protective equipment (PPE) use is of concern as both dairy consumption and participation in animal husbandry activities have been seen to increase odds of seropositivity for both pathogens. A One Health prioritization of zoonotic disease would help to bring together the relevant sectors to adequately resource prevention and control of zoonoses of public health concern in Togo, which may particularly impact workers in close contact with animals.