Eric M. Fèvre’s research while affiliated with University of Liverpool and other places

Climate change is having unprecedented impacts on human health, including increasing infectious disease risk. Despite this, health systems across the world are currently not prepared for novel disease scenarios anticipated with climate change. While the need for health systems to develop climate change adaptation strategies has been stressed in the past, there is no clear consensus on how this can be achieved, especially in rural areas in low- and middle-income countries that experience high disease burdens and climate change impacts simultaneously. Here, we highlight the need to put health systems in the context of climate change and demonstrate how this can be achieved by taking into account all aspects of infectious disease risk (i.e., pathogen hazards, and exposure and vulnerability to these pathogen hazards). The framework focuses on rural communities in East Africa since communities in this region experience climate change impacts, present specific vulnerabilities and exposure to climate-related hazards, and have regular exposure to a high burden of infectious diseases. Implementing the outlined approach can help make health systems climate adapted and avoid slowing momentum towards achieving global health grand challenge targets.

Rabies vaccination in domestic dog populations has increased globally in a bid to protect human health. Surveillance efforts, however, are inconsistent in endemic regions such as in sub‐Saharan Africa, due to fragmented reporting and limited diagnostic capacity for suspected cases, limiting successful monitoring and evaluation of vaccination campaigns. Here, we conducted a pilot study aiming to strengthen rabies surveillance by combining community‐based surveillance with field‐based diagnostic testing in pastoral and agro‐pastoral communities in central Kenya; communities which are frequently marginalised from health systems. During the 6‐month pilot study, there were 14 alerts of suspected rabid dogs in the community, of which eight were tested and five diagnostically confirmed as rabid. Two positive samples processed successfully for whole genome sequencing indicated that the rabies variant circulating in central Kenya during the study period belonged to the Africa 1b subclade, which is similar to variants identified in eastern Kenya and Tanzania, suggesting regional transmission. This pilot study indicates that rabies continues to circulate in the region and that community‐based surveillance, when combined with enhanced diagnostic testing, can help alleviate underreporting and guide vaccination campaigns.

Porcine cysticercosis (PC) is an important public health problem, especially in sub-Saharan Africa, but limited information is available on the prevalence of infection in pigs entering the food chain. Existing diagnostic methods vary in accuracy and efficiency; whole carcass dissection is the most reliable method but is labour-intensive and destroys the carcass so can only be used in a research setting. Serological tests offer lower specificity, while meat inspection and lingual examination lack sensitivity, hampering accurate estimates and the removal of infected pigs from the food chain. Here, we provide the first estimates of PC prevalence in abattoirs in Rwanda. We use whole carcass dissection to determine the diagnostic accuracy of a commercial antigen-ELISA to estimate the true prevalence of infection across Rwanda and identify Taenia species affecting local pigs. We carried out a cross-sectional survey in 6 abattoirs across Rwanda (n = 744 pigs), with whole carcass dissection of a subset of 67 pigs. Cysts were detected in 20/67 (30%) of carcasses, with >1000 cysts in 9/20 (45%) of infected pigs. All cysts were identified as Taenia solium by PCR-RFLP, with no cysts of Taenia hydatigena found. The antigen-ELISA showed a sensitivity of 90% (95% CI: 68–99) and specificity of 85% (95% CI: 72–94), when compared to dissection. Using these estimates, the true prevalence was calculated as 25–43% in two abattoirs in south-west Rwanda, and 2–3% in the rest of the country. Fewer than half of infected pigs were detected by tongue palpation and post-mortem veterinary inspection. Our data indicate a high prevalence of PC in Rwandan abattoirs. Tongue palpation and veterinary inspections, as currently carried out, have little impact in removing cyst-infested pigs from the food chain. Additional interventions are needed, such as proper pig husbandry, treatment and vaccination against cysticercosis, health education, improved sanitation and hygiene, and improved processing and cooking of meat.

Rift Valley fever (RVF) is a viral zoonosis, which is considered as a threat to food security in the Horn of Africa. In Kenya, RVF is the 5th ranked priority zoonotic disease due to its high morbidity and mortality, frequent outbreak events, and associated socioeconomic impacts during outbreak events. In 2018, an RVF outbreak was confirmed in Kenya's Siaya, Wajir, and Marsabit counties. During this outbreak, 30 people were confirmed infected with RVF through laboratory tests; 21 in Wajir, 8 in Marsabit, and 1 in Siaya Counties. Seventy-five (75) households (15 cases and 60 controls) were selected and interviewed using a case-control study design in 2021 (?). A case was a household with a member who was diagnosed with RVF in 2018. In addition, a total of 1029 animals were purposively selected within these households and serologically tested for RVF. The study aimed to estimate the contribution of various risk factors to RVF human occurrence in Kenya with a special focus on Wajir County. Wajir County was chosen due to high number of confirmed human cases reported in the 2018 outbreak. A univariable regression model revealed that owner-reported RVF virus exposure in livestock significantly increased the odds of an RVF human case in the household by 32.7 times (95 % CI 4.0–267.4). The respondent being linked to a goat flock that was IgG-positive increased the odds of an RVF human case by 3.8 times (95 % CI 1.17–12.3). In the final multivariable analysis, the respondent being linked to their own animals affected by RVF increased odds of having an RVF human case in the household by 56.9 times (95 % CI 4.6–700.4), while the respondent being linked to a neighbor household member affected decreased odds of having a RVF human case by 0.1 times (95 % CI 0.08–0.75). In summary, these results have revealed a potential link for the spread of RVF infection from animals to humans in pastoralist households, hence it is critical to carry out targeted, community education, One Health surveillance, prevention, and control measures against the disease. This will be critical to protecting humans against potential spillovers of infections during outbreak events in livestock.

Slaughterhouses may be hotspots for the transmission of antimicrobial resistant (AMR) pathogens. To obtain information on the AMR landscape in Kenyan slaughterhouses, we collected swabs of the environment, animal carcasses, and workers. Bacterial isolates were identified in 101/193 (52.3 %) samples, and most showed resistance to streptomycin (68.7 %), ampicillin (48.7 %), and tetracycline (42.5 %). Multi drug resistance was exhibited by 35/80 isolates (43.8 %; 95 % CI: 33.2–54.9 %), while Extended Spectrum Beta Lactamase was expressed in 5/80 isolates (6.3 %; 95 % CI: 2.6–14.3 %). These findings illustrate the presence of resistant bacteria throughout the slaughterhouse environment, posing a risk to workers and meat consumers and highlighting the need for an integrated surveillance system along the food chain.

Rift Valley fever virus (RVFV) causes disease outbreaks in livestock and humans; however, its inter-epidemic circulation is poorly understood, similar to other arboviruses affecting cattle such as bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV). Serum samples were collected in Baringo County, Kenya from 400 cattle, accompanied by a risk factor questionnaire. Serological tests were then conducted to determine the exposure of cattle to RVFV, BTV, and EHDV. RVFV, BTV, and EHDV IgG seroprevalence rates were 15.5%, 91.5%, and 91%, respectively. Seropositivity for RVFV, BTV, and EHDV was significantly higher in adult cattle, as well as in females for RVFV. Cattle with herd owners aged between 30-39 years were less likely to be seropositive for RVFV compared to those with owners over the age of 60 years. High seroprevalence of BTV and EHDV in cattle indicates significant exposure and the subclinical circulation of these viruses, presenting a risk of outbreaks to sheep and naïve cattle. Moreover, the detection of RVFV-seropositive young cattle born after the last reported outbreak suggests inter-epidemic circulation of the virus. Overall, monitoring these arboviruses in cattle is crucial in understanding their distribution and seroprevalence during inter-epidemic periods.