Intensification of food production has the potential to drive increased disease prevalence in food plants and animals. Microsporidia are diversely distributed, opportunistic, and density-dependent parasites infecting hosts from almost all known animal taxa. They are frequent in highly managed aquatic and terrestrial hosts, many of which are vulnerable to epizootics, and all of which are crucial for the stability of the animal-human food chain. Mass rearing and changes in global climate may exacerbate disease and more efficient transmission of parasites in stressed or immune-deficient hosts. Further, human microsporidiosis appears to be adventitious and primarily associated with an increasing community of immune-deficient individuals. Taken together, strong evidence exists for an increasing prevalence of microsporidiosis in animals and humans, and for sharing of pathogens across hosts and biomes.

Smallholder pig production in Uganda is constrained by poor management and high disease burden, with African swine fever (ASF) being one of the most important contributors. However, data to develop appropriate evidence-based disease mitigating interventions along the pig value chain are lacking. This study aimed at determining risk factors associated with the occurrence of outbreaks of ASF in selected districts. A cross-sectional survey of 1195 pig-keeping households in three districts was carried out between April and July 2013. Households were classified into one of three value chain domains (VCDs) based on where the production was located and where most of the products were sold: rural-rural (R-R), rural-urban (R-U) and urban-urban (U-U). Findings revealed that crop farming is the most common primary activity in the R-R and R-U VCDs, while pig keeping was the most common primary activity in the U-U VCDs. Pigs are mostly kept tethered or left to roam in the R-R and R-U VCDs, while in the U-U VCDs, they are mostly confined in corrals. Nearly 20% of the farmers whose farms were hit by an ASF outbreak subsequently sold all their pigs (healthy and sick) to the market in panic. Factors that positively correlated with recent ASF outbreaks were prompt disposal of dead pigs on farms (P < 0.001, OR = 2.3), wild animals present in the village (P < 0.001, OR = 1.7) and farmers sourcing drugs from stockists (P < 0.001, OR = 1.6); while protective factors were the presence of perimeter fences (P = 0.03, OR = 0.5), attendance of farmers at secondary-school level and above (P < 0.001, OR = 0.6), routine cleaning of the pig pens (P < 0.001, OR = 0.6) and pigs being the only livestock kept by farmer (P = 0.01, OR = 0.7). Given the current situation, there is a need to raise awareness among farmers and other value chain actors of biosecurity measures and create incentives for farmers to report ASF cases.

In Eastern Africa, small-scale pig keeping has emerged as a popular activity to generate additional household income. Infections of pigs with gastrointestinal helminths can limit production output, increase production costs, and pose zoonotic risks. A cross-sectional, community-based study in three districts in Eastern and Central Uganda examined the prevalence of gastrointestinal helminthes and associated risk factors in 932 randomly sampled pigs. Using the combined sedimentation-flotation method, 61.4 % (58.2–64.5 %, 95 % confidence interval [CI]) tested positive for one or more gastrointestinal helminths, namely, strongyles (57.1 %, 95 % CI), Metastrongylus spp. (7.6 %, 95 % CI), Ascaris suum (5.9 %, 95 % CI), Strongyloides ransomi (4.2 %, 95 % CI), and Trichuris suis (3.4 %, 95 % CI). Coccidia oocysts were found in 40.7 % of all pigs sampled (37.5–44.0 %, 95 % CI). Significant differences across the three districts were observed for the presence of A. suum (p < 0.001), Metastrongylus spp. (p = 0.001), S. ransomi (p = 0.002), and coccidia oocysts (p = 0.05). All animals tested negative for Fasciola spp. and Balantidium coli. Thirty-five variables were included in univariable analyses with helminth infection as the outcome of interest. A causal model was generated to identify relationships among the potential predictors, and consequently, seven variables with p ≤ 0.15 were included in a multivariable analysis for helminth infection. The final regression models showed that routine management factors had a greater impact on the prevalence of infection than regular, preventive medical treatment or the level of confinement. Factors that negatively correlated with gastrointestinal infection were the routine removal of manure and litter from pig pens (p ≤ 0.05, odds ratio [OR] = 0.667) and the routine use of disinfectants (p ≤ 0.05, OR = 0.548).

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 typhoidalSalmonellaand Dengue virus. An increase in the PMr ofKlebsiellaspp. infections was observed over time. Furthermore, the status of patients as either inpatient or outpatient predicted the PMr ofHaemophilusspp. 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.

The success of a systematic review depends on the availability, accessibility and quality of literature related to the review question. This paper presents the literature found in four systematic reviews conducted for a selection of zoonotic hazards in four livestock value chains in Africa, as well as setting out the challenges in conducting the reviews. The protocol was designed following international standards, and addressed four questions around prevalence, risk factors, control options and impact of various hazards and populations. Searches were conducted in four online databases. Articles were screened for relevance, and quality was assessed before data extraction. Literature on zoonotic hazards was in general scarce and access to full articles was limited. Overall, 25–40% of papers were considered poor quality. The diversity of approaches and designs in the studies compromised the ability to generate summarized estimates. We found that the emphasis of veterinary research has been on livestock problems rather than public health issues, although this seems to be shifting in the last decade; we also found there are limited studies on impact and control. While increasing literature is being published around zoonoses in Africa, this is still inadequate to appropriately inform policy and guide research efforts.