Biology subjects

Nyakarahuka, L.

Publications and source records attributed to Nyakarahuka, L..

3 recordsLinked to original sources

bioRxiv2026

Crop-specific agricultural land use and Rift Valley fever outbreaks in Uganda: a longitudinal compositional analysis

Rift Valley fever (RVF) is a mosquito-borne disease that can cause severe illness and death in both humans and livestock. Since 2016, Uganda has experienced recurrent but localized RVF outbreaks concentrated in the countrys southwestern region. The ecological drivers of this emergence remain unclear, as outbreaks have occurred throughout the year and show little association with meteorological patterns. We evaluated whether crop cultivation, particularly banana cultivation, is associated with RVF outbreak occurrence after controlling for likely confounders. We conducted a longitudinal study of human-inhabited 5 x 5 km grid cells across southwestern Uganda from 2016-2024. Annual Sentinel-2 satellite imagery composites were used to classify land cover into banana, coffee, ground crops, and non-crop categories, and the proportion of each land type was calculated for every grid-cell year. Because land cover proportions are compositional, isometric log-ratio transformations were used to estimate the independent effects of each land type. Confounding was addressed through propensity weighting, and crop substitution effects were estimated using g-computation. Banana land cover was the only land type consistently associated with increased RVF outbreak likelihood. In grid-cell years with low baseline banana cover, a 10-percentage point substitution from other land classes into banana was associated with a 1.64-fold increase in the odds of an RVF outbreak (95% CI: 1.17-2.29). In a simplified banana-only model, each 10-percentage point increase in banana cover was associated with a 1.21-fold increase in outbreak odds (95% CI: 1.02-1.43). Holding banana cover constant, substitutions among coffee, ground crop, and non-crop land showed weak or null associations. These findings suggest that banana cultivation may be an important ecological feature influencing RVF transmission dynamics and outbreak risk in southwestern Uganda. Author SummaryRift Valley fever (RVF) is a mosquito-borne disease that affects both humans and livestock and has caused repeated outbreaks in southwestern Uganda since 2016. While rainfall and flooding are often linked to RVF outbreaks elsewhere, Ugandas recent outbreaks have occurred across seasons and are not well explained by weather patterns alone. We investigated whether agricultural land use could help explain where outbreaks occur. Using satellite imagery from 2016-2024, we measured the amount of banana cultivation, coffee cultivation, ground crops, and non-crop land across southwestern Uganda and evaluated their association with RVF outbreak occurrence. We found that areas with greater banana cultivation were consistently more likely to experience RVF outbreaks, even after accounting for environmental and demographic factors. In contrast, coffee, ground crops, and non-crop land showed little evidence of an independent association with outbreak risk. These findings suggest that banana cultivation may create ecological conditions that favor RVF transmission. Rather than indicating that bananas themselves cause disease, the results point to banana-growing landscapes as potential environments where interactions among mosquitoes, livestock, and humans may increase transmission opportunities. Understanding these local ecological drivers could help improve surveillance, risk assessment, and prevention strategies for RVF in Uganda and other endemic regions.

ecology↗

bioRxiv2025

Knowledge, Attitudes and Practices on Antimicrobial Resistance Among Practising Veterinary and Para-veterinary Professionals in Zambia

In this study, we aimed to assess the knowledge, attitudes, and practices (KAP) of veterinary and para-veterinary professionals concerning antimicrobial resistance (AMR), in order to identify key drivers of inappropriate antimicrobial use and gaps in current stewardship efforts. Data was collected from a cross-sectional survey of 144 veterinary and para-veterinary professionals (n=144) using an online structured self-administered questionnaire in ZOHO software. We analyzed data using descriptive statistics and logistic regression in IBM SPSS Statistics Version 25. The findings revealed a high foundational knowledge of AMR, with 66.7% correctly defining AMR. The majority of respondents (82%) acknowledged that overuse of antimicrobials reduces their effectiveness and expressed strong support for mitigation efforts, with 95.8% endorsing farmer education as a key strategy. However, significant gaps in practice persisted: 75% of animal owners frequently initiated antibiotic use without supervision; professionals largely relied on empirical treatment (62.5%); and only 20.8% of professionals routinely performed antimicrobial susceptibility testing (AST), due to barriers like cost and laboratory accessibility. Logistic regression analysis revealed no significant associations between socio-demographic variables and levels of AMR knowledge or attitudes. This suggests that barriers to responsible antimicrobial use may be more structural than individual. We conclude that while Zambian practicing veterinary and para-veterinary professionals possess strong AMR awareness and positive attitudes, risky practices do persist. We recommend strengthening AMR stewardship with a holistic One Health approach by improving veterinary services to promote more appropriate and effective antimicrobial use. Author SummaryAntibiotics are essential for treating sick animals, but their misuse can lead to antimicrobial resistance, where bacteria no longer respond to the drugs meant to kill them. This problem threatens both animal and human health. In Zambia, veterinary and para-veterinary professionals are actively involved in administering treatments and supporting decisions related to antibiotic use in livestock and pets. We wanted to understand what these professionals know, believe, and do when it comes to using antibiotics responsibly. To find out, we surveyed 144 veterinary and para-veterinary professionals from across the country. We learned that most of them were aware that misuse of antibiotics can make treatments less effective and that drug-resistant bacteria can spread between animals and people. Many also supported educating farmers and working with human health experts to tackle the issue. However, we also discovered that antibiotics were often used in animals without proper testing or diagnosis, mainly because of limited laboratory access and cost concerns. Our findings show that while knowledge and attitudes are strong, actual practices need improvement. We believe improved access to diagnostic services, more explicit rules, and ongoing training can help veterinary and veterinary paraprofessionals protect both animal and public health from the growing threat of antibiotic resistance.

scientific communication and education↗

bioRxiv2021

Genetic Diversity of Bundibugyo Ebolavirus from Uganda and the Democratic Republic of Congo

BackgroundThe Ebolavirus is one of the deadliest viral pathogens which was first discovered in the year 1976 during two consecutive outbreaks in the Democratic Republic of Congo and Sudan. Six known strains have been documented. The Bundibugyo Ebolavirus in particular first emerged in the year 2007 in Uganda. This outbreak was constituted with 116 human cases and 39 laboratory confirmed deaths. After 5 years, it re-emerged and caused an epidemic for the first time in the Democratic Republic of Congo in the year 2012 as reported by the WHO. Here, 36 human cases with 13 laboratory confirmed deaths were registered. Despite several research studies conducted in the past, there is still scarcity of knowledge available on the genetic diversity of Bundibugyo Ebolavirus. We undertook a research project to provide insights into the unique variants of Bundibugyo Ebolavirus that circulated in the two epidemics that occurred in Uganda and the Democratic Republic of Congo Materials and MethodsThe Bioinformatics approaches used were; Quality Control, Reference Mapping, Variant Calling, Annotation, Multiple Sequence Alignment and Phylogenetic analysis to identify genomic variants as well determine the genetic relatedness between the two epidemics. Overall, we used 41 viral sequences that were retrieved from the publicly available sequence database, which is the National Center for Biotechnology and Information Gen-bank database. ResultsOur analysis identified 14,362 unique genomic variants from the two epidemics. The Uganda isolates had 5,740 unique variants, 75 of which had high impacts on the genomes. These were 51 frameshift, 15 stop gained, 5 stop lost, 2 missense, 1 synonymous and 1 stop lost and splice region. Their effects mainly occurred within the L-gene region at reference positions 17705, 11952, 11930 and 11027. For the DRC genomes, 8,622 variant sites were identified. The variants had a modifier effect on the genome occurring at reference positions, 213, 266 and 439. Examples are C213T, A266G and C439T. Phylogenetic reconstruction identified two separate and unique clusters from the two epidemics. ConclusionOur analysis provided further insights into the genetic diversity of Bundibugyo Ebolavirus from the two epidemics. The Bundibugyo Ebolavirus strain was genetically diverse with multiple variants. Phylogenetic reconstruction identified two unique variants. This signified an independent spillover event from a natural reservoir, rather a continuation from the ancestral outbreak that initiated the resurgence in DRC in the year 2012. Therefore, the two epidemics were not genetically related.

genomics↗