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Abstract Background Ticks and tick-borne diseases (TTBDs) are a significant threat to livestock production in sub-Saharan Africa. Transhumance pastoralism practiced in Karamoja region and other factors like cattle trade, communal grazing and the presence of wildlife predispose cattle to TTBDs. Tick species abundance and distribution data can be used as a tool for early disease diagnosis and inform tick control strategies. However, these data for north-eastern Uganda are currently limited; previous surveys were relatively localized and targeted fewer cattle kraals and numbers. Methods We randomly collected tick specimens from 1,534 cattle spread across Karamoja region in both the peak month of the rainy (May 2020) and the dry (February2021) seasons. The ticks were identified using morpho-taxonomic keys and the tick species identities confirmed by the 16 S rRNA gene sequencing and phylogenetic analysis. Results A collection of 18,637 ticks was examined and fifteen tick species from three genera (ten Rhipicephalus; three Amblyomma; two Hyalomma species) were identified. Rhipicephalus appendiculatus was the most dominant (37.9%) tick species, followed by Amblyomma variegatum (32.3%); A. lepidum (17.3%); R. evertsi evertsi (7.8%); and R. decoloratus (1.4%). Eight of these tick species were ubiquitous in the study districts while six were found in isolated areas. The peak month of the dry season collection was associated with a higher proportion of tick-infested cattle (91%) compared to the peak month of the rainy season (89.8%); a difference that was not found statistically significant (χ 2 = 0.5077, n = 1385, p = 0.476). The overall cattle infestation rate was mainly dominated by five tick species namely: A. variegatum (55%), R. appendiculatus (53%), A. lepidum (41%), R. evertsi (22%), and R. decoloratus (8%). The proportion of tick-infested cattle was highest in Napak District (95.4%) and lowest in Amudat District (80.9%) during the peak month of the rainy season. Napak and Amudat Districts also had the highest and lowest proportion of tick-infested cattle (94.8% and 80.7% respectively) during the peak month of the dry season. Rhipicephalus microplus was confirmed in Amudat, Kaabong and Napak districts. Conclusion This study demonstrates high tick infestation rates in cattle by a battery of tick species in Karamoja region. We identified both R. microplus and R. decoloratus which indicates that R. microplus has recently been introduced in this region. This calls for effective tick control responses to prevent further spread of this invasive cattle tick specie.

To date, information on Cryptosporidium spp. infection status among people and wild animals living at the wildlife-human interface such as Queen Elizabeth National Park (QENP) is scarce. The aim of this study is to document the molecular detection of Cryptosporidium spp. in wild animals, and people, around QENP in the Kasese District. A total of 308 patients from four health centres and 252 wildlife animals from six species across 13 sampling areas were analysed microscopically and with PCR for Cryptosporidium spp. detection. The parasitological and molecular prevalence of Cryptosporidium spp. in humans was 40% and 53%, respectively; Kasenyi Health Centre recorded the highest percentage of positive stool samples for both tests. Wildlife species had an overall molecular percentage positivity of 30.16%; however, considering individual animal species that were sampled, the Waterbucks had the highest positivity rate, that is, 54.54%. All the samples were confirmed as genus Cryptosporidium with less species discrimination as our PCR target was a short fragment. There is a need to investigate the risk factors that predispose to high Cryptosporidium infection in the study area, especially in Kasenyi. In-depth investigation of the genetic diversity of Cryptosporidium spp. circulating at the human, livestock, and wildlife interface is imperative in devising disease management strategies.

Abstract Background Rhipicephalus microplus, an invasive tick species of Asian origin and the main vector of Babesia species, is considered one of the most widespread ectoparasites of livestock. The tick has spread from its native habitats on translocated livestock to large parts of the tropical world, where it has replaced some of the local populations of Rhipicephalus decoloratus ticks. Although the tick was reported in Uganda 70 years ago, it has not been found in any subsequent surveys. This study was carried out to update the national tick species distribution on livestock in Uganda as a basis for tick and tick-borne disease control, with particular reference to R. microplus. Methods The study was carried out in Kadungulu, Serere district, south-eastern Uganda, which is dominated by small scale livestock producers. All the ticks collected from 240 cattle from six villages were identified microscopically. Five R. microplus specimens were further processed for phylogenetic analysis and species confirmation. Results The predominant tick species found on cattle was Rhipicephalus appendiculatus (86.9 %; n = 16,509). Other species found were Amblyomma variegatum (7.2 %; n = 1377), Rhipicephalus evertsi (2.3 %; n = 434) and R. microplus (3.6 %; n = 687). Phylogenetic analysis of the 12S rRNA, 16S rRNA and ITS2 gene sequences of R. microplus confirmed the morphological identification. Conclusions It is concluded that R. microplus has replaced R. decoloratus in the sampled villages in Kadungulu sub-county, since the latter was not any longer found in this area. There is currently no livestock movement policy in force in Uganda, which could possibly limit the further spread of R. microplus ticks. Future surveys, but also retrospective surveys of museum specimens, will reveal the extent of distribution of R. microplus in Uganda and also for how long this tick has been present on livestock without being noticed.

Antimicrobial peptides (AMPs) constitute a broad range of bioactive compounds in diverse organisms, including fish. They are effector molecules for the innate immune response, against pathogens, tissue damage and infections. Still, AMPs from African Catfish, Clarias gariepinus, skin mucus are largely unexplored despite their possible therapeutic role in combating antimicrobial resistance. In this study, African Catfish Antimicrobial peptides (ACAPs) were identified from the skin mucus of African Catfish, C. gariepinus. Native peptides were extracted from fish mucus scrapings in 10% acetic acid (v/v) and ultra-filtered using 5 kDa molecular weight cut-off membrane. The extract was purified using C18 Solid-Phase Extraction. The antibacterial activity was determined using the Agar Well Diffusion method and broth-dilution method utilizing Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922). Thereafter, Sephadex G-25 gel filtration was further utilized in bio-guided isolation of the most active fractions prior to peptide identification using Orbitrap Fusion Lumos Tribrid Mass Spectrometry. The skin mucus extracted from African Catfish from all the three major lakes of Uganda exhibited antimicrobial activity on E. coli and S. aureus. Lake Albert’s C. gariepinus demonstrated the best activity with the lowest MIC of 2.84 and 0.71 μg/ml on S. aureus and E. coli, respectively. Sephadex G-25 peak I mass spectrometry analysis (Data are available via ProteomeXchange with identifier PXD029193) alongside in silico analysis revealed seven short peptides (11–16 amino acid residues) of high antimicrobial scores (0.561–0.905 units). In addition, these peptides had a low molecular weight (1005.57–1622.05 Da) and had percentage hydrophobicity above 54%. Up to four of these AMPs demonstrated α-helix structure conformation, rendering them amphipathic. The findings of this study indicate that novel AMPs can be sourced from the skin mucus of C. gariepinus. Such AMPs are potential alternatives to the traditional antibiotics and can be of great application to food and pharmaceutical industries; however, further studies are still needed to establish their drug-likeness and safety profiles.

Abstract Background Lumpy skin disease (LSD) is an infectious viral disease of cattle caused by a Capripoxvirus. LSD has substantial economic implications, with infection resulting in permanent damage to the skin of affected animals which lowers their commercial value. In Uganda, LSD is endemic and cases of the disease are frequently reported to government authorities. This study was undertaken to molecularly characterize lumpy skin disease virus (LSDV) strains that have been circulating in Uganda between 2017 and 2018. Secondly, the study aimed to determine the phylogenetic relatedness of Ugandan LSDV sequences with published sequences, available in GenBank. Results A total of 7 blood samples and 16 skin nodule biopsies were screened for LSDV using PCR to confirm presence of LSDV nucleic acids. PCR positive samples were then characterised by amplifying the GPCR gene. These amplified genes were sequenced and phylogenetic trees were constructed. Out of the 23 samples analysed, 15 were positive for LSDV by PCR (65.2%). The LSDV GPCR sequences analysed contained the unique signatures of LSDV (A11, T12, T34, S99, and P199) which further confirmed their identity. Sequence comparison with vaccine strains revealed a 12 bp deletion unique to Ugandan outbreak strains. Phylogenetic analysis indicated that the LSDV sequences from this study clustered closely with sequences from neighboring East African countries and with LSDV strains from recent outbreaks in Europe. It was noted that the sequence diversity amongst LSDV strains from Africa was higher than diversity from Eurasia. Conclusion The LSDV strains circulating in Uganda were closely related with sequences from neighboring African countries and from Eurasia. Comparison of the GPCR gene showed that outbreak strains differed from vaccine strains. This information is necessary to understand LSDV molecular epidemiology and to contribute knowledge towards the development of control strategies by the Government of Uganda.

Abstract Background Lumpy skin disease (LSD) is a transboundary cattle disease caused by a Capripoxvirus of the family Poxviridae. In Uganda, documented information on the epidemiology of the disease is rare and there is no nationwide control plan, yet LSD is endemic. This study set out to investigate the seroprevalence of lumpy skin disease and determine the risk factors for LSD seropositivity, by carrying out a cross-sectional study in 21 districts of Uganda. Results A total of 2,263 sera samples were collected from 65 cattle herds and an indirect ELISA was used to screen for lumpy skin disease virus (LSDV) antibodies. We used univariable and multivariable mixed effect logistic regression models to identify risk factors for LSD seropositivity. The overall animal and herd-level seroprevalences were 8.7% (95% CI: 7.0–9.3) and 72.3% (95% CI: 70.0–80.3), respectively. Animal-level seroprevalence in Central region (OR = 2.13, p = 0.05, 95% CI: 1.10–4.64) was significantly different from the Northern region (Reference) and Western region (OR = 0.84, p = 0.66, 95% CI: 0.39–1.81). Management type, sex, age, mean annual precipitation > 1000 mm, and drinking from communal water sources were statistically significant risk factors for occurrence of anti-LSDV antibodies in cattle. Breed, region, herd size, contact with buffalo and other wildlife and introduction of new cattle did not have a statistically significant association with being positive for LSDV. Conclusion We report a high herd-level LSDV seroprevalence in Uganda with a moderate animal-level seroprevalence. Cattle with the highest risk of LSD infection in Uganda are those in fenced farms, females > 25 months old, in an area with a mean annual rainfall > 1000 mm, and drinking from a communal water source.

Abstract Background Lumpy skin disease (LSD) is a devastating transboundary viral disease of cattle which causes significant loss in production. Although this disease has been reported in Uganda and throughout East Africa, there is almost no information about its epidemiology, spatial or spatio-temporal distribution. We carried out a retrospective study on the epidemiology of LSD in Uganda between the years 2002 and 2016, using data on reported outbreaks collected monthly by the central government veterinary administration. Descriptive statistics were computed on frequency of outbreaks, number of cases, vaccinations and deaths. We evaluated differences in the number of reported outbreaks across different regions (agro-ecological zones), districts, months and years. Spatial, temporal and space-time scan statistics were used to identify possible epidemiological clusters of LSD outbreaks. Results A total of 1161 outbreaks and 319,355 cases of LSD were reported from 55 out of 56 districts of Uganda. There was a significant difference in incidence between years (P = 0.007) and across different regions. However, there was no significant difference in the number of outbreaks per month (P = 0.443). The Central region reported the highest number of outbreaks (n = 418, 36%) followed by Eastern (n = 372, 32%), Southwestern (n = 140, 12%), Northern (n = 131, 11%), Northeastern (n = 37, 3%), Western (n = 41, 4%) and Northwestern (n = 22, 2%) regions. Several endemic hotspots for the circulation of LSD were identified in the Central and Eastern regions using spatial cluster analyses. Outbreaks in endemic hotspots were less seasonal and had strikingly lower mortality and case-fatality rates than the other regions, suggesting an underlying difference in the epidemiology and impact of LSD in these different zones. Conclusion Lumpy Skin disease is endemic in Uganda, with outbreaks occurring annually in all regions of the country. We identified potential spatial hotspots for LSD outbreaks, underlining the need for risk-based surveillance to establish the actual disease prevalence and risk factors for disease maintenance. Space-time analysis revealed that sporadic LSD outbreaks tend to occur both within and outside of endemic areas. The findings from this study will be used as a baseline for further epidemiological studies for the development of sustainable programmes towards the control of LSD in Uganda.

This paper describes an assessment of the patterns of peste des petits ruminants virus circulation in the Karamoja subregion of Uganda conducted to identify the communities that maintain the virus and inform the development of a targeted vaccination strategy. Participatory epidemiological methods were used to develop an operational hypothesis for the patterns of PPR in Karamoja that was subsequently validated through outbreak investigation and genomics. The participatory epidemiological assessment included risk mapping with livestock owners, community animal health workers and veterinarians and indicated there were two critical foci of virus transmission on the Uganda-Kenya border. One was located in two adjacent subcounties of Kotido and Kaabong Districts in northern Karamoja and the other in Loroo subcounty of Amudat District in southern Karamoja. Participants reported that these were locations where outbreaks were usually first observed in Karamoja and subsequently spread to other areas. Following the participatory assessment, surveillance activities were implemented across the Karamoja subregion in 2018. Three outbreak were detected, investigated and sampled. Two outbreaks were located in the northern and one on the southern focus of transmission. No Outbreaks were diagnosed in Karamoja outside of these foci during 2018. Genomics indicated different clusters of viruses were associated with the northern and southern foci that were more closely related to other East African isolates than to each other. This indicates these are two separate systems of virus circulation which should be explicitly addressed in eradication as separate cross-border systems that require integrated cross-border interventions.