Spatio-temporal analysis of sheep and goat pox outbreaks in Uganda during 2011-2022.

BACKGROUND: Sheep and goat pox (SGP) caused by sheep poxvirus (SPV) and goat poxvirus (GPV) respectively; are transboundary and World Organisation for Animal Health (WOAH)-notifiable viral diseases. There is barely any coherent information about the distribution and prevalence of SGP for Uganda. We therefore conducted this study to describe the temporal and spatial distribution of SGP suspected outbreaks in Uganda for the period 2011-2020 as well as serologically confirm presence of SGP antibodies in suspected SGP outbreaks reported in 2021-2022. RESULTS: Thirty-seven [37] SGP outbreaks were reported across the country during the study period. North-eastern region [that comprises of Karamoja region] had the highest number of outbreaks [n = 17, 45%]; followed by Central [n = 9, 2.4%], Northern [n = 8, 2.2%] and Western region [n = 3, 0.08%]. Reports from district veterinary personnel indicate that the prevalence of; and mortality rate and case fatality rate associated with SGP were 0.06%, 0.02% and 32% respectively. There was a steady increase in the number of reported SGP outbreaks [x̄ = 4] over the study period. Seropositivity of SGPV antibodies in outbreak sheep and goats that were investigated during the study period [2021-2022] was [n = 41, 27%, 95 CI;] CONCLUSION: Our analyses of SGPV passive and active reports indicate that SGP is present in Uganda with a decade long average of four outbreaks per annum. During this period, about a third of all SGPV-clinically infected animals died. SPG is therefore a major constraint to small ruminant health and productivity in Uganda. Introduction of animals from infected herds and breach in farm biosecurity were the most important predictors of SGP outbreaks. In addition to the already existing SGP commercial vaccines, small ruminant screening for SGPV before introducing them to naïve herds and ensuring on farm biosecurity should be part of the SGP control tool pack for Ugandan small ruminant farmers.

Rabies in Uganda: rabies knowledge, attitude and practice and molecular characterization of circulating virus strains.

BACKGROUND: Rabies is a deadly preventable viral disease that affects all warm-blooded animals and widespread in many regions including Africa. The disease remains of major public health importance in Uganda. The purpose of this study was to establish Knowledge, Attitude, Practice (KAP) of Rabies in Moyo and Ntoroko districts and to characterize Rabies virus (RABV) strains from seven districts of Uganda with consistent prevalence of rabies. METHODS: KAP survey data were collected based on animal biting history by interviewing the head of the veterinary departments, the medical centers and selected households from the study sites. Data were obtained from 84 households in Ntoroko and Moyo districts. Thirty-five (35) brain samples were collected from bovine, dogs, goats, foxes, jackals ad sheep between 2011 and 2013. Samples were tested using fluorescent antibody test (FAT), One step RT-PCR (following RNA extraction) and partial RABV N gene was sequenced by Sanger method before phylogenetic and phylogeographic analyses of sequences. RESULTS: Scarcity of post-exposure prophylaxis services in the health centers was noted. Poor attitude of wound washing and deficiency of knowledge on how to handle wounds related to dog bites and the significance among household participants lacked. There is a high risk of rabies infection due to a limited dog's vaccination. Dog biting episodes in humans were of 75.00 and 62.50% in Moyo and Ntoroko districts respectively. Twenty-seven (27) samples tested positive for rabies by FAT and PCR. Ugandan sequences were closely related (97% nucleotide id) to the rabies virus sequences from Tanzania, Rwanda, Burundi, Nigeria, Central African Republic and Sudan with both the "Africa 1A" and "Africa 1B" RABV clades represented. A putative new clade 1D was also detected. CONCLUSIONS: Rabies remains a public health hazard in Uganda. There is urgent need to establish advocacy programs in both schools and communities to curtail the spread of rabies. Increasing the knowledge regarding wound washing, post-exposure prophylaxis and dogs vaccination would enhance prevention of rabies. A strong collaboration between medical and veterinary sectors under a one health platform is required to ensure sufficient preventative services to the communities.

Spatial and temporal distribution of lumpy skin disease outbreaks in Uganda (2002-2016).

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.

Assessment of the economic viability of goat management systems in Goma Sub County and Mukono Town Council in Mukono District, Uganda.

This study sought to assess the profitability of the goat enterprises under different management systems. The research covered two selected sub-counties of Mukono District (Goma and Mukono Town Council). A total of 888 goats from 129 herds/farms were studied. Descriptive statistical and gross margins analyses were performed. The management system of goats in the two sub-counties was mainly by tethering. Most of the goats kept were adult female goats. Most farmers had small herds and did not keep records. Male goats were more valued on average among the crossbred goats. In the exotic types, the adult female goats were valued on average. Local goats fetch low prices. With respect to gross margins, that free range had incurred more losses, while tethering made most profits followed by zero grazing and zero grazing combined with tethering, respectively, without considering the non-monetary aspects. Farmers using the tethering management system, encountered most of the problems of lack of pastures and veterinary services. The farmers required assistance from different donors, through provision of hybrid goats and improvement of veterinary services. The management system for goat keeping in the study area was poor, especially among local breed goat farmers who use tethering management system, though it had high gross margin. There is a need to educate farmers on proper goat husbandry and provision of some farm inputs.

Brucellosis seroprevalence in livestock in Uganda from 1998 to 2008: a retrospective study.

A total of 17,359 samples were analysed serologically, of which 1,061, 15,758 and 585 samples were from Makerere, Entebbe and Tororo laboratories, respectively, were used to determine the seroprevalence of brucellosis. The overall seroprevalence of brucellosis was 10% while from individual laboratories was 38%, 32% and 7% for Makerere, Entebbe and Tororo laboratories, respectively. Majority of these positive brucellosis test results were in the cattle corridor with P value = 0.399. There were significant differences in brucellosis seroprevalence among species (P value = 0.014). The trends of brucellosis seroprevalence among the different species were decreasing with time but were highest in bovine species (P value = 0.043). Brucellosis seroprevalence had a bimodal monthly pattern corresponding with rainfall. The study showed that brucellosis was prevalent, though the trend of the disease has declined over years. It was recommended that regular disease surveillance, control programmes and further studies be carried out in the country.

Overcoming the challenges of pen-side molecular diagnosis of African swine fever to support outbreak investigations under field conditions.

African swine fever (ASF) is a devastating disease of pigs. Without a vaccine, early detection and rapid diagnosis of ASF is a crucial step towards effective disease control. In many countries where ASF is endemic, laboratory infrastructure including sampling and sample shipment is inadequate, and a rapid laboratory confirmation would require that the diagnosis is performed at regional laboratories close to the pig farms of concern, or even at the farm-side. This study intended to evaluate measures including sample preparation methods, a dried-down assay, and a portable, battery-powered real-time PCR instrument, to improve molecular diagnosis under field conditions. A simple dilution of blood samples, either in Phosphate-buffered saline or a commercial buffer, worked similarly to beads-based nucleic acid extraction using a magnet as the core equipment; the latter method did work as well for those samples with low viral load or high Ct values. The real-time PCR assay using a Universal ProbeLibrary (UPL) probe tolerated suspected inhibitory substances present in the prepared samples better, whereas the dried-down assay had a higher diagnostic sensitivity. Additionally, an inhibition control assay proved to be helpful in avoiding false negative results when interpreting negative results of samples that might be of low quality or with inadequate reduction in inhibitory substances. When tested with synthetic DNA standards, the portable instrument performed at a level approaching stationary thermocyclers. In summary, the developments of suitable sample preparation methods, robust and thermal-stable real-time PCR assays with inhibition control, and battery-powered portable thermocyclers with middle-throughput offer one way forward to provide rapid, reliable molecular diagnosis under challenging field conditions.

Spatial and temporal distribution of foot-and-mouth disease in four districts situated along the Uganda-Tanzania border: Implications for cross-border efforts in disease control.

Foot-and-mouth disease (FMD) is one of the major trans-boundary animal diseases in East Africa causing economic loss to farmers and other stakeholders in the livestock industry. Foot-and-mouth disease occurs widely in both Uganda and Tanzania with annual outbreaks recorded. With the recent introduction of the Progressive Control Pathway for FMD control (PCP-FMD) in eastern Africa, knowledge of the spatial and temporal distribution of FMD at the border area between Uganda and Tanzania is helpful in framing engagement with the initial stages of the PCP. Retrospective data collected between 2011 and 2016 from four districts located along the border areas of Uganda and Tanzania, recorded 23 and 59 FMD outbreaks, respectively, for the entire study period. Analysis showed that 46% of the 82 recorded outbreaks occurred in 20% of sub-counties and wards immediately neighbouring the Uganda-Tanzania border and 69.5% of the outbreaks occurred during the dry months. While the serotypes of the FMD virus responsible for most outbreaks reported in this region were not known, previous research reported South African Territory (SAT) 1, SAT 2 and O to be the serotypes in circulation. The results from this study provide evidence of the endemic status of FMD on the Uganda-Tanzania border and emphasise that the border area should be given due consideration during FMD control drives and that cross-border coordination should be prioritised. With the limited data on circulating serotypes in this area, there is a need for more vigilance on FMD case detection, laboratory diagnostic confirmation and provision of more complete documentation of outbreaks. This work further recommends more studies on cross-border livestock movement coupled with phylogenetics in order to understand the spread of the FMD in the border area.

Corrigendum: Spatial and temporal distribution of foot-and-mouth disease in four districts situated along the Uganda-Tanzania border: Implications for cross-border efforts in disease control.

No abstract available.