Sylvester Ochwo

Dr. Sylvester Ochwo


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 November 2017 in BMC Veterinary Research
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DMDennis Muhanguzi
Dennis Muhanguzi
AMAlbert Mugenyi
Albert Mugenyi
GBGodfrey Bigirwa
Godfrey Bigirwa
MKMaureen Kamusiime
Maureen Kamusiime
AKAnn Kitibwa
Ann Kitibwa
RTRobert Tweyongyere
Robert Tweyongyere
Nagana (African Animal Trypanosomiasis-AAT) and tick-borne diseases (TBDs) constrain livestock production in most parts of sub-Saharan Africa. To this realisation, Uganda government set up an African trypanosomiasis (AT) control unit, which among other activities generates national tsetse control priority maps using apparent tsetse density data. Such maps underestimate mechanically transmitted AAT and thus ought to be refined using actual AT prevalence data. We therefore set out to generate up-to-date cattle and donkey trypanosomiasis prevalence data as well as find out the constraints to livestock production in Karamoja region in a bid to re-define AT control priority in this region. Livestock keepers and animal health workers indicated that TBDs and AAT were the most important livestock diseases in Karamoja region. The prevalence of Trypanosoma spp. in cattle and donkeys was 16.3% (95% CI: 12.4–21.1%) and 32.4% (95% CI; 20.2–47.6%) respectively. Trypanosoma vivax (12.1%) and Trypanosoma congolense savannah (29.6%) were the most prevalent Trypanosoma spp. in cattle and donkeys respectively. Majority of the cattle (85.7%) and more than half of the donkey (57.1%) herds were positive for Trypanosoma spp. African animal trypanosomiasis and TBDs are the most important constraints to livestock production in Karamoja region. In order to improve livestock production and hence Karamajong livelihoods, government of Uganda and her development partners will need to invest in livestock health programs particularly targeting tsetse and TBD control.

8 July 2019 in BMC Veterinary Research
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Journal Article
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SOSylvester Ochwo
Sylvester Ochwo
Kimberly VanderWaalKimberly VanderWaal
Kimberly VanderWaal
AMAnna Munsey
Anna Munsey
JNJoseph Nkamwesiga
Joseph Nkamwesiga
CNChristian Ndekezi
Christian Ndekezi
FMFrank Norbert Mwiine
Frank Norbert Mwiine
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. 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. 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.

3 April 2020 in Parasites & Vectors
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Journal Article
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DMDennis Muhanguzi
Dennis Muhanguzi
JBJoseph Byaruhanga
Joseph Byaruhanga
WAWilson Amanyire
Wilson Amanyire
CNChristian Ndekezi
Christian Ndekezi
SOSylvester Ochwo
Sylvester Ochwo
FJFrans Jongejan
Frans Jongejan
Background: Rhipicephalus microplus, an invasive tick species of Asian origin and the main vector ofBabesiaspecies, 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 ofRhipicephalus decoloratusticks. 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 toR. 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. FiveR. microplusspecimens were further processed for phylogenetic analysis and species confirmation.Results: The predominant tick species found on cattle wasRhipicephalus appendiculatus(86.9 %;n= 16,509). Other species found wereAmblyomma variegatum(7.2 %;n= 1377),Rhipicephalus evertsi(2.3 %;n= 434)andR. microplus(3.6 %;n= 687). Phylogenetic analysis of the12SrRNA,16SrRNA and ITS2 gene sequences ofR. microplusconfirmed the morphological identification.Conclusions: It is concluded thatR. microplushas replacedR. decoloratusin 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 ofR. microplusticks. Future surveys, but also retrospective surveys of museum specimens, will reveal the extent of distribution ofR. microplusin Uganda and also for how long this tick has been present on livestock without being noticed.

12 August 2013 in Journal of Veterinary Medicine
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David Kalenzi AtuhaireDavid Kalenzi Atuhaire
David Kalenzi Atuhaire
SOSylvester Ochwo
Sylvester Ochwo
MAMathias Afayoa
Mathias Afayoa
FMFrank Norbert Mwiine
Frank Norbert Mwiine
IKIkwap Kokas
Ikwap Kokas
LOLonzy Ojok
Lonzy Ojok
African swine fever (ASF) is a contagious viral disease, which can cause up to 100% mortality among domestic pigs. In Uganda there is paucity of information on the epidemiology of the disease, hence a study was carried out to elucidate the patterns of ASF outbreaks. Spatial and temporal analyses were performed with data collected monthly by the district veterinary officers (DVOs) and sent to the central administration at MAAIF from 2001 to 2012. Additionally, risk factors and the associated characteristics related to the disease were assessed based on semistructured questionnaires sent to the DVOs. A total of 388 ASF outbreaks were reported in 59 districts. Of these outbreaks, 201 (51.8%) were reported in districts adjacent to the national parks while 80 (20.6%) were adjacent to international borders. The number of reported ASF outbreaks changed over time and by geographical regions; however, no outbreak was reported in the North-Eastern region. ASF was ranked as second most important disease of pigs, and it occurred mostly during the dry season (P=0.01). Pig movements due to trade (OR 15.5, CI 4.9–49.1) and restocking (OR 6.6, CI 2.5–17.3) were the major risk factors. ASF control strategies should focus on limiting pig movements in Uganda.

21 February 2020 in BMC Veterinary Research
Verified
Journal Article
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SOSylvester Ochwo
Sylvester Ochwo
Kimberly VanderWaalKimberly VanderWaal
Kimberly VanderWaal
CNChristian Ndekezi
Christian Ndekezi
JNJoseph Nkamwesiga
Joseph Nkamwesiga
AMAnna Munsey
Anna Munsey
FMFrank Norbert Mwiine
Frank Norbert Mwiine
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.

1 June 2018 in BMC Veterinary Research
Verified
Journal Article
Open access
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SOSylvester Ochwo
Sylvester Ochwo
Kimberly VanderWaalKimberly VanderWaal
Kimberly VanderWaal
AMAnna Munsey
Anna Munsey
CNChristian Ndekezi
Christian Ndekezi
RMRobert Mwebe
Robert Mwebe
FMFrank Norbert Mwiine
Frank Norbert Mwiine
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. 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. 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.