Browsing by Author "Nkamwesiga, Joseph"

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    Identification of Peste des Petits Ruminants Transmission Hotspots in the Karamoja Subregion of Uganda for Targeting of Eradication Interventions
    (Frontiers in veterinary science, 2019) Nkamwesiga, Joseph; Coffin-Schmitt, Jeanne; Ochwo, Sylvester; Mwiine, Frank Norbert; Palopoli, Annabella; Ndekezi, Christian; Isingoma, Emmanuel; Nantima, Noelina; Nsamba, Peninah; Adiba, Rogers; Hendrickx, Saskia; Mariner, Jeffrey C.
    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.
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    Invasive Cattle Ticks in East Africa: Morphological and Molecular Confirmation of The Presence of Rhipicephalus Microplus in South‑Eastern Uganda
    (Parasites & Vectors, 2020) Muhanguzi, Dennis; Byaruhanga, Joseph; Amanyire, Wilson; Ndekezi, Christian; Ochwo, Sylvester; Nkamwesiga, Joseph; Mwiine, Frank Norbert; Tweyongyere, Robert; Fourie, Josephus; Madder, Maxime; Schetters, Theo; Horak, Ivan; Juleff, Nick; Jongejan, Frans
    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.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.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.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.
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    Measurement and Sampling Error in Mixed-Methods Research for the Control of Peste Des Petits Ruminants in the Karamoja Subregion of Northeastern Uganda: A Cautionary Tale
    (Preventive Veterinary Medicine, 2021) Coffin-Schmitt, Jeanne L.; Moore, Emily V.; McKune, Sarah L.; Nkamwesiga, Joseph; Isingoma, Emmanuel; Nantima, Noelina; Adiba, Rogers; Mwiine, Frank Norbert; Nsamba, Peninah; Hendrickx, Saskia; Mariner, Jeffrey C.
    A team of interdisciplinary researchers undertook a mixed methods, participatory epidemiology (PE) based study as part of a pilot project for localized control of Peste des petits ruminants (PPR), a small ruminant disease of high socio-economic impact. Mixed methods research combines qualitative and quantitative methods, allowing iterative comparison of results to arrive at a more comprehensive and informed outcome. In this study, the use of PE and a household survey (HHS) resulted in contradictory results. However, the mixed methods approach also facilitated the detection and the explanation of bias in the HHS, which may have gone undetected and unexplored had only one method been used. Results show that logistical constraints leading to a failure to apply key aspects of the sampling strategy led to problematic gender/ethnic composition of the HHS sample population. Additionally, while PE findings on local disease and terminology were integrated during HHS development and training, there is apparent measurement error related to enumerator bias in HHS results, possibly due to insufficient respondent understanding or a lack of analytic clarity. The extensive nature of the PE, surveillance methodologies used in the initial site assessment, and formative research for the HHS allowed for a critical analysis and interpretation of HHS results as well as reflection on the research process. The findings of this paper underscore the (1) flexibility and utility of participatory methods, (2) the importance of mixed methods research in designing health interventions, and (3) the necessity of tight integration of study design with team planning for implementation of research in environments such as Karamoja, Uganda. If all three are to be achieved not only researchers but funders must provide these space and structure beginning in the study design phase. These findings are relevant in many places, but have particular importance for international, interdisciplinary teams working from various on-and-off-site locations with traditional or indigenous knowledge systems.
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    Molecular Detection and Phylogenetic Analysis of Lumpy Skin Disease Virus from Outbreaks in Uganda 2017–2018
    (BMC veterinary research, 2020) Ochwo, Sylvester; VanderWaal, Kimberly; Ndekezi, Christian; Nkamwesiga, Joseph; Munsey, Anna; Witto, Sarah Gift; Nantima, Noelina; Mayanja, Franklin; Okurut, Anna Rose Ademun; Atuhaire, David Kalenzi
    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.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.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.
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    Seroprevalence of contagious bovine pleuropneumonia (CBPP) in cattle from Karamoja region, North-eastern Uganda
    (BioMed Central Ltd, 2024-03) Tweyongyere, Robert; Nkamwesiga, Joseph; Etiang, Patrick; Mugezi, Israel; Wamala, Henry; Wasswa, Auther Tamale; Kamusiime, Maureen; Ainebyoona, Solomon; Abizera, Harriet; Mwiine, Frank Norbert; Muhanguzi, Dennis
    Background Contagious bovine pleuropneumonia [CBPP] is a transboundary animal disease of cattle caused by Mycoplasma mycoides subsp. mycoides [Mmm]. CBPP causes severe economic losses to livestock producers in sub-Saharan Africa mainly due to high mortality, morbidity, reduction in productivity as well as livestock trade restrictions. This study aimed at determining seroprevalence of Mmm in cattle from Karamoja region, north-eastern Uganda; data that are required to design and implement risk based CBPP control program. Methods We randomly collected blood samples from 2,300 cattle spread across Karamoja region. Serum was extracted and screened for antibodies against Mycoplasma mycoides subsp. mycoides [Mmm] using the competitive enzyme linked immunosorbent assay [cELISA]. Results A quarter [25.4%; 95% CI: 23.7-27.3] of the screened cattle [n = 2,300] were sero-positive for Mmm. Amudat and Kaabong districts recorded the lowest [12.3%] and highest [30.7%] Mmm seroprevalence respectively. Increasing age, overnight stay in cattle kraals and location [certain districts, villages, herds and sub counties] of the cattle herds, the factors that promote animal commingling, were the most significant risk factors of seroconversion with Mmm. Conclusion Results from this study indicated a higher seroprevalence of Mmm in Karamoja region cattle herds. This could be due to the increased frequency of CBPP outbreaks in recent years. To be effective, CBPP vaccination programs should target high risk herds along the international borders and other hotspot areas [e.g., parishes or sub counties] where cattle commingling is high. Keywords: Karamoja region, Uganda, Seroprevalence, CBPP, cELISA, Cattle