Boosting Uganda’s investment in livestock development

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Epidemiology of peste des petits ruminants in Uganda
(Thesis, 2024) Nkamwesiga, Joseph
Peste des petits ruminants (PPR) is a viral disease that affects domestic small ruminants (goats and sheep) and some wild small ruminants. By 2015, more than 70 countries in Africa and Asia were confirmed as affected although the threat to Europe through Turkey and Bulgaria was quickly neutralised. In Uganda, PPR was first reported in 2007 the Karamoja subregion of northeastern Uganda in 2007, a region comprised of 9 different districts. PPR persisted in this region. Upon eradication of Rinderpest in 2011, PPR was identified as the next target for eradication because of how closely related their aetiologies and epidemiological situations were. Indeed, in 2016, the Food and Agriculture Organization of the United Nations (FAO) and the World Organisation for Animal Health (WOAH) launched a four-stage global PPR control and eradication (PPR-GCEP) by 2030. The control plan was set up to leverage on the momentum gained from PPR control activities to tackle other small ruminant diseases identified by small ruminant keepers through joint activities such as concurrent vaccination against multiple diseases. The PPR-GCEP demands that every PPR affected country complies with the program and implements respective activities to warrant progression from one stage to another until PPR is eradicated following a self-administered PPR Monitoring and Assessment Tool (PMAT). After all steps are achieved, countries will apply for declaration of freedom from disease and continue with activities aimed at maintenance of disease-free status. This thesis was designed to update the PPR epidemiological situation in Uganda, by generating data to fit into PPR-GCEP stage 1 (assessment stage) as well as identify areas for targeting of interventions – which is the cornerstone for the PPR-GCEP stage III (control stage), activities that directly contribute the PPR-GCEP. To achieve the set objectives, this study employed a range of advanced epidemiology, and social network analysis techniques to analyse archived PPR outbreak data and small ruminants movement data respectively. Additionally, the study employed molecular biology and molecular epidemiology techniques to identify the circulating PPR virus and other relevant coinfections in all cases of PPR-like disease reported in Uganda during the study period (202-2022). Despite the disease persistence in this region for over a decade before it spread to other districts of Uganda, this study identified that the Karamoja subregion was now a diminishing hotspot whereas two new foci of transmission had come up in the central and southwestern regions of Uganda. Concentration of control interventions by government of Uganda and development partners in the Karamoja subregion coupled with rampant shipment of animals between districts from the northern, central, and western regions could have resulted in this shift in the disease focus. However, the districts in the pastoral production system (where the Karamoja subregion falls), had the highest levels of exposure to PPRV as compared to agropastoral and mixed cop-livestock production systems because of the stark difference in the small ruminant management practices amongst these systems. Small ruminants in the pastoral production system are allowed to roam freely on a large expanse of land whereas the those in the other systems are somewhat restricted in movement by fenced farms and or tethering by ropes which greatly protects limits their chances of contact with other flocks with potentially infected animals. This study confirmed PPRV, CCPP, ORFV and GTPV coinfection among animals from 15 different reports of PPR-like disease that were investigated in this study. This observation further complicates field clinical diagnosis of PPR especially in countries without extensive laboratory diagnostics capacity such as Uganda. In conclusion, there is need to incorporate the detected coinfections in the panel of molecular diagnostics in Uganda to be able to achieve the target of effective PPR control of PPR and other small ruminant diseases. Furthermore, this study reports for the first-time coinfection of other important small ruminant diseases together with PPRV, an observation we believe will improve preparedness for proper disease management options such as chemotherapeutic treatment and vaccination to simultaneously target different disease pathogens. Animal movement control especially at international borders needs to be strengthened to reduce the likelihood of importing or exporting PPR infected small ruminants. Findings of this study provide a basis for more robust timing and prioritization of control interventions such as vaccination to contribute to the global goal of control and eradication by 2030. For instance, these findings can be used to test a risk based PPR vaccination program by prioritising vaccination of small ruminants in PPR Up Trend districts. The districts that were identified as influential in the small ruminant networks can be good starting points to correctly institute animal disease control measures especially quarantine, vaccination and enhanced biosecurity. Such influential districts have previously been linked with the likelihood of driving the spread of infectious diseases in a very short time because of how quickly animals from them can potentially reach many districts in the country. The districts such as Kaberamaido, Lira, Nabilatuk that demonstrated high levels of connectivity especially by the different centrality measures should be prioritized for surveillance and control activities to increase the impact and effectiveness of such activities. Districts such as Kampala, Mukono, Wakiso and Lira with high degree centrality and betweenness would increase the accuracy and sensitivity of active surveillance efforts other than blindly implementing such activities. This would in turn improve timely detection of disease outbreaks and reduce the spatial extent and impact thus improving the profitability of small ruminant production venture. Prioritization of interventions in terms of both space and time and for example districts with uptrend, drought-prone and those with high density of small ruminants and the time of the year when the amount of rainfall is low. Targeting PPR control interventions (vaccination and livestock movement control) to and from pastoral and agro-pastoral small ruminant production systems that are prone to PPR incursions is recommended to prevent PPRV spread to low-risk smallholder small ruminant production systems.
Network analysis of small ruminant movements in Uganda: Implications for control of transboundary animal diseases
(Journal Article, 2025-01) Nkamwesiga, Joseph; Rascón-García, K.; Lumu, P.; Kiara, Henry K.; Perez, A.; Muhanguzi, D.; Roesel, Kristina
Domestic animals are moved for reasons that are mutually beneficial to the animal and the farmer. Some examples include the need for fresh grazing grounds and watering points, or the need to access livestock markets for income to sustain farmers’ livelihoods. However, livestock mobility is a key risk factor for the transmission of transboundary animal diseases. Contact tracing of individual animals and flocks is very challenging, especially in most low-income countries, due to a lack of efficient livestock traceability systems. Despite these challenges, low-income countries, such as Uganda, issue paper-based animal movement permits (AMPs) to ensure only clinically healthy animals are moved following a physical inspection. In this study, we used national approximately 9 years of (2012–2020) small ruminant movement data obtained from archived AMPs in Uganda to describe small ruminant movement networks. The movement networks were described using social network analysis (SNA) approaches implemented in R software to identify and visualize relationships between individual and groups districts in Uganda. Lira, Kaberamaido, Nabilatuk, Mbarara, Kiruhura, Kampala, and Wakiso were identified as districts with the highest degree (in and out-degree) and betweenness among other centrality measures. Our results suggest these districts could be the most important bridges connecting the various regions of the country. Tailoring control interventions to such districts with high incoming and high outgoing shipments, or bridges, would accelerate the nation’s ability to timely detect outbreaks, prevent or mitigate further spread, and contain diseases in their original foci, respectively. We also identified areas for active surveillance, vaccination, quarantine, and biosecurity measures-staging depending on prevailing circumstances. These findings will be used to guide the national small ruminant infectious diseases control strategies and subsequently contribute to national and global initiatives, such as the 2030 Peste des petits ruminants (PPR) eradication program.
Biosecurity measures and effects on health performance and antibiotic use in semi-intensive broiler farms in Uganda
(Journal Article, 2025-06) Ayebare, Dreck; Mbatidde, Irene; Kemunto, Naomi P.; Muloi, Dishon M.; Ibayi, Eugine L.; Nielsen, S.S.; Ndoboli, Dickson; Roesel, Kristina; Tenhagen, B.-A.; Moodley, Arshnee
Background: Effective biosecurity measures prevent the spread of pathogens, thereby reducing the need for antibiotic use on livestock farms. However, quantitative data on these practices and health outcomes in semi-intensive broiler farms in low-income settings is limited. A longitudinal study in Wakiso, Uganda, aimed to evaluate biosecurity practices, health performance, and antibiotic use in such farms. Methods: The FarmUSE survey tool was used to collect data from 19 farms over two production cycles. A biosecurity risk assessment tool was used to quantify biosecurity. Blood samples (n = 342) were collected and analyzed using the ProFLOK® assay to assess antibody responses to vaccines for Newcastle disease (NCD), Infectious Bronchitis (IB), and Infectious bursal disease (IBD). Results: Median biosecurity scores were 26.3 % for external measures, 55.6 % for internal measures, and an overall score of 38.5 %. Sixteen farms reported respiratory signs, and 12 had gastrointestinal issues, with median mortality rates of 2.9 % in the first cycle and 4.6 % in the second. Antibiotic use was reported by 84 % and 77 % of farms in the first and second cycles, respectively. The most used antibiotics were tetracyclines, fluoroquinolones, and macrolides, with the highest usage occurring during the brooding phase. Good antibody responses were reported in only 10.5 % of flocks for NCD and 16 % for IBD, while all farms had poor responses against IB. Conclusion: Recurrent clinical signs could be attributed to insufficient biosecurity and inadequate vaccination outcomes, resulting in high antibiotic usage despite low mortality rates. Improving diagnostic access and strengthening the vaccine supply chain are essential. Identifying feasible and cost-effective biosecurity practices for semi-intensive broiler farms can enhance health outcomes, reduce antibiotic use, and boost productivity.
Using mobile syndromic surveillance at slaughter in Kenya and Uganda
(Presentation, 2024-11-15) Cook, Elizabeth A.J.; Mugizi, Denis; Obilil, Innocent; Roesel, Kristina; Bett, Bernard K.
Non-typhoidal Salmonella among slaughterhouse workers and in the pork value chain in Uganda
(Poster, 2024-09-23) Kivali, Velma; Roesel, Kristina; Dohoo, I.; Alinaitwe, Lordrick; Bugeza, James K.; Hoona, J.J.; Mugizi, Denis R.; Kankya, C.; Sinh Dang-Xuan; Szabo, I.; Rösler, U.; Friese, A.; Cook, Elizabeth A.J.
Key messages

Bacteria such as non-typhoidal Salmonella can be transmitted through cross-contamination in the pork value chain.

Improving hygiene and pork handling practices at slaughterhouses and retail points is essential to ensure food safety.

Slaughterhouses could be used for sentinel surveillance of zoonotic infections in humans and animals.
Non-typhoidal Salmonella among slaughterhouse workers and in the pork value chain in selected districts of Uganda
(Journal Article, 2024-09-17) Kivali, Velma; Roesel, Kristina; Dohoo, I.; Alinaitwe, Lordrick; Bugeza, James K.; Hoona, J.J.; Mugizi, Denis R.; Kankya, C.; Sinh Dang-Xuan; Szabo, I.; Rösler, U.; Friese, A.; Cook, Elizabeth A.J.
Introduction: Non-typhoidal Salmonella (NTS) is a major cause of gastroenteritis worldwide, often associated with meat consumption and meat processing. Research on NTS infection and circulating serovars in meat value chains in Uganda is limited. We aimed to establish NTS prevalence, antimicrobial resistance, and risk factors among slaughterhouse workers, and to identify potentially zoonotic serovars in the pork value chain. Material and methods: We conducted a nationwide cross-sectional survey, collecting 364 stool samples from livestock slaughterhouse workers and 1,535 samples from the pork value chain: mesenteric lymph nodes, fecal samples, swabs of carcass splitting floor, cleaning water, meat handlers hand swabs, carcass swabs, raw pork, cooked pork, and mixed raw vegetables. Samples were cultured for isolation of NTS, and subsequently serotyped according to White–Kauffmann–Le Minor scheme. Antimicrobial resistance profiles were determined using tube microdilution and Sensititre® EUVSEC3® plates. Semi- structured questionnaires with 35 questions were used to collect data on demographics, work related risk factors and activities outside the slaughterhouse. Results and discussion: Overall NTS prevalence was 19.2% (365/1899). Proportions at slaughter were; 46.7% in floor swabs, 30.5% in carcass swabs, 20.5% in pig faeces,19.2% in mesenteric lymph nodes,18.4% in hand swabs, 9.5% in water and 5.2% in slaughterhouse workers. At retail, proportions were 33.8% in pork chopping surface, 33.1% in raw pork, 18.9% in hand swabs, 4.0% in cooked pork and 0.7% in vegetables. Sixty-one serovars were identified, with significant overlap between humans and the pork value chain. Overall, zoonotic S. Zanzibar, monophasic serovars of S. subspecies salamae (II) and subspecies enterica (I), S. Typhimurium and S. Newport, were the most prevalent. S. Typhimurium was predominant in humans and exhibited multi-drug resistance. NTS infection was significantly associated with eating, drinking, or smoking while working (OR = 1.95, 95% CI: 0.67-2.90%, p = 0.004). The detected NTS serovars in slaughterhouse workers could be a potential indicator of circulating serovars in the general population. The persistent presence of NTS along the pork value chain highlights occurrence of cross-contamination and the potential for transmission to consumers and slaughterhouse workers. This emphasizes the need to reduce Salmonella prevalence on pig farms and improve hygiene and pork handling practices at slaughter and retail points.
Genomic epidemiology of Rift Valley fever virus involved in the 2018 and 2022 outbreaks in livestock in Rwanda
(Journal Article, 2024-07-17) Nsengimana, I.; Juma, John; Roesel, Kristina; Gasana, M.N.; Ndayisenga, F.; Muvunyi, C.M.; Hakizimana, E.; Hakizimana, J.N.; Eastwood, G.; Chengula, A.A.; Bett, Bernard K.; Kasanga, C.J.; Oyola, Samuel O.
Rift Valley fever (RVF), a mosquito-borne transboundary zoonosis, was first confirmed in Rwanda’s livestock in 2012 and since then sporadic cases have been reported almost every year. In 2018, the country experienced its first large outbreak, which was followed by a second one in 2022. To determine the circulating virus lineages and their ancestral origin, two genome sequences from the 2018 outbreak, and thirty-six, forty-one, and thirty-eight sequences of small (S), medium (M), and large (L) genome segments, respectively, from the 2022 outbreak were generated. All of the samples from the 2022 outbreak were collected from slaughterhouses. Both maximum likelihood and Bayesian-based phylogenetic analyses were performed. The findings showed that RVF viruses belonging to a single lineage, C, were circulating during the two outbreaks, and shared a recent common ancestor with RVF viruses isolated in Uganda between 2016 and 2019, and were also linked to the 2006/2007 largest East Africa RVF outbreak reported in Kenya, Tanzania, and Somalia. Alongside the wild-type viruses, genetic evidence of the RVFV Clone 13 vaccine strain was found in slaughterhouse animals, demonstrating a possible occupational risk of exposure with unknown outcome for people working in meat-related industry. These results provide additional evidence of the ongoing wide spread of RVFV lineage C in Africa and emphasize the need for an effective national and international One Health-based collaborative approach in responding to RVF emergencies.
Risk-based control of peste des petits ruminants in Uganda
(Brief, 2024-05) Nkamwesiga, Joseph; Korennoy, F.; Lumu, P.; Nsamba, P.; Mwiine, F.N.; Roesel, Kristina; Wieland, Barbara; Perez, A.; Kiara, Henry K.; Muhanguzi, D.
Antimicrobial use and antimicrobial resistance in Escherichia coli in semi-intensive and free-range poultry farms in Uganda
(Journal Article, 2024-06) Mbatidde, Irene; Ndoboli, Dickson; Ayebare, Dreck; Muloi, Dishon; Roesel, Kristina; Ochieng, Linnet; Dione, Michel M.; Tenhagen, B.-A.; Biryomumaisho, S.; Wampande, E.; Wieland, Barbara; Olsen, J.E.; Moodley, Arshnee
Livestock associated antimicrobial resistance (AMR) can reduce productivity and cause economic losses, threatening the livelihoods of poor farming communities in low-income settings. We investigated the practices and risk factors for increased antibiotic use, and AMR in Escherichia coli including resistance to human critically important antibiotics like cefotaxime and colistin in semi-intensive and free-range poultry farms in Uganda. Samples and farm management data were collected from 402 poultry farms in two districts between October 2021 to March 2022. Samples were processed to isolate E. coli and to quantify cefotaxime (CTX) and colistin (COL) resistant coliforms. The identification of presumptive E. coli isolated on MacConkey agar without antibiotics, was confirmed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and subjected to antimicrobial susceptibility testing by disk diffusion using EUCAST guidelines. Our models indicated that antibiotic use was associated with production intensity, and type of feed used. Moreover, semi-intensive farmers had better knowledge on antibiotic use compared to farmers in the free-range system. In semi-intensive farms, 52% harbored COL^R and 57% CTX^R coliforms. In free-range farms, 54% had COL^R and 67% CTX^R coliforms. Resistance to tetracycline, ampicillin and enrofloxacin were more frequent in semi-intensive farms compared to the free-range farms. Multi-drug resistant E. coli were identified in both poultry production systems despite different management and antibiotic use practices. There was no significant relationship between antibiotic use and resistance for the six antibiotics tested.
Choice heuristics and livestock farmers' preference heterogeneity for Rift Valley fever vaccines in Uganda
(Journal Article, 2024-08) Asindu, Marsy; Abdulai, A.; Bett, Bernard K.; Roesel, Kristina; Ouma, Emily A.
Rapid spread and erratic outbreaks of Rift Valley fever (RVF) disease across the African continent continues to pose serious threat to animal, public health, and regional livestock trade. Failure to institute timely control measures will have serious implications on food security and livelihoods. Among existing control options for the disease, vaccines are reported to be the most cost-effective. However, no RVF vaccines are currently registered for use in Uganda. Prior to approval, reservations exist concerning the uptake of vaccines by farmers as they have to weigh in several features and associated risks before acceptance. This study utilizes data from 444 livestock farming households in Uganda to elicit farmers’ preference heterogeneity and the influence of choice heuristics on their preferences for RVF vaccines. The empirical results reveal that two livestock farmer segments exist with respect to RVF vaccine preference. The single dose vaccine attribute is the most highly valued by farmers. Further, livestock farmers’ conditional perceptions and risk attitudes play a major role in vaccine choice decisions. The paper highlights the need for careful consideration of livestock farmers’ preference heterogeneities and intrinsic motivations such as risk attitudes and conditional perceptions when designing policy instruments for the promotion of RVF vaccination programmes.
Cross-sectional serosurvey of Leptospira species among slaughter pigs, goats, and sheep in Uganda
(Journal Article, 2024-03-15) Alinaitwe, Lordrick; Aturinda, C.J.; Lubega, A.; Kivali, Velma; Bugeza, James; Wainaina, M.; Richter, M.H.; Hoona, J.J.; Roesel, Kristina; Mayer-Scholl, A.; Cook, Elizabeth A.J.; Kankya, C.; Dürr, S.
Introduction Leptospira are a group of bacteria, including pathogenic types that cause leptospirosis. In Uganda, Leptospira exposure has been reported in humans, with domesticated animals being speculated as the source. However, comparable evidence of Leptospira prevalence and circulating serovars/serogroups in animals is only documented for cattle, and dogs. Our study determined Leptospira seroprevalence, associated risk factors and serogroups circulating among slaughtered pigs, goats, and sheep in Uganda. Methods During an 11-month cross-sectional survey in selected slaughter facilities in three regions of Uganda, we collected blood from 926 pigs, 347 goats, and 116 sheep. The age, sex, breed, and origin of each sampled animal were noted. The samples were tested for anti-Leptospira antibodies using the microscopic agglutination test, based on a panel of 12 serovars belonging to 12 serogroups. Results Leptospira seroprevalence was 26.67% (247/926, 95%CI 23.92–29.61) among pigs, and 21.81% (101/463, 95%CI 18.29–25.80) in goats and sheep (small ruminants). L. interrogans Australis and L. kirschneri Grippotyphosa were the commonest serovars among pigs, as was L. borgpeterseniiTarassovi in small ruminants. Pigs sourced from the Eastern (Odds Ratio [OR] = 2.82, 95%CI 1.84–4.30) and Northern (OR = 3.56, 95%CI 2.52–5.02) regions were more likely to be seropositive, compared to those from the Central region. For small ruminants, being female (OR 2.74, 95% CI 1.69–4.57) and adult (OR 4.47, 95% CI 1.57–18.80) was significantly more associated with Leptospira seropositivity. Conclusion/significance Detection of a moderate seroprevalence, and several Leptospira serogroups among pigs, sheep, and goats from all regions of Uganda, supports existing reports in cattle and dogs, and implies widespread Leptospira exposure in domestic animals in Uganda. These findings may inform future programs for the control of leptospirosis in livestock in Uganda.
Sero-prevalence and risk factors associated with occurrence of anti-Brucella antibodies among slaughterhouse workers in Uganda
(Journal Article, 2024-03-18) Bugeza, James; Roesel, Kristina; Mugizi, Denis; Alinaitwe, Lordrick; Kivali, Velma; Kankya, C.; Moriyon, I.; Cook, Elizabeth A.J.
Introduction Brucellosis is a febrile zoonosis occurring among high-risk groups such as livestock keepers and abattoir workers and is a public health priority in Uganda. The technical complexities of bacteriological and molecular methods make serological approaches the cornerstone of diagnosis of human brucellosis in resource limited settings. Therefore, proper application and interpretation of serological tests is central to achieve a correct diagnosis. Materials and methods We conducted a cross-sectional study to estimate the seroprevalence and factors associated with anti-Brucella antibodies among slaughterhouse workers processing ruminants and pigs in three regions of the country with serial testing using a combination of the Rose Bengal Test (RBT) and the BrucellaCapt test. An authorized clinician collected 543 blood samples from consenting abattoir workers as well as attribute medical and social demographic data. Univariable and multivariable logistic regression were used to determine factors associated with anti-Brucella sero-positivity. Results and discussion The sero-prevalence among ruminant slaughterhouse workers ranged from 7.3% (95% CI: 4.8–10.7) using BrucellaCapt to 9.0% (95% CI: 6.3–12.7) using RBT. Slaughterhouse workers from the Eastern regions (AOR = 9.84, 95%CI 2.27–69.2, p = 0.006) and those who graze animals for alternative income (AOR = 2.36, 95% CI: 1.91–6.63, p = 0.040) were at a higher risk of exposure to Brucella. Similarly, those who wore Personal Protective Equipment (AOR = 4.83, 95%CI:1.63–18.0, p = 0.009) and those who slaughter cattle (AOR = 2.12, 95%CI: 1.25–6.0, p = 0.006) were at a higher risk of exposure to Brucella. Those who slaughter small ruminants (AOR = 1.54, 95%CI: 1.32–4.01, p = 0.048) were also at a higher risk of exposure to Brucella. Conclusions and recommendations Our study demonstrates the combined practical application of the RBT and BrucellaCapt in the diagnosis of human brucellosis in endemic settings. Both pharmaceutical (e.g., routine testing and timely therapeutic intervention), and non-pharmaceutical (e.g., higher index of suspicion of brucellosis when investigating fevers of unknown origin and observation of strict abattoir hygiene) countermeasures should be considered for control of the disease in high-risk groups.
Training manual for frontline animal extension service providers on antimicrobial resistance in poultry production
(Training Material, 2023-12-30) Kakooza, S.; Eneku, W.; Ayebare, Dreck; Ndoboli, Dickson; Mbatidde, Irene; Waiswa, J.; Barasa, M.; Roesel, Kristina; Moodley, Arshnee
Participatory survey of risk factors and pathways for Rift Valley fever in pastoral and agropastoral communities of Uganda
(Journal Article, 2023-12) Tumusiime, Dan; Nijhof, A.M.; Groschup, M.H.; Lutwama, J.; Roesel, Kristina; Bett, Bernard K.
To assess pastoralists’ and agropastoralists’ knowledge on Rift Valley fever (RVF), participatory epidemiological studies were conducted with 215 livestock keepers and 27 key informants in Napak, Butebo, Isingiro and Lyantonde districts, Uganda, between January and February 2022. Livestock keepers in all four districts had knowledge of RVF and even had local names or descriptions for it. Pastoralists and agropastoralists possessed valuable knowledge of RVF clinical descriptions and epidemiological risk factors such as the presence of infected mosquitoes, living in flood-prone areas, and excessive rainfall. RVF was ranked among the top ten most important cattle diseases. Pastoralists called RVF Lonyang, symbolizing a disease associated with jaundice, high fever, abortions in pregnant cows, and sudden death in calves. Key informants identified infected domestic animals, the presence of infected mosquitoes, livestock movement and trade, and infected wild animals as risk pathways for the introduction of RVF into an area. Drinking raw blood and milk was perceived as the most likely pathway for human exposure to RVF virus; while the highest consequence was high treatment costs. The results indicate that pastoralists provided key epidemiological information that could be essential for designing an effective national RVF surveillance and early warning system.
Antimicrobial resistance and stewardship among stakeholders of the poultry value chain in Wakiso and Soroti districts, Uganda: Knowledge, attitudes and practices report
(Report, 2023-10-30) Ssajjakambwe, P.; Atuheire, C.; Okello, J.; Kakooza, S.; Waiswa, J.; Ayebare, Dreck; Roesel, Kristina; Moodley, Arshnee
Using epi-zones to harmonize control of peste des petits ruminants (PPR)
(Report, 2023-10-30) Wieland, Barbara; Jones, B.; Kiara, Henry K.; Getahun, Yasin; Campbell, Zoë A.; Kotchofa, Pacem; Lule, Peter M.; Nkamwesiga, Joseph; Mdetele, D.; Ferrari, Mireille; Roesel, Kristina
Towards the harmonized control of peste des petits ruminants in the epizone Burundi–DR Congo–Rwanda–Uganda–Tanzania
(Report, 2023-10-30) Mabirizi, Alex; Nkamwesiga, Joseph; Lule, Peter M.; Kiara, Henry K.; Okoth, Edward; Roesel, Kristina
Seroprevalence and risk factors of peste des petits ruminants in different production systems in Uganda
(Journal Article, 2023-12) Nkamwesiga, Joseph; Lumu, P.; Nalumenya, D.P.; Korennoy, F.; Roesel, Kristina; Wieland, Barbara; Pérez, A.; Kiara, Henry K.; Muhanguzi, D.
Peste des petits ruminants (PPR) is a highly contagious and fatal disease of mostly domestic goats and sheep. First reported in Uganda in 2007, the extent of peste des petits ruminants virus (PPRV) exposure, geographical distribution and risk factors of its transmission and spread are not clearly understood. In this study, we used cluster random sampling methodology to select study villages from three districts representing three different production systems along Uganda’s “cattle corridor”. Between October and December 2022, 2,520 goat and sheep serum samples were collected from 252 households with no history of PPR vaccination in the past one year. The household heads were interviewed to assess possible risk factors of PPRV transmission using a structured questionnaire. The serum samples were screened with a commercial competitive enzyme-linked immunosorbent assay (cELISA) for PPRV antibodies. The determined overall true seroprevalence of PPRV was 27.3% [95% CI: 25.4–29.1]. The seroprevalence of PPRV antibodies in different production systems was 44.1% [95% CI: 40.6–47.7], 31.7% [95% CI: 28.4–35.0] and 6.1% [95% CI: 4.4–7.9] for pastoral, agropastoral and mixed crop-livestock production systems respectively. A mixed-effects multivariable logistic regression model revealed strong statistical evidence of association between female animals and PPRV antibody seropositivity compared to males [OR=2.45, 95% CI: 1.7–3.5, p < 0.001]. The likelihood of being PPRV antibody seropositive significantly increased with increasing small ruminant age. Animals older than 3 years were more than three times as likely to be PPRV seropositive compared to animals aged under 1 year [OR= 3.41, 95% CI: 2.39–4.85, p < 0.001]. There was no statistical evidence of association between small ruminant species and PPRV antibody seropositivity (p = 0.423). Village flocks that interacted with neighboring flocks daily during grazing (IRR = 1.59, 95% CI: 1.19–2.13) and watering around swamps (IRR = 1.59, 95% CI: 1.19–2.13) were highly correlated with increased number of PPRV seropositive animals as compared to flocks that were more restricted in grazing and watered around other water sources other than swamps. Flocks from pastoral and agropastoral production systems were more than 10 times more likely to have seropositive animals than mixed crop-livestock flocks. Targeting PPR control interventions (vaccination and livestock movement control) to pastoral and agro-pastoral small ruminant production systems that are very prone to PPR incursions is recommended to prevent PPRV spread to low-risk smallholder mixed crop-livestock production systems.
Reservoirs of pathogenic Leptospira species in Uganda
(Presentation, 2023-06-29) Alinaitwe, Lordrick; Wainaina, Martin; Dürr, S.; Kankya, C.; Kivali, Velma; Bugeza, James; Richter, M.; Roesel, Kristina; Cook, Elizabeth A.J.; Mayer-Scholl, A.
Reservoirs of pathogenic Leptospira species in Uganda
(Abstract, 2022-11-16) Alinaitwe, Lordrick; Dürr, S.; Kankya, C.; Cook, Elizabeth A.J.; Mayer-Scholl, A.
Introduction: Leptospira are spirochete bacteria, including pathogenic species that cause leptospirosis, a zoonotic disease endemic in the tropics. In Uganda, Leptospira seroprevalence has been reported among outpatients at three hospitals, with human-animal interaction implicated as source of human Leptospira exposures. However, corresponding animal Leptospira infection has only been demonstrated in cattle, leaving the status in several potential reservoirs like other livestock species and environmental sources unknown. The current study aims at determining the occurrence, and risk factors for Leptospira infection among livestock species and environmental sources in Uganda. Method: From a nationwide cross-sectional survey in major livestock slaughter facilities, we performed a real-time PCR test on 2,063 livestock kidney samples from 844 cattle, 761 pigs, 341 goats,117 sheep; and on 93 small mammals. Small mammals (rodents and shrews) were trapped at slaughter facilities and communities within a 500metre radius from slaughter facilities. Age, sex, breed and origin of each sampled animal were noted. Leptospira prevalence was estimated and risk factors for infection among livestock species determined using univariate logistic regression model. Results: Leptospira infection was detected in 43 of 2,063 livestock samples tested (2.08%, 95% C.I = 1.52-2.80). Infection was highest in sheep (5.13% C.I = 2.25-10.80), 3.32% (95% C.I = 2.26-4.75) in cattle, 1.76% (95% C. I=0.77-3.70) in goats, and 0.39 (95% C.I = 0.10-1.13) in pigs. Pigs were significantly less infected compared to all other species (p‐value= 0.0008). Indigenous livestock breeds were more infected (p‐value =0.005) compared to their exotic and crossed counterpart. Additionally, older livestock species were significantly infected than the younger ones (p‐value = 0.052). None of the small mammals tested positive. Conclusion: Livestock in Uganda reserve pathogenic Leptospira species, with sheep and cattle especially of indigenous breed being more significant reservoirs. Small mammals may play a limited role in Leptospira maintenance and transmission in Uganda.

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