Cross-sectional serosurvey of Leptospira species among slaughter pigs, goats, and sheep in Uganda.

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. borgpetersenii Tarassovi 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.

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.

Sero-prevalence and factors associated with anti-Brucella antibodies in slaughter livestock in Uganda.

Introduction: Brucellosis is endemic in Uganda and is a major cause of production losses in livestock. Early detection and quantification of the disease is vital for its control and eradication. The aim of this study was to assess the sero-prevalence and factors associated with anti-Brucella antibodies in slaughtered livestock. Materials and methods: Sera from 886 cattle, 925 small ruminants, and 900 pigs were collected from regional abattoirs in Northern, Eastern and Central Uganda. To estimate sero-prevalence, sera were serially tested using a combination of the Rose Bengal Test (RBT) and Native Hapten (NH) immunoprecipitation test. True sero-prevalence was estimated using the Rogan-Gladden estimator considering the sensitivity and specificity of the NH immunoprecipitation test. Multivariable logistic regression was used to assess factors associated with seropositivity for anti-Brucella antibodies. Results and discussion: Small ruminants showed the highest seroprevalence (6.7%, 95% CI = 4.2-7.1) followed by cattle (3.8%, 95% CI = 2.4-4.9) and pigs (2.8%, 95% CI = 1.1-2.9). Seropositivity for anti-Brucella antibodies was associated with region of origin (OR = 4.6,95%CI=1.49-17.75, p = 0.013) for cattle; sex (OR = 2.90, 95% C = 1.5-6.34, p = 0.004), age (OR=4.04, 95% CI = 1.07-8.52, p = 0.006) and species (OR = 2.53, 95% CI = 1.08-6.98, p = 0.048) for small ruminants; and finally sex for pigs (OR = 2.88, 95% CI = 1.07-8.52, p = 0.041). Progressive control interventions must include both cattle and small ruminants since they play a bigger role in the maintenance and dissemination of Brucella. The interventions should adopt a risk-based approach with regions at higher risk being given top priority. Bacteriological and molecular studies should be undertaken to clarify the role of pigs and the goat-cattle cross infections in the epidemiological cycle of brucellosis in Uganda.

Genome-wide diversity and structure variation among lablab [Lablab purpureus (L.) Sweet] accessions and their implication in a Forage breeding program.

Most orphan crops have not been fully sequenced, hence we rely on genome sequences of related species to align markers to different chromosomes. This hinders their utilisation in plant population improvement programs. Utilising the advances in the science of sequencing technologies, the population structure, relatedness, and genetic diversity among accessions can be assessed quickly for better exploitation in forage breeding programs. Using DArTseq technology, we studied the genetic and structural variation in 65 Lablab purpureus (L.) Sweet conserved gene-bank accessions using 9320 DArTseq-based SNPs and 15,719 SilicoDart markers. These markers had a low discriminating ability with mean polymorphic information content (P.I.C.) of 0.14 with DArTseq-based SNPs and 0.13 with SilicoDart markers. However, the markers had a high mean call rate of 73% with DArTseq-based SNPs and 97% with SilicoDart markers. Analysis of molecular variance revealed a high within populations variance (99.4%), indicating a high gene exchange or low genetic differentiation (PhiPT = 0.0057) among the populations. Structure analysis showed three allelic pools in variable clusters of ΔK = 3 and 6. Phylogenetic tree of lablab accessions showed three main groups with variable membership coefficients. Most pairs of accessions (40.3%) had genetic distances between 0.10 and 0.15 for SilicoDart markers, while for DArTseq-based SNPs, (46.5%) had genetic distances between 0.20 and 0.25. Phylogenetic clustering and minimum spanning analysis divided the 65 accessions into three groups, irrespective of their origin. For the first time, this study produced high-density markers with good genom coverage. The utilisation of these accessions in a forage program will base on the information from molecular-based grouping. The outcomes uncovered the presence of noteworthy measure of variety in Uganda, CIAT and ILRI accessions, thus demonstrating an opportunity for further marker-trait-association studies. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10722-021-01171-y.

Prevalence and control implications of bovine trypanosomes in endemic areas of northern Uganda.

African animal trypanosomiasis (AAT), a disease complex caused by tsetse fly-transmitted Trypanosoma brucei brucei, T. congolense savannah ITS, and T. vivax, continues to inflict heavy losses to the animal industry in terms of decreased livestock production and productivity. Live bait technology and chemotherapy have been used as a control strategy in northern Uganda since 2006 with minimal success. Here, we report the results of a cross-sectional study carried out in Lango subregion, Uganda, to assess the species prevalence of bovine trypanosome in cattle using the internal transcribed spacer (ITS) of trypanosome ribosomal DNA (rDNA). Blood samples were collected from 1090 cattle by ear vein puncture and screened using a single pair of primers designed to amplify ITS ribosomal DNA (rDNA). Our results indicate an overall prevalence of 40.18% (438/1090, 95% CI 30.82-54.51). T. vivax constituted 32.66% (356/1090), T. congolense 2.39% (26/1090), T. brucei 1.28% (14/1090), T. godfreyi 0.09%(1/1090), T. brucei and T. congolense 0.36% (4/1090), T. brucei and T. vivax 1.47% (16/1090), T. vivax and T. congolense 1.65% (18/1090), T. vivax and T. simiae 0.18% (2/1090), and T. vivax and T. godfreyi 0.09% (1/1090) of infections. Over 91.7% of infections involved single species, while 9.5% were mixed infections. Over 90.2% (37/41) of the mixed infections involved T. vivax as one of the species, while 53.7% (22/41) involved T. congolense. The high prevalence of AAT and the continued presence of T. brucei raise public health concerns because of the zoonotic implications. An integrated approach that involves mass treatment of cattle, vector, and animal movement control should be adopted to reduce the risk of both AAT and HAT.

Correction to: Seroprevalence of bovine brucellosis and associated risk factors in Nakasongola district, Uganda.

In the originally published article, the name of the fifth author was incorrectly presented as Godfroid Jacques. The correct name is Jacques Godfroid.

Comparison of the efficacy of crude methanolic extracts of Cassia occidentalis and Euphorbia hirta with levamisole-HCL against gastrointestinal nematodes of economic importance to goat production in Uganda.

Natural compounds from medicinal plants provide safe and sustainable alternatives to synthetic anthelmintics. In this study, we assessed in vitro and in vivo anthelmintic activity of Cassia occidentalis (NH-A) and Euphorbia hirta (NH-B) and compared it with levamisole-HCl. The shoots of NH-A and whole plant of NH-B were used to prepare extracts using 70% methanol which were used in the in vitro and in vivo assays. In vitro assays of crude methanolic extracts (CMEs) of NH-A and NH-B on larvae of mixed gastrointestinal nematodes (GINs) of goats revealed mortalities of 95.7% (at 100 mg ml-1) and 98.1% (at 50 mgml-1) 24 h postexposure. In vivo assays of NH-A administered orally at doses of 100, 300, 900, and 2700 mg kg-1 bwt revealed dose- and time-dependent anthelmintic effects in goats experimentally infected with mixed species of GINs. NH-B exhibited similar properties when administered at doses of 50, 100, 200, and 400 mg kg-1 bwt. Both NH-A (900 mg kg-1 bwt) and levamisole (7.5 mg kg-1 bwt) achieved a 100% reduction in fecal egg count per gram (EPG) on day 21 and day 14 respectively posttreatment. NH-B (400 mg kg-1 bwt) achieved 93.1% and 86.1% reduction in fecal EPG 7 and 14 days postexposure respectively compared with 88.2% and 82.3% reduction with levamisole-HCl 7 and 14 days postexposure. Our results show that extracts of both plants can disrupt helminth lifecycles by suppressing the egg-laying capacity in adult worms but also kill their infective larvae. Future studies should aim at establishing synergies or antagonisms between the two plant extracts and further development for control of helminths in goats.

Factors associated with persistence of African animal trypanosomiasis in Lango subregion, northern Uganda.

African animal trypanosomiasis (AAT) continues to inflict heavy losses on livestock production especially cattle in terms of decreased production and productivity in Uganda. AAT is a disease complex caused by tsetse fly-transmitted Trypanosoma brucei brucei, Trypanosoma brucei rhodesiense, Trypanosoma congolense, and Trypanosoma vivax. The disease is most important in cattle but also known to cause serious losses in pigs, camels, goats, and sheep. Several control measures including live bait technology, mass treatment of cattle with trypanocidal drugs, and deployment of tsetse traps have been used in the past 10 years, but the problem still persists in some areas. This necessitated an exploration of the factors associated with continued trypanosome infections in cattle, which are also known reservoirs for the zoonotic trypanosomiasis. A structured questionnaire was administered to 286 animal owners from 20 villages purposively selected from Lira, Kole, and Alebtong districts of Lango subregion to obtain information on the factors associated with persistence of infection. Over 50% of the respondents reported trypanosomiasis as a major challenge to their livestock. Land ownership (P = 0.029), type of livestock kept (P = 0.000), disease control strategy employed (P = 0.000), source of drugs (P = 0.046), and drug preparation (P = 0.017) were associated with persistent AAT infection. We recommend continued farmer sensitization on the threat of AAT and the available prevention and control options. The use of isometamidium chloride for prophylaxis against trypanosomiasis is highly recommended. There is also a need to foster qualified private veterinary drug supply in the region.

Seroprevalence of bovine brucellosis and associated risk factors in Nakasongola district, Uganda.

A cross-sectional study was carried out between November 2015 and January 2016 to determine the seroprevalence of Brucella antibodies in cattle raised under communal, fenced farms and tethering systems and the associated factors. Seven hundred twenty-eight bovine sera were collected and tested with rose Bengal test as a screening test and the indirect enzyme-linked immunosorbent assay as a confirmatory test. Animal- and herd-level data were collected and binary logistic regression was used to assess the potential risk factors. True animal- and herd-level prevalence was highest in the fenced farms (4.5% (95%CI, 2.3-6.9) and 19.5% (95%CI, 8.2-32.7) respectively). The risks for natural brucellosis infection were sharing water with wild animals (OR = 0.21, 95%CI, 0.104-0.83), herd size (medium: OR = 0.089, 95%CI 0.017-0.449; large: OR = 0.024, 95%CI 0.003-0.203), fenced farms (OR = 3.7, 95% CI, 1.7-7.9), sex (OR = 0.03, 95%CI, 0.01-0.079), and lactation (OR = 0.013, 95%CI, 0.004-0.049). Changes in rangeland tenure and the shift towards intensive cattle production have influenced brucellosis epidemiology. Future studies should aim at identifying the infecting Brucellae and examining the role of wildlife in brucellosis epidemiology.

Participatory evaluation of delivery of animal health care services by community animal health workers in Karamoja region of Uganda.

AIM: An evaluation exercise was carried out to assess the performance of Community Animal Health Workers (CAHWs) in the delivery of animal health care services in Karamoja region, identify capacity gaps and recommend remedial measures. MATERIALS & METHODS: Participatory methods were used to design data collection tools. Questionnaires were administered to 204 CAHWs, 215 farmers and 7 District Veterinary Officers (DVOs) to collect quantitative data. Seven DVOs and 1 Non Government Organization (NGO) representative were interviewed as key informants and one focus group discussion was conducted with a farmer group in Nakapiripirit to collect qualitative data. Questionnaire data was analyzed using SPSS version 19. Key messages from interviews and the focus group discussion were recorded in a notebook and reported verbatim. RESULTS: 70% of the farmers revealed that CAHWs are the most readily available animal health care service providers in their respective villages. CAHWs were instrumental in treatment of sick animals, disease surveillance, control of external parasites, animal production, vaccination, reporting, animal identification, and performing minor surgeries. Regarding their overall performance 88.8%(191/215) of the farmers said they were impressed. The main challenges faced by the CAHWs were inadequate facilitation, lack of tools and equipments, unwillingness of government to integrate them into the formal extension system, poor information flow, limited technical capacity to diagnose diseases, unwillingness of farmers to pay for services and sustainability issues. CONCLUSIONS AND RECOMMENDATIONS: CAHWs remain the main source of animal health care services in Karamoja region and their services are largely satisfactory. The technical deficits identified require continuous capacity building programs, close supervision and technical backstopping. For sustainability of animal health care services in the region continuous training and strategic deployment of paraprofessionals that are formally recognised by the traditional civil service to gradually replace CAHWs is recommended.