Epidemiology and impact of foot-and-mouth disease in districts located along the Uganda and Tanzania border

A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy in Life Sciences of the Nelson Mandela African Institution of Science and TechnologyThe Uganda-Tanzania border area lies within the main risk areas for foot-and-mouth disease (FMD) circulation. With the introduction of the progressive control pathway for FMD in eastern Africa, reliable information on FMD epidemiology along the Uganda-Tanzania border area is important in informing the pathway such that, strategic collaborative controls are designed. The scarcity of information on FMD impact in both Uganda and Tanzania, leaves a gap in information critical for justification for national and regional expenditures for FMD intervention. The objectives of the present study were to; (i) determine the spatial and temporal distribution of FMD in districts along the Uganda–Tanzania border between 2011 and 2016 (ii) determine genetic relationships between FMD viruses circulating between 2016 and 2017 and, (iii) ascertain the impact of FMD on income and food security. The study was carried out in the border districts of Missenyi and Kyerwa in Tanzania and Rakai and Isingiro in Uganda. For objective (i), retrospective data was compiled and analysed in R and maps were drawn using QGIS. Results showed that 46% of the 82 recorded outbreaks occurred in sub-counties/wards immediately neighbouring the Uganda-Tanzania border and 69.5% of the outbreaks occurred during dry months. For objective (ii), 43 samples were analysed using PCR and 11 were successfully sequenced. Sequences were analysed and trees drawn using MEGA 7. Phylogenetic analysis of the VP1 coding region showed that serotype O viruses obtained belonged to EA-2 topotype and clustered together with an average sequence divergence of 4.9%. Obtained serotype A viruses belonged to Africa-G1 topotype, formed one cluster with a 7.4% sequence divergence. For objective (iii) data was collected from 288 households using a structured questionnaire. Results showed significant reduction in income from livestock and livestock products sales by over 60%, whereas livestock market prices decreased by nearly half. Forty nine percent of farmers reported calf mortalities and milk consumption in households reduced by 57% in Rakai and Isingiro and 48% in Missenyi. These findings provide information helpful for policy reform, and designing better strategies for FMD control. The study recommends comprehensive regional studies to be implemented in border areas

Molecular characterization of serotype O foot-andmouth disease virus from pigs: Implications for multispecies approach to disease control in Uganda

In Uganda, where foot-and-mouth disease (FMD) control is mainly done through vaccination, constant monitoring of outbreaks and phylogenetic studies are important in designing effective disease control strategies. These efforts however, have mainly concentrated on cattle since they are the main visible disease hosts. In this study, the molecular characteristics of the VP1 coding sequences of the pigderived FMD virus and its phylogenetic relationship with other historical Ugandan FMD virus sequences are determined. Sixty seven samples were collected from three districts of south western Uganda and subjected to RT-PCR. Partial VP1 capsid protein coding sequences of 12 positive samples were amplified and sequenced using serotype specific primers. Eight sequences were successfully obtained, all of which were from domestic pigs. All samples were confirmed as belonging to serotype O using BLAST search. Phylogenetic analysis of the test sequences with selected sequences, showed a close relatedness (average of 3.77% pair-wise distance) to viruses isolated from central and western Uganda in the years 2005 and 2006 from cattle. These results show that domestic pigs in the western region of Uganda have been infected with the same circulating strain of FMDV and play a potentially important role in FMD maintenance and spread.Keywords: Foot-and-mouth disease (FMD), pig-derived FMDV sequence, persistence, domestic pigsAfrican Journal of Biotechnology Vol. 12(19), pp. 2547-255

Low topotype diversity of recent foot-and-mouth disease virus serotypes O and A from districts located along the Uganda and Tanzania border

Foot-and-mouth disease (FMD) is one of the most important livestock diseases in East Africa with outbreaks reported annually that cause severe economic losses. It is possible to control disease using vaccination, but antigenic matching of the vaccine to circulating strains is critical. To determine the relationship between foot-and-mouth disease viruses circulating in districts along the Uganda and Tanzanian border between 2016 and 2017 and currently used vaccines, phylogenetic analysis of the full VP1 virus sequences was carried out on samples collected from both sides of the border. A total of 43 clinical samples were collected from animals exhibiting signs of FMD and VP1 sequences generated from 11 of them. Eight out of the 11 sequences obtained belonged to serotype O and three belonged to serotype A. The serotype O sequences obtained showed limited nucleotide divergence (average of 4.9%) and belonged to topotype East Africa-2, whereas the most common O-type vaccine strain used in the region (O/KEN/77/78) belonged to East Africa-1. The serotype A viruses belonged to topotype Africa-G1 (average nucleotide divergence 7.4%), as did vaccine strain K5/1980. However, vaccine strain K35/1980 belonged to Africa G VII with an average sequence divergence of 20.5% from the study sequences. The genetic distances between current vaccine strains and circulating field strains underscores the crucial need for regular vaccine matching and the importance of collaborative efforts for better control of FMD along this border area

Leptospira seroprevalence among ugandan slaughter cattle: comparison of sero-status with renal Leptospira infection

Despite evidence of both human and animal; Leptospira; exposures in Uganda, the epidemiology of the disease is still not well-investigated. Contact with animals and their environments have been pointed out as potential source of infection with; Leptospira; species in humans; and cattle may be an important reservoir in Uganda. In this cross-sectional study, we estimated the prevalence of anti-; Leptospira; antibodies by the standard microscopic agglutination test (MAT); and associated risk factors among slaughtered cattle. We also compared the performance of the MAT used in this study against a; lipL32; based real time PCR (qPCR) assay previously conducted on the kidneys and urine of the same slaughter cattle as tested in this reported study. Of 500 cattle sampled, 27.8% (95% CI 23.9-32.0) tested positive (titer ≥ 100) to at least one; Leptospira; serovar, with the majority of seropositive cattle reacting to serovars Tarassovi (sg Tarassovi) (11.6%), Sejroe (Sg Sejroe) (7.8%), and Australis (Sg Australis) (5.2%). Older animals had 2.8 times (95% CI 1.0-8.2,; p; -value 0.055) greater odds of being seropositive than younger ones (<1.5 years). The sensitivity and specificity of the MAT over the qPCR were 65.9% (95% CI 50.1-79.5) and 75.9% (95% CI 71.7-79.7), respectively; with a negative predictive value of 95.8% and positive predictive value of 20.9%. In conclusion, slaughter cattle in this study were significantly exposed to pathogenic; Leptospira; species of mainly the Tarassovi, Sejroe, and Australis serogroups, with seroprevalence being higher among older cattle. The high specificity and negative predictive value of MAT as used in this study when compared to the qPCR assay may imply a rather strong association between seronegativity and absence of renal; Leptospira; infection. However, MAT predictability for renal; Leptospira; infection may be interpreted cautiously since predictive values of diagnostic tests are dependent on prevalence

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

A scoping review of zoonotic parasites and pathogens associated with abattoirs in Eastern Africa and recommendations for abattoirs as disease surveillance sites

Abattoirs are facilities where livestock are slaughtered and are an important aspect in the food production chain. There are several types of abattoirs, which differ in infrastructure and facilities, sanitation and PPE practices, and adherence to regulations. In each abattoir facility, worker exposure to animals and animal products increases their risk of infection from zoonotic pathogens. Backyard abattoirs and slaughter slabs have the highest risk of pathogen transmission because of substandard hygiene practices and minimal infrastructure. These abattoir conditions can often contribute to environmental contamination and may play a significant role in disease outbreaks within communities. To assess further the risk of disease, we conducted a scoping review of parasites and pathogens among livestock and human workers in abattoirs across 13 Eastern African countries, which are hotspots for zoonoses. Our search results (n = 104 articles) showed the presence of bacteria, viruses, fungi, and macroparasites (nematodes, cestodes, etc.) in cattle, goats, sheep, pigs, camels, and poultry. Most articles reported results from cattle, and the most frequent pathogen detected was Mycobacterium bovis, which causes bovine tuberculosis. Some articles included worker survey and questionnaires that suggested how the use of PPE along with proper worker training and safe animal handling practices could reduce disease risk. Based on these findings, we discuss ways to improve abattoir biosafety and increase biosurveillance for disease control and mitigation. Abattoirs are a ‘catch all’ for pathogens, and by surveying animals at abattoirs, health officials can determine which diseases are prevalent in different regions and which pathogens are most likely transmitted from wildlife to livestock. We suggest a regional approach to biosurveillance, which will improve testing and data gathering for enhanced disease risk mapping and forecasting. Next generation sequencing will be key in identifying a wide range of pathogens, rather than a targeted approach.The US Defense Threat Reduction Agency Biological Threat Reduction Program R-00716- 19-0 (DTRA) administered by the US Department of Defense.https://www.frontiersin.org/journals/public-health#am2024Veterinary Tropical DiseasesSDG-02:Zero HungerSDG-03:Good heatlh and well-bein

Occurrence of Foot-and-Mouth Disease Virus Serotypes in Uganda and Tanzania (2003 to 2015): A Review and Implications for Prospective Regional Disease Control

This research article published by the Journal of Agricultural Science, 2020Endemic foot-and-mouth disease (FMD) presents a global economic challenge to the livestock industry. The progressive control pathway for FMD (PCP-FMD) specifies successive steps through which a country/region can reduce FMD virus circulation and impact. These steps are reliant on understanding and obtaining knowledge on FMD epidemiology, to inform development of appropriate disease interventions like vaccination and quarantine programs. Currently, Uganda and Tanzania are in the early stages of the PCP-FMD. This review was undertaken to determine FMDV serotype distribution in Uganda and Tanzania between 2003 and 2015. The paper also presents the vaccine strains used in both countries for the same period viz avis the circulating topotypes. The review highlights four (O, A, SAT 1 and SAT 2) and five (O, A, SAT 1, SAT 2 and SAT 3) serotypes that occurred in Uganda and Tanzania respectively in the thirteen year period. Observations revealed that reported circulating serotypes O and A in the two countries belonged to similar topotypes, East African 2 (EA-2) and AFRICA respectively. The SAT 1 viruses in Tanzania belonged to topotype I and differed from the Ugandan SAT 1s that belonged to topotype IV. Similarly, the SAT 2s in both countries belonged to different topotypes: IV in Tanzania and I in Uganda. This review additionally, underscores the spatial distribution of FMDV serotypes in Uganda and Tanzania and highlights regions in both countries that had high serotype diversity. The paper recommends definitive disease diagnoses, molecular serotype characterisation and matched vaccination deployment for improved disease control

Analysis of patterns of livestock movements in the Cattle Corridor of Uganda for risk-based surveillance of infectious diseases

IntroductionThe knowledge of animal movements is key to formulating strategic animal disease control policies and carrying out targeted surveillance. This study describes the characteristics of district-level cattle, small ruminant, and pig trade networks in the Cattle Corridor of Uganda between 2019 and 2021.MethodologyThe data for the study was extracted from 7,043 animal movement permits (AMPs) obtained from the Ministry of Agriculture, Animal Industry and Fisheries (MAAIF) of Uganda. Most of the data was on cattle (87.2%), followed by small ruminants (11.2%) and pigs (1.6%). Two types of networks representing animal shipments between districts were created for each species based on monthly (n = 30) and seasonal (n = 10) temporal windows. Measures of centrality and cohesiveness were computed for all the temporal windows and our analysis identified the most central districts in the networks.ResultsThe median in-degree for monthly networks ranged from 0–3 for cattle, 0–1 for small ruminants and 0–1 for pigs. The highest median out-degrees for cattle, small ruminant and pig monthly networks were observed in Lira, Oyam and Butambala districts, respectively. Unlike the pig networks, the cattle and small ruminant networks were found to be of small-world and free-scale topologies.DiscussionThe cattle and small ruminant trade movement networks were also found to be highly connected, which could facilitate quick spread of infectious animal diseases across these networks. The findings from this study highlighted the significance of characterizing animal movement networks to inform surveillance, early detection, and subsequent control of infectious animal disease outbreaks

A scoping review of zoonotic parasites and pathogens associated with abattoirs in Eastern Africa and recommendations for abattoirs as disease surveillance sites

Abattoirs are facilities where livestock are slaughtered and are an important aspect in the food production chain. There are several types of abattoirs, which differ in infrastructure and facilities, sanitation and PPE practices, and adherence to regulations. In each abattoir facility, worker exposure to animals and animal products increases their risk of infection from zoonotic pathogens. Backyard abattoirs and slaughter slabs have the highest risk of pathogen transmission because of substandard hygiene practices and minimal infrastructure. These abattoir conditions can often contribute to environmental contamination and may play a significant role in disease outbreaks within communities. To assess further the risk of disease, we conducted a scoping review of parasites and pathogens among livestock and human workers in abattoirs across 13 Eastern African countries, which are hotspots for zoonoses. Our search results (n = 104 articles) showed the presence of bacteria, viruses, fungi, and macroparasites (nematodes, cestodes, etc.) in cattle, goats, sheep, pigs, camels, and poultry. Most articles reported results from cattle, and the most frequent pathogen detected was Mycobacterium bovis, which causes bovine tuberculosis. Some articles included worker survey and questionnaires that suggested how the use of PPE along with proper worker training and safe animal handling practices could reduce disease risk. Based on these findings, we discuss ways to improve abattoir biosafety and increase biosurveillance for disease control and mitigation. Abattoirs are a ‘catch all’ for pathogens, and by surveying animals at abattoirs, health officials can determine which diseases are prevalent in different regions and which pathogens are most likely transmitted from wildlife to livestock. We suggest a regional approach to biosurveillance, which will improve testing and data gathering for enhanced disease risk mapping and forecasting. Next generation sequencing will be key in identifying a wide range of pathogens, rather than a targeted approach

Comprehensive transcriptome of the maize stalk borer, Busseola fusca, from multiple tissue types, developmental stages, and parasitoid wasp exposures

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