School of Veterinary Medicine and Animal Resources (SVAR)

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Browsing School of Veterinary Medicine and Animal Resources (SVAR) by Subject "African swine fever"
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    Biosecurity practices and seroprevalence of African swine fever in Kasawo and Katosi Sub-Counties, Mukono District
    (Makerere University, 2024) Otuba, Geofrey
    African swine fever is one of the major constraints to pig farming causing devastating economic losses for the farmers and wiping out entire pig farms. The majority of the pig farms in Uganda are small-scale and this heavily impacts the livelihood of farmers exacerbating the problem of poverty among the rural poor. African swine fever is endemic in Uganda and frequent outbreaks have been reported all over the country in recent years. The factors responsible for the occurrence of these outbreaks are poorly understood especially at the farm level. This study aims to provide an understanding of the factors responsible for the continued circulation of African swine fever and also give an insight into the extent of the African swine fever challenge. Blood samples were collected from pigs in different pig farms and tested for African swine fever antibodies using competitive ELISA. In addition, to further understand the biosecurity and husbandry practices at the farms, a questionnaire was designed and administered to collect data from the different farms where blood samples were picked. The seroprevalence for African swine fever in both Katosi and Kasawo sub-counties was 0%. 73% of the pig farmers were aware of the existence of African swine fever in pigs. There was a significant difference in African swine fever awareness for pig farmers with farm records (p=0.017) and those who had training in pig husbandry (p=0.025). 70% of the farms had their pigs housed and only 0.7% of the farms were fenced. Only 4% of the pig farms had footbaths. 29% of the farms reported African swine fever outbreaks in the previous twelve months. Pig farmers practices of slaughtering and selling of sick pigs, sharing boars, buying pigs from other farms, among others were the main risk factors for the spread of African swine fever. The majority of farms were grossly lacking in biosecurity implementation at the farm level. Though evidence of chronic African swine fever was not found in pigs, the occurrence of African swine fever remains a big challenge for the pig farmers in Mukono District. Surveillance and the establishment of gazetted abattoirs in Mukono District are crucial for controlling African swine fever in Mukono District.
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    Pig lymphnode lesions and an immunohistochemical analysis on selected abattoir-derived lymphnode samples for the presence of African Swine fever virus
    (Makerere University, 2010-06) Ssajjakambwe, Paul
    The economy of Uganda is largely dependent on agriculture, and both crop and animal production contribute up to 29.9% of the national Gross Domestic Product (GDP). Although pig products constitute an important source of affordable animal protein for humans, swine diseases are a great limiting factor in the achievement of these goals. ASF has been reported in Uganda almost annually in sporadic form. This research was designed to investigate pig lymphnode lesions and an immunohistochemistry analysis on selected abattoir derived lymphnode samples for the presence of African Swine Fever (ASF) antigen. A total of 258 samples were collected for the study, with examination of collected lymphnode samples for gross and histopathological lesions. Ninety highly suspect lymphnode samples were then subjected to Immunohistochemistry (IHC) analysis for presence of African Swine Fever Virus antigen using polyclonal antibodies. The major gross lesion manifested was haemorrhagic lymphnodes 94 (36.4%). Others 17 (6.6%) presented with haemorrhage and edema, lymphnode necrosis 76 (29.4%) and atrophy 32 (12.4%) The least observed lesion was plain enlargement 6 (2.3%) whereas 156 (60.4%) without a significant lesion. On histopathology, the most observed lesion was parenchymal haemorrhage 131(50.8%). Others observed were subcapsular haemorrhage 97 (37.6%), and medullary haemorrhage 46 (17.8%). Follicular necrosis 126 (48.8%), follicular hyperplasia 124 (48.1%), lymphoid depletion 22 (8.5%), lymphoid proliferation 86 (33.3%) and eosinophil accumulation 48 (18.6%). The ninety (90) samples highly suspicious for African swine fever virus infection were subjected to IHC investigation. Twenty two (24.4%) samples presented positive for the viral antigen of interest. The origin and number of the pigs from which positive samples were identified on IHC was:- Jinja 3 (0.033%), Sembabule 3 (0.033%), Kiboga 3 (0.033%), Kayunga 2 (0.022%), Soroti 5 (0.05%), Masaka 4 (0.04%)and Luwero 2 (0.022%), Soroti and Masaka districts registering the highest number of cases amongst the sampled animals. These districts occasionally report ASF out breaks although confirmatory diagnosis is not usually carried out. Based on the findings of the study, it’s observed that there were lymphnode samples containing the ASFV antigen, an indication of subclinical or chronic form of the disease as clinical signs were not manifested in the live animals; implying that African swine fever is an endemic disease of pigs within Uganda. However, much as a number of lymphnodes presented with gross and microscopic lesions highly suggestive for the ASF virus infection and yet were negative on IHC, confirmatory diagnosis is the best option to ascertain the status of the case rather than rely on the elementary tools of diagnosis i.e. gross and histopathological lesions plus clinical signs. Further research involving field studies other than abattoir sites would provide an insight on the ASF strains responsible for the outbreaks of the disease in the country with possible goal of developing a vaccine for ASFV infection as treatment can`t do much.