Prevalence and Distribution of Foot-and-Mouth Disease Virus Serotypes and Serotype O Subtypes in Kenya in 2019 and 2020
| dc.contributor.author | Mumo, Josiah Judith | |
| dc.date.accessioned | 2025-03-07T06:25:16Z | |
| dc.date.available | 2025-03-07T06:25:16Z | |
| dc.date.issued | 2024-10 | |
| dc.description | A Thesis Submitted In Partial Fulfillment Of The Requirements For The Award Of The Degree Of Master Of Science (Microbiology) In The School Of Pure And Applied Sciences Of Kenyatta University October, 2024 Supervisor: 1. Antony Kebire 2.Joseph Kamau 3.Abraham Sangula | |
| dc.description.abstract | Livestock is a source of livelihood, contributing to the reduction of poverty in many parts of the globe. In Africa, livestock is an asset, a source of food and income. In Kenya, approximately 12% of the country’s Gross Domestic Product (GDP) is contributed by livestock production and similarly, 42% of the agricultural GDP. Additionally, livestock offers employment to 50% of the agricultural labour force. Animal diseases, however, pose a great challenge in the industry among them being FMD (Foot-and-Mouth Disease), which is a transboundary viral disease typical among the cloven-hoofed animals. This disease has a huge economic impact on farmers as it affects many animals and disrupts the trade in animals as well as their products. It is also known to be endemic in most parts of the world including Africa, exists in seven serotypes (A, O, SAT 1, SAT 2, SAT 3, C, and Asia 1) and numerous subtypes (topotypes) and the antisera from one serotype cannot neutralize another serotype. Moreover, the movement of infected animals is closely linked with the spread of the disease, and quarantine measures and vaccination are key in controlling its spread, especially in endemic areas. In Kenya, the disease occurrence and severity have continued to increase despite the implemented control measures. A cross sectional study was done to establish the disease prevalence, distribution, circulating serotype O topotypes, and their genetic divergence from the current vaccine strain. A total of 267 bovine epithelial samples were analysed, sourced from cattle presenting with clinical disease in the years 2019 and 2020. FMDV (Foot-and-Mouth Disease Virus) antigen detection and serotyping ELISA was performed and those positive for serotype O antigen were further analyzed for genetic diversity. Viral RNA was extracted from the confirmed serotype O samples using PureLink® Viral RNA/DNA Mini Kit from Invitrogen according to the manufacturer’s instructions. The partial FMDV VP 1 gene was amplified through RT (Reverse Transcription) PCR (Polymerase Chain Reaction) and directly sequenced. The generated sequences were edited using BioEdit version 7.2.5 and phylogenetically analysed using MEGA X version 10.2.6 by neighbor-joining at 1000 bootstrap replicates before viewing them through Tree view. The antigen detection and serotyping gave an overall virus prevalence of 65.9% (176/267). From the same results, serotype SAT 1 had the highest prevalence of 45.5%(80/176) followed by serotype O at 37.5% (66/176). Serotype SAT 2 had a prevalence of 14.2% (25/176) and serotype A had the least of 2.8% (5/176). The phylogenetic analysis on FMDV serotype O revealed that all the sequences analysed were of the EA (East African) 2 topotype. The genetic analysis of these sequences showed a divergence from the current vaccine strain by the replacement of some amino acids on the gene. This study, therefore, confirms that the 2019 and 2020 outbreaks were predominantly caused by serotype SAT 1 with some serotype O viruses causing these outbreaks likely to have mutated and not being covered by the current vaccine for serotype O. This information is useful to disease control policymakers, implementors and farmers in effecting disease control at their specific levels and recommends continual monitoring of the FMDV serotypes and topotypes that are in circulation, and regularly matching the vaccine strain with the circulating viruses to ensure effective vaccination measures. | |
| dc.description.sponsorship | Kenyatta University | |
| dc.identifier.uri | https://ir-library.ku.ac.ke/handle/123456789/29724 | |
| dc.language.iso | en | |
| dc.publisher | Kenyatta University | |
| dc.title | Prevalence and Distribution of Foot-and-Mouth Disease Virus Serotypes and Serotype O Subtypes in Kenya in 2019 and 2020 | |
| dc.type | Thesis |