Browsing by Subject "zoonosis"
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(2022)Crimean Congo haemorrhagic fever (CCHF) is an emerging, tick-borne viral pathogen. Found on three continents, it is the most widespread of all tick-borne pathogens, but accurate geographical limits and epidemiology in Africa are still mostly unknown. Ticks act as both vectors and reservoirs, and the transmission cycle involves both wild and domestic animals and may occasionally spill over to humans. Further healthcare-related infections from human to human are common. With a high mortality rate and no cure or vaccine, CCHF is considered a major public health threat in endemic countries. This licentiate thesis consists of a literature review and an experimental work section. The literature review covers the basics of tick ecology, tick-borne diseases and viral haemorrhagic fevers with a focus on Africa and Kenya. These are used as foundations to understand CCHF in detail, encompassing virology, epidemiology, diagnostics, symptoms, treatment and prevention. The experimental work entails PCR-screening of ticks collected from South-eastern Kenya for the CCHF virus. The main objective of the study was to find whether CCHF is circulating in free-roaming ticks collected from two conservancies in the Taita Hills area. Taita Hills are located in Taita-Taveta county, near the Helsinki University research centre in Wundanyi. The ticks were collected by the Vapalahti virology team in 2018. This thesis involved the RNA extraction and measurement from the ticks and screening for CCHF virus with RT-qPCR. The results were negative for all 57 units of ticks processed. The study was a part of a larger research project, “Preparedness for emerging zoonotic infections in Kenya”. Previous publications on CCHF are lacking from this part of Kenya, so this study was a valuable part of primary research to establish the geographical limits and members of the enzootic cycle in Taita Hills. It would be essential to continue examining ticks from animal sources in addition to human serology, to further establish evidence of possible CCHF occurrence in the area. Mapping the prevalence and epidemiology of zoonotic and tick-borne pathogens is especially critical now, when climate change and diminishing biodiversity stir and alter disease emergence in an unprecedented manner.
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(2024)The emergence of zoonotic viruses has been a great concern and threat for global public health. It is important to be aware of the persistence and circulation of zoonoses and their natural hosts in their habitants where wildlife-human interaction can more likely occur. Not many studies have been published regarding the situation in Ireland. In this study, we concentrated in three viral zoonoses, poxviruses, hantaviruses, and arenaviruses, that were screened and detected from Irish rodents specifically bank voles (Myodes glareolus) and wood mice (Apodemus sylvaticus) collected in spring and fall 2021 and spring 2022. By using serological approach such as indirect immunofluorescence assay (IFA), 683 rodent heart samples were screened. Based on serological screening, molecular assays were performed to detect each virus from tissue samples. As a result of the serological screening, 34 antibody-positives either for pox- (CPXV), hanta- (PUUV, DOBV), and arenaviruses (LCMV) were found from which 15 were CXPV, five PUUV, 11 DOBV and three LCMV. The seroprevalence was ranging from 0.4% to 2.2%. When it comes to molecular detection, no viral genome was identified in any of the tissue samples. Although the seroprevalences were low, this study presents the first evidence of CXPV, PUUV, DOBV and LCMV exposures found in Ireland. These findings suggest that there is a possibility of circulation of these viruses among wild rodents and therefore novel risks for viral transmission should be considered. Further research requires increased effort to monitor these viruses and their wildlife hosts in Ireland.
Now showing items 1-2 of 2