Browsing by Author "Cronje, Nadine"
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- ItemThe diversity of coronaviruses in Southern African bat populations(Stellenbosch : Stellenbosch University, 2017-12) Cronje, Nadine; Preiser, Wolfgang; Schoeman, Corrie; Ithete, Ndapewa; Stellenbosch University. Faculty of Health Sciences. Dept. of Pathology. Medical Virology.ENGLISH ABSTRACT: Coronaviruses are RNA viruses encompassing four genera. The alpha- and betacoronaviruses have commonly been associated with mild disease in humans. However, outbreaks of severe respiratory disease in 2002 and 2012 led to the identification of novel highly pathogenic human coronaviruses, SARS- and MERS-CoV, respectively. Bats, order Chiroptera, are believed to be the reservoir host from which all mammalian coronaviruses have emerged. To date, few studies have been published on coronaviruses in South African bats. With little known about the diversity and prevalence of bat coronaviruses in this region; this study aimed to describe the existing coronavirus diversity within South African bat populations as well as factors that might influence bat-coronavirus ecology. It detected nine different coronavirus species, eight alphacoronaviruses and one betacoronavirus, from ten different bat species. The study not only demonstrated that diverse coronaviruses can be found in different bat species of Southern Africa but lends additional support to an ongoing circulation of MERS-related betacoronaviruses in South African bats, with divergent variants detected in two different vespertilionid bat species. A species-specific surveillance of Neoromicia capensis (Cape serotine) bats detected three different bat coronavirus species and revealed genetic diversity across different geographic regions. Several instances of coinfection with two different coronaviruses were detected, demonstrating the potential for recombination that could lead to the emergence of a new coronavirus that might have zoonotic potential. This study demonstrated that both host and environmental factors may influence CoV ecology. Female Neoromicia capensis bats trapped at low altitude sites within the Forest biome had the highest likelihood of being coronavirus positive. Discrepancies between detection rates obtained with different screening assays led to the adoption of an improved approach and recommendations for future bat coronavirus surveillance studies were made.
- ItemMolecular characterisation and epidemiology of enterovirus-associated aseptic meningitis in the Western and Eastern Cape Provinces, South Africa 2018–2019(Elsevier B.V., 2021-04) Nkosi, Nokwazi; Preiser, Wolfgang; Van Zyl, Gert; Claassen, Mathilda; Cronje, Nadine; Maritz, Jean; Newman, Howard; McCarthy, Kerrigan; Ntshoe, Genevie; Essel, Vivien; Korsman, Stephen; Hardie, Diana; Smuts, HeidiBackground: Enteroviruses are amongst the most common causes of aseptic meningitis. Between November 2018 and May 2019, an outbreak of enterovirus-associated aseptic meningitis cases was noted in the Western and Eastern Cape Provinces, South Africa. Objectives: To describe the epidemiology and phylogeography of enterovirus infections during an aseptic meningitis outbreak in the Western and Eastern Cape Provinces of South Africa. Methods: Cerebrospinal fluid samples from suspected cases were screened using a polymerase chain reaction targeting the 5’UTR. Confirmed enterovirus-associated meningitis samples underwent molecular typing through species–specific VP1/VP2 primers and pan-species VP1 primers. Results: Between November 2018 and May 2019, 3497 suspected cases of aseptic meningitis were documented in the Western and Eastern Cape Provinces. Median age was 8 years (range 0–61), interquartile range (IQR=4–13 years), 405/735 (55%) male. 742/3497 (21%) cases were laboratory – confirmed enterovirus positive by routine diagnostic PCR targeting the 5’UTR. 128/742 (17%) underwent molecular typing by VP1 gene sequencing. Echovirus 4 (E4) was detected in 102/128 (80%) cases. Echovirus 9 was found in 7%, Coxsackievirus A13 in 3%. 10 genotypes contributed to the remaining 10% of cases. Synonymous mutations were found in most cases, with sporadic amino acid changes in 13 (12.7%) cases. Conclusion: The aseptic meningitis outbreak was associated with echovirus 4. Stool samples are valuable for molecular typing in CSF confirmed EV-associated aseptic meningitis.