Faculty of Health Sciences
School of Medicine
Department of Medical Virology
Selected Highlights from Research Findings
The Respiratory and Zoonosis group under leadership of Professor M. Venter is affiliated to the National Institute for Communicable Diseases where she heads the Respiratory Virus Unit which houses the World Health Organisation Regional Influenza Reference Laboratory (the National Influenza Centre). This has lead to a drastic expansion of the programme that includes projects related to respiratory viruses, influenza and emerging zoonotic viruses associated with neurological disease. Postgraduate research students and postdoctoral fellows in this department that are part of the Respiratory and Zoonotic Disease Programme are invlovd in research on the pathogenesis, molecular epidemiology, host genetics, immune response and development of novel disgnostic tools to detect respiratory and zoonotic viruses under mentorship of Professor M. Venter. The main focus of the respiratory virus group is respiratory syncytial virus (RSV) as well as newly described respiratory viruses while the zoonosis group looks at diseases in humans and animals associated with neurological and respiratory syndromes that may cause zoonotic infections in humans. The main focus of the group is West Nile and virus discovery.
Contact person: Prof M Venter.
For the Emerging Neurological Diseases and Zoonosis Programme, the pathogenesis of zoonotic viruses such as West Nile virus's (WNV) were investigated in South Africa. In order to determine if WNV is being missed as a cause of neurological disease in South Africa, a 3 year study that uses horses as sentinel animals fordetecting WNV disease was completed. WNV was identified in several fatal cases of severe neurological disease and we showed that up to 30% of unexplained neurological infections in horses may be due to WNV. Virus discoveryprojects were also carried out on the cases that tested negative for common viruses and Wesselsbron virus, Sindbis virus, Middelburg virus and an uncharacterised Bunyavirus named, Shuni virus was identified as causes of neurological disease in horses that have zoonotic potential and should be investigated in human cases of neurological disease. These viruses were also identified in several fatal cases of neurological disease in wildlife, including Rhinoceros, suggesting that animal vaccines should be investigated to protect valuable animals. Genome sequencing of these isolated are underway. Finally a new differential diagnostic tool for aseptic meningitis have been developed and validated against clinical specimens. This low density macroarray does not require expensive equipment to use and will be invaluable in the identification of causes on aseptic meningitis outbreaks in Africa. Using this test the group were able to identify clinical cases of WNV, Rify Valley Fever, rabies as well as 30 other causes of neurological infections in Africa. The findings of the zoonosis group has beenpresented at 2 international and 2 local conferences in 2010 and pubished in 2 high impact journals. A new state of the art high level containment laboratory (BSL-3+) that will form part of the zoonosis unit will soon be completed on the medical campus, the first of its kind at the University of Pretoria. This wil facilitate the expansion of the zoonosis work and establish the "One Health" Programme in South Africa.
Contact person: Prof M Venter.
The Respiratory virus group has made excellent progress over the past year in the investigation of viral causative agents of pneumonia in hospitalised children. A quantitative multiplex realtime PCR that can detect 13 differnet respiratory viruses in 4 realtime RTPCR reactions have been developed and published in the Journal of Virological Methods. This technique was subsequently used to screen 30-50% of all respiratory virus specimens that tested negtive for conventional viruses in the Department of Medical Virology/ NHLS routine diagnostic laboratory during 2006 and 2007 and identified viruses in 70% of specimens. Findings of this study suggest that Respiratory Syncytial virus remain the number one cause of severe pneumonia in children in hospitals in Pretoria. Various newly identified respiratory viruses were detected that play an important role in lower respiratory tract disease and have not previously been investigated in South Africa. This test was subsequently used to screen specimens from patients in Kenya and the results indicated that an intervention that prevents RSV could reduce severe pneumonia admisions by a third in children. The results were published in the Journal of the American Medical Association. The group has also been actively involved in describing the molecular epidemiology of the influenza A H1N1 pandemic in the country and have presented this data at several international conferences and World Health Organisation meetings in 2010 and publised in 3 high impact journals. The data was used to help identify the appropriate virus strains to be included in the 2011 Southern Hemisphere Influenza Vaccine. A study of the genetics of severe pneumonia in South African children was completed and polymorphisms in the VDR and JUN genes identified that are associated with enhanced disease in children during RSV infection. Investigation of differences in the G and NS proteins of RSV strains associated with mild and severe disease is nearly completed. In this study it was shown that the Subtype A genotypes GA2 and GA5 were more likely to be associated with severe disease that the newly identified subtype B BA genotype. Strains that have most of the G-protein deleted were also identified in children with pneumonia suggesting that RSV does not require the G-protein to cause secere disease in immunocompromised children. Quasispecies were also for the first time identified in the NS proteins of RSV. Investigation of the importance of a new subtype of Rhinovirus in pnumonia in SouthAfrica is also nearly completed.
Contact person: Prof M Venter.
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