Publications by authors named "Walda van Zyl"

Enteroviruses cause a wide range of neurological illnesses such as encephalitis, meningitis, and acute flaccid paralysis. Two types of enteroviruses, echovirus E4 and E9, have recently been detected in South Africa and are known to be associated with meningitis and encephalitis. The objective of this study was to characterize enterovirus strains detected in cerebrospinal fluid specimens of hospitalized patients in the private and public sector to identify genotypes associated with meningitis and encephalitis.

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Patients with severe primary immunodeficiency are at risk for complications from live-attenuated vaccines. Here, we report a case of a vaccine-associated paralytic polio and Bacille Calmette-Guérin disease in a 6-month-old girl with severe combined immunodeficiency resulting from homozygous recombinant activating gene 1 deficiency. The patient was successfully treated with intravenous immunoglobulins and oral pocapavir for poliovirus, and antimycobacterial therapy for regional Bacille Calmette-Guérin disease, allowing stem cell transplant.

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The genogroup II genotype 4 (GII.4) noroviruses are a major cause of viral gastroenteritis. Since the emergence of the Sydney_2012 variant, no novel norovirus GII.

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Article Synopsis
  • - The bag-mediated filtration system (BMFS) was created to improve the environmental surveillance of poliovirus (PV) and complements traditional methods focused on acute flaccid paralysis to help with PV eradication efforts in Nairobi, Kenya, from April to September 2015.
  • - During the study, environmental samples were collected and processed using two methods: BMFS (which filtered over 3 liters) and a grab sample method (collecting 1 liter). The samples were then analyzed for poliovirus presence using various techniques, including rRT-PCR.
  • - Results showed that BMFS detected Sabin polioviruses more frequently than the other method, especially Sabin-like PV type 3, indicating its effectiveness for environmental monitoring, while no
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Article Synopsis
  • This study highlights the importance of enteric virus surveillance due to their low infectious doses and long environmental persistence, using a novel bag-mediated filtration system (BMFS).
  • The researchers found that enteroviruses and PMMoV were present in 100% of wastewater samples collected from various sites in Kenya, while other viruses like adenovirus and norovirus were detected in most samples.
  • The consistent presence of these viruses indicates their potential use as contamination indicators and emphasizes the need for effective monitoring of water sources worldwide.
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Background: The World Health Organization has recommended that rotavirus (RV) vaccines be included in all national immunization programs as part of a strategy to control RV-associated diarrheal diseases. Hospital-based surveillance of RV infection is therefore crucial in monitoring the impact pre- and post-vaccine introduction and also to document changes in genotype distribution. This study sought to determine the RV genotypes circulating in the eastern region of Kenya before introduction of the RV vaccine.

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In this study, a competitive internal amplification control (IAC) was constructed for application in the real-time reverse transcription-polymerase chain reaction detection of sapoviruses (SaVs). A SaV RNA standard was also created for quantification of the virus. The IAC was included in the screening of environmental samples for SaVs.

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Human adenoviruses (HAdVs) cause a wide range of clinical syndromes and are classified in seven species, A-G, comprising 52 serotypes. HAdV-A31, -F40, and -F41 have been associated with diarrhea in infants and young children. In developing countries gastroenteritis is a major cause of morbidity and mortality in children and, in comparison to rotaviruses, there are no data on the HAdVs associated with diarrhea in pediatric patients in Kenya.

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Our study aimed to evaluate the oral cavity as a reservoir from where Helicobacter pylori may be transmitted. Histology and PCR amplification were performed. Eighty-four percent of the stomach biopsies tested positive; however, H.

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After exposure to the oral poliovirus vaccine (OPV), immunocompetent persons excrete poliovirus (PV) vaccine strains for a limited period. In contrast, immunodeficient individuals remain sometimes chronically infected, and in some cases, PV excretion times as long as 10 years have been reported. During prolonged replication in the human intestine, the PV vaccine strain almost invariably reverts its attenuated character and acquires neurovirulent properties (vaccine-derived PVs, or VDPVs), which resemble wild-type PV strains.

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Adenoviruses are of major public health importance and are associated with a variety of clinical manifestations, i.e. gastroenteritis, eye infections and respiratory infections.

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