Rotavirus vaccination within the South African Expanded Programme on Immunisation
ABSTRACT Diarrhoeal diseases are ranked the third major cause of childhood mortality in South African children less than 5years, where the majority of deaths are among black children. Acute severe dehydrating rotavirus diarrhoea remains an important contributor towards childhood mortality and morbidity and has been well documented in South Africa. As the preventive strategy to control rotavirus diarrhoea, South Africa became the first country in the WHO African Region to adopt the rotavirus vaccine in the national childhood immunisation programme in August 2009. The rotavirus vaccine in use, Rotarix(®), GSK Biologicals, is given at 6 and 14weeks of age, along with other vaccines as part of Expanded Programme on Immunisation (EPI). Studies which facilitated the introduction of rotavirus vaccine in South Africa included the burden of rotavirus disease and strain surveillance, economic burden of rotavirus infection and clinical trials to assess the safety and efficacy of vaccine candidates. This paper reviews the epidemiology of rotavirus in South Africa, outlines some of the steps followed to introduce rotavirus vaccine in the EPI, and highlights the early positive impact of vaccination in reducing the rotavirus burden of disease based on the post-marketing surveillance studies at Dr George Mukhari hospital, a sentinel site at University of Limpopo teaching hospital in Pretoria, South Africa, which has conducted rotavirus surveillance for >20years.
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ABSTRACT: Group A rotaviruses (RVAs) are the leading cause of severe gastroenteritis and eventually death among infants and young children worldwide, and disease prevention and management through vaccination is a public health priority. In August 2009, Rotarix™ was introduced in the South African Expanded Programme on Immunisation. As a result, substantial reductions in RVA disease burden have been reported among children younger than 5 years old. Rotavirus strain surveillance post-vaccination is crucial to, inter alia, monitor and study the evolution of vaccine escape strains. Here, full-genome sequence data for the 11 gene segments from 11 South African G1P rotavirus strains were generated, including 5 strains collected from non-vaccinated children during the 2004-2009 rotavirus seasons and 6 strains collected from vaccinated children during the 2010 rotavirus season. These data were analyzed to gain insights into the overall genetic makeup and evolution of South African G1P rotavirus strains and to compare their genetic backbones with those of common human Wa-like RVAs from other countries, as well as with the Rotarix™ and RotaTeq™ G1P vaccine components. All 11 South African G1P strains revealed a complete Wa-like genotype constellation of G1-P-I1-R1-C1-M1-A1-N1-T1-E1-H1. On the basis of sequence similarities, the South African G1P strains (with the exception of strain RVA/Human-wt/ZAF/1262/2004/G1P) were closely related to each other (96-100% identity in all gene segments). Comparison to the Rotarix™ and RotaTeq™ G1P vaccine components revealed a moderate nucleotide identity of 89-96% and 93-95%, respectively. The results indicated that none of the gene segments of these 11 South African G1P strains were vaccine-derived. This study illustrates that large-scale next generation sequencing will provide crucial information on the influence of the vaccination program on evolution of rotavirus strains. This is the first report to describe full genomic analyses of G1P RVA strains collected from both non-vaccinated and vaccinated children in South Africa. J. Med. Virol. 9999: XX-XX, 2014. © 2014 Wiley Periodicals, Inc.Journal of Medical Virology 05/2014; DOI:10.1002/jmv.23971 · 2.22 Impact Factor
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ABSTRACT: Group A rotaviruses (RVA) are among the main global causes of severe diarrhea in children under the age of 5years. Strain diversity, mixed infections and untypeable RVA strains are frequently reported in Africa. We analysed rotavirus-positive human stool samples (n=13) obtained from hospitalised children under the age of 5years who presented with acute gastroenteritis at sentinel hospital sites in six African countries, as well as bovine and porcine stool samples (n=1 each), to gain insights into rotavirus diversity and evolution. Polyacrylamide gel electrophoresis (PAGE) analysis and genotyping with G-(VP7) and P-specific (VP4) typing primers suggested that 13 of the 15 samples contained more than 11 segments and/or mixed G/P genotypes. Full-length amplicons for each segment were generated using RVA-specific primers and sequenced using the Ion Torrent and/or Illumina MiSeq next-generation sequencing platforms. Sequencing detected at least one segment in each sample for which duplicate sequences, often having distinct genotypes, existed. This supported and extended the PAGE and RT-PCR genotyping findings that suggested these samples were collected from individuals that had mixed rotavirus infections. The study reports the first porcine (MRC-DPRU1567) and bovine (MRC-DPRU3010) mixed infections. We also report a unique genome segment 9 (VP7), whose G9 genotype belongs to lineage VI and clusters with porcine reference strains. Previously, African G9 strains have all been in lineage III. Furthermore, additional RVA segments isolated from humans have a clear evolutionary relationship with porcine, bovine and ovine rotavirus sequences, indicating relatively recent interspecies transmission and reassortment. Thus, multiple RVA strains from sub-Saharan Africa are infecting mammalian hosts with unpredictable variations in their gene segment combinations. Whole-genome sequence analyses of mixed RVA strains underscore the considerable diversity of rotavirus sequences and genome segment combinations that result from a complex evolutionary history involving multiple host species. Copyright © 2015. Published by Elsevier B.V.Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 02/2015; 31. DOI:10.1016/j.meegid.2015.02.011 · 3.22 Impact Factor
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ABSTRACT: This case report describes diagnosis and management of intussusception in an 8-month-old baby girl seen at the Ventersdorp District Hospital, South Africa. According to the vaccination card, the child had been immunized with rotavirus vaccine with the last dose given 6 months and 2 weeks before presentation to Ventersdorp Hospital. This case of intussusception was unlikely associated with rotavirus vaccination.The Pediatric Infectious Disease Journal 01/2014; 33 Suppl 1:S104-6. DOI:10.1097/INF.0000000000000097 · 3.14 Impact Factor