MRC Diarrhoeal Pathogens Research Unit

Pretoria, South Africa

MRC Diarrhoeal Pathogens Research Unit

Pretoria, South Africa
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Page N.,South African National Institute for Communicable Diseases | Page N.,MRC Diarrhoeal Pathogens Research Unit | Esona M.,Centers for Disease Control and Prevention | Seheri M.,MRC Diarrhoeal Pathogens Research Unit | And 5 more authors.
Journal of Medical Virology | Year: 2010

Reviews of the global distribution of rotavirus genotypes have revealed the continuous circulation of G8 strains in Africa, often responsible for more cases of rotavirus disease than the more common G1-G4 rotavirus strains. During the study, genotype G8 strains from Malawi, Kenya, and South Africa were detected and the VP7 and VP4 genes of selected specimens were sequenced. Results indicated that G8 strains appeared to reassort frequently and were associated with P[6], P[4], and P[8] specificity. Phylogenetic analysis suggested that G8 strains occurred in a North/South African phylogenetic divide. In addition, G8 strains appear to be able to infect non-human primates and strains with close phylogenetic relationships were detected in the same year on two continents. Any rotavirus vaccine introduced into African environments will need to demonstrate protective efficacy against unusual genotype combinations, new serotypes, and animal strains. Therefore, continuous monitoring of rotavirus strains in human and animal populations in Africa is a necessity. J. Med. Virol. 82:2073-2081, 2010. © 2010 Wiley-Liss, Inc.


Mapaseka S.L.,MRC Diarrhoeal Pathogens Research Unit | Dewar J.B.,MRC Diarrhoeal Pathogens Research Unit | Dewar J.B.,University of South Africa | Van Der Merwe L.,Biostatistics Unit | And 9 more authors.
Journal of Infectious Diseases | Year: 2010

Rotavirus is considered to be the most common cause of serious acute dehydrating diarrhea worldwide. However, there is a scarcity of information on rotavirus disease burden in sub-Saharan Africa. Methods. We conducted prospective, hospital-based surveillance for rotavirus diarrhea among children <5 years of age at the tertiary care Dr. George Mukhari Hospital (DGM) and at the Brits district Hospital (BH) in the Gauteng and North West Provinces in South Africa; we estimated that up to 80% of children <5 years of age in their catchment areas who are hospitalized for diarrhea are admitted to one of these hospitals. Results. At DGM, 2553 children <5 years of age were admitted for diarrhea from January 2003 through December 2005, and 852 children <5 years of age were treated for diarrhea at BH during 2004-2005. We examined stool specimens from 450 children (53%) at BH and from 1870 children (73%) admitted to DGM. An estimated 22.8% (95% confidence interval [CI], 21.2%-24.5%) of the children hospitalized with diarrhea at DGM were rotavirus positive, and the corresponding figure at BH was 18.2% (95% CI, 14.9%-22.1%). Among children <5 years of age admitted to DGM for any reason, an estimated 5.5% (95% CI, 5.1%-6.0%) had rotavirus diarrhea. Our incidence estimates suggest that 1 in 43-62 children in the area is likely to be hospitalized with rotavirus diarrhea by 2 years of age. Conclusions. Prevention of serious rotavirus illness by vaccination will substantially reduce not only the disease burden among young children but also the case load in South African health care facilities. © 2010 by the Infectious Diseases Society of America.


Steele A.D.,MRC Diarrhoeal Pathogens Research Unit | Reynders J.,MRC Diarrhoeal Pathogens Research Unit | Scholtz F.,MRC Diarrhoeal Pathogens Research Unit | Bos P.,MRC Diarrhoeal Pathogens Research Unit | And 5 more authors.
Journal of Infectious Diseases | Year: 2010

Background. A phase II, randomized, double-blind, placebo-controlled study was conducted in South Africa during 2003-2004 to evaluate the safety, reactogenicity, and immunogenicity of 2 regimens of the live attenuated oral human rotavirus vaccine RIX4414 when coadministered with the Expanded Program on Immunization childhood vaccines, including oral polio vaccine. Methods. Healthy infants were randomized (2:2:1) to receive either 2 doses of RIX4414 ( ; at np190 10 and 14 weeks, with placebo at 6 weeks), 3 doses of RIX4414 (np189; at 6, 10, and 14 weeks), or 3 doses of placebo (np96), all with concomitant routine vaccinations. The antirotavirus IgA seroconversion rate was assessed using enzyme-linked immunosorbent assay at 2 months after the last dose of RIX4414 or placebo. Antipolio types 1, 2, and 3 antibodies were measured using a virus neutralization assay. Solicited symptoms were recorded for 15 days after each dose. Results. The antirotavirus IgA seroconversion rates were similar in the RIX4414 2- and 3-dose groups (44.3% and 44.4%, respectively; Pp.544, by 1-sided Fisher exact test) and antirotavirus IgA geometric mean concentrations were also comparable. Seroprotection rates for antipolio types 1, 2, and 3 antibodies were high (93%-100%) and were not significantly different among groups. Solicited symptoms reported within 15 days after vaccination were similar in all groups. Conclusions. The immune seroconversion response to the RIX4414 vaccine with 3 doses was not superior to the 2-dose regimen. There was no interference by either regimen with antibody response to oral polio vaccine, and RIX4414 was well tolerated when given with routine vaccinations. © 2010 by the Infectious Diseases Society of America.


Steele A.D.,MRC Diarrhoeal Pathogens Research Unit | De Vos B.,Glaxosmithkline | Tumbo J.,MEDUNSA | Reynders J.,MRC Diarrhoeal Pathogens Research Unit | And 4 more authors.
Vaccine | Year: 2010

A double-blind, placebo-controlled phase II trial (e-Track 444563-014/. NCT00346892) was conducted in South Africa to evaluate the co-administration of RIX4414 (live-attenuated human G1P[8] rotavirus vaccine) and oral poliovirus vaccine (OPV) administered simultaneously. Healthy infants (n=450) were randomized into three groups (RIX4414 + OPV, RIX4414 + IPV or Placebo + OPV) to receive two oral doses of RIX4414/placebo with OPV or IPV using two vaccination schedules (6-10 weeks and 10-14 weeks). Serum anti-rotavirus IgA antibodies (ELISA) and neutralizing antibodies (micro-neutralization assay) to poliovirus serotypes 1, 2 and 3 were measured. Co-administration of RIX4414 with OPV did not result in a decrease in the high sero-protection rates against poliovirus serotypes 1, 2 and 3 detected after the third OPV dose (98-100%). The anti-rotavirus IgA antibody sero-conversion rates were higher for the 10-14 weeks schedule (55-61%) compared to the 6-10 weeks schedule (36-43%). Solicited symptoms were reported at similar rates between RIX4414 and placebo groups and no serious adverse events related to RIX4414 were reported. This study provided evidence that RIX4414 can be co-administered with routine EPI immunizations including OPV and that two doses of RIX4414 were well tolerated and immunogenic in South African infants. © 2010.


PubMed | MRC Diarrhoeal Pathogens Research Unit
Type: Clinical Trial, Phase II | Journal: Vaccine | Year: 2010

A double-blind, placebo-controlled phase II trial (e-Track 444563-014/NCT00346892) was conducted in South Africa to evaluate the co-administration of RIX4414 (live-attenuated human G1P[8] rotavirus vaccine) and oral poliovirus vaccine (OPV) administered simultaneously. Healthy infants (n=450) were randomized into three groups (RIX4414+OPV, RIX4414+IPV or Placebo+OPV) to receive two oral doses of RIX4414/placebo with OPV or IPV using two vaccination schedules (6-10 weeks and 10-14 weeks). Serum anti-rotavirus IgA antibodies (ELISA) and neutralizing antibodies (micro-neutralization assay) to poliovirus serotypes 1, 2 and 3 were measured. Co-administration of RIX4414 with OPV did not result in a decrease in the high sero-protection rates against poliovirus serotypes 1, 2 and 3 detected after the third OPV dose (98-100%). The anti-rotavirus IgA antibody sero-conversion rates were higher for the 10-14 weeks schedule (55-61%) compared to the 6-10 weeks schedule (36-43%). Solicited symptoms were reported at similar rates between RIX4414 and placebo groups and no serious adverse events related to RIX4414 were reported. This study provided evidence that RIX4414 can be co-administered with routine EPI immunizations including OPV and that two doses of RIX4414 were well tolerated and immunogenic in South African infants.

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