Epidemiological study of the G serotype distribution of group A rotaviruses in Kenya from 1991 to 1994

Abstract

An epidemiological study on the G serotype distribution of group A rotaviruses (GARV) isolated in Kenya was carried out in one urban hospital in Nairobi and in two rural hospitals in Nanyuki and Kitui to clarify the prevalent G serotypes before future introduction of the ready licensed rotavirus vaccine in Kenya. A total of 1,431 stool specimens were collected from children, who were mainly outpatients, aged from 0 to 6 years old with acute gastroenteritis from August 1991 to July 1994. Samples positive for GARV by conventional ELISA were then analyzed by subgrouping and serotyping ELISA and by PAGE. To ascertain the G serotypes of viruses in samples that were unable to be typed by serotyping ELISA, polymerase chain reaction was also attempted. The prevalence of GARV was 28.4% in the urban hospital, 22.5% in Nanyuki, and 13.7% in Kitui. Among rotavirus-positive samples, subgroup II rotaviruses were detected in 63.1%, and subgroup I rotaviruses were 25.9%. Serotype G4 was most prevalent, accounting for 41.6% followed by 23.3% of serotype G1, 17.0% of serotype G2, and serotype G3 was rarely isolated. Seven strains of serotype G8/P1B rotavirus was detected for the first time in Kenya by RT-PCR. Eleven specimens with an unusual composition of subgroup, serotype, and electropherotype were atypical GARV in which the P-serotype was P1A, P1B, or P2. Although uncommon GARV serotype G8/P1B and atypical GARV were detected, the four major GARV serotypes, G1 through G4, should be targeted at this moment for vaccination to control this diarrheal disease in Kenya. Continuous monitoring of the G- and P-serotype distribution of GARV should provide important information about the impact of rotavirus vaccination in Kenya.

G8Rotavirus Strains Isolated in the Democratic Republic of Congo Belong to the DS-1-Like Genogroup

“…(G8P [4] and G2P [6] HRV strains were designated DS-1 like by RNA-RNA hybridization or electropherotype.) The G8 specificity (shown in yellow) is believed to be of bovine origin, and it has been suggested that G8 was introduced into HRV strains during several separate reassortment events (1,10,11,31,44,63). The P [6] specificity (shown in blue) is found in humans and pigs (38) and is present in more than a quarter of the HRV isolates found on the African continent (59).…”

“…The P [6] specificity (shown in blue) is found in humans and pigs (38) and is present in more than a quarter of the HRV isolates found on the African continent (59). DS-1-like HRV isolates with G8P [4] specificity have been found on several occasions on the African continent (12,13,18,44,46,63) and most likely acquired the G8 specificity through a reassortment event between a DS-1-like HRV and an RV with the G8 specificity (Fig. 4A).…”

“…Since then, isolated human cases of G8 RV infection have been found in Finland, Italy, the United Kingdom, Brazil, Australia, Japan, and India with long and short electrophoretic patterns and with SG I and SG II specificities (8,11,21,31,33,48,60,63). By far, the most G8 HRVs were found all over the African continent (Malawi, Nigeria, Egypt, Kenya, South Africa, Guinea-Bissau, and Ghana), and in a few epidemiological surveys, G8 was the predominant G genotype (3,7,12,13,18,19,26,44,63). G8 HRVs have been detected in combination with a large number of VP4 specificities: P [1], P [2], P [4], P [6], P [8], P [10], and P [14] (13,19,22,31,33,53,61).…”

Genetic and Antigenic Characterization of Rotavirus Serotype G9 Strains Isolated in Australia between 1997 and 2001

“…The P genotypes are in brackets, whereas the P serotypes are open numbers. Epidemiological studies have shown that serotypes G1, G2, G3, and G4, associated with P1A (8) or P1B (4), have been the most common serotypes causing severe disease in children globally over the last 20 years (35,40). Genetic and antigenic variation has been recorded within the G1, G2, G3, and G4 serotypes (38).…”

Molecular Characterization in the VP7, VP4 and NSP4 Genes of Human Rotavirus Serotype 4 (G4) Isolated in Japan and Kenya

“…G I rotavirus has been the most predominant type in the world, while G4 rotavirus has been predominant in Kenya and some other countries occasionally (13,25). In this report we characterized G4 rotavirus in more detail.…”