Winifred Dove

Predominance of Rotavirus P(4)G2 in a Vaccinated Population, Brazil

We identified 21 rotaviruses in 129 patients with diarrhea in a Brazilian city with high rotavirus vaccine coverage. All rotaviruses were genotype P[4]G2 with 1 mixed infection with P[NT]G9. Although virus predominance could have occurred randomly, the vaccine may be less protective against P[4]G2. Prospective surveillance is urgently needed.

Rotavirus strain diversity in Blantyre, Malawi, from 1997 to 1999.

ABSTRACT In a 2-year study of viral gastroenteritis in children in Blantyre, Malawi, the diversity of rotavirus strains was investigated by using electropherotyping, reverse transcription-PCR amplification of the VP7 and VP4 genes (G and P genotyping), and nucleotide sequencing. Of 414 rotavirus strains characterized, the following strain types were identified: P[8], G1 (n = 111; 26.8%); P[6], G8 (n = 110; 26.6%); P[8], G3 (n = 93; 22.5%); P[4], G8 (n = 31; 7.5%); P[8], G4 (n = 21; 5.1%); P[6], G3 (n = 12; 2.9%); P[6], G1 (n = 7; 1.7%); P[6], G9 (n = 3; 0.7%); P[6], G4 (n = 3; 0.7%); P[4], G3 (n = 1; 0.2%); and mixed (n = 15; 3.6%). While all strains could be assigned a G type, seven strains (1.7%) remained P nontypeable. The majority of serotype G8 strains and all serotype G9 strains had short electropherotype profiles. All remaining typeable strains had long electropherotypes. Divergent serotype G1 rotaviruses, which contained multiple base substitutions in the 9T-1 primer binding site, were commonly identified in the second year of surveillance. Serotype G2 was not identified. Overall, G8 was the most frequently identified VP7 serotype (n = 144; 34.8%) and P[8] was the most frequently detected VP4 genotype (n = 227; 54.8%). Partial sequence analysis of the VP4 gene of genotype P[8] rotaviruses identified three distinct clusters, which predominantly (but not exclusively) comprised strains belonging to a distinct VP7 serotype (G1, G3, or G4). As a result of mutations in the 1T-1 primer binding site, strains belonging to each cluster required a separate primer for efficient typing. One cluster, represented by P[8], G4 strain OP354, was highly divergent from the established Wa and F45 VP4 P[8] lineages. As is the case for some other countries, the diversity of rotaviruses in Malawi implies that rotavirus vaccines in development will need to protect against a wider panel of serotypes than originally envisioned.

Apparent extinction of non-G2 rotavirus strains from circulation in Recife, Brazil, after the introduction of rotavirus vaccine.

The introduction of a G1P[8] rotavirus vaccine in Recife, Brazil, caused a decrease in rotavirus detection from 27% (March–May, 2006) to 5.0% (March–May, 2007), with all strains becoming G2, against which less protection had been predicted.

Human bocavirus infection among children, Jordan.

Human bocavirus was detected in 57 (18.3%) of 312 children with acute respiratory infection (ARI) who required hospitalization in Jordan. It was also detected in 30 (21.7%) of 138 children with severe ARI, in 27 (15.5%) of 174 with mild or moderate disease, and in 41 (72%) of 57 with other pathogens.

Human Metapneumovirus and Respiratory Syncytial Virus, Brazil

We describe the epidemiologic and clinical characteristics of 111 children attending clinics and hospitals in Aracaju, northeast Brazil, with acute respiratory infections attributable to human metapneumovirus (HMPV), respiratory syncytial virus (RSV), or both in May and June 2002. Fifty-three (48%) children were infected with RSV alone, 19 (17%) with HMPV alone, and 8 (7%) had RSV/HMPV co-infections.

Incidence of Rotavirus and All-Cause Diarrhea in Northeast Brazil Following the Introduction of a National Vaccination Program

BACKGROUND & AIMS Rotavirus vaccines were introduced in Brazil in 2006; we evaluated their effects in the state of Sergipe, Brazil. METHODS We performed a cross-sectional survey of children with diarrhea attending emergency services in Aracaju, Brazil, between October 2006 and April 2008 and a cluster sampling survey to assess vaccination coverage. Vaccine efficacy was assessed using the screening method. Diarrhea consultation and hospitalization data (2003-2007) were obtained from state and national surveillance systems. RESULTS Rotavirus was detected in 59 of 534 stool samples (11%) from children attending emergency services. The number of rotavirus-positive samples decreased from 18 of 74 (24%) in 2006 to 31 of 321 (9.5%) in 2007 and 10 of 136 (7.4%) in 2008 (P < .01). Diarrhea severity was greater in children with rotavirus (P < .01) but decreased over time (P < .001). Of the rotaviruses detected, 56 of 59 (95%) were P[4]G2 genotype, 1 was P[4]G-non-typeable (NT), 1 was P[NT]G2, and 1 was P[NT]GNT. Diarrhea consultations decreased from 3020 in 2004 to 604 in 2007; reductions were greatest among children under 5 years old. Diarrhea hospitalizations decreased from 2121 in 2003 to 1176 in 2007. Vaccine coverage was 90.3%. Vaccines were highly effective against the strain P[8]G1; efficacy against P[4]G2 genotype was 89% (95% confidence interval: 0.87-0.92) in Aracaju and 95% in Sergipe. CONCLUSIONS Since vaccines were introduced in 2006, there has been an overall reduction in diarrhea consultations and hospitalizations in northeast Brazil, with the greatest reductions in young children. This might have resulted from vaccination and improved sanitation. Although a single rotavirus genotype (P[4]G2) was recovered, vaccine efficacy was high against this genotype.

Human bocavirus in Iranian children with acute respiratory infections

Human bocavirus (HBoV), a virus discovered in Sweden in 2005, has been associated with acute respiratory infections in young children and subsequent reports suggest that HBoV may have a worldwide distribution. This report describes the frequency and clinical presentation of HBoV in 261 Iranian children<5 years old with acute respiratory infections attending two regional hospitals in Rasht, Iran in the winter of 2003–2004. Polymerase chain reaction (PCR) and reverse transcription PCR (RT‐PCR) were used for the detection of HBoV and other respiratory pathogens from nasopharyngeal specimens. HBoV was detected in 21 (8%) children. Fifteen (12%) of these children were identified among 122 children admitted to hospital and 6 (4%) from 139 outpatients (P < 0.05). Most children with HBoV were less than 2 years (17/21, 81%) and 7 (33%) were less than 1 year old. Although HBoV was identified in all ages it affected slightly older children than the respiratory syncytial virus (RSV). The frequency of the virus varied from 1 (3%) in 40 patients in November to 7 (12%) of 61 in February, suggesting a seasonal pattern during the autumn and early winter. Seven children had co‐infections with RSV, adenovirus or influenza A. The relatively high frequency of HBoV suggests that the virus may contribute substantially to acute respiratory infections in children. J. Med. Virol. 79:539–543, 2007.

Effect of concomitant HIV infection on presentation and outcome of rotavirus gastroenteritis in Malawian children

BACKGROUND Rotaviruses represent important causes of severe diarrhoea in early childhood. We examined the effect of HIV infection on the presentation and outcome of rotavirus gastroenteritis in Malawian children. METHODS Children younger than 5 years who were treated for acute gastroenteritis at the Queen Elizabeth Central Hospital in Blantyre from July, 1997, to June, 1999, were enrolled. Children with rotavirus diarrhoea, with and without HIV infection, were followed up for up to 4 weeks after hospital discharge. Rotavirus disease severity (assessed with a 20-point score), duration of rotavirus shedding, and seroresponse to rotavirus were compared between HIV-infected and HIV-uninfected children. FINDINGS 786 inpatients (median age 8 months, 271 [34%] of whom were HIV-1-infected) and 400 outpatients (median age 9 months, 65 [16%] of whom were HIV-infected) were enrolled. Rotavirus was detected less frequently among HIV-infected children (102 of 336 [30%]) than among HIV-uninfected children (348 of 850 [41%], (relative risk 0.71 [95% CI 0.53-0.87], p=0.0007). There were no differences in rotavirus disease severity for hospitalised children with and without HIV infection, but HIV-infected children were more likely to die during follow-up (11/50 [22%]) than HIV-uninfected children (0/61, p<0.0001). Of 29 HIV-infected and 45 HIV-uninfected children who completed follow-up, six (21%) HIV-infected children shed rotavirus, compared with two (4%) HIV-uninfected children (4.66 [1.01-21.51], p=0.05), but shedding was not associated with diarrhoea. Three-quarters of children exhibited a four-fold rise of serum IgG or IgA to rotavirus, which did not vary by HIV status. INTERPRETATION Malawian children with concomitant HIV infection resolved acute rotavirus infections. Rotavirus vaccine safety and immunogenicity in HIV-infected infants should now be determined.

Molecular epidemiology and disease severity of respiratory syncytial virus in relation to other potential pathogens in children hospitalized with acute respiratory infection in Jordan.

Human respiratory syncytial virus (HRSV) is the major viral cause of acute lower respiratory tract infections in children. Few data about the molecular epidemiology of respiratory syncytial virus in developing countries, such as Jordan, are available. The frequency and severity of infections caused by HRSV were assessed in hospitalized Jordanian children <5 years of age compared with other potential etiological agents. Overall a potential pathogen was detected in 78% (254/326) of the children. HRSV was detected in 43% (140/326) of the nasopharyngeal aspirates. HRSV was found more frequently during the winter (January/February), being less frequent or negligible by spring (March/April). Analysis of 135 HRSV‐positive strains using restriction fragment length polymorphism showed that 94 (70%) belonged to subgroup A, and 41 (30%) to subgroup B. There were also two cases of mixed genotypic infection. Only four of the six previously described N genotypes were detected with NP4 predominating. There were no associations between subgroup or N‐genogroup and disease severity. HRSV was significantly associated with more severe acute respiratory infection and the median age of children with HRSV was lower than for those without. Next in order of frequency were adenovirus (116/312: 37%), human bocavirus (57/312: 18%), rhinovirus (36/325: 11%), Chlamydia spp. (14/312: 4.5%), human metapneumovirus (8/326: 2.5%), human coronavirus NL63 (4/325: 1.2%), and influenza A virus (2/323: 0.6%). Influenza B; parainfluenza viruses 1–4, human coronavirus HKU1 and Mycoplasma pneumoniae were not detected. J. Med. Virol. 80:168–174, 2008.

Molecular phylogenetic and evolutionary analyses of Muar strain of Japanese encephalitis virus reveal it is the missing fifth genotype

Japanese encephalitis virus (JEV) is the most important cause of epidemic encephalitis worldwide but its origin is unknown. Epidemics of encephalitis suggestive of Japanese encephalitis (JE) were described in Japan from the 1870s onwards. Four genotypes of JEV have been characterised and representatives of each genotype have been fully sequenced. Based on limited information, a single isolate from Malaysia is thought to represent a putative fifth genotype. We have determined the complete nucleotide and amino acid sequence of Muar strain and compared it with other fully sequenced JEV genomes. Muar was the least similar, with nucleotide divergence ranging from 20.2 to 21.2% and amino acid divergence ranging from 8.5 to 9.9%. Phylogenetic analysis of Muar strain revealed that it does represent a distinct fifth genotype of JEV. We elucidated Muar signature amino acids in the envelope (E) protein, including E327 Glu on the exposed lateral surface of the putative receptor binding domain which distinguishes Muar strain from the other four genotypes. Evolutionary analysis of full-length JEV genomes revealed that the mean evolutionary rate is 4.35 × 10(-4) (3.4906 × 10(-4) to 5.303 × 10(-4)) nucleotides substitutions per site per year and suggests JEV originated from its ancestral virus in the mid 1500s in the Indonesia-Malaysia region and evolved there into different genotypes, which then spread across Asia. No strong evidence for positive selection was found between JEV strains of the five genotypes and the E gene has generally been subjected to strong purifying selection.