PubMed Health⌕ Search

Biomedical subjects

N A Cunliffe

Publications and source records attributed to N A Cunliffe.

At least 19 recordsLinked to original sources
PubMed2004

Epidemiology of rotavirus diarrhoea in Iranian children.

Human rotavirus is the most important cause of severe diarrhoea in infants and young children worldwide. We describe the aetiology of viral diarrhoea and the characteristics of rotavirus infection in Shahrekord, Iran. Two hundred and fifty nine children <5 years old admitted to Hajar Hospital, 245 children with acute diarrhoea attending primary health centres in Shahrekord, and 114 children hospitalised for elective surgery were selected from October 2001 to August 2002. Stool samples were screened for enteric viruses using EM. Rotaviruses were characterised using ELISA, reverse transcription-polymerase chain reaction (RT-PCR), and electropherotyping. One hundred and eighty six viruses were identified, of which 146 (78%) were rotavirus. The second most frequent virus was coronavirus, followed by calicivirus. Rotaviruses exhibited a marked seasonal variation, being most frequently isolated from November to February (50% of rotavirus recovered) and affected mostly children <2 years old. The RT-PCR successfully typed 139 of the 146 (95%) rotavirus G types and 124 (85%) P types. The most frequent P type was, P[8] in 108 (74%), P[4] in 16 (11%), and was P non-typeable in 22 (15%). Among the G types, G1 was identified in 120 (82%), G2 in 19 (13%), and was G-non-typeable in 7 (5%). Our results are the first report of rotavirus genotypes affecting Iranian children. The most frequent G and P types (G1, G2, P[8], and P[4]) are similar to those reported from around the world and will be covered by existing rotavirus vaccines targeting G types G1-G4.

Antigens, Viral↗
PubMed2003

Characterization of rotaviruses causing diarrhoea in Vietnamese children.

Faecal samples from 123 children admitted to the Centre for Tropical Diseases in Ho Chi Minh city, Vietnam, with acute watery diarrhoea were screened by negative-stain electron microscopy for viral enteropathogens. In addition to the 48 children who were found to be infected with rotavirus only, one had both rotavirus and astrovirus, two had adenovirus 40/41, and one had astrovirus only. The rotaviruses were subjected to molecular analysis by electropherotyping, G- and P-genotyping (by reverse-transcriptase PCR), and amplicon sequencing. By use of newly designed PCR primers, all 49 isolates could be G-genotyped and all but one P-genotyped. Novel variants of G1-G1*--were the most commonly detected G-genotype and such variants of P[8]-P[8*]--were the second commonest P-genotype. The P[8*] and G1* amplicons were, respectively, only 92%-93.4% and 88.1%-89% similar to the corresponding sequences from the prototype P[8] G1 rotavirus, Wa. Several unusual P- and G-genotype combinations were detected. Four (8%) of the children investigated were each found to be co-infected with two different rotaviruses. These data add to our knowledge of the continuing evolution and diversity of human rotaviruses, and should help in the rational design of vaccines.

Adenoviridae↗
PubMed2002

Detection and characterization of rotaviruses in hospitalized neonates in Blantyre, Malawi.

In five separate fecal collections spanning three years, group A rotaviruses were detected by enzyme-linked immunosorbent assay in 35 (25%) of 142 specimens obtained from nondiarrheic, hospitalized neonates in Blantyre, Malawi. Molecular characterization of each strain identified, for the first time in neonates, a short electropherotype, genotype P[6], G8 strain type, similar to the dominant, cocirculating community strain detected in symptomatic infants in Blantyre. Partial sequence analysis of the VP4 and NSP4 genes of neonatal and community strains failed to identify changes which could explain the differences in clinical outcome. Neonatal serotype G8 rotaviruses should be considered as potential rotavirus vaccine candidates for use in Malawi.

Capsid↗
PubMed2001

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.

Chi-Square Distribution↗
PubMed2001

Plasma HIV burden in Malawian children co-infected with rotavirus.

Fifty-eight HIV-infected children with acute rotavirus diarrhea were tested for plasma HIV RNA. There was no difference between acute and convalescent mean viral loads, and little change in CD4 cell counts. Compared with the 16 children who died within 4 weeks, 31 survivors had slightly lower viral loads at presentation and significantly higher CD4 cell counts. Low CD4 cell counts, but not HIV-1-RNA concentrations, were predictive of Death. Local, enteric rotavirus infection did not appear to affect blood HIV viral load or CD4 cell counts in this small group of children.

Acute Disease↗
PubMed2001

Detection of group C rotavirus in children with acute gastroenteritis in Blantyre, Malawi.

Among 606 children who were treated for acute gastroenteritis at the Queen Elizabeth Central Hospital in Blantyre, Malawi, Group C rotavirus (Gp C RV) was detected by enzyme-linked immunosorbent assay in fecal specimens from 16 (3.9%) of 408 inpatients and in 4 (2.0%) of 198 outpatients. Thirteen (65%) children excreting Gp C RV were coinfected with Group A rotavirus.

Acute Disease↗
PubMed2001

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

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.

Amino Acid Sequence↗
PubMed2000

Molecular characterization of serotype G9 rotavirus strains from a global collection.

Between 1992 and 1998, serotype G9 human rotavirus (RV) strains have been detected in 10 countries, including Thailand, India, Brazil, Bangladesh, Malawi, Italy, France, the United States, the United Kingdom, and Australia, suggesting the possible emergence of the fifth common serotype worldwide. Unlike the previously characterized reference G9 strains (i.e., WI61 and F45), the recent G9 isolates had a variety of gene combinations, raising questions concerning their origin and evolution. To identify the progenitor strain and examine the on-going evolution of the recent G9 strains, we characterized by genetic and antigenic analyses 16 isolates obtained from children with diarrhea in India, Bangladesh, the United States, and Malawi. Specifically, we sequenced their VP7 and NSP4 genes and compared the nucleotide (nt) and deduced amino acid sequences with the reference G9 strains. To identify reassortment, we examined the products of five gene segments; VP4, VP7, and NSP4 genotypes (genes 4, 9, and 10); subgroups (gene 6); electropherotypes (gene 11); and the genogroup profiles of all of the recent G9 isolates. Sequence analysis of the VP7 gene indicated that the recent U.S. P[6],G9 strains were closely related to the Malawian G9 strains (>99% nt identity) but distinct from G9 strains of India ( approximately 97% nt identity), Bangladesh ( approximately 98% nt identity), and the reference strains ( approximately 97% nt identity). Phylogenetic analysis identified a single cluster for the U.S. P[6],G9 strains that may have common progenitors with Malawian P[6],G9 strains whereas separate lineages were defined for the Indian, Bangladeshi, and reference G9 strains. Northern hybridization results indicated that all 11 gene segments of the Malawian P[6],G9 strains hybridized with a probe derived from a U.S. strain of the same genotype and may have the same progenitor, different from the Indian G9 strains, whereas the Bangladesh strains may have evolved from the U.S. G9 progenitors. Overall, our findings suggest that much greater diversity among the newly identified G9 strains has been generated by reassortment between gene segments than through the accumulation of mutations in a single gene.

Antigens, Viral↗
PubMed2000

Molecular and serologic characterization of novel serotype G8 human rotavirus strains detected in Blantyre, Malawi.

During a 2-year study of diarrhea among children in Blantyre, Malawi, greater than 50% of rotavirus strains genotyped by using reverse transcription-polymerase chain reaction possessed previously unrecognized combinations of the neutralization proteins VP7 and VP4. Serotype G8 rotaviruses, which have been identified recently in several African countries, were found to possess P[4] or P[6] VP4 genotype specificity. Two of these short electropherotype rotaviruses were further investigated: these comprised a P[6], G8 representative strain (MW23) and a P[4], G8 representative strain (MW333). The VP7 gene sequences of both strains exhibited greatest homology to human and animal serotype G8 rotaviruses. Sequence analysis of the VP4 gene of MW23 indicated closest identity to the P2A[6], G9 strain US1205 from the United States. The VP4 gene of MW333 was most closely related to the P[4], G12 strain L26 isolated in the Philippines and the Australian P[4], G2 strain RV-5. The NSP4 gene sequences of both strains were classified in NSP4 genetic group I. RNA-RNA hybridization demonstrated that each of these two strains is related to the DS-1 genogroup of human rotaviruses. Subgroup analysis and virus neutralization confirmed complete antigenic characterization of MW23 as subgroup I, P2A[6], G8 and MW333 as subgroup I, P1B[4], G8. The similarity of the VP7 gene sequences of the prototype strains described in this report to bovine serotype G8 rotaviruses suggests that they may represent human/bovine reassortant viruses.

Animals↗
PubMed1999

Viral gastroenteritis.

A large number of viruses can be found in the human intestine. Some (bacteriophages) infect the bacteria present as normal flora and others use the gut as a portal of entry. This review examines the virology, pathogenesis, immunology, epidemiology, clinical features, treatment and prevention of the viral enteropathogens. Rotavirus is undoubtedly the most important, causing an estimated 800,000 deaths each year, especially in developing countries. Recently, an oral live quadrivalent rhesus rotavirus vaccine has been licensed for use in the USA. It has great potential but there are a number of hurdles to be overcome before it can be given to infants in developing countries. Molecular techniques are revolutionizing our understanding of rotavirus pathogenesis, and the tremendous diversity of Caliciviridae and Astroviridae, as well as producing new diagnostic techniques and vaccines.

Journal Article↗
PubMed1999

Rotavirus G and P types in children with acute diarrhea in Blantyre, Malawi, from 1997 to 1998: predominance of novel P[6]G8 strains.

One hundred rotavirus strains detected in children with acute diarrhea in Blantyre, Malawi, between July 1997 and January 1998 were characterized for G (VP7) and P (VP4) types by using multiplex, heminested, reverse transcription-polymerase chain reaction. A novel P[6]G8 rotavirus strain was identified in 42% of the specimens. The remaining strains comprised P[8]G3 (20%), P[6]G3 (10%), P[4]G8 (9%), P[6]G9 (3%), P[8]G4 (2%), P[6]G4 (2%), and P[4]G3 (1%). Rotavirus strains with mixed G or P types were identified in 2% of the specimens. Nine percent of the strains were nontypeable with the primers used. The P[6] genotype was identified in 57% of strains overall. This first description of serotype G8 rotavirus as a predominant strain has important implications for vaccine development in Africa. The finding of novel P/G combinations (P[6]G8 and P[4]G8) highlights the extraordinary diversity of rotaviruses in some countries.

Acute Disease↗
PubMed1998

A prospective controlled study of the association of Streptococcus bovis with colorectal carcinoma.

AIM: To investigate the ability of Streptococcus bovis to colonise colorectal cancers. PATIENTS: 19 patients with colorectal cancer and 23 controls without malignancy. SETTING: University teaching hospital. METHODS: Prospective study comparing unselected patients with known colorectal cancer with age and sex matched controls. Carcinoma tissue from patients with colorectal cancer and normal colonic mucosa, stool, and blood from both patients and control subjects were cultured. RESULTS: In contrast to published data, the faecal carriage rate was similar in cancer (11%) and control groups (13%). CONCLUSIONS: Faecal colonisation by Str bovis in colorectal cancer patients is lower than previously reported and does not differ significantly from controls.

Adenocarcinoma↗
PubMed1998

Epidemiology of rotavirus diarrhoea in Africa: a review to assess the need for rotavirus immunization.

Rapid progress towards the development of rotavirus vaccines has prompted a reassessment of the disease burden of rotavirus diarrhoea in developing countries and the possible impact of these vaccines in reducing diarrhoeal morbidity and mortality among infants and young children. We examined the epidemiology and disease burden of rotavirus diarrhoea among hospitalized and clinic patients in African countries through a review of 43 published studies of the etiology of diarrhoea. The studies were carried out from 1975 through 1992, and only those in which a sample of more than 100 patients with diarrhoea were specifically screened for rotavirus by using an established diagnostic test were included. Rotavirus was detected in a median of 24% of children hospitalized for diarrhoea and in 23% who were treated as outpatients; 38% of the hospitalized patients with rotavirus were < 6 months and 81% were < 1 year of age. Rotavirus was detected year-round in nearly every country and generally exhibited distinct seasonal peaks during the dry months. In 5 countries where rotavirus strains had been G-typed, 74% of strains were of one of the four common serotypes (G1 to G4), G1 was the predominant serotype, and 26% were non-typeable. This cumulative experience from 15 African countries suggests that rotavirus is the most important cause of severe diarrhoea in African children and that most strains in circulation today belong to common G types that are included in reassortant vaccines. Wherever large numbers of cases of rotavirus diarrhoea occur early in infancy, immunization at birth may protect the children before their first symptomatic infection.

Africa↗
PubMed1997

Sequence analysis demonstrates that VP6, NSP1 and NSP4 genes of Indian neonatal rotavirus strain 116E are of human origin.

We have sequenced the genes encoding the inner capsid protein VP6 and the nonstructural proteins NSP1 and NSP4 of the Indian neonatal serotype P8[11]G9 human/bovine reassortant candidate vaccine rotavirus strain 116E. These three genes share a high degree of sequence and deduced amino acid homology with human prototype strain Wa. Our results confirm and extend those of previous RNA-RNA hybridization studies which suggested that these genes are of human origin, and will facilitate examination of the host immune response to 116E induced by natural infection and vaccination.

Amino Acid Sequence↗
PubMed1997

Sequence analysis of NSP4 gene of human rotavirus allows classification into two main genetic groups.

The rotavirus nonstructural glycoprotein NSP4 may represent the first identified viral enterotoxin. We have sequenced reverse transcription-polymerase chain reaction (RT-PCR)-generated fragments of 16 NSP4 genes of human rotavirus (HRV) strains from six different countries, representing seven different G and P type combinations. Based on the amount of sequence divergence between these and 11 previously sequenced NSP4 genes of human and animal rotaviruses, three distinct genetic groups could be recognized. Most strains within a group were closely related to each other at the nucleotide (nt) and amino acid (aa) levels (usually <10% divergence) but more distantly related (maximum 30.0% nt divergence and 24.7% aa divergence) to members of the other groups. Intergroup variation occurred in two highly variable regions of NSP4 (aa 16-34 and aa 131-148). The NSP4 "toxic peptide" (aa 114-135) exhibited aa variation at its carboxy terminus both within and between genetic groups. The largest group (genetic group II) contained HRV strains of subgroup II specificity (including genotypes P[8]G1, P[8]G3, P[6]G3, and P[8]G5 and serotype P8[11]G9), and the smaller group (genetic group I) contained HRV strains of subgroup I specificity (genotype P[4]G2). The NSP4 sequence of the rhesus rotavirus vaccine strain was distinct from all other strains and formed the third group (genetic group III). The NSP4 genes of animal rotaviruses UK, NCDV, and SA11 (genetic group I) and YM (genetic group II) and two possible human-animal rotavirus reassortant strains, Brazilian P[8]G5 and Indian P[11]G9 (genetic group II), could also be classified into one of these groups, suggesting a close evolutionary relationship between human and animal NSP4 genes. These results will facilitate studies of the host immune response to NSP4, which may be relevant to future HRV vaccine design.

Amino Acid Sequence↗