Search PubMed⌕ Search

Biomedical subjects

R I Glass

Publications and source records attributed to R I Glass.

At least 55 records · Page 3Linked to original sources
PubMed2000

Astrovirus diarrhea in Egyptian children.

This study describes the epidemiology of astrovirus diarrhea among a population-based cohort of 397 children aged <3 years residing in rural Egypt from 1995 to 1998. The age-specific incidence rates of astrovirus diarrheal episodes per person-year were 0.38 for infants aged <6 months, 0.40 for those aged 6-11 months, 0.16 for those aged 12-23 months, and 0.05 for those aged 24-35 months. The overall incidence rate of astrovirus diarrhea was the same as that of rotavirus diarrhea, 0.19 episodes per person-year. Astrovirus infection was pathogenic and associated with severe dehydration in 17% of the cases. The most frequent serotype was HAstV-1, and, in order of decreasing frequency, HAstV-5, HAstV-8 and HAstV-3, HAstV-6, HAstV-4, and HAstV-2. In determining whether astrovirus diarrhea was associated with a reduced incidence of subsequent disease, there was evidence to suggest HAstV-1 homotypic immunity but not heterotypic immunity. Because we observed 38% of the incidence of astrovirus diarrhea to occur in infants aged <6 months, a candidate astrovirus vaccine would have to confer immunity very early in life.

Astroviridae Infections↗
PubMed2000

A foodborne outbreak of gastroenteritis associated with Norwalk-like viruses: first molecular traceback to deli sandwiches contaminated during preparation.

In March 1998, an outbreak of acute gastroenteritis occurred among students at a Texas university. Overall, 125 ill students sought medical care. Case-control studies revealed that illness was significantly associated with eating foods from the university's main cafeteria deli bar on 9 and 10 March. Stool specimens from 9 (50%) of 18 ill students and samples of deli ham showed evidence of Norwalk-like viruses (NLVs) by reverse-transcriptase (RT) polymerase chain reaction (PCR) assay. A food handler who prepared sandwiches for lunch on 9 March reported that her infant had been sick with watery diarrhea since just before the outbreak. A stool sample from the infant was positive for NLV by RT-PCR, and the sequence of the amplified product was identical to that of amplified product from deli ham and students' stool specimens. This is the first time RT-PCR and sequence analysis have successfully confirmed viral contamination of a food item likely to have been contaminated by a food handler.

Adolescent↗
PubMed2000

An outbreak of cryptosporidiosis linked to a foodhandler.

In September and October 1998, a cryptosporidiosis outbreak occurred on a Washington, DC, university campus. In a case-control study of 88 case patients and 67 control subjects, eating in 1 of 2 cafeterias was associated with diarrheal illness (P<.001). Morbidity was associated with eating dinner on 22 September (odds ratio, 8.1; 95% confidence interval, 3.4-19.5); weaker associations were found for 6 other meals. Cryptosporidium parvum was detected in stool specimens of 16 (70%) of 23 ill students and 2 of 4 ill employees. One ill foodhandler with laboratory-confirmed C. parvum prepared raw produce on 20-22 September. All 25 Cryptosporidium isolates submitted for DNA analysis, including 3 from the ill foodhandler, were genotype 1. This outbreak illustrates the potential for cryptosporidiosis to cause foodborne illness. Epidemiologic and molecular evidence indicate that an ill foodhandler was the likely outbreak source.

Adolescent↗
PubMed2000

Cold weather seasonality of gastroenteritis associated with Norwalk-like viruses.

Norwalk-like viruses (NLVs) are the most common cause of acute nonbacterial gastroenteritis in adults, but little is known about their seasonality. The lack of specific diagnostic tools impeded study of these viruses in the past, and surveys using electron microscopy often grouped NLVs with other unrelated viruses. A search of the scientific literature found eight surveys of gastroenteritis, which were conducted for at least 1 year, that specifically identified NLVs. Unpublished data from laboratories of 4 NLV researchers were also used. These surveys, which were conducted in eight countries, reported sporadic cases and outbreaks of NLV-associated gastroenteritis among all age groups. The monthly occurrence of these cases and outbreaks was plotted, and while transmission occurred year-round in most surveys, a cold weather peak was demonstrated in 11 of the 12 studies. This key epidemiologic feature of the viruses has important implications concerning their mode of transmission and for understanding the etiology of acute gastroenteritis in adults.

Adult↗
PubMed2000

The epidemiology of enteric caliciviruses from humans: a reassessment using new diagnostics.

In the United States, acute gastroenteritis is one of the most commonly noted illnesses on hospital discharge records and death certificates, yet few of these cases have an etiologic diagnosis. The application of new molecular diagnostic methods has shown caliciviruses (previously referred to as the Norwalk family of viruses or small round structured viruses) to be the most common cause of acute gastroenteritis (AGE) outbreaks in the United States, and they may emerge as a common cause of sporadic cases of AGE among both children and adults. Novel molecular methods have permitted outbreak strains to be traced back to their common source and have led to the first identification of virus in implicated vehicles of infection-water, shellfish, and foods contaminated both at their source and by food handlers. The broad application of these methods to routine diagnosis in hospitals and public health laboratories is advancing our appreciation of the full burden of calicivirus-associated diarrhea, and it is opening new avenues for its prevention and control.

Acute Disease↗
PubMed2000

Surveillance of rotavirus strains in the United States: identification of unusual strains. The National Rotavirus Strain Surveillance System collaborating laboratories.

Rotavirus strains from 964 fecal specimens collected from children at 11 U.S. hospital laboratories from November 1997 to March 1998 and from samples collected at 12 laboratories from November 1998 to March 1999 were typed for G and P proteins. Serotype G1 was the predominant serotype in 1997-1998 (88%), followed by G2 (6.2%), G9 (3.3%), and G3 (1.5%). This pattern was similar to that seen in 1998-1999: G1 (79%), G2 (15%), G9 (3.0%), G4 (1.6%), and G3 (0.3%). Novel P[9] strains were identified in both seasons, and analysis of a 364-nucleotide fragment from gene segment 4 of one of the strains demonstrated 97.3% nucleotide identity with the prototype P3[9],G3 strain, AU1, isolated in Japan. This is the first report of a human AU1-like strain in the United States. These results reinforce our initial findings that serotype G9 persists in the United States but has not become a predominant strain and that the common serotypes G1 to G4 account for almost 90% of strains in circulation. Other uncommon strains exist in the United States but may have been overlooked before because of their low prevalence and the use of inadequate diagnostic tools.

Child↗
PubMed2000

Trends in intussusception-associated hospitalizations and deaths among US infants.

CONTEXT: The newly licensed tetravalent rhesus-human reassortant rotavirus vaccine has been withdrawn following reports of intussusception among vaccinated infants. OBJECTIVE: To describe the epidemiology of intussusception-associated hospitalizations and deaths among US infants. DESIGN: This retrospective cohort study examined hospital discharge data from the National Hospital Discharge Survey for 1988-1997, Indian Health Service (IHS) for 1980-1997, California for 1990-1997, Indiana for 1994-1998, Georgia for 1997-1998, and MarketScan for 1993-1996, and mortality data from the national multiple cause-of-death data for 1979-1997 and linked birth/infant death data for 1995-1997. PATIENTS: Infants (<1 year old) with an International Classification of Diseases, Ninth Revision, Clinical Modification code for intussusception (560.0) listed on their hospital discharge or mortality record, respectively. RESULTS: During 1994-1996, annual rates for intussusception-associated infant hospitalization varied among the data sets, being lowest for the IHS (18 per 100 000; 95% confidence interval [CI] = 9-35 per 100 000) and greatest for the National Hospital Discharge Survey (56 per 100 000; 95% CI = 33-79 per 100 000) data sets. Rates among IHS infants declined from 87 per 100 000 during 1980-1982 to 12 per 100 000 during 1995-1997 (relative risk =7.6, 95% CI = 3.2-18.2). Intussusception-associated hospitalizations were uncommon in the first 2 months of life, peaked from 5 to 7 months old, and showed no consistent seasonality. Intussusception-associated infant mortality rates declined from 6.4 per 1 000 000 live births during 1979-1981 to 2.3 per 1 000 000 live births during 1995-1997 (relative risk = 2.8, 95% CI = 1.8-4.3). Infants whose mothers were <20 years old, nonwhite, unmarried, and had an education level below grade 12 years were at an increased risk for intussusception-associated death. CONCLUSIONS: Intussusception-associated hospitalization rates varied among the data sets and decreased substantially over time in the IHS data. Although intussusception-associated infant deaths in the United States have declined substantially over the past 2 decades, some deaths seem to be related to reduced access to, or delays in seeking, health care and are potentially preventable.intussusception, hospitalizations, deaths, risk factors, infants.

Black People↗
PubMed2000

Diarrhea-associated hospitalizations among children in Hawaii.

OBJECTIVE: To estimate the burden of diarrhea-associated hospitalizations among children in Hawaii. DESIGN: Retrospective analysis of hospital discharge records. PATIENTS: Children from 1 month through 4 years of age with a diarrhea-associated diagnosis listed on the hospital discharge record in Hawaii. SETTING: Acute care hospitals in the state of Hawaii, 1994 through 1997. RESULTS: During 1994-1997, 2288 children (11.3% of all hospitalizations for children < 5 years of age) had a diarrhea-associated diagnosis listed at hospital discharge. The average annual incidence (per 10,000 children) of diarrhea-associated hospitalizations was 62.3; the incidence was higher for children < 1 year (101.6) than for those 1 through 4 years of age (52.7). Rates for Hawaii were lower than national rates during 1993 through 1995 (US annual rate of 89 per 10,000 children). The median length of hospital stay was 2 days for diarrhea-associated hospitalizations, and 3 days for hospitalizations specifically associated with rotavirus-related diarrhea. Diarrhea-associated hospitalizations were highest during the period December through June. CONCLUSIONS: Diarrhea is an important cause of hospitalization among children in Hawaii, where approximately 1 in 32 children may be hospitalized by 5 years of age. The age-specific and temporal trends reported here are consistent with those previously described for rotavirus-associated hospitalizations, suggesting that this pathogen is a major contributor to the overall morbidity from diarrhea.

Child, Preschool↗
PubMed1999

Epidemiology of rotavirus diarrhea in Egyptian children and implications for disease control.

Reliable epidemiologic data are essential for formulating effective policy to control rotavirus disease through immunization. The objective of this study was to describe the epidemiology of rotavirus diarrhea in a population-based cohort of children under 3 years of age residing in Abu Homos, Egypt, in 1995-1996. Rotavirus diarrhea incidence rates (episodes per person-year) were 0.13 for infants aged <6 months, 0.61 for those aged 6-11 months, 0.17 for those aged 12-23 months, and 0.15 for those aged 24-35 months. Fifty-six percent of children with rotavirus diarrhea had clinical dehydration; 90% of rotavirus diarrheal episodes occurred between July and November. In infants under 1 year of age, receipt of breast milk was associated with a lower incidence of rotavirus diarrhea. No other sociodemographic or environmental factor was found to be significantly associated with rotavirus diarrhea. Of 46 rotavirus isolates with strains identified, 41 (89%) were G serotypes 1 and 2. Rotavirus diarrhea was a major cause of morbidity in this cohort. Promotion of breastfeeding may exert a protective effect in young infants in this setting, but improvements in water and sanitation are unlikely to be effective preventive measures. The use of effective immunization against rotavirus in early infancy should be considered a public health priority.

Age Distribution↗
PubMed1999

Genetic and antigenic characterization of a serotype P[6]G9 human rotavirus strain isolated in the United States.

During an epidemiologic survey of rotavirus infections established to monitor the prevalent G serotypes circulating in the United States, human P[6]G9, subgroup I rotavirus strains causing symptomatic infections were identified as the fourth most common serotype. In this report we describe the molecular and antigenic characterization of one of these P[6]G9 isolates (US1205). Neutralization and sequencing studies have demonstrated that both outer capsid proteins, VP7 and VP4, of US1205 are closely related to but genetically and antigenically distinguishable from those of standard G9 strains (e.g., F45, WI61) and standard P2A[6] strains (e. g., ST3, M37). Thus the complete antigenic type of US1205 is P2A[6]G9, subgroup I. Sequence analysis of the VP6 and NSP4 genes of US1205 indicates that strain US1205 possessed VP6 subgroup I and NSP4A genotype specificities. Finally, Northern hybridization studies suggest that the P[6]G9 strains are closely related to members of the DS-1 genogroup except for their P[6] VP4 gene, which has been commonly identified in strains of both major human genogroups, and their G9 VP7 gene, which may have been derived by reassortment with a Wa genogroup strain. Examination of historic collections and prospective surveillance of strains will be needed to determine whether this strain has been present for some time or if it is emerging to compete with the other common serotypes of rotavirus.

Amino Acid Sequence↗
PubMed1999

Characterization of unusual G8 rotavirus strains isolated from Egyptian children.

We report the first detection of P[14], G8 rotaviruses isolated in Egypt from the stool of children participating in a 3 year study of rotavirus epidemiology. Two strains, EGY1850 and EGY2295, were characterized by a serotyping enzyme immunoassay (EIA), virus neutralization, and sequence analysis of the genes encoding VP7 and the VP8* portion of the VP4 gene. These two strains shared a high level of homology of their VP7s (87.8% nucleotide [nt], 97.2% amino acid [aa]) and VP4s (89.6% nt, 97.1% aa) and had the highest VP7 identity to serotype G8 (> 82% nt, > 92% aa) and VP4 identity to genotype P[14] (> or = 81% nt, > 91% aa) strains. Serological results with a VP7 G8-specific and VP4 P[14]-specific neutralizing monoclonal antibodies supported the genetic classification of EGY1850 and EGY2295 as P[14], G8. Genogroup analysis supports earlier findings that human G8 rotaviruses may be genetically related to bovine rotaviruses. These findings demonstrate that our understanding of the geographic distribution of rotavirus strains is incomplete, emphasize the need to monitor rotavirus serotypes, and extend the known distribution of serotype G8 and genotype P[14] strains in Africa.

Animals↗
PubMed1999

Detection of field isolates of human and animal group C rotavirus by reverse transcription-polymerase chain reaction and digoxigenin-labeled oligonucleotide probes.

Rotaviruses (RV) are important etiological agents of acute gastroenteritis in infants and young children, as well as the young of a variety of animals worldwide. These viruses belong to Reoviridae family and contain a genome of 11 segments of double-stranded RNA (dsRNA). Two major proteins, VP4 and VP7, encoded by genome segments 4 and 7, 8 or 9, respectively, evoke a neutralizing antibody response and form the basis for the current classification of group (gp) A rotavirus into P (VP4) and G (VP7) serotypes. Although much recent progress has been made on the molecular biology of gp C RV, routine methods to detect and discriminate human, porcine, and bovine strains are not available widely. In this study, a multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) and digoxigenin-labeled (dig) oligonucleotide probes using chemiluminescence has been developed to detect and discriminate VP7 genes from culture-adapted and field isolates of human, porcine and bovine gp C RV. The multiplex RT-PCR and dig-probes were specific for the VP7 genes of human, porcine and bovine gp C RV and allowed detection and characterization of single and mixed infections of porcine gp C RV with porcine gp A or gp B rotaviruses. Detection rates for gp C RV were more than 50% when compared with polyacrylamide gel electrophoresis. These new diagnostic assays may help determine the epidemiological importance of these viruses in human and animal infections.

Animals↗
PubMed1999

Trends in hospitalizations associated with gastroenteritis among adults in the United States, 1979-1995.

Gastroenteritis (GE) is among the most common illnesses of humans but the burden of disease, its epidemiology, and the distribution of pathogens in adults have not been fully examined. This information is needed to plan prevention strategies particularly for high-risk groups. This study is a retrospective analysis of data from the National Hospital Discharge Survey for the years 1979 through 1995 which describes the disease burden and epidemiology of hospitalizations associated with GE among adults in the United States. Diarrhoea was listed as a diagnosis on an average of 452,000 hospital discharges per year representing 1.5% of all hospitalizations among adults. The annual number of GE hospitalizations has decreased by 20% from approximately 500,000 in 1979 to 400,000 in 1995. The aetiology of 78% of cases coded as GE was undetermined. Until the aetiology of disease can be better established, specific strategies for prevention cannot be developed.

Adult↗
PubMed1999

Sequence analysis of the NSP4 gene from human rotavirus strains isolated in the United States.

Two major and one minor genotype of the rotavirus NSP4 gene have been described. The sequences of 29 NSP4 genes from rotavirus isolates obtained in the United States during the 1996-1997 rotavirus season (types P[8]G1, P[8]G9, P[4]G2 and P[6]G9) and 10 strains isolated during previous rotavirus seasons (types P[8]G1 and P[4]G2) were determined. All NSP4 genes from strains with short E types (6 P[4]G2, 4 P[6]G9) belonged to genotype NSP4A, whereas all 19 strains with long E types (16 P[8]G1, 3 P[8]G9) had NSP4 genes of genotype NSP4B. Genetic variation within genotypes was low ( < or = 2.3% for both NSP4A and NSP4B), confirming that the NSP4 genes are highly conserved. Nonetheless, at least two distinct sub-lineages could be detected within each genotype: strains isolated in the same year, regardless of geographic location, were more closely related or even identical at the deduced amino acid level; strains isolated in different years were more distinct. Thus, geographic distance did not affect genetic distance. Northern hybridization analysis with NSP4A and NSP4B total gene probes failed to detect any unusual combinations of the VP6 and NSP4 genes in 31 additional isolates from the 1996-1997 rotavirus season.

Amino Acid Sequence↗