Showing papers by "Joseph S. Bresee published in 2001"

"Norwalk-like viruses". Public health consequences and outbreak management.

Abstract: "Norwalk-like viruses" (NLVs) cause outbreaks of gastroenteritis and are spread frequently through contaminated food or water. Molecular diagnostics now enables detecting viruses in clinical and environmental specimens, linking of NLV strains causing outbreaks in multiple geographic locations, and tracing them to their sources in contaminated food or water. This report reviews recent advances in NLV detection and provides guidelines and recommendations for investigating NLV-related outbreaks, including specimen collection and disease prevention and control. This report also updates information provided in CDC's previously published, Viral Agents of Gastroenteritis: Public Health Importance and Outbreak Management (MMWR 1990;39 [No. RR-5]: 1-24). These CDC recommendations are intended for public health professionals who investigate outbreaks of acute gastroenteritis but could be useful in academic and research settings as well.

Gastroenteritis viruses: an overview.

Abstract: Acute gastroenteritis is among the most common illnesses of humankind, and its associated morbidity and mortality are greatest among those at the extremes of age, children and the elderly. In developing countries, gastroenteritis is a common cause of death in children < 5 years that can be linked to a wide variety of pathogens. In developed countries, while deaths from diarrhoea are less common, much illness leads to hospitalization or doctor visits. Much of the gastroenteritis in children is caused by viruses belonging to four distinct families--rotaviruses, caliciviruses, astroviruses and adenoviruses. Other viruses, such as the toroviruses, picobirnaviruses, picornavirus (the Aichi virus), and enterovirus 22, may play a role as well. Viral gastroenteritis occurs with two epidemiologic patterns, diarrhoea that is endemic in children and outbreaks that affect people of all ages. Viral diarrhoea in children is caused by group A rotaviruses, enteric adenoviruses, astroviruses and the caliciviruses; the illness affects all children worldwide in the first few years of life regardless of their level of hygiene, quality of water, food or sanitation, or type of behaviour. For all but perhaps the caliciviruses, these infections provide immunity from severe disease upon reinfection. Epidemic viral diarrhoea is caused primarily by the Norwalk-like virus genus of the caliciviruses. These viruses affect people of all ages, are often transmitted by faecally contaminated food or water, and are therefore subject to control by public health measures. The tremendous antigenic diversity of caliciviruses and short-lived immunity to infection permit repeated episodes throughout life. In the past decade, the molecular characterization of many of these gastroenteritis viruses has led to advances both in our understanding of the pathogens themselves and in development of a new generation of diagnostics. Application of these more sensitive methods to detect and characterize individual agents is just beginning, but has already opened up new avenues to reassess their disease burden, examine their molecular epidemiology, and consider new directions for their prevention and control through vaccination, improvements in food and water quality and sanitary practices.

Multistate outbreak of Norwalk-like virus gastroenteritis associated with a common caterer.

Abstract: In February 2000, an outbreak of gastroenteritis occurred among employees of a car dealership in New York. The same meal was also supplied to 52 dealerships nationwide, and 13 states reported illness at dealerships where the banquet was served. A retrospective cohort study was conducted to identify risk factors associated with the illness. Stool samples were collected to detect Norwalk-like virus, and sera were drawn and tested for immunoglobulin A antibodies to the outbreak strain. By univariate analysis, illness was significantly associated with consumption of any of four salads served at the banquet (relative risk = 3.8, 95% confidence interval: 2.5, 5.6). Norwalk-like virus was detected by reverse transcription-polymerase chain reaction assay in 32 of 59 stool samples from eight states. Nucleotide sequences of a 213-base pair fragment from 16 stool specimens collected from cases in eight states were identical, confirming a common source outbreak. Two of 15 workers at caterer A had elevated immunoglobulin A titers to an antigenically related Norwalk-like virus strain. This study highlights the value of molecular techniques to complement classic epidemiologic methods in outbreak investigations and underscores the critical role of food handlers in the spread of foodborne disease associated with Norwalk-like virus.

Cost of diarrhea-associated hospitalizations and outpatient visits in an insured population of young children in the United States

Abstract: Objective. To assess the financial and clinical burden of diarrhea- and rotavirus-associated disease among a population of privately insured US children. Methods. For the period 1993 through 1996, we analyzed medical claims data from a large, administrative database containing information on ∼300 000 children <5 years of age to examine trends in, and costs associated, with hospitalizations and outpatient visits for diarrhea. Results. An annual average of 1186 diarrhea-associated hospitalizations (35 per 10000 children <5 years) and 33 386 outpatient visits (943 per 10 000 children <5 years) were reported, accounting for 4% of all hospitalizations and 2% of all outpatient visits among children <5 years of age. Diarrhea-associated hospitalizations and outpatient visits showed a distinct winter-spring peak consistent with that of rotavirus infection. The excess of diarrhea-associated events occurring during the winter-spring peak accounted for an average of 50% of all diarrhea-associated hospitalizations and 18% of all diarrhea-associated outpatient visits. The median cost (in 1998 constant dollars) of a diarrhea-associated hospitalization was $2307, and that for a rotavirus-associated hospitalization was $2303. Median costs of diarrhea- and rotavirus-associated outpatient visits were $47 and $57, respectively. Conclusions. Diarrhea is an important cause of morbidity in this insured population of young children. The epidemiologic features of diarrhea-associated events suggest that rotavirus is an important contributor to the overall morbidity from diarrhea. These disease burden and cost estimates should provide useful information with which to assess the costs and benefits of future interventions for rotavirus-associated illness.

Safety and immunogenicity of tetravalent rhesus-based rotavirus vaccine in Bangladesh.

Abstract: BACKGROUND Rotavirus is the most common cause of severe gastroenteritis among children worldwide. OBJECTIVES To compare the safety, immunogenicity and shedding patterns of rhesus rotavirus (RRV)-tetravalent vaccine vs. placebo among infants in rural Bangladesh. METHODS A double blinded, placebo-controlled trial was conducted in which infants (n = 120) were randomly assigned to receive three doses of either vaccine or placebo administered at approximately 6, 10 and 14 weeks of age together with routine immunizations. Data on possible adverse effects of vaccinations were collected daily for 7 days after each dose. Stool samples were collected after each dose, and serum samples were obtained before the first and after the third vaccination. RESULTS Fever (> or = 38 degrees C), as measured by study assistants, was noted more frequently among vaccinees (15%) than among placebo recipients (2%) during the 7 days after vaccination but was not reported more frequently by parents of vaccinees vs. placebo recipients. Overall 87% of vaccinees had an antibody response (measured by IgA or anti-RRV-neutralizing antibodies) after vaccination compared with 32% of placebo recipients. Rates of seroconversion were higher among subjects with lower levels of prevaccination antibodies and those who shed rotavirus after vaccination. Vaccine strain viruses were detected in stools from placebo vaccine recipients who had evidence of IgA seroconversion. CONCLUSIONS In this population RRV-tetravalent vaccine was comparably immunogenic and safe as in trials conducted in developed countries, where this vaccine has been proved effective in preventing severe rotavirus diarrhea. These data support continued evaluation of rotavirus vaccines in developing countries.