We conducted a systematic review of studies that used reverse transcription–PCR to diagnose norovirus (NoV) infections in patients with mild or moderate (outpatient) and severe (hospitalized) diarrhea. NoVs accounted for 12% (95% confi dence interval [CI] 10%–15%) of severe gastroenteritis cases among children <5 years of age and 12% (95% CI 9%–15%) of mild and moderate diarrhea cases among persons of all ages. Of 19 studies among children <5 years of age, 7 were in developing countries where pooled prevalence of severe NoV disease (12%) was comparable to that for industrialized countries (12%). We estimate that each year NoVs cause 64,000 episodes of diarrhea requir

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Systematic literature review of role of noroviruses in sporadic gastroenteritis.

Noroviruses: a comprehensive review.

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Astrovirus infections in humans and animals – Molecular biology, genetic diversity, and interspecies transmissions

Acute gastroenteritis is one of the most common diseases worldwide. In developed countries, viruses, particularly noroviruses, are recognized as the leading cause. In The Netherlands, the surveillance of gastroenteritis outbreaks with suspected viral etiologies (as determined by Kaplan criteria) was established by the National Institute for Public Health and the Environment in 1994. This paper presents an overview of viral gastroenteritis outbreaks reported from 1994 through 2005. A minimum epidemiological data set consisting of the associated setting(s), the probable transmission mode, the date of the first illness and the date of sampling, the number of persons affected, and the number of hospitalizations was requested for each reported outbreak. Stool samples were tested for the presence of norovirus, sapovirus, rotavirus, astrovirus, adenovirus, and Aichi virus by electron microscopy, enzyme-linked immunosorbent assay, and/or reverse transcription-PCR. A total of 6,707 stool samples from 941 gastroenteritis outbreaks were investigated. Noroviruses were detected as the causative agent in 735 (78.1%) of the outbreaks, and rotaviruses, adenoviruses, and astroviruses were found to be responsible for 46 (4.9%), 9 (1.0%), and 5 (0.5%) outbreaks, respectively. Among the gastroenteritis outbreaks in which a mode of transmission was identified, most outbreaks (38.1%) were associated with person-to-person transmission, and the majority (54.9%) of the outbreaks investigated were reported by residential institutions. Since 2002, the total number of outbreaks reported and the number of unexplained outbreaks have increased. Furthermore, the number of rotavirus-associated outbreaks has increased, especially in nursing homes. Despite thorough testing, 115 (12.2%) outbreaks suspected of having viral etiologies remain unexplained. Increases in numbers of reported outbreaks may indicate undefined changes in the criteria for reporting or the emergence of new pathogens.

Etiological Role of Viruses in Outbreaks of Acute Gastroenteritis in The Netherlands from 1994 through 2005

Temporal and spatial fluctuations in the genotype distribution of human rotaviruses are continuously observed in surveillance studies. New genotypes, such as G9 and G12, have emerged and spread worldwide in a very short time span. In addition, reassortment events have the potential to contribute substantially to genetic diversity among human and animal rotaviruses. With the recent introduction of the two rotavirus vaccines, RotaTeq and Rotarix, in many countries, it appears that the total number of hospitalizations due to rotavirus infections is being reduced, at least in developed countries that implemented a universal immunization program. However, continued surveillance is warranted, especially regarding the long-term effects of the vaccines. No data analyses are available to clarify whether rotavirus vaccine introduction would allow other rotavirus P and G genotypes, which are not covered by the current vaccines, to emerge into the human population and fill the apparent gap. This kind of data analysis is essential, but its interpretation is hampered by natural and cyclical genotype fluctuations.

Rotavirus disease and vaccination: impact on genotype diversity.

Dual infections associated with acute infectious diarrhoea and its microbiological, epidemiological and clinical findings have been evaluated in patients selected from a comprehensive survey of children under 4 years old, admitted to hospital emergency rooms from October 1996 to November 1997. A total of 820 children (433 males and 387 females) were enrolled. Stools were tested for rotavirus, adenovirus, astrovirus and bacterial enteropathogens. Patients were grouped according to age, and the seasonality of mixed infections was evaluated. Clinical trends and severity of gastrointestinal disease by Ruuska's score were also analysed. Mixed infections were identified in 39 cases (5 %), of which 23 were males and 16 were females. The majority of cases were in the 7–18-month age group (26 cases) and occurred in autumn (67 %). Virus–virus co-infections were more frequent (26/39) than virus–bacteria co-infections (13/39). More than two infectious agents were detected in only four cases. The most common viral co-infections were rotavirus–astrovirus (13/26) and rotavirus–adenovirus (10/26). The present report is the first prospective analysis of clinical–epidemiological trends of dual infections in young Spanish children with acute viral gastroenteritis. Our results emphasize the clinical importance of mixed infections as a cause of severe diarrhoea in children.

Acute viral gastroenteritis: proportion and clinical relevance of multiple infections in Spanish children

In Spain, diarrhea remains a major cause of illness among infants and young children. To determine the prevalence of rotavirus genotypes and temporal and geographic differences in strain distribution, a structured surveillance study of hospitalized children 11.4% of the samples studied during 2005.

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Javier Colomina

Papers

Acute viral gastroenteritis: proportion and clinical relevance of multiple infections in Spanish children

Human rotavirus G9 and G3 as major cause of diarrhea in hospitalized children, Spain.

Parasitación asintomática por Diphyllobothrium latum en un niño español de 3 años

Neurorretinitis por Bartonella spp. no henselae

Diagnóstico de tuberculosis genitourinaria y reacción en cadena de la polimerasa