Epidemiology of rotavirus in Portugal: G9 as a major cause of diarrhoea in non-hospitalised children

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Abstract

Background

Rotavirus is a major cause of gastroenteritis in children worldwide, but there is no data available on the incidence of rotavirus gastroenteritis or on the strains circulating in Portugal.

Methods

We determined prospectively the incidence of rotavirus infection in non-hospitalised children and the genotypes circulating during one winter season in the central region of Portugal.

Results

Rotavirus was found in 45% of the samples tested. The peak incidence was in February (54% positive) and March (60% positive). Genotyping was performed in 195 samples; unexpectedly, G9P[8] was present in 90% of the cases, a much higher percentage than previously reported in other countries.

Conclusions

These results contribute to the assessment of the burden of disease attributable to rotavirus in Portugal and facilitate preparation for intervention by vaccination. The predominance of G9 in Portugal is unlikely to be a local phenomenon, and may be observed elsewhere in Portugal and Europe. The epidemiology of rotaviruses in Portugal should be monitored in subsequent years.

Introduction

Rotavirus (RV) is a major cause of acute gastroenteritis (AG) in children, being responsible for more than 500,000 deaths each year, the majority in developing countries (Lepage, 2006, Parashar et al., 2003, Rheingans et al., 2006). In addition to causing morbidity and mortality in children, RV gastroenteritis imposes a major economic burden on health care systems and families (Rheingans et al., 2006, Soriano-Gabarró et al., 2006).

The European Medicine Evaluation Agency (EMEA) has approved two vaccines for use in Europe. The formulation of a country-specific vaccination policy will require country-specific studies to more accurately understand the burden of disease caused by RV.

There is no data available on the incidence of RV gastroenteritis or on the strains circulating in Portugal.

The purpose of this study was to describe the impact of RV gastroenteritis on paediatric outpatients in the central region of Portugal, and to analyse the most common genotypes of RVs circulating during the annual epidemic season, before the introduction of RV vaccines.

Section snippets

Materials and methods

Hospital Pediátrico de Coimbra is a tertiary hospital with an emergency service (ES) that admits children between 0 and 13 years of age from all the central region of Portugal, covering a population of 400,000 children. Approximately, 50,000 children are seen annually. These may be referred from other hospitals or general practitioners, but the majority are brought by their parents. There is no other paediatric ES in the city or in the surrounding area.

Results

During the 5 months studied, 642 children under 3 years of age with AG were seen at our ES. A stool sample was collected for RV antigen detection from 475 (74%) cases. A total of 216 (45%) cases of AG were positive for RV. The proportion of RV-positive cases was as follows: February 73/134 (54%), March 74/124 (60%), April 29/85 (34%), May 18/67 (27%) and June 22/65 (34%).

A total of 195 samples were available for genotyping, of which 9 (4.6%) were negative in the PCR assay, indicating a

Discussion

RV is a major cause of gastroenteritis in paediatric outpatients practice in the central region of Portugal. AG in children impacts widely on their families and society in general, leading to increased medical expenditure, loss of productivity, extra childcare costs and/or loss of already contracted childcare, and pain and suffering caused to children and their families (Rheingans et al., 2006).

The incidence of individual serotypes in a particular region can fluctuate annually, and within the

Conflict of interest

None.

Acknowledgements

We thank Timo Vesikari for his comments on the manuscript. We are also grateful to the study nurses and laboratory staff.

This work was supported by a grant from sanofi pasteur MSD.

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