Astrovirus Diarrhea in Egyptian Children

Abstract

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.

Virus Diversity in a Winter Epidemic of Acute Diarrhea in France

“…The uncommon type 8 was detected in three samples from patients living in the same region. This type has been described in the United Kingdom (GenBank accession number Z66541, showing 93.7 to 94.4% identity with the three type 8 strains described here) and was recently reported in Australia, Egypt, and Mexico (25,26,27). An important diversity of astrovirus strains, including type 8, was also reported in Barcelona during the same period as our study (17).…”

Prevalence and Genetic Diversity of Human Astroviruses in Mexican Children with Symptomatic and Asymptomatic Infections

“…The high diversity of astrovirus types is not uncommon and has also been reported in countries like Bangladesh, Egypt, Spain, and England (6,10,15,25).…”

“…Typing surveys indicate that HAstV type 1 (HAstV-1) is the most prevalent, types 2 to 4 are common, and types 5 to 7 are less common, while type 8 has only recently been identified (4-6, 14, 15, 21). These studies have shown that it is not uncommon to find two or more astrovirus types circulating in one region during a given period of time, and they have also described variations in the prevalent astrovirus type with time (6,10,14,15,21,22,28).…”

Astrovirus infection in children living in the Central West region of Brazil

“…These results agree with those from a study carried (AG) in relation to the period of year (1994-1996 and 1998-2001) out by López et al (2000) which analyzed children up to ten years from Spain. Studies have shown that astroviruses occur preferentially during the colder months of the year (Phan et al 2004, Galdiero et al 2005) even though other investigations have shown a higher viral incidence during warmest months (Guerrero et al 1998, Naficy et al 2000. Other studies report a year-round occurrence of astroviurs infection (Schnagl et al 2002, Giordano et al 2004.…”

“…The astroviruses are recognized as one of the most common cause of viral gastroenteritis in infants and young children in worldwide (Giordano et al 2001) and its seasonality is variable according to the geographic region (Naficy et al 2000, Guix et al 2002. The main symptom of the astrovirus infections is a watery and mild diarrhea, which generally results in mild diarrheic disease (Matsui & Greenberg 2001), although a recent study has described astrovirus infection related to severe dehydrating gastroenteritis among isolated Brazilian communities (Gabbay et al 2006).…”