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A prospective study of astrovirus diarrhea of infancy in Mexico City
M L Guerrero1, J S Noel, D K Mitchell
1Department of Infectious Disease, National Institute of Nutrition, Mexico City, Mexico.
Insights
Human astrovirus caused 5% of diarrhea cases in young Mexican children, presenting as mild secretory illness. Astrovirus-associated diarrhea was less severe than rotavirus or coinfections.
Area of Science:
- Pediatrics
- Infectious Diseases
- Virology
Background:
- Diarrheal diseases are a major cause of childhood morbidity globally.
- Human astrovirus (HAstV) is an underrecognized enteric pathogen.
- Limited data exist on HAstV epidemiology in developing countries.
Purpose of the Study:
- To characterize the epidemiology and clinical presentation of HAstV-associated diarrhea.
- To identify common HAstV serotypes in young children.
- To compare the severity of HAstV diarrhea with other enteric infections.
Main Methods:
- Longitudinal study of 214 children from birth to 18 months in Mexico City.
- Stool specimens collected during 510 diarrhea episodes.
- Enzyme immunoassays used to detect HAstV and other enteric pathogens; serotyping performed.
Main Results:
- HAstV detected in 5% of diarrhea episodes (26/510), incidence 0.1/child-year.
- Diarrhea characterized by median 4 stools/24h, 3-day duration, 20% vomiting, 7% fever; no dehydration.
- Serotype 2 was most common (35%); HAstV diarrhea was less severe than rotavirus or coinfections (P=0.008).
Conclusions:
- HAstV is a significant cause of mild diarrhea in young children in this Mexican cohort.
- Serotype 2 is the predominant HAstV type.
- HAstV infections are generally less severe than other common causes of childhood diarrhea.
Aim:
To describe the epidemiologic and clinical characteristics of astrovirus-associated diarrhea in a cohort of young children from a periurban community in Mexico City.
Methods:
From November, 1988, through December, 1991, a total of 214 children were enrolled in a longitudinal study of diarrhea and monitored from birth to 18 months of age. A stool specimen was collected during each episode of diarrhea. Specimens from a total of 510 diarrhea episodes were tested for astrovirus by enzyme immunoassay and examined for other enteric pathogens. The antigenic types of astrovirus were determined by a typing enzyme immunoassay.
Results:
Astrovirus was detected in 26 (5%) of 510 diarrhea episodes, with an incidence rate of 0.1 episode/child year; the highest rate was in children 13 to 18 months of age. Astrovirus-associated diarrhea was characterized by a median of 4 stools (range, 2 to 10) during the first 24 h, a median duration of 3 days (range, 1 to 21), vomiting (20%), and fever (7%). No cases of dehydration or repeat symptomatic infections were observed. Coinfection with another pathogen was detected in 11 of the 26 episodes (42%). Serotype 2 (35%) was most common, followed by serotypes 4 (15%), 3 (11%), and 1 and 5 (4% each); 31% were nontypable. Astrovirus-associated diarrhea was less severe, as measured by the number of stools (4.3 +/- 1.9), than diarrhea caused by rotavirus (7.1 +/- 2.8) or when coinfections occurred (5.5 +/- 1.6; P = 0.008).
Conclusions:
Astrovirus was associated with 5% of the episodes of diarrhea in this cohort of young Mexican children and presented as a mild secretory diarrhea. Five predominant antigenic types were detected with type 2 being the most common.