Sequential Gastroenteritis Episodes Caused by 2 Norovirus Genotypes - Volume 20, Number 6—June 2014 - Emerging Infectious Disease journal - CDC
Volume 20, Number 6—June 2014
Sequential Gastroenteritis Episodes Caused by 2 Norovirus Genotypes
Author affiliations: National Institutes of Health, Bethesda, Maryland, USA
Noroviruses are major pathogens associated with acute gastroenteritis in persons of all ages. It is estimated that each year in developing countries, noroviruses are responsible for up to 200,000 deaths of children <5 years of age (1). Moreover, in the United States, because of the successful implementation of vaccination against rotaviruses, noroviruses have emerged as the leading cause of severe gastroenteritis requiring medical intervention among infants and young children (2).
Noroviruses are genetically diverse, and differences in the major capsid protein (VP1) have led to their classification into 6 genogroups (GI–GVI) and ≈30 genotypes. Noroviruses from genogroups GI, GII, and GIV infect humans; worldwide, GII.4 is the most prevalent genotype (3–5). Expression of VP1 results in self-assembly of virus-like particles that have been used to examine structural and antigenic differences among genotypes (3,6–8). However, lack of an in vitro cell culture system has hindered the ability to establish serotype differences by neutralization. Initial evidence for the existence of at least 2 distinct norovirus serotypes came from early studies among volunteers; these studies showed that infection with Norwalk or Hawaii viruses (representing GI and GII, respectively) did not induce cross-protection (9). Evidence also exists for the periodic emergence of new GII.4 strain variants that cause large global epidemics, possibly driven by escape from herd immunity (5,10). Further understanding of the natural history of these viruses is needed to establish the potential role of genotypic and antigenic variation in vaccine development.
Dr Green is chief of the Caliciviruses Section of the National Institute of Allergy and Infectious Diseases, National Institutes of Health. Her research is directed toward the prevention and control of acute gastrointestinal disease caused by noroviruses.
We thank Rachel J. Dexter and Ronald W. Jones for their technical assistance and Stanislav V. Sosnovtsev for helpful discussions.
This research was funded by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health.
Dr Parra is a visiting fellow at the National Institute of Allergy and Infectious Diseases, National Institutes of Health. His research interests include epidemiology, immunology, and vaccine development against gastrointestinal viral infections.
- Figure 1. Characterization of norovirus detected in stool samples and levels of local IgA responses for each infectionA) Phylogenetic tree of the major capsid protein (VP1) region from representative norovirus strains...
- Figure 2,. AppendixDifferences in the major capsid protein (VP1) between norovirus strains GII.4 and GII.6A) Amino acid sequence alignment of the VP1 sequencesThe shell (S) domain is highlighted with a dark...
Suggested citation for this article: Parra GI, Green KY. Sequential gastroenteritis caused by 2 norovirus genotypes. Emerg Infect Dis [Internet]. 2014 Jun [date cited].http://dx.doi.org/10.3201/eid2006.131627