title: Pattern of circulation of norovirus GII strains during natural infection.
abstract: Norovirus (NoV) is considered a major cause of nonbacterial gastroenteritis among people of all ages worldwide, but the natural course of infection is incompletely known. In this study, the pattern of circulation of NoVs was studied among 146 children and 137 adults in a small community in southwestern Cameroon. The participants provided monthly fecal samples during a year. NoV RNA was detected in at least one sample from 82 (29%) of the participants. The partial VP1 region could be sequenced in 36 NoV GII-positive samples. Three different genotypes were identified (GII.1, GII.4, and GII.17), with each genotype circulating within 2 to 3 months and reappearing after a relapse period of 2 to 3 months. Most infections occurred once, and 2 episodes at most within a year were detected. No difference in the frequency of NoV infection between children and adults was recorded. The same genotype was detected for a maximum of 2 consecutive months in 3 children only, suggesting that a less than 30-day duration of viral shedding in natural infection was common. Reinfection within a year with the same genotype was not observed, consistent with short-term homotypic immune protection. The study revealed that NoV strains are circulating with a limited duration of viral shedding both in the individuals and the population as part of their natural infection. The results also provide evidence of cross-protective immunity of limited duration between genotypes of the same genogroup.
authors.affiliation: Department of Infectious Diseases/Section of Clinical Virology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden Section For Clinical Research, Redeem Biomedical System, Douala, Cameroon james.ayukekbong@microbio.gu.se.
authors.forename: James Ayukepi
authors.initials: JA
authors.lastname: Ayukekbong
authors.affiliation: Section For Clinical Research, Redeem Biomedical System, Douala, Cameroon.
authors.forename: Cajetan
authors.initials: C
authors.lastname: Fobisong
authors.affiliation: Section For Clinical Research, Redeem Biomedical System, Douala, Cameroon.
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Tah
authors.affiliation: Department of Infectious Diseases/Section of Clinical Virology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Lindh
authors.affiliation: Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon.
authors.forename: Theresia
authors.initials: T
authors.lastname: Nkuo-Akenji
authors.affiliation: Department of Infectious Diseases/Section of Clinical Virology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Bergström
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017250:Caliciviridae Infections / Q000453:epidemiology / Q000276:immunology / Q000821:virology*; D002163:Cameroon / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D056738:Cross Protection; D005243:Feces / Q000821:virology; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D029322:Norovirus / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D011446:Prospective Studies; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D013997:Time Factors; D017201:Virus Shedding; D055815:Young Adult
chemical_list: D012367:RNA, Viral