Seroprevalence and seroincidence of Norwalk-like virus infection among Brazilian infants and children

Abstract

To determine the importance of Norwalk-like viruses (NLVs) as pediatric pathogens in a developing country, the seroprevalence and seroincidence of this group of viruses in a cohort of children less than 4 years of age in an urban shantytown in northeastern Brazil was examined. Serum samples were collected approximately every 6 months from 135 children who were surveyed three times each week for diarrhea and vomiting. NLV IgG was measured by an enzyme immunosorbent assay (EIA) with recombinant Norwalk virus capsid protein. Overall NLV seroprevalence was 71%, and the overall NLV seroconversion rate was 0.7 seroconversions per child-year. The highest age-specific NLV seroconversion rate (0.8 seroconversions per child-year) was observed in the 13-24-month age group. For all study children, the incidence of diarrhea and vomiting was significantly greater (P < 0.01) during time periods spanned by serum pairs that indicated NLV seroconversion compared with time periods without NLV seroconversion. However, NLV seroconversion was not associated with gastrointestinal symptoms during the first year of life.

Heterotypic Humoral and Cellular Immune Responses following Norwalk Virus Infection

“…Third, the data suggest that even an expanded panel of VLPs may not be able to do more than differentiate between a norovirus genogroup I versus II infection. This is an important issue in the context of outbreak investigation, where we have found subjects to be more willing to donate serum than stool samples for analysis and longitudinal epidemiological studies that use sera collected over time to draw conclusions about the epidemiology of endemic norovirus infections (84). Lastly, these data also suggest that conserved antigenic epitopes among GI strains likely exist, arguing for the need for the development of comprehensive monoclonal antibody panels for epitope mapping.…”

Noroviruses: A comprehensive review

“…Prevalence of antibodies to NoVs is high among children <5 years of age indicating exposure early in life [55][56][57][58][59][60][61][62] ; antibodies to NoVs are lowest during the first year of life and rise after 2 years of age. 63,64 NoV infections occur worldwide and although some studies demonstrated a greater prevalence and younger age of acquisition of antibody among children in developing countries compared with those in industrialized countries, these differences were not consistently observed.…”

Noroviruses associated with acute gastroenteritis in a children's day care facility in Rio de Janeiro, Brazil

“…The genomic diversity of noroviruses in children in a Brazilian shantytown was investigated by Parks et al (17). Sero-prevalence and sero-incidence studies for norovirus have shown a 71% rate in Brazilian children (18); 39 to 100% of Amazonian Indians were found to have antibodies to Norwalk virus (19) and 67 to 91% of Chilean adults and children had antibodies to Mexico and Norwalk virus (20,21). Norovirus studies of the paediatric population have been undertaken in various countries including Argentina (22), Japan (23)(24)(25), South Africa (26), Canada (27), Mexico (28,29), Spain (30), France (31), Germany (32), and Finland (33,34).…”