The Initial Timing and Burden of Viral Gastrointestinal Infections in Australian Infants

Abstract

The timing and nature of initial infections by potentially vaccine-preventable gastrointestinal viruses (group-F adenoviruses, classic human astrovirus, norovirus I/II, and sapovirus I/II/IV/V) was investigated in a community-based birth cohort. Weekly stool samples were collected from 158 children aged <2 years in an Australian subtropical city. Median age at initial infection was lowest for norovirus II (13.8 months) followed by sapovirus (14.3 months) and classic human astrovirus (17.6 months), and was >24 months for the remaining viruses. Norovirus II and sapovirus were most often associated with acute gastroenteritis symptoms (57% and 44%, respectively). Overall, healthcare was sought for 45% of symptomatic initial infections, which varied between 17% for norovirus I to 55% for norovirus II. Age at initial infection was lower when participants were exposed to other children. Norovirus II and sapovirus were the most important pathogens in this cohort, providing further evidence for them being priority targets for vaccine development.

Epidemiology of Norovirus in the First 2 Years of Life in an Australian Community-based Birth Cohort

“…An Australian community-based birth cohort, the Observational Research in Childhood Infectious Diseases (ORChID) study, found that 36% and 78% of children had their first norovirus genogroup I (GI) and genogroup II (GII) infections, respectively by age 2 years. 20 Furthermore, norovirus GII was one of the most common enteric viruses detected in the cohort. The median age for the initial infection by norovirus GII was 13.8 months, with 57% of episodes associated with gastrointestinal symptoms, 55% of which led to healthcare visits.…”

Sapovirus Infections in an Australian Community-Based Healthy Birth Cohort During the First 2 Years of Life

“…Until recently, Australian studies were limited to those conducted 20 years ago where sapoviruses were detected in <5% of hospital-presenting and hospitalized children with AGE [ 10 , 11 ]. However, over the last decade, sapovirus laboratory diagnostics have changed to more sensitive molecular techniques and multipathogen platforms, leading to higher detection rates [ 12 , 13 ].…”

“…An Australian community-based birth cohort, the Observational Research in Childhood Infectious Diseases (ORChID) study where >90% of participants were vaccinated against rotavirus, found that sapovirus and norovirus were the most common viruses associated with AGE during the first 2 years of life [ 13 ]. In this cohort, sapoviruses were first detected at a median age of 14 months, and by age 2 years they were identified in 79% of participants.…”