Viral shedding in gastroenteritis in children caused by variants and novel recombinant norovirus infections

Abstract

Human norovirus (NoV) is the leading cause of acute gastroenteritis and the rapid transmission of NoV renders infection control problematic. Our study aimed to investigate viral shedding in gastroenteritis in children caused by variants of emerging norovirus strains infections. We used RNA-dependent RNA polymerase (RdRp) sequencing to measure NoV genome copies in stool to understand the relationship between the clinical manifestations and viral shedding in hospitalized patients. The near full-length NoV genome sequence was amplified via reverse transcription-polymerase chain reaction (RT-PCR) and NoV recombination was analyzed using the Recombination Analysis Tool (RAT). From January 2015 to March 2018, 77 fecal specimens were collected from hospitalized pediatric patients with confirmed NoV gastroenteritis. The NoV genotypes were GII.4 (n = 22), non-GII.4 (n = 14), GII.4 Sydney (n = 21), and GII.P16–GII.2 (n = 20). Viral load increased from days 2 to 9 from the illness onset, resulting in an irregular plateau without peaks. After day 9, the viral load declined gradually and most viral shedding in feces ceased by day 15. The average viral load was highest in GII.4 Sydney followed by GII.P16–GII.2 infections and lowest in non-GII.4 infections. GII.4 unclassified infections showed the longest viral shedding time, followed by GII.4 Sydney infections, GII.P16–GII.2 recombinant infection resulted in the shortest duration. NoVs evolved to form a group of GII.P16–GII.2 variants during the 2017 to 2018 period. The viral load and shedding period and was different in variants of NoV infections in children. High mutation rate of emerging and re-emerging variants was observed to an enhanced epidemic risk rendering continuous surveillance.

Significantly Longer Shedding of Norovirus Compared to Rotavirus and Adenovirus in Children with Acute Gastroenteritis

“…The peak shedding of norovirus has been reported to occur between symptom onset to 5 days after infection [ 25 ], with over 10 9 copies of viral particles shed in one gram of feces [ 6 ]. Cheng et al reported that among hospitalized pediatric patients, norovirus viral load increased between days 2 and 9 following illness onset, and most norovirus shedding in feces ceased by day 15, with an average viral load of 7.25 log genome copies/mL for all samples [ 26 ]. In our study, we did not observe an increase in viral load after illness onset, but the median viral load of norovirus on Day 0 was 9.9 log GE copies/g stool, and it remained persistently high on Day 5 (9.7 log GE copies/g stool).…”

Rotavirus infection in children: clinical and etiological structure and analysis of vaccine prophylaxis

“…По степени выраженности обезвоживания: I степень -74%, II степень -4%, III степень -22%. Микст-формы РВИ выявлялись в виде гастроэнтерита в 80 (88,9%) случаях и энтероколита -в 10 (11,1%) в среднетяжёлой (81%) и тяжёлой (19%) формах [20][21][22]. По степени выраженности -с эксикозом I (63%), II (18%), III (19%) степени.…”

Serological Humoral Immunity Following Natural Infection of Children with High Burden Gastrointestinal Viruses

“…Infection follows a fecal-oral route, with infection possible with small amounts of virion exposure [124][125][126][127]. Once infected, children may shed virus for weeks post-infection [128]. Human norovirus is highly transmissible, especially in enclosed locations with a high density of people [103,129].…”