Symptomatic and asymptomatic infections of rotavirus, norovirus, and adenovirus among hospitalized children in Xi'an, China

Abstract

Rotavirus (RV), norovirus (NoV), and adenovirus (AdV) have been reported as the common viral pathogens of acute gastroenteritis in children. To determine the prevalence of RV, NoV, and AdV infections among hospitalized children with and without symptoms of acute gastroenteritis, fecal specimens, and data on clinical symptoms were collected from 201 children with diarrhea and 53 children without diarrhea admitted to the Xi'an Children's Hospital in Xi'an, China between March 2009 and May 2010. RV, NoV, and AdV were identified in 68.7% (138/201), 20.4% (41/201), and 5.0% (10/201), respectively, of children with diarrhea. These three viruses were also detected in 13.2% (7/53), 35.9% (19/53), and 9.4% (6/53), respectively, of children without diarrhea. Diarrheal children infected with RV alone showed the average severity score of 6.5, statistically significant higher than the average score of 5.3 in children with unidentifiable viruses. GII.3 and GII.4 were the only two NoV genotypes identified, and the GII.4 sequences were genetically close to GII.4 2006b cluster. These findings highlight the importance of NoV as a causative agent of pediatric diarrhea after RV based on the clinical and epidemiological characteristics of NoV infection, and particularly convey information of asymptomatic infections of enteric viruses in young children.

Role of noroviruses as aetiological agents of diarrhoea in developing countries

“…We and other investigators have detected noroviruses in persons without gastroenteritis in prospective longitudinal studies, suggesting that asymptomatic infection may be relatively common (Ayukekbong et al, 2013;Bucardo et al, 2010;Zhang et al, 2011). The length of observation in these studies suggests that asymptomatic infection is not necessarily occurring as pre-or post-symptomatic shedding of the virus.…”

Asymptomatic Viral Gastrointestinal Infection: The Missing Link?

“…Viruses are never normal flora; nevertheless, a small proportion of asymptomatic subjects are found to have transient viruses in stools. [11][12][13] Thus, it is possible to have virus in stool without diarrhea. Furthermore, it is known that a virus can be found in stool while causing distant effects without local gastrointestinal symptoms; for example, poliovirus.…”

Norovirus vaccines: Correlates of protection, challenges and limitations

“…3 It was suggested that children in the developing countries can exhibit higher prevalence of antibodies directed against NoV as compared to developed countries due to early exposure, even though inconsistently. Previous studies indicated that infection with enteric viruses including NoV is significantly associated with early age [46][47][48] and consequently early exposure leads to development of immunity against the virus. In a recent longitudinal study held in the Cameroon, 49 reports show that adults and children show similar rates of infections with the virus.…”

“…59,60 More than 90% of individuals are seropositive to NoV by the time they reach adulthood; however, the role of pre-existing immunity is still not fully understood when related to protection or reducing the risk of acquiring new NoV infections. 15 The fact that asymptomatic infection occurs at an early age as reported by outbreak and human challenge studies 48,[61][62][63] provides critical insight to the potential reservoir of transmission at an early age and its clear implication on the need for an effective vaccine.…”