Acute diarrhea is still a significant health problem in children in the world, including in Indonesia. However, studies on the causes of acute diarrhea in Indonesia are still limited. Norovirus (NoV) is the leading cause of sporadic cases and outbreaks of acute diarrhea, not only in children but also in adults. It is estimated that NOV causes 12% of cases of severe acute diarrhea (hospitalized) in children under five years and 12% of cases of mild and moderate diarrhea (outpatient) at any age. NoV is transmitted through, among other things, food or water contaminated with the patient’s feces. After a short incubation (12-48 hours), symptoms appear in nausea, vomiting, watery diarrhea, and abdominal pain. Diarrhea is a significant cause of illness and death due to NOV. In countries implementing Rotavirus vaccination, NoV is the most common cause of acute diarrhea in children. However, rotavirus vaccination is not in the national immunization program in Indonesia.
The contribution of NOV as a cause of acute diarrhea in Indonesia is still not widely known because studies are still limited. Several studies have reported the incidence of NOV in several cities in Indonesia, including: in Jakarta (Subekti et al., 2002) by 21% (period 1997 to 1999) with symptoms in the form of loose stools, vomiting, stomach cramps, and fever and Mataram (Elmaida et al., 2018) of 31.6% (2017) in children less than five years of age with symptoms of vomiting, fever, severe diarrhea but without dehydration. Nirwati et al. (2019) reported that the NoV genogroup GII was dominant in children with acute diarrhea. Besides, there were several other genotypes, namely GII.1, GII.2, GII.4 Sydney 2012, GII.6, GII.15, GII.17, GII. 21, and GI. 3. In the asymptomatic population, genotype GII.1, GII.2, GII.4 Sydney 2012, GII.17 was detected. However, the relationship between the molecular characteristics of NoV and its infection symptoms is not clear.
Norovirus is an RNA virus from the family Caliciviridae. Norovirus consists of seven genogroups (GI – GVII), and genogroups are further divided into genotypes. Genogroups NoV I, II, and IV frequently infect humans with more than 30 genotypes characterized in these genogroups. Noroviruses are widely distributed with considerable genetic diversity. This study aims to identify the incidence of acute diarrhea due to NOV and the characteristics of its clinical symptoms, and the distribution of the NoV genotype in children in several hospitals in Jambi. Data from the Indonesian Ministry of Health (2018) shows 8% of children diarrhea cases in Jambi, but there is no data on the causative agent. In this study, identification of NoV genotype was carried out molecularly by reverse-transcriptase PCR and sequencing, and clinical data were obtained through medical records.
As many as 15.4% of children with acute diarrhea showed positive NoV. The most common clinical manifestations are fever, vomiting, and severe diarrhea, while the level of dehydration differs between children with positive and HIV positive and negative children. Besides, severe diarrhea is only found in malnourished children. Interestingly, the NoV genotype identified in Jambi is different from the distribution of the NoV genotype reported from other regions in Indonesia.
Unlike other regions, the proportion of genogroups NoV I and II is the same (50% each), with the most dominant genotype, namely GI.4 followed by GII.6 in Jambi. Previous studies reported that patients with GI.4 and GII.6 genotype NoV infection showed severe symptoms with high Vesikari scores. Based on his phylogenetic tree analysis, it is suspected that the presence of foreign workers from various countries who have entered Jambi province in the last three years has contributed to the spread of the NoV genotype. Surveillance of acute diarrhea due to NOV in Jambi needs to be continued to investigate the association of NoV infection with particular outbreaks and control acute diarrhea due to NOV in children.
Link: Predominance of norovirus GI.4 from children with acute gastroenteritis in Jambi, Indonesia, 2019 https://onlinelibrary.wiley.com/doi/epdf/10.1002/ jmv.26057