Risk Factors for Norovirus Infections and Their Association with Childhood Growth: Findings from a Multi-Country Birth Cohort Study

Norovirus gastroenteritis in children under-five years hospitalized for diarrhea in two cities of northeast India: A retrospective study

PURPOSE

Norovirus gastroenteritis, known to cause 'winter vomiting disease' is increasingly being identified as a major cause of viral gastroenteritis worldwide. The impact and prevalence of this viral disease are lacking in many parts of India including northeast India. This study aimed to determine the prevalence and association of norovirus gastroenteritis among under-five-year-old hospitalized children in two cities in northeast India (Dibrugarh in Assam & Dimapur in Nagaland).

MATERIALS AND METHODS

A retrospective analysis of 407 randomly selected diarrheal stool samples was conducted using a commercial multiplex probed-based real-time RT-PCR assay capable of detecting six-viral gastroenteritis pathogens including Norovirus GI, Norovirus GII, Rotavirus, Human Adenovirus, Human Astrovirus, and Sapovirus.

RESULTS

Results showed that norovirus was detected in 18.4% of the samples (75/407; 95% CI: 14.8%-22.5%), with norovirus genogroup II being the predominant group in 97.3% of norovirus cases. A significant association of norovirus diarrhea was found with seasonality, with higher prevalence in colder months compared to warmer months (22.4% vs 9.1%, p-value:0.002). Additionally, 66.7% (50/75) of cases of norovirus gastroenteritis had reported vomiting as the major symptom and had a shorter duration of diarrhea (p-value 0.03). Co-infections with other viral pathogens were seen in 45.9% (187/407) of the cases. The detection of rotavirus was 67.1% (273/407), human adenovirus (45.9%; 187/407), sapovirus and astrovirus (5.9%, 24/407 each), and norovirus GI (0.5%, 2/407) among the cases.

CONCLUSION

This study reports the prevalence of norovirus gastroenteritis in northeast India and further highlights that norovirus gastroenteritis is responsible for substantial cases of hospitalization of under-five years children in the region.

High prevalence of norovirus GII.4 Sydney among children with acute gastroenteritis in Bangladesh, 2018-2021

BACKGROUND

Active molecular surveillance and rapid diagnosis method to track an outbreak of norovirus in Bangladesh is lacking. This study aims to determine the genotypic diversity, molecular epidemiology and evaluate a rapid diagnosis method.

METHODS

A total of 404 fecal specimens were collected from children aged below 60 months from January 2018 to December 2021. All samples were analyzed by reverse transcriptase polymerase chain reaction molecular sequencing of partial VP1 nucleotide. Immunochromatography kit (IC, IP Rota/Noro) was evaluated against reference test method.

RESULTS

We found norovirus in 6.7 % (27 of 404) fecal specimens. A wide diversity of norovirus genotype including GII.3, GII.4, GII.5, GII.6, GII.7, and GII.9 were detected. Norovirus strain GII.4 Sydney-2012 was the most predominant (74 %, 20 of 27) followed by GII.7 (7.4 %), GII.9 (7.4 %), GII.3 (3.7 %), GII.5 (3.7 %) and GII.6 (3.7 %), respectively. Co-infection of rotavirus and norovirus (19 [4.7 %] of 404) was the most prevalent. We found higher odds of prolonged health impact [OR 1.93 (95 % CI 0.87-3.12) (p = .001)] among patients with co-infection. The incidence of norovirus was significant among the children below 24 months (p = 0.001). Significant relation of temperature with the cases of norovirus was detected (p = 0.001). The IC kit provided high specificity (99.3 %) and sensitivity (100 %) for the detection of norovirus.

CONCLUSIONS

This study will provide an integrated insight on the genotypic diversity and rapid identification method of norovirus in Bangladesh.

Household Surveillance for Norovirus Gastroenteritis in a Nicaraguan Birth Cohort: A Nested Case-Control Analysis of Norovirus Risk Factors

Norovirus causes a large proportion of pediatric acute gastroenteritis (AGE) worldwide, and no vaccines are currently available. To inform public health measures against norovirus gastroenteritis, we assessed risk factors in a case-control study nested in a birth cohort study in Nicaragua. Between June 2017 and January 2022, we followed children weekly for AGE episodes, and collected stool specimens from symptomatic children. Risk factors for AGE were collected during routine weekly visits. Norovirus was detected in stools using real-time reverse transcriptase polymerase chain reaction and positive specimens were genotyped using Sanger sequencing. We included 40 norovirus-positive AGE children matched 1:2 to controls and conducted bivariate and multivariable analyses of norovirus AGE risk factors. Among typeable norovirus infections, GII.4 were more severe than non-GII.4 (four/twenty-one vs. one/nine) and accounted for all emergency visits and hospitalizations. Adjusted conditional logistic regression found that female sex and higher length-for-age Z score were protective against norovirus AGE; a dirt floor in the home, sharing cups or bottles, and recent contact with someone with AGE symptoms were associated with norovirus AGE, though estimates were highly imprecise. Reducing contact with symptomatic persons and with saliva or other bodily fluids on cups or floors could reduce infant norovirus incidence.

Gut biomolecules (I-FABP, TFF3 and lipocalin-2) are associated with linear growth and biomarkers of environmental enteric dysfunction (EED) in Bangladeshi children

In the current world, a major challenge to diagnose environmental enteric dysfunction (EED) is the lack of validated non-invasive biomarkers. Intestine derived molecules, including intestinal fatty acid binding protein (I-FABP), trefoil factor-3 (TFF3), lactoferrin, lipocalin-2 (LCN2), and mucin-2, have been reported as indicators of intestinal inflammation and gut health. Therefore, we aimed to investigate the levels of these bio-molecules as biomarkers of EED among under-2 children in Bangladesh. A total of 140 children were recruited in a case–control design. All the biomarkers were measured by ELISA. Spearman’s rank correlation was performed to see the correlation between the biomarkers and the EED score. Moreover, multivariable linear regression was performed to investigate the association of biomarkers with length-for-age z-score (LAZ). TFF3 correlates positively with myeloperoxidase (r = 0.26, p < 0.05) and EED score (r = 0.17, p < 0.05). Likewise, LCN2 correlates positively with myeloperoxidase (r = 0.37, p < 0.05), neopterin (r = 0.33, p < 0.05) and EED score (r = 0.31, p < 0.05). Moreover, multivariable linear regression revealed a negative association of I-FABP with LAZ of the study participants. Our results imply that TFF3 and LCN2 might be promising biomarkers to diagnose intestinal inflammation and EED, while I-FABP is negatively associated with linear growth of Bangladeshi children.