BACKGROUND

Noroviruses (NoVs) are the leading cause of diarrheal disease among all age groups worldwide, with an increased burden in developing countries. As there is no surveillance, epidemiological data is limited in Ethiopia. Hence, this study aimed to investigate the prevalence and associated factors of NoV infection among patients with diarrhea in the Amhara National Regional State, Ethiopia.

METHODS

A prospective health facility-based cross-sectional study was conducted from May 2021 to November 2021. A total of 550 study participants of all age groups with symptoms of diarrhea were proportionately assigned to the four study areas, area with three health facilities. Study participants were systematically sampled in each health facility. A fecal sample from each case was collected. The RNA was extracted and tested for NoV by one-step RT-PCR. Sociodemographic and other variables were gathered using a pre-tested questionnaire. A descriptive analysis was performed. Both binary and multiple logistic regressions were utilized to identify factors associated with NoV infection. Variables with a p-value < 0.05 in the final model were considered statistically significant.

RESULTS

Five hundred nineteen out of 550 samples were analyzed (94.4% response rate). The overall prevalence of NoV was 8.9% (46/519). The positivity rates were higher among the elderly (33.3%) and under-5 children (12.5%). Both genogroup I and genogroup II (GII) were identified, with GII being the predominant, at 82.6% (38/46). Of all participants, only 20% reported a history of vomiting. Norovirus infection was more prevalent among participants from Debre Tabor (AOR = 4, 95%CI: 1.2-14) and Bahir Dar areas (AOR = 3.6, 95%CI: 1.04-11) compared to Debre Markos. Additionally, older adults (AOR = 7, 95% CI: 2-24) and under-5 children (AOR = 3.5, 95% CI: 2.8-12) were disproportionately affected compared to adults. The previous history of diarrhea (AOR = 3.6, 95% CI: 1.7-7) was a significant factor contributing to NoV infections. Moreover, the odds of NoV infection were higher among individuals with a high frequency of diarrhea (AOR = 15.3, 95%CI: 7.6-43) and vomiting (AOR = 3.5, 95%CI: 1.5-8).

CONCLUSIONS

The prevalence of NoV was considerably high, with the predominance of NoV-GII. The positivity rate was higher among the extreme age groups and varied across the study areas. To obtain a comprehensive understanding of the virus`s epidemiology and its genetic diversity, further research is warranted.