Changes in norovirus incidence in Victoria, Australia, during the COVID-19 pandemic, 2020-2021.

There were 142 norovirus positive outbreaks in Victoria for the 2020-2021 calendar years; however, almost half of these (48.6%) occurred in Q1 (January-March) of 2021. For the two-year period, 69.0% of all norovirus positive outbreaks were in childcare settings, and the predominant genotype was GII.P16/GII.2 (64.9%) followed by GII.P31/GII.4_2012 (20.9%). Norovirus incidence was particularly low in 2020 (n = 26) and close to average in 2021 (n = 116), but genotype diversity was low in both years. With the thought that 2022 will approach a more normal aspect to socialising and travel, norovirus incidence in 2022 may be predicted to increase above typical levels.

HOSPITILISATIONS FOR NOROVIRUS DECREASE DURING THE COVID-19 PANDEMIC

Background Gastrointestinal infections cause a significant burden to the Australian healthcare system each year, with acute gastroenteritis infections costing up to $359 million AUD ($258 million USD) in 2016. Viral causes of gastroenteritis, particularly Norovirus, account for the majority of these cases. Given the contagious nature of many causes of bacterial and viral gastroenteritis, it was hypothesized that widespread lockdowns and increased public health focus on regular hand hygiene would contribute to a reduction in hospital presentations with gastrointestinal infections. Melbourne, Victoria, Australia first went into lockdown in March 2020 and remained in various forms of lockdown until late 2020. Methods A retrospective study comparing rates of hospitalization for bacterial and viral gastroenteritis was performed at The Royal Melbourne Hospital between February-August in both 2019 and 2020. Rates of admission were compared between the two years, as well as the causative organism and the outcome of the presentation. Descriptive statistics were provided to summarise demographic characteristics. Outcomes between the two years were compared using paired t-tests for continuous variables and Pearson chi-square for categorical variables. All data analysis was performed using Stata 16.1 and p-values £0.05 were considered statistically significant. Results Demographic data are summarised in Table 1. 283 patients were hospitalized with gastroenteritis in 2019 pre-pandemic, compared to 147 in 2020 during the COVID-19 pandemic. There was a significant reduction in the number of patients admitted with positive fecal cultures from 2019 to 2020 (87 vs 57, p < 0.01). The number and percentage of patients presenting with Norovirus reduced by greater than 90% in 2020 compared to 2019 (Table 2) (Odds Ratio: 0.093 [Confidence Interval: 0.02-0.41], p<0.01). There was a reduction in the number of presentations with Salmonella, however, this did not reach statistical significance (p=0.50). The number of patients presenting with Clostridium difficile significantly increased in 2020 compared to 2019 (21 versus 25, p=0.01) (Table 2). Rates of antibiotic treatment and intensive care admission were greater in 2020 compared to 2019 however there was no significant difference in biomarkers, length of stay, or mortality (Table 2). Conclusion A significant decrease in the incidence of hospitalization secondary to acute gastrointestinal infections was observed during the COVID-19 pandemic. Norovirus presentations decreased by greater than 90% between 2019 and 2020. The rate of other GI infections was similar between pre-pandemic and pandemic time points. These findings suggest that public health measures, such as social distancing and hand hygiene, may be a useful adjunct to prevent Norovirus infections in the future and could result in significant healthcare savings.(Table Presented)TABLE 1: PATIENT DEMOGRAPHICS(Table Presented) TABLE 2: GASTROINTESTINAL CULTURE POSITIVE INFECTIONS 2019 VERSUS 2020

THE IMPACT OF THE CORONAVIRUS PANDEMIC AND GOVERNMENT LOCKDOWNS ON GASTROINTESTINAL DISEASE HOSPITALIZATIONS, INPATIENT MORTALITY, AND ENDOSCOPY UTILIZATION IN CALIFORNIA: A STATE-WIDE POPULATION-LEVEL ANALYSIS

Background: In the wake of the Coronavirus pandemic, there was a drastic decline in healthcare resource utilization for preventive, elective, and emergency care. It is unclear how this affected gastrointestinal (GI) outcomes. As such, we sought to investigate the impact of the Covid-19 pandemic and subsequent lockdowns on inpatient GI outcomes and endoscopy utilization in California. Methods: Using the all-payer California State Inpatient Database for 2018-2020, we explored year-to-year and 2020 month-to-month trends in hospitalizations, length of stay, and inpatient mortality (all-cause&viral pneumonia-specific) for common inpatient GI diagnoses including acute pancreatitis, diverticulitis, cholelithiasis, noninfectious gastroenteritis, upper and lower GI bleeding, Clostridium difficile, viral gastroenteritis, inflammatory bowel disease, and acute cholangitis using joinpoint, linear, and logistic regression modeling. We also investigated endoscopy utilization for GI emergencies during the pandemic. Results: For all 12 GI conditions studied, there was a 15% hospitalization rate reduction in 2020 compared to prior years (173,535 in 2018, 174,827 in 2019, and 148,762 in 2020). A significant decrease in disease-specific hospitalizations (ptrend< 0.0001) was observed except in nonvariceal upper GI bleeding, lower GI bleeding, and ulcerative colitis (UC) admissions [Table 1]. Compared to 2019, all-cause inpatient mortality in 2020 was higher in hospitalizations for acute pancreatitis (0.5% vs. 0.6%, p= 0.029), diverticulitis (0.4% vs 0.6%, p=0.04), nonvariceal upper GI bleeding (1.8% vs 2.1%, p=0.003), and Crohn's disease (1.7% vs 2.2%, p=0.004) [Table 1]. The 2020 month-tomonth trend analysis showed the lowest hospitalization rates in April, November, and December 2020, coinciding with the peaks of the pandemic. Fortunately, despite these nadirs in GI hospitalizations, the month-to-month inpatient mortality trend analysis did not show a significant increase, except in UC hospitalizations (p-trend=0.048). There was also a significant increase in viral pneumonia (p<0.001) and viral pneumonia complicated by respiratory failure (p<0.001) among GI hospitalizations. For all GI emergencies (upper/lower GI bleeding, acute cholangitis, and food impactions), endoscopy utilization within the first 24 hours was comparable between 2019 & 2020, except for acute nonvariceal GI bleeding (32.5% in 2019 vs 30.3% in 2020, p<0.001). Conclusions: Our findings suggest that the Covid-19 pandemic resulted in a significant decline in hospitalization rates for common GI conditions in California particularly in April, November and December 2020. All-cause mortality rates were significantly higher among acute pancreatitis, diverticulitis, nonvariceal upper GI bleeding, and Crohn's disease hospitalizations. However, 2020 emergency endoscopy rates were mostly comparable with 2019. (Figure Presented) Figure 1: Trends in number of hospitalizations, total hospital stay in days, and allcause inpatient mortality of selected GI diseases in California from 2018 to 2020. (Figure Presented) Figure 2: Endoscopy utilization rates for GI emergencies in California from 2018 to 2020

Return of Norovirus and Rotavirus Activity in Winter 2020‒21 in City with Strict COVID-19 Control Strategy, China.

A rapid decrease in viral gastroenteritis during winter 2019-20 and a return of norovirus and rotavirus activity during winter 2020-21 were observed while multiple nonpharmaceutical interventions for coronavirus disease were in effect in Hong Kong. The initial collateral benefit of coronavirus disease countermeasures that reduced the viral gastroenteritis burden is not sustainable.

Association among sentinel surveillance, meteorological factors, and infectious disease in Gwangju, Korea.

The outbreak of new infectious diseases is threatening human survival. Transmission of such diseases is determined by several factors, with climate being a very important factor. This study was conducted to assess the correlation between the occurrence of infectious diseases and climatic factors using data from the Sentinel Surveillance System and meteorological data from Gwangju, Jeollanam-do, Republic of Korea. The climate of Gwangju from June to September is humid, with this city having the highest average temperature, whereas that from December to February is cold and dry. Infection rates of Salmonella (temperature: r = 0.710**; relative humidity: r = 0.669**), E. coli (r = 0.617**; r = 0.626**), rotavirus (r = - 0.408**; r = - 0.618**), norovirus (r = - 0.463**; r = - 0.316**), influenza virus (r = - 0.726**; r = - 0.672**), coronavirus (r = - 0.684**; r = - 0.408**), and coxsackievirus (r = 0.654**; r = 0.548**) have been shown to have a high correlation with seasonal changes, specifically in these meteorological factors. Pathogens showing distinct seasonality in the occurrence of infection were observed, and there was a high correlation with the climate characteristics of Gwangju. In particular, viral diseases show strong seasonality, and further research on this matter is needed. Due to the current COVID-19 pandemic, quarantine and prevention have become important to block the spread of infectious diseases. For this purpose, studies that predict infectivity through various types of data related to infection are important.

Rotavirus gastroenteritis in children hospitalized in northeastern Poland in 2006-2020: Severity, seasonal trends, and impact of immunization.

OBJECTIVES: The introduction of the rotavirus vaccine in 2006 significantly reduced childhood incidence of acute gastroenteritis (AGE) worldwide. The rotavirus vaccine was included in Poland's national immunization program in 2021. Our study aimed to summarize the epidemiology of AGE in northeastern Poland prior to 2021 and to evaluate the effectiveness of voluntary, out-of-pocket rotavirus childhood vaccination on the incidence of rotavirus AGE. METHODS: A review of patients aged 0-17 years with gastroenteritis hospitalized between 2006 and 2020 in northeastern Poland in the context of rotavirus vaccine coverage in the region. RESULTS: Rotavirus was the most common agent of gastroenteritis in hospitalized patients. The seasonality of rotavirus gastroenteritis peaked between February and May in each year of study, except for 2020, when the COVID-19 pandemic skewed any viable comparison of seasonality. Rotavirus vaccine coverage in northeastern Poland did not exceed 25% during the study period and had no impact on hospitalization numbers. CONCLUSIONS: Rotavirus was the primary causative agent of AGE in children hospitalized in northeastern Poland during the study period. Voluntary vaccinations did not affect the number of hospitalizations due to rotavirus AGE. Our data suggest that universal immunization is key to achieving a significant reduction of rotavirus-associated diarrhea.