COVID-19 impact on viral hepatitis in Italy: a time-series analysis

BACKGROUND: Worldwide there has been a sharp decrease in the number of notified cases of any type of viral hepatitis during the pandemic period. This study aims to investigate the impact of COVID-19 on viral hepatitis in Italy. METHODS: This was a retrospective study that analysed data extracted from the “Integrated Epidemiological System of Acute Viral Hepatitis” (SEIEVA) online platform from 1994 to 2022 in the Piedmont region of Northern Italy. Descriptive statistics were used to compare data from the pandemic period (2020-2022) to three years of pre-pandemic period (2017-2019). Second, a univariate ARIMA temporal forecast model based on the years 1994-2019 was built to predict how many cases should have been registered in the pandemic period. The Wilcoxon test was performed to detect if there was a statistically significant difference between the observed and predicted values. RESULTS: The time elapsed between the onset of symptoms and the serological test, potentially indicative of challenges related to hospital access, was delayed by a couple of days (median 7, 2-12 IQR) in the three-year period 2020-2022 compared to 2017-2019 (median 5, 3-9 IQR). The same occurred considering the time between the positive test and the epidemiological interview (median 6, 3-16 IQR vs median 4, 2-9 IQR). Although the ARIMA forecasting model confirmed a downward trend, the observed values of notified cases were lower than expected. A statistically significant difference was found between predicted and observed values (p = 0.004). CONCLUSIONS: Although it is difficult to assess the impact of COVID-19 on the transmission of viral hepatitis, the results of this study suggest a lower accuracy of the surveillance. It will be important to restore the previous levels of attention and investigation, monitoring the trend in the coming years. The World Health Organization's goal is the eradication of viral hepatitis. COVID-19 may have slowed down the process. KEY MESSAGES: • It is important to keep up the level of attention towards viral hepatitis, which seems to have decreased following the COVID-19 pandemic. • It will be important to pay attention to the trend of notified cases in the coming years to establish more precisely the level of impact of the pandemic.