Our study highlights a low prevalence of HBV and HCV in the study population (0.5% and 0.5%, 95% CI 0.0006–0.02, respectively).
We do not have data about HCV screening in the pre-COVID-19 era from our hospital, but we can assume that the frequency of screening during the study period was reduced compared to the past . Conversely, in other areas of Northern Italy, the SARS-CoV-2 pandemic was thought to be exploited to increase HCV screening in the Italian population and achieve the WHO goal of HCV elimination . Among patients with a positive HCV serology in our study population, five out of 11 showed severe clinical conditions, thus further investigations were not conducted. On the other hand, almost all HCV-Ab positive patients had anamnestic reports of medical visits or hospitalisations before the study was performed, and therefore had missed the opportunity for a previous diagnosis and eradication.
While analysing the patients’ characteristics, we found that more than half of HCV-Ab positive patients were aged > 60 years, according to the high prevalence of HCV in the second part of the twentieth century [2, 10], and about 20% were IDU, a known risk factor for HCV infection [2, 10].
Although the prevalence of chronic HBV and HCV is still unknown, some authors hypothesised that there is a high number of HCV infected individuals still undiagnosed in Italy . Through a mathematical model, they estimated undiagnosed HCV to be about 281,809 individuals in October 2019 .
Even if extensive screening can reduce hospitalisation, costs and deaths related to chronic hepatitis , the perception based on our results is that the screening could be narrowed down to suit people with HCV infection risk factors, such as period of birth, drug abuse, blood transfusion and/or surgical procedure before the 90s [2, 10, 14]. In addition, it is important that patients with a new diagnosis of chronic HCV infection are referred to care .
Furthermore, the prevalence of chronic HBV infection was low in our study since only two patients had positive HBsAg, and we expected an even lower prevalence in people born in Italy after HBV vaccination became mandatory in 1990 .
Similar to HCV chronic hepatitis, we can assume that the screening for HBV was higher in the pre-pandemic period . Moreover, a recent study conducted in the United States demonstrates that conducting HBV screenings for a population is cost-effective even when the estimated prevalence is low, because it can help to prevent chronic HBV infection complications .
Even when the prevalence of active chronic HBV infection was low, we found a high proportion of previous HBV infections with HBcAb positivity (about 20%). People with HBcAb positivity are at risk of reactivation of HBV infection when exposed to immunosuppressive therapies [19, 20]. As some immunosuppressive drugs used for COVID-19, like tocilizumab and baricitinib can lead to HBV reactivation , HBV screening should be offered with significant attention paid to patients eligible for these therapies, even though the risk appears to be low in patients with previous and resolved HBV infections . Most data stems from studies about autoimmune diseases in which these medications were administered together with some other agents, such as high dose and prolonged corticosteroids therapy or other disease-modifying antirheumatic drugs (DMARDs) [23, 24]. In our study population, only 320/1429 (22%) patients potentially to be treated with immunosuppressive therapies were screened for HBcAb, a low percentage which was probably due to the pandemic era. However, even in an overworked period, clinicians should maintain diagnostic and therapeutic appropriateness. Nonetheless, not all patients with SARS-CoV-2 infections need immunosuppressive therapies, especially after the introduction of vaccination and outpatients’ therapies .
The first limitation of our study is that serology for HBV and/or HCV was tested in only 27% of patients admitted to the hospital for SARS CoV-2 infection in the study period. Furthermore, our study is retrospective and the seroprevalence screening of HBV and HCV chronic infection in the pre-pandemic era is unknown to us. The second limitation is that during the first wave of the COVID-19 pandemic, medical efforts were focused on COVID-19 instead of routine patient management and the best clinical approach. This could have also reduced the linkage of patients with a new diagnosis of chronic HBV and HCV hepatitis to care . Yet another limitation is that 95% of patients were Caucasian, and only 0.5% were from Africa and Asia, a population with a higher prevalence of chronic HBV and HCV infection compared to Italy [27, 28].
Since the median age of our study population is 70 years, we conducted the screening on the population with the higher prevalence of chronic HBV and HCV infection in Italy (9, 10), and therefore we can assume that the prevalence of chronic viral hepatitis is low among the non-selected population.
In conclusion, diagnosing people living with chronic viral hepatitis is challenging due to the absence of symptoms other than liver decompensated cirrhosis. A tailored screening in people with known risk factors for hepatitis might be preferable to universal screening in low prevalence areas, even though prompt diagnostic workout should begin in case of clinical or laboratory suspicion of hepatitis and in those patients starting immunosuppressive treatments. Moreover, a targeted effort could give benefits on the linkage to care and epidemiological control and reduce the risk of losing patients to follow-up in a wide screening.
Nevertheless, our study reports the prevalence and not the incidence of HBV and HCV chronic hepatitis. Even if we think that a tailored screening should be preferred instead of a universal one, surveillance of chronic hepatitis should be performed to identify a possible trend reversal.