SARS-CoV-2 sero-surveillance in Greece: evolution over time and epidemiological attributes during the pre-vaccination pandemic era

BACKGROUND: Nation-wide SARS-CoV-2 seroprevalence surveys provide valuable insights into the course of the pandemic, including information often not captured by routine surveillance of reported cases. METHODS: A serosurvey of IgG antibodies against SARS-CoV-2 was conducted in Greece between March and December 2020. It was designed as a cross-sectional survey repeated at monthly intervals. The leftover sampling methodology was used and a geographically stratified sampling plan was applied. RESULTS: Of 55,947 serum samples collected, 705 (1.26%) were found positive for anti-SARS-CoV-2 antibodies, with higher seroprevalence (9.09%) observed in December 2020. Highest seropositivity levels were observed in the "0-29" and "30-49" year age groups. Seroprevalence increased with age in the "0-29" age group. Highly populated metropolitan areas were characterized with elevated seroprevalence levels (11.92% in Attica, 12.76% in Thessaloniki) compared to the rest of the country (5.90%). The infection fatality rate (IFR) was estimated at 0.451% (95% CI: 0.382-0.549%) using aggregate data until December 2020, and the ratio of actual to reported cases was 9.59 (7.88-11.33). CONCLUSIONS: The evolution of seroprevalence estimates aligned with the course of the pandemic and varied widely by region and age group. Young and middle-aged adults appeared to be drivers of the pandemic during a severe epidemic wave under strict policy measures

Functional role of the secretin/secretin receptor signaling during cholestatic liver injury

Liver diseases are a major health concern and affect a large proportion of people worldwide. There are over 100 types of liver disorders, including cirrhosis, cholangiocarcinoma (CCA), hepatocellular carcinoma, and hepatitis. Despite the relevant number of people who are affected by liver diseases, and the increased awareness with regard to these disorders, the number of deaths corresponding to liver injury is expected to increase in the foreseeable future. One of the possible reasons for this is that a complete comprehension of the mechanisms of hepatic damage involving specific liver anatomical districts is lacking, and, as a consequence, current treatments available are suboptimal

Does tourism affect the long term course of COVID-19 pandemic in a country of destination? Evidence from a popular Greek island in 2020 where control measures were implemented

Greece opened its points of entry on July 1, 2020, with specific guidelines for travellers arriving by sea, air or land. The aim of this article is to examine the effect of tourism on the long term course of the Coronavirus Disease 2019 (COVID-19) pandemic during the pre-vaccination era (June to December 2020) on the popular Greek island of Crete. To achieve this, a cross-sectional serosurvey, repeated at monthly intervals, was conducted to compare the seroprevalence in Crete with seroprevalence in the mainland of Greece. Crete welcomed nearly 2,000,000 travellers during the 2020 summer season. Left-over serum samples were collected and obtained from public and private laboratories located in Greece, including the island of Crete. These samples were tested for the presence of anti-SARS-CoV-2 IgG antibodies. A total of 55,938 samples were collected, 3,785 of which originated from Crete. In Crete, the seroprevalence ranged between 0% (June 2020) and 2.58% (December 2020), while the corresponding seroprevalence in Greece was 0.19% and 10.75%, respectively. We identified 4.16 times lower seropositivity in Crete (2.58%) in comparison with the mainland of Greece (10.75%) during December 2020. Moreover, the monthly infection fatality rate (IFR) in Crete was calculated at 0.09%, compared with 0.21% in mainland Greece for December 2020. The island of Crete presented more than four times lower seroprevalence than the mainland of Greece, despite being a highly attractive tourist destination. This evidence supports the idea that tourism may not have affected the long term course of the COVID-19 pandemic in Greece. However, due to contradicting results from previous studies, further investigation is needed

Functional Role of the Secretin/Secretin Receptor Signaling During Cholestatic Liver Injury

Liver diseases are a major health concern and affect a large proportion of people worldwide. There are over 100 types of liver disorders, including cirrhosis, cholangiocarcinoma (CCA), hepatocellular carcinoma, and hepatitis. Despite the relevant number of people who are affected by liver diseases, and the increased awareness with regard to these disorders, the number of deaths corresponding to liver injury is expected to increase in the foreseeable future. One of the possible reasons for this is that a complete comprehension of the mechanisms of hepatic damage involving specific liver anatomical districts is lacking, and, as a consequence, current treatments available are suboptimal. A major burden in the clinical setting are chronic cholestatic liver diseases (e.g., primary biliary cholangitis [PBC], primary sclerosing cholangitis [PSC], biliary atresia), which target the biliary epithelium and are characterized by cholestasis.(1, 2) Because the secretin (Sct)/secretin receptor (SR) axis (expressed only by cholangiocytes in the liver)(3, 4) is the major regulator of ductal bile secretion,(5, 6) it is intuitive that this axis plays a key role in the maintenance of biliary homeostasis during the progression of cholangiopathies. For instance, PBC is characterized by reduced bicarbonate secretion, a phenomenon possibly impeding the formation of an HCO3 canalicular film (“bicarbonate umbrella”) on bile ducts, which has protective properties against highly concentrated bile acids (BAs).(1, 7, 8) In this review, we examined the molecular mechanisms by which the Sct/SR axis regulates biliary function and the homeostasis of the biliary epithelium in normal and pathophysiological conditions

Epidemiology of intra-abdominal infection and sepsis in critically ill patients: “AbSeS”, a multinational observational cohort study and ESICM Trials Group Project

Purpose: To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock). Methods: We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis. Results: The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation. Conclusion: This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection