Passengers on repatriation flights to Greece from the UK, Spain and Turkey were screened with oropharyngeal swabs on arrival for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Despite almost all passengers being asymptomatic, many tested positive (3.6% from the UK, 6.3% from Spain and 6.3% from Turkey), indicating widespread transmission of SARS-CoV-2 in these countries.

The COVID-19 pandemic represents one of the greatest challenges in modern medicine. The disease is characterized by a variable clinical phenotype, ranging from asymptomatic carriage to severe and/or critical disease, which bears poor prognosis and outcome because of the development of severe acute respiratory distress syndrome (SARS) requiring ICU hospitalization, multi-organ failure and death. Therefore, the determination of risk factors predisposing to disease phenotype is of outmost importance. The aim of our study was to evaluate which predisposing factors, including MBL2 genotyping, affected clinical phenotype in 264 COVID-19 patients. We demonstrated that older age along with underlying comorbidities, primarily obesity, chronic inflammatory disorders and diabetes mellitus, represent the most important risk factors related to hospitalization, the development of pneumonia and SARS. Moreover, we found that the presence of the MBL deficiency-causing B allele (rs1800450) was significantly associated with almost 2-fold increased risk for developing pneumonia and requiring hospitalization , suggesting its usage as a molecular predictor of severe disease in SARS-CoV-2 infected individuals.

The estimation of anti-SARS-CoV-2 IgG antibodies is possibly the best approach to accurately establish the number of infected individuals and the seroprevalence of COVID-19 within a population. Thus, several commercial immunoassays have recently been developed. The purpose of our study was to assess the performance of five commonly used immunoassays in Greece (3 ELISA, namely Euroimmun SARS-CoV-2, GA GENERIC SARS-CoV-2 and Vircell COVID-19; and 2 chemiluminescent, namely ABBOTT SARS-CoV-2 and ROCHE Elecsys Anti-SARS-CoV-2 test) for the detection of anti-SARS-CoV-2 IgG antibodies. Sera specimens derived from 168 individuals were utilized to assess the specificity and sensitivity score of each assay. Among them, we included 99 COVID-19 patients (29 asymptomatic, 36 with symptom onset 4 to 14 days before serum sampling, and 34 with symptom initiation ≥ 15 days ago), and 69 volunteers with sera specimens collected prior to the SARS-CoV-2 outbreak and maintained at −80°C. We demonstrated that chemiluminescent immunoassays exhibit a significantly higher specificity score but a lower sensitivity, compared to ELISA immunoassays. Moreover, immunoassays detecting IgG antibodies against SARS-CoV-2 N protein instead of S protein alone are more reliable, considering both specificity and sensitivity scores. Interestingly, all asymptomatic patients displayed anti-SARS-CoV-2 IgG antibodies, confirmed by at least two immunoassays. We suggest that chemiluminescent assays could be used as screening methods for the detection of anti-SARS-CoV-2 antibodies to evaluate the possible prevalence of disease in the general population, while ELISA assays would be more reliable to evaluate, and follow-up confirmed COVID-19 patients.

We reviewed Greek law (legislation, historic Royal Decrees, and modern Presidential ones, 1833-2010) pertinent to control of communicable diseases and compared this body of Greek law with the revised International Health Regulations. Greece authorizes and regulates communicable disease control commensurate with public health risks, and integrates the principles of equality, objectivity, and respect for human rights. Despite strength at the level of principles, Greek law lacks coherence, clarity, and systematization. An inadequate body of regulations means legislation falls short of adequate implementing authority and guidelines; public health authorities often cannot find or understand the laws, nor are they certain about allocation of jurisdictional authority. We identified areas for improvement.

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