COVID-19 in the mediterranean area: Epidemiology and main disease characteristics - A narrative review

In December 2019, Chinese researchers identified a novel coronavirus in humans that caused acute respiratory syndromeofficially called coronavirus disease (COVID-19) as of February 11, 2020. At the beginning of the outbreak, the Mediterranean countries seemed to be spared from the health and social disaster happened in China. Unfortunately, the spread of the virus ran faster than forecasts and Italy was unfortunately then followed by Spain, France and other countries in counting many cases and deaths. The World Health Organization declared COVID-19 a pandemic on March 11th, 2020. A retrospective analysis of big data from Google Trends, using an infodemiology approach, shows how internet traffic search on COVID-19 may figure on the spread curve. The clinical aspects of COVID-19 range from poor or mild symptomatic patients to severe respiratory disease which can quickly lead patients to respiratory failure and admission to intensive care units. Multi-organ involvement and different types of symptoms other than respiratory have been described. Nowadays the vaccination is still under investigation and there is not a specific treatment approved for COVID-19. While several drugs and therapeutic strategies are currently under investigation and deserve further well-designed, prospective epidemiological and clinical studies with high methodological standards, the literature highlights the role of Chloroquine and its less toxic derivative Hydroxychloroquine in the therapeutical management of COVID-19. Those drugs have been proposed as a potential treatment for COVID-19 and clinical trials are undergoing to evaluate this drug. However have known oxidative properties that could decrease glutathione levels and may cause severe haemolysis in G6PD-deficient patients. Deficient G6PD alleles are distributed worldwide; a conservative estimate is that at least 400 million people carry a mutation in the G6PD gene causing deficiency, the Mediterranean most frequent variant is a class II allele (1-10% of residual activity). With worldwide spread of COVID-19, also in regions with a high prevalence of G6PD deficiency, physicians should be aware of this possible correlation.