The covid-19 pandemic is still present and we are directly or indirectly affected by it. The skin is one of the organs that has some manifestations not only during the course of the disease, but also long after recovery and also after vaccination. Hair is one of the parts that, like the skin, may show disorders during and after recovery of the infection and also after vaccination. In this issue, we aimed to provide an overview of the effects of covid-19 and vaccination on hair. We also express the instrumental role of hair in the study of other diseases, including psychological problems.

The Coronavirus disease 2019, identified by Chinese researchers to be the caused by a novel enveloped betacoronavirus, Severe Acute Respiratory Syndrome Coronavirus-2 which was first isolated in Wuhan, China has been declared a global pandemic by the world health organization. The virus has several structural proteins that contributed to its pathogenesis such as spikes, membrane, envelop and nucleocapsid protein facilitating its attachment, entry and cell-to-cell transmission. The virus is readily transmitted through human-to-human contact and there is presently no approved vaccine for its prevention. This study was carried out to review the epidemiology of Severe Acute Respiratory Syndrome Coronavirus-2, its host and reservoir, pathogenesis, transmission, clinical manifestation and potential treatment options for the infection.

Coronaviruses cause diseases such as the Middle East respiratory syndrome and acute respiratory syndrome. SARS-CoV-2, which causes covid-19 and ongoing pandemic, was first identified in Wuhan, China. SARS-CoV-2 mainly infects the respiratory tract leading to infect other organs. Gastrointestinal symptom, for instance, have been widely reported in patients with covid-19. In fact, numerous investigations have shown that SARS-CoV-2 can be detected in feces and this may be associated with the risk of viral transmission. The presence of SARS-CoV-2 in human feces and transmission in the sewage system is a public health concern. Therefore, wastewater-based epidemiology can play a critical role in the early detection of covid-19 outbreaks in rural and urban areas. Compared to conventional viral detection methods, it has been suggested that SARS-CoV-2 can be rapidly detected in sewage even one week before observing the symptom in a population. In this study, we first focus on the importance of sewage system monitoring and screening to control the covid-19 pandemic and the required protocols and factors to remove and to disinfect wastewater from the virus to provide safe water recycling and environmental health protection.

Although skin manifestations of covid-19 were reported later than major organs affected, but it seems that they have gained relatively defined and definite described patterns. Regardless of strength and quantity of published papers and reports of rare cases, generally reported cutaneous manifestations are similar. However affection of vairous nail lesions have been mentioned recently. Even though no skin finding is recognized as specific, this does not mean not to look for and describe skin and nail changes. Common skin findings could be observed in many cutaneous diseases. In this issue, we decided to review literature about nail apparatus affected by covid-19.

In 2019, a new coronavirus (covid-19) was discovered in Wuhan, China, which soon spread all over the world. The main hallmark of the disease includes fever, diarrhea, vomiting, and dry cough with dyspnea in half of the patients and acute respiratory distress syndrome (ARDS). Currently, no definitive treatment or prevention therapy exists for covid-19 but scientists and researchers all over the world are relentlessly working to understand covid-19 to discover novel therapeutic tools and vaccines. Today, photodynamic therapy (PDT) has been investigated as a noninvasive therapy for the treatment of this pandemic and was able to increase the healing process with the help of appropriate photosensitizers by targeting the pathogen inside the patient's body.

covid-19 is nowadays a pandemic disease. It affects various aspects of human life including physical and mental health and also socio-economic situations. In this review, we attempt to present a brief selection of abundant published papers about pathogenesis, skin manifestations, treatment challenges in different conditions and prevention.

Background and Objectives Coronavirus disease 2019 (covid-19) which is caused by SARS-COV-2 has affected most parts of the world in a short period. Transfusion services are also affected during the emergence of a pandemic of this magnitude. Due to the widespread outbreak of SARS-COV-2, new guidelines have been adopted in blood transfusion centers. Considering the impact of the SARS-COV-2 pandemic on blood transfusion services, blood donation, blood safety, and the use of blood products as a treatment for covid-19 are addressed in this article. Materials and Methods In this review, keywords were searched in Science Direct, PubMed, and Scopus databases, and the sites of Nature Science, Elsevier, Cell, BMJ, Blood, Transfusion, and Lancet journals, and finally 99 articles were used. Results In this article, in addition to a brief review of patient blood management, blood safety, and donor safety during the covid-19 pandemic, the use of blood products as a treatment is considered. Conclusions Hospitals and blood centers have created new policies and guidelines to protect donors and blood supplies including adding new questions to the donor questionnaire and adopting new deferrals for covid-19 infection and vaccination. Although hyperimmune plasma (convalescent plasma) is proposed as a possible treatment, there are some contradictions in this field.