Introduction respiratory diseases

There are different types of biological agents such as viruses, bacteria, fungi, and other microorganisms which could be able to have a direct effect on human health.  Among them, inhalation viruses are more important because of their rapid and sometimes uncontrollable transmission. Some of them, like SARS and MERS, became a threat to human health in recent decades. (1)

Nowadays, a virus named Covide-19 is causing the infection of more than 229 million people and more than 4.7 million deaths in the world (2). The speed of the outbreak and the number of cases has prompted the World Health Organization to announce an epidemic situation. At the same time, the different studies on the prevention methods and fabrication of the medical solutions have been evaluated. But, production of the vaccine and medical drugs takes time and needs a complete study on their effects.

Why do we need to wear a face mask?