They're the most common cause of stomach bugs (gastroenteritis) in the UK. Each year, it's estimated that between 600,000 and 1 million people in the UK catch norovirus. The illness is sometimes called the winter vomiting bug because it's more common in winter. However, you can catch the virus at any time of the year.hey're the most common cause of stomach bugs (gastroenteritis) in the UK. Each year, it's estimated that between 600,000 and 1 million people in the UK catch norovirus. The illness is sometimes called the winter vomiting bug because it's more common in winter. However, you can catch the virus at any time of the year.
On the contrary, individuals who are carriers for the sickle cell disease (with one sickle gene and one normal hemoglobin gene, also known as sickle cell trait) have some protective advantage against malaria.
Melanin= provides some protection against the damaging effects of ultraviolet light. Langerhans cells= found in the epidermis, they alert the immune system to the presence of potentially harmful microbial invaders. Macrophages= found in the dermis, they phagocytize bacteria and viruses that manage to bypass the Langerhans cells of the epidermis.