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.
The CD4 cells (also called T-helper cells) are an important part of the immune system because they fight germs and infections. HIV attacks CD4 cells and reduces the number of them in your body. Without treatment, HIV slowly weakens the immune system, making it harder for your body to fight off illness or infection.