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.
How malaria is spread. The plasmodium parasite is spread by female Anopheles mosquitoes, which are known as 'night-biting' mosquitoes because they most commonly bite between dusk and dawn. If a mosquito bites a person already infected with malaria, it can also become infected and spread the parasite on to other people.here are many different types of plasmodium parasite, but only five types cause malaria in humans. These are: 1  Plasmodium falciparum â mainly found in Africa, it is the most common type of malaria parasite and is responsible for most malaria deaths worldwide.