Intestinal parasites: the most common infections in the world, with about 1 billion roundworm, 900 million hookworm and 500 million whipworm infections. Giardia, a micro-organism passed in dirty drinking water, infects one in three people.
Diarrhoeal disease: 1.5 billion cases and 3 million deaths a year among children under five; a million adults die.
Acute respiratory infection (including the common cold): on average everyone has about two colds a year.
Vaccine-preventable disease: in 1989 there were 49 million cases of measles, 45.8 million of whooping cough, 1.5 million of tetanus and 190,000 of polio.
Sexually transmitted diseases: 250 million cases a year, including a million with HIV, the Aids virus.
Schistosomiasis (bilharzias): 200 million are infected with this tropical parasite.
Malaria: about 100 million cases a year in African countries south of the Sahara, and a million deaths. Five million cases annually elsewhere.
Tuberculosis: 8 million new cases a year, 3 million deaths.
Hepatitis: two in every five people with hepatitis B - more than 2 billion. One million deaths a year.
Statistics: WHOReuse content