About one-third of the human population is infected with a parasite called Toxoplasma gondii, but most of them don't know it. Though Toxoplasma causes no symptoms in most people, it can be harmful to individuals with suppressed immune systems, and to fetuses whose mothers become infected during pregnancy. Particularly dangerous strains, found mainly in South America, are the leading cause of blindness in Brazil. Toxoplasma is one of the very few parasites that can infect nearly any warm-blooded animal. Its spores are found in dirt and easily infect farm animals such as cows, sheep, pigs and chickens. Humans can be infected by eating undercooked meat or unwashed vegetables. Read more
Humans may have originally caught malaria from gorillas, scientists say. Until now, it was thought that the human malaria parasite split off from a chimpanzee parasite when humans and chimpanzees last had a common ancestor. But researchers from the US, three African countries, and Europe have examined malaria parasites in great ape faeces. They found the DNA from western gorilla parasites was the most similar to human parasites. Read more
Cat-lovers may be more neurotic than other people as a result of a feline parasite that could ultimately also be responsible for international cultural differences, according to a radical theory published today.
More than a quarter of the world's population - ranging from about seven per cent of the UK population to almost 70 per cent in Brazil - is infected with Toxoplasma -gondii, a relative of the malaria bug, which also infects rats, giving them a suicidal attraction to cats.