Читать книгу Parasitology - Alan Gunn - Страница 77

This species has a worldwide distribution, but it is not common anywhere and infections are normally relatively benign. Natural infections are common in chimpanzees, but these seldom live near human dwellings, and they are probably not an important reservoir of infection. Humans and chimpanzees both experience latent P. malariae infections that persist for many years. Unlike P. vivax and P. ovale, the sudden occurrence of malarial symptoms after a period of good health is not a result of hypnozoite activation. Instead, the parasite persists within the blood for years, possibly even for life, at a very low parasitaemia and it is only when some change in the immune status of the host occurs that the numbers increase sufficient to cause fever. Unlike P. vivax and P. ovale, the merozoites of P. malariae preferentially invade older red blood cells.