Malaria parasites found in lymph nodes

Jan 23, 2006, 18:20 GMT


PARIS, France (UPI) -- French researchers say they`ve discovered the malaria parasite Plasmodium not only develops in the liver, it also has been found developing in lymph nodes.

In the first quantitative, real-time imaging study of Plasmodium through mammalian tissue, researchers at the Pasteur Institute in Paris found parasites developing in the lymph nodes of research mice.When a mosquito infected with Plasmodium bites a mammal, the immature parasites travel to the animal`s liver, which, until now, scientists thought was the only place they could develop, Menard said.
But the researchers found about 25 percent of the parasites injected by mosquito bites ended up in lymph nodes close to the site of the bite. No parasites appeared in more distant lymph nodes.

Within about four hours of the mosquito bite, many of the lymph-node parasites appeared degraded and were also seen interacting with key mammalian immune cells, suggesting the immune cells were destroying them.

Menard and colleagues report their findings in the February issue of the journal Nature Medicine, available online.