Course of West Nile Infection Charted

Mar. 19 -- WEDNESDAY, March 18 (HealthDay News) -- Scientists in South Africa recently had the rare opportunity to follow the West Nile virus from initial infection through symptoms and recovery in a 29-year-old lab worker who had accidentally jabbed herself with an infected needle.

In particular, the researchers followed the trajectory of cytokines, a type of signaling molecule in the body, as the patient progressed through the illness.

"There are currently no specific treatments for neurological West Nile virus infections," said Marietjie Venter, head of the respiratory and emerging neurological virus program in the department of medical virology at the University of Pretoria in South Africa and co-author of a letter in the March 19 issue of the New England Journal of Medicine. "Cytokines may serve as potential targets for treatment," Venter said.

Another expert said the importance of the report lies more in the basic science knowledge it provides for West Nile, which has been endemic in North America since its first appearance in 1999.

"They were able to link the course of the infection to basic science," said Dr. Pascal James Imperato, dean and distinguished service professor at State University of New York (SUNY) Downstate Medical Center in New York City. "The interest here lies in the range of cytokines which were produced and the levels at which they were produced at different points of time."

People infected with West Nile, which is typically passed from birds to mosquitoes to humans, can experience a range of symptoms, from mild, flu-like aches and pains to life-threatening encephalitis (inflammation of the brain).

These researchers, in effect, had the opportunity to carry out a serendipitous controlled trial when the 29-year-old woman, who was HIV-negative, pricked herself with the needle.

The woman's symptoms began one week after the needle mishap and included, at first, backache and stiffness in the neck. This was soon followed by a mild fever and symptoms of meningoencephalitis (inflammation of the brain and surrounding membrane) such as severe headache, sensitivity to light and joint pain.