Your chances of having long-term effects as a result of West Nile Virus (WNV) infection are the same, regardless of whether your infection was mild or more serious, say researchers from the University of North Dakota School of Medicine and Health Science. The most common long-term effects are depression, tremors, fatigue, memory problems, extremity weakness, word-finding difficulty and headaches.

Since WNV arrived in North America in 1999, it has become the most common arboviral infection in the continent. Before this study, very little was known about the long term effects of WNV infection.

(Arboviral = Any virus transmitted by arthropods, such as mosquitoes and ticks, that can cause encephalitis, yellow fever and dengue)

You can read about this new study in Clinical Infectious Diseases, September 15 issue.

The researchers examined 49 patients who had been infected with WNV 13 months after they had been diagnosed. Some had had West Nile Virus fever (mild form) while others had developed encephalitis and meningitis.

The researchers tested the patients’ quality of life, functional ability, level of fatigue, level of depression, and cognitive function.

The researchers found that there appeared to be a substantial amount of ongoing symptoms, both among those who had been diagnosed with West Nile fever as well as those who had had more serious diseases.

24 (49%) of the patients went on to have long term effects, regardless of the severity of their disease, said the scientists. One quarter of them went on to have moderate to severe depression, over four fifths experienced fatigue, and one fifth had tremors.

Dr. Paul Carson, team leader, said he hoped the study may raise awereness that WNV poses a substantial public health threat.

Long-Term Clinical and Neuropsychological Outcomes of West Nile Virus Infection
Paul J. Carson, Patrick Konewko, Kimberly S. Wold, Paul Mariani, Sunil Goli, Paula Bergloff, and Ross D. Crosby
Clinical Infectious Diseases 2006;43:723-730
Click Here To View Abstract

Written by: Christian Nordqvist
Editor: Medical News Today