April 22, 2009

West Nile Virus and Lyme Disease


We live in Texas. How serious is the West Nile virus, and what are its symptoms?



The West Nile virus first caused an epidemic in the United States in 1999 in New York City. It is a virus spread to people by mosquitoes and can also infect animals and birds. Since 1999 the disease has spread across the country, and some 30,000 symptomatic cases have been reported. It is assumed that more than 1 million people have been infected, but not everyone has symptoms.
It’s estimated that 1 of every 150 cases will be symptomatic, so clearly not all cases are reported.
The virus typically causes inflammation of the brain or its lining membranes, called meninges—which is meningitis. About 5 to 7 percent of symptomatic cases may result in death.
The West Nile virus is being recognized as a much more formidable illness than was previously understood. About 50 percent of patients get encephalitis (brain inflammation); 30 percent get meningitis; 20 percent have an uncomplicated fever. Unfortunately, 60 percent experience continued problems with fatigue, weakness, depression, personality changes, memory deficits, and muscle weakness.
Recovery occurs in about 60 percent of the cases, but up to 40 percent continue with less than full recovery, and 60 percent of those with encephalitis experience persistent problems.
Depression plagues a third of the patients, and about 45 percent note personality changes with anger and irritability being prominent.
Obviously, this is a nasty infection that is better avoided. This means installing good screens on doors and windows to keep mosquitoes out of the house. Insect repellant can be very helpful, as can long sleeves and pants. As the virus settles into the bird population, it can be expected that the infection will become endemic.
It is likely that a vaccine will become available, as trials are currently underway. The extent of the disease within the U.S. will become apparent during the next few years, but to date, every state but Alaska and Maine have reported cases.                                                                 


Can Lyme disease be spread by mosquitoes?



Lyme disease is caused by bites from ticks, not mosquitoes. In North America it is caused exclusively by an organism called Borrelia burgdorferi, which is typically transmitted by the tiny tick that afflicts the white-tailed deer. In Europe, there are other Borrelia—B. afzelii and B. garinii, along with B. burgdorferi—that can cause Lyme disease. A nasty infection, it may cause a typical rash called erythema migrans, which looks like a target on the skin.
In addition, it can cause nerve and heart problems as well as arthritis. Fever, headache, lethargy, and depression are other symptoms. Delayed diagnosis, inadequate treatment, or resistance may result in a prolonged illness in which muscle pains, apathy, and loss of concentration may continue.
In the event long-term antibiotic therapy does not result in improvement, the term “post-Lyme disease syndrome” has been used.
Clearly, it is wise to use insect repellant on clothing and skin of the legs if walking in tall grass; and a careful inspection for ticks after possible exposure, with immediate removal of the tick, is advisable. Save the tick in some alcohol so the doctor can see it. But do not panic; not everyone who is bitten gets Lyme disease. Some estimate there is about a 1-in-40 chance. 


Send your questions to: Ask the Doctors, Adventist Review, 12501 Old Columbia Pike, Silver Spring, Maryland 20904. Or you may send your questions via e-mail to [email protected]. While this column is provided as a service to our readers, Drs. Landless and Handysides unfortunately cannot enter into personal and private communication with our readers. We recommend that you consult with your personal physician on all matters of your health.

Allan R. Handysides, M.B., Ch.B., FRCPC, FRCSC, FACOG, is director of the General Conference Health Ministries Department; Peter N. Landless, M.B., B.Ch., M.Med., F.C.P.(SA), F.A.C.C., is ICPA execu-
tive director and associate director of Health Ministries.