Steve Quayle News Alerts

Sept. 5, 2002

The number of people infected with the West Nile virus has surpassed 850 and the death toll has hit 43, health officials reported Thursday. Meanwhile, medical detectives are investigating whether a Mississippi woman contracted the virus through a blood transfusion, the second suspected incident in which West Nile was transmitted through the U.S. blood supply.

THE WOMAN received 18 units of blood during an obstetrical procedure in July, said Dr. Anthony A. Marfin, a West Nile specialist at the Centers for Disease Control and Prevention. Four weeks after the operation, she was diagnosed with West Nile encephalitis, he said.

Marfin cautioned that the woman, who has since recovered, may have been infected by a mosquito, as other West Nile victims have, noting that she lived in a state with many cases of the disease and reported having numerous mosquito bites. But health officials were investigating the possibility that she contracted the virus through the blood transfusion, and blood products from donors to the patient were withdrawn from blood banks, the CDC said.

MORE CASES, DEATHS
The CDC reported that it had confirmed a total of 854 human cases as of Thursday, nearly 400 in the last week alone. Diagnosed cases have come from 28 states and the District of Columbia.

Most people who become infected never show symptoms, so there could be as many as 110,000 to 150,000 people in the United States with the virus who will never know it, Marfin said. That number is likely to grow in the coming weeks as West Nile peaks, but cases should drop off as the weather gets colder and disease-carrying mosquitoes disappear, officials said.

Forty-three people have died of West Nile this year, including a man who officials are virtually certain contracted the virus after receiving an organ transplant in Atlanta. Three others who received organs from the same Georgia woman also have West Nile.

Until now, human infection had been blamed solely on mosquito bites.

Authorities are trying to determine how the organ donor caught West Nile; they suspect that she was infected either by a mosquito bite or from a blood transfusion.

The woman had received blood from more than 60 people as doctors tried to save her after a severe car accident, and CDC investigators were collecting samples from each of the donors to check for traces of the virus. They have recalled the remaining blood from these donors and are working to track down and test about a dozen other people who received transfusions from the same donors.

The CDC was advising transplant doctors to be alert for West Nile in their patients, but there have been no changes in national blood or transplant policies.

The Food and Drug Administration issued an alert two weeks ago warning the nation’s blood banks of a theoretical risk of transmitting West Nile through blood transfusions. Now they have urged blood banks to pay particular attention to would-be donors, screening out anyone who is sick and may have West Nile.

But many people infected do not appear to be sick, and there is no blood screening test available now. So even if the disease does prove blood-borne, there is little more that can be done.

The West Nile virus is a mosquito-borne flavivirus common in Africa, West Asia and the Middle East. It was first seen in the eastern United States in the summer of 1999.Many people who are infected with West Nile virus experience no symptoms. Others may experience mild symptoms, such as low-grade fever, headache and body aches, skin rash or swollen lymph nodes, within three to 15 days. In some people, particularly the elderly, children or people with weak immune systems, the virus can cause encephalitis (inflammation of the brain tissue), which can result in permanent neurological damage and, in rare cases, death. Encephalitis symptoms include the rapid onset of severe headache, high fever, stiff neck, muscle weakness and coma. Some at-risk cities spray pesticides to reduce mosquito populations. In areas where the virus has been found, people should take the following precautions to avoid exposure to mosquitoes:

* From April to October, minimize time spent outdoors at dawn, dusk and in the early evening, when mosquitoes are most active.
* Wear long-sleeved shirts and long pants when outdoors.
* Apply insect repellent sparingly to exposed skin and clothing, according to manufacturer’s directions. Repellent may irritate the eyes and mouth so avoid applying it to the hands of children.
* Make sure that doors and windows having tight-fitting screens.
* Remove water-holding containers from your property, such as discarded tires, tin cans, ceramic pots and plastic containers to eliminate standing water, which serves as breeding grounds for mosquitoes.
* Change the water in bird baths at least once a week.
* Drain water from pool covers and keep pools and hot tubs cleaned and chlorinated.

“We’re obviously very concerned,” Eve Slater, assistant secretary for health at the Department of Health and Human Services, said Thursday. “Screening methods can’t be developed overnight.”

However, experts emphasized that the risk of contracting West Nile from blood was significantly lower than the risk of forgoing any procedure that would require a transfusion.

“If you need a transfusion, you’re very ill and need the blood. And the risk of transmission of West Nile is so remote at this point, as I understand it, that it should not be a deterrent,” said Dr. Robert Jones, chief executive of the New York Blood Center in Manhattan.

For each person who becomes severely ill, experts believe 30 more get mildly sick and 120 get infected but show no symptoms. It is possible that those healthy but infected people could transmit the virus to others.

In the most severe cases, West Nile causes a potentially fatal brain inflammation. Other patients get a flu-like illness, with fever, headache and muscle pains, that lasts two or three days.

West Nile, which emerged in the United States just three years ago, when it first appeared on this continent, has struck other countries for decades, from the tip of Africa up to Europe and throughout Asia. It is spread by mosquitoes, which are infected by birds and then infect people when they bite.

MOSQUITO-CONTROL GRANTS
Thursday, the House Energy and Commerce Committee approved legislation that would authorize $100 million in grants to communities for mosquito-control programs. The measure must compete with other programs for actual funds during the budget process.
Counting the cases
Too many communities have not have conducted assessments of the problem or prepared plans to control mosquitoes, said the committee’s chairman, Republican Billy Tauzin of Louisiana, the state hardest hit by West Nile. He said that just 18 of 64 Louisiana parishes had programs under way.

http://www.msnbc.com/news/788671.asp