West Nile Virus Found In Denver's Donated Blood
Bonfils Finds Four Positive Cases In Past 15 Days
POSTED: 6:15 a.m. MDT July 16, 2003
UPDATED: 11:27 a.m. MDT July 16, 2003
DENVER -- Four people who've donated blood to the Bonfils Blood Center in Denver in the past 15 days have tested positive for West Nile virus.
Since July 1, when a new test was implemented to screen for the mosquito-borne disease, Bonfils has tested nearly 8,000 units of blood and found four positive cases, spokeswoman Jessica Maitland said. The blood was quarantined and not given to any patients.
Two cases were reported Friday and two on Monday. Bonfils said none of the donors who tested positive had any flulike symptoms that are associated with West Nile virus.
Bonfils is retesting the blood samples to make sure there are no false positives.
"When you develop a test that is that sensitive, you're going to have false positives because there is a certain amount of cross-reactivity in all of these tests. So we expect to see false positives just like we see false HIV positives, Hepatitis C and other things," said William Dickey, president of Bonfils Blood Center.
The process to retest the samples could take several weeks. The four donors are letting doctors draw blood to see if they have developed antibodies to the virus.
The head of communicable diseases for the state Department of
Public Health and Environment said he would be surprised if each of
the four donors is confirmed to have been infected. He aid it's very unusual that there would be such a high number of human cases all at once.
Eighty percent of people infected with the virus do not develop any symptoms. It takes three to 14 days for symptoms to appear after a person is bitten by an infected mosquito. And about one in 150 people infected will develop severe illness with high fever, stupor, and convulsions or may die. Symptoms of the illness can include fever, headache and vomiting and symptoms typically last a few days and can clear up on their own.
Less than 1 percent of people who are bitten by mosquitoes develop any symptoms of the disease. But the risk increases the more time you spend outdoors. Last year, the first year that West Nile virus was found in Colorado, 14 residents tested positive for the virus. All recovered.
Meanwhile, Bonfils said the blood supply in use right now is safe.
So far this year, West Nile virus has been confirmed in 15 Colorado counties, with infections reported only in horses and birds.
Since July 1, when a new test was implemented to screen for the mosquito-borne disease, Bonfils has tested nearly 8,000 units of blood and found four positive cases, spokeswoman Jessica Maitland said. The blood was quarantined and not given to any patients.
Two cases were reported Friday and two on Monday. Bonfils said none of the donors who tested positive had any flulike symptoms that are associated with West Nile virus.
Bonfils is retesting the blood samples to make sure there are no false positives.
"When you develop a test that is that sensitive, you're going to have false positives because there is a certain amount of cross-reactivity in all of these tests. So we expect to see false positives just like we see false HIV positives, Hepatitis C and other things," said William Dickey, president of Bonfils Blood Center.
 INTERACTIVE  All About West Nile Larvicides May Help Control Virus Discuss: Virus Overblown? Worried About West Nile Virus? Preventive Measures?
RESOURCES  Colorado Hotline:CO-HELP or 877-462-2911  Fight the Bite ColoradoSymptomsCDCCases By County General InfoInsecticide TipsHorse Info |
Copyright 2003 by TheDenverChannel.com. The Associated Press contributed to this report. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
