CDC Warns: West Nile Threatens Health of Older Americans

Article excerpt

While news headlines focus on the deadly potential of Severe Acute Respiratory Syndrome, scientists at the Centers for Disease Control and Prevention (CDC) in Atlanta are reminding health providers in aging that with the advent of summer-and its surfeit of mosquitoes-the West Nile virus poses a rare but unmistakable threat to the health of Americans, especially elders. CDC experts discussed their concerns during a symposium at the 2003 Joint Conference of the National Council on the Aging and American Society on Aging (ASA) in Chicago in March. ASA also produced a new background paper on the disease that the organization developed in cooperation with CDC to promote media attention to this issue.

According to the ASA-CDC background paper, very few people get sick from the bite of infected mosquitoes, but among those who do, the biggest risk for severe cases of illness from the West Nile virus is among people age 50 or older. Elders who become infected with the virus stand the greatest chance of suffering severe illness, and even death. According to preliminary totals, more than 4,000 cases of West Nile virus infection occurred in 2002, resulting in about 250 deaths. All but 10 who died were people age 50 or older, and their median age was 78.


Older people should be concerned and should be careful about protecting themselves against the disease, but they should avoid panic. "Should they change their entire life? No. Should they modify their lifestyle slightly? Yes," stated Lyle Petersen, deputy director of the Division of Vector-Borne Infectious Diseases at CDC. The division has monitored the spread of the virus as it moved westward from New York, where the first cases appeared in 1999.

He indicated that older people with an active lifestyle, who are often outdoors for recreation or exercise, ironically have the greatest potential risk for contracting the West Nile virus. Prospective victims are vigorous people hiking in the woods, hunting and fishing, or spending happy hours in their gardens. "The older people the virus tends to infect are pretty healthy people," Petersen said.

Initially, mosquitoes get the virus when they feed on infected birds, which have the virus in their blood, then spread it when they bite animals and people. The virus itself is in the mosquito's salivary glands, and is transmitted when the insect bites victims to draw blood. In addition to humans, birds and even reptiles, the West Nile virus has infected cats, dogs, horses and many other mammals. There is no evidence that humans can get the West Niles virus from contact with these animals, and there are no indications that the disease can be contracted by those who eat game birds or other animals that might have been infected, say CDC scientists.

According to the agency, the virus apparently has been transmitted through blood transfusions in a few cases, and-in at least one instance-through organ donation, but these facts should not deter anyone from donating blood or getting blood transfusions. More than 4 million people a year receive blood or blood products, and the procedure is safe. As a precautionary measure, however, the CDC said doctors should notify local public-health departments of any cases in which patients show symptons of infection with the West Nile virus (possibly including headaches, body aches and fever, and, occasionally, a skin rash and swollen lymph nodes) within four weeks of receiving a blood transfusion or undergoing an organ transplant.


The reassuring news is that comparatively few mosquitoes are infected with the West Nile virus, and, even among people bitten by a virus-laden mosquito, 80% will show absolutely no symptoms of any ailment. One in five who are bitten, however, will get West Nile fever, according to the CDC.

Because the condition is so new to the United States, it often goes unidentified. Patients and their doctors often think West Nile fever symptoms indicate only a touch of the flu or some other common, nonthreatening ailment. …