Good news for virus-ridden area residents: this year's local flu outbreak apparently peaked in mid-February, and in the last two weeks the number of cases reported from hospitals, clinics and nursing homes has begun to decrease.
Local health authorities said the current influenza outbreak already seems worse than the last few seasons, and bumper crops of other seasonal respiratory and gastrointestinal viruses have added to the toll.
Locally and nationally, the strains of influenza virus producing most of this winter's illness are Influenza A, type H3N2, the type most often responsible for severe outbreaks and deaths of elderly people and others with chronic illnesses.
The flu season is likely to last at least through March, and it is still too early to say whether its impact nationally will be worse than outbreaks of previous years, said Dr. Noreen Hynes, an epidemiologist with the Centers for Disease Control.
"The season is still relatively young," she said. It "got rolling later than last season."
The last outbreak of the H3N2 type of influenza occurred in the winter of 1984-85 and caused 58,000 deaths, mostly among elderly and chronically ill residents of the United States, Hynes said. This year's outbreak could have a similar impact, particularly since 90 percent of the virus samples isolated by the medical researchers in Atlanta belong to two strains, known as the Sichuan and Victoria strains, that differ substantially from those in this year's flu vaccine.
Hynes said this meant that the vaccine, while it will probably still help prevent a severe case of flu, may not have provided as much protection as usual.
Although health authorities cannot count influenza cases precisely, there are suggestions that in the Washington area, the outbreak appears to be abating.
At the pediatric ambulatory center at Children's Hospital, children with high fevers and coughs swelled the daily patient count by 50 percent from late January through mid-February. But for the last two weeks, the center has been "a good bit quieter," said Dr. George Cohen, its medical director. A virologist at the hospital said positive cultures of the H3N2 virus from patient specimens had also decreased in the last two weeks.
At Potomac Electric Power Co., the number of employees staying home because of illness was well above last year's figures during the first three weeks of February, but in the last week the absence rate has been similar to last year's, said spokeswoman Nancy Moses.
Doctors at student health centers at several universities in Washington are also reporting fewer patients with fever, cough and muscle aches, said Martin E. Levy, administrator of preventive health services for the District.
Virginia was one of eight states still reporting widespread cases of flu to the Centers for Disease Control last week, Hynes said.
In Maryland the flu outbreak appears to be abating, said Dr. Sam Shekar, a CDC health officer at the state health department. "It hit us late and it hit us hard," he said. Fifty nursing homes in the state had reported outbreaks, half of them in the Washington metropolitan area, he said.
Cohen said influenza typically produces fever that lasts for a week or more, along with headaches, muscle aches, pain upon moving the eyes and a severe cough and runny nose. "Big kids and adults will often feel really washed out for another week beyond that," he said. He said he advised patients to drink fluids and take over-the-counter painkillers other than aspirin to control fever, since taking aspirin for influenza has been associated with Reye's syndrome, a serious liver disorder.