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Making Us Gasp Researchers Find Shocking Number Of Cockroaches, Surprising Link To Childhood Asthma

Mon., June 10, 1996

Five years ago, a team of researchers set out to determine why asthma is such a severe urban health problem.

They penetrated the worst neighborhoods in seven big cities and spent $17 million vacuuming up dust, administering allergy tests and poring over the medical records of poor children.

In a few months, their first formal reports will hit the medical journals; perhaps 50 papers will be published. But in the end, the piles of data largely boil down to a single nasty word:


The surprising result is likely, in time, to change the way the medical world thinks about childhood asthma. Already, those in charge of the study view these bugs as a serious public health hazard.

Dr. Richard Evans, an asthma specialist at Children’s Memorial Hospital in Chicago, hardly paused when asked to name the most urgent step to prevent the problem he treats every day.

“The one thing I would do is help people eliminate cockroaches.” Certainly, other problems besides roaches contribute to asthma among the poor - decrepit housing, the so-so quality of doctoring at some Medicaid clinics, fragmented families.

Furthermore, asthma is hardly restricted to the poor; it is the most common chronic illness of childhood.

Yet, the disease takes its greatest toll in the nation’s poorest locales. In New York City, for instance, 8.6 percent of children in the Bronx have asthma, double the rate for urban residents nationally. Seeing people on street corners taking puffs from asthma inhalers is commonplace.

Children’s asthma usually is caused by an allergic reaction to a substance that makes them wheeze, called an antigen. And of all the possible asthma-provoking materials youngsters encounter in homes, cockroach antigens appear to be the most powerful.

Identifying the antigens in poor children’s asthma was a top goal of the National Cooperative Inner City Asthma Study.

At the start, the experts assumed the culprit would turn out to be the dust mite, the microscopic bug that, along with cats, is the leading cause of asthma in the suburbs.

But no. After testing 1,528 children under age 10 and visiting half their homes, the researchers discovered the leading antigen by far was proteins in the droppings and carcasses of Blattella germanica, the German cockroach.

It turned out that 38 percent of the asthmatic youngsters were allergic to roaches. But even more surprising to the doctors involved were the staggering quantities of cockroach crud in these apartments.

A hint of wonder, even horror, tinges their voices when they talk about where they found cockroach residue.

Levels often were sky-high in kitchens, of course, and bathrooms. But the stuff was everywhere in the apartments - even the beds.

“There were huge levels of cockroach antigens, much higher than has ever been reported,” said Dr. Peyton Eggleston of Johns Hopkins University, one of the researchers. “Almost every house had detectable levels.”

This is not much of a surprise to Keith LaRue, an exterminator for American Pest Management of Tacoma Park, Md., who helped gather samples for the study.

One recent beautiful spring morning, he made his rounds through some of the most depressing neighborhoods in the nation’s capital.

His first stop was on Martin Luther King Boulevard in southwest Washington, at a dark one-bedroom basement apartment in a big brick complex. Stomach-churning stink filled the dead air.

“What you smell,” he said simply, “is roach.”

The kitchen walls were speckled brown with cockroach droppings. LaRue opened a cupboard and lifted a frying pan. Four or five roaches darted away.

More ran over the plates, around the cereal boxes, under the refrigerator, into the full garbage can, up the walls and into the crack between the door trim and the ceiling. On the floor were too many to count - live ones, dead ones. The floor hadn’t been swept in a long time.

It was 9:30 a.m. In the bedroom, a young woman and her two babies slept on one of the three beds. None of them stirred while LaRue did his work.

Meanwhile, in the living room, two 50-ish men watched TV from the sofas where they had spent the night.

John and his friend Joseph offered a few details about the woman sleeping in the next room: She’s Tina, she’s 22 and she has asthma.

LaRue guessed the apartment was home to maybe 5,000 German cockroaches.

“This is typical in this area,” he said.

LaRue may have underestimated. Rick Brenner, a cockroach expert at the U.S. Department of Agriculture, counted the German cockroaches in about 1,000 low-income apartments in Gainesville, Fla. The median number per unit - 13,000.

The levels of infestation are particularly important. Dr. Alkis Togias of Johns Hopkins, who is looking at a cross section of teenage asthma victims in Baltimore, found that the more cockroaches in victims’ homes, the greater the teens’ chance of being allergic to roaches and the more severe their asthma.

Half of the poor asthma victims in his study were allergic to roaches compared with just 10 percent of adolescents from upper-income families.

“As we have built more energy-efficient structures, humans now breathe less fresh air than they ever have,” the USDA’s Brenner said.

With little air exchange, antigens from bugs, molds, cats and dogs build up inside houses.

Wall-to-wall carpeting, another feature of new construction, also grows heavy with trapped antigens, even in clean-looking homes.

MEMO: This sidebar appeared with the story: 13,000 PER APARTMENT A count of the German cockroaches in about 1,000 low-income apartments in Gainesville, Fla., showed the median number per unit was 13,000.

This sidebar appeared with the story: 13,000 PER APARTMENT A count of the German cockroaches in about 1,000 low-income apartments in Gainesville, Fla., showed the median number per unit was 13,000.

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