Chicago Tribune (CT) - SUNDAY, April 21, 1996 Edition: CHICAGOLAND FINAL Section: NEWS Page: 1 Word Count: 2,277
Paul Salopek, Tribune Staff Writer.

Bringe's peaceful street, a skate-boarder's dream, winds up a hill overlooking the sky-colored currents of the Mississippi River. The lawns are flawless. The corner Kwik Trip store boasts FedEx service for the neighborhood professionals. And as for the whining bugs--well, they just came with the woodsy turf of her subdivision, a bedroom community for the nearby city of La Crosse, Wis.

But then, last summer, a hungry mosquito bored into Bringe's 10-year-old son Jonathan. An exotic virus in the insect's saliva--most likely picked up from local chipmunks or squirrels--invaded his bloodstream. And the disease began attacking his nervous system.

"The doctors didn't know what it was--they told us it was a flu and to just wait it out," said Bringe, a school psychologist. "He had chills. He dehydrated. He burned up with fever for four days."

On the fifth day, specialists finally pegged the symptoms to La Crosse encephalitis, a disease rare in humans that leaves half of its victims brain damaged. The mosquitoes that carry the virus breed in tree holes in the moist hollows of limestone bluffs--prime real estate for the new housing developments sprouting around La Crosse.

Though Jonathan recovered, the Bringes, like thousands of otherwise healthy families before them, have joined the shaken ranks of Americans falling ill--and sometimes dying--in one of the nation's unlikeliest hot zones of emerging disease: the crab grass jungles of suburbia.

Just as the deadly Ebola virus erupted from distant Third World rain forests to infect encroaching villagers, medical experts now warn that the same phenomenon--the crush of humanity pushing into natural habitats--is spawning a bestiary of similar, if less lethal, scourges at the expanding edges of U.S. cities.

Subdivisions and ranchettes chewing into America's forests, farmland and deserts are entangling the nation's suburbanites--some 100 million people, a number that has tripled since World War II--in the life cycles of germs that normally infect local deer, rodent or bird populations, experts say. The link between animals and humans can be anything as seemingly innocuous as mosquitoes, ticks, or fleas--or even airborne dust.

La Crosse encephalitis, the granddaddy of suburban plagues, was discovered in the 1960s and has burned through hundreds of households in the Upper Midwest. Rocky Mountain spotted fever--a tick-borne disease that made headlines in the 1970s--still strikes about 500 people every year. And Lyme disease--also carried by ticks--is rapidly becoming pandemic, its rashes, fevers and joint inflammations sickening at least 13,000 victims annually in 44 states.

More worrisome, however, are newer ailments, some of them fatal, that are felling humans in the epidemiological equivalent of drive-by shootings--picking off a few victims at a time before quietly subsiding into the landscape.

"Suburbia is our version of pushing those pan-African highways into the rain forest and running into unhappy things like Ebola or the HIV virus"--both diseases suspected to have been transmitted from animals to humans, said John Flaherty, an infectious disease expert at the University of Illinois at Chicago who tracks Lyme outbreaks in the Midwest. "I have no doubt whatsoever that we'll continue to see new things pop up. It's the penalty of getting closer to nature."

Others see the issue from the opposite end of the microscope.

"Look at it this way," said Roger Nasci, a mosquito expert with the U.S. Centers for Disease Control and Prevention, an agency that monitors emerging health threats. "It's not so much a problem of spreading disease as of spreading people. The real outbreak in this country is a people outbreak."

Either way, the diseases leaping the species barrier and infecting the burgeoning numbers of lawnmower-pushing Homo sapiens in their midst seem to be increasing in both variety and bite.

Ehrlichiosis, identified only in the early 1990s, infects humans through the same deer tick that transmits Lyme. Its health effects, however, are far more severe. Carried harmlessly in the systems of forest mice or deer, ehrlichiosis destroys white blood cells in humans, thus ravaging the victims' immune systems. Though still relatively rare, one East Coast strain has afflicted 400 people. Another strain, with its epicenter in the Upper Midwest, has sickened 200 and killed four--mainly, doctors say, because sufferers mistook their summer feverishness for flu and put off taking life-saving antibiotics until too late.

"The reason nobody has real solid numbers on these diseases is that few people even recognize them," said David Walker, an infectious disease expert at the University of Texas at Galveston who is stalking a mysterious new Lyme-like malady in the South. "Most of these things won't kill you unless you let them--they're basically testing out humans as hosts, and fortunately the fit still isn't perfect."

One mystery germ that did fit, however, almost killed Cindy Barry, of Annapolis, Md., within hours.

Barry, a 44-year-old homemaker and free-lance journalist, was playing Frisbee one sunny morning last April when she began feeling listless. Two days later, she lay in hospital quarantine, her immune system crippled by what doctors believe was a tick-borne disease: She and her family had recently moved into a home on a wooded, two-acre lot frequented by deer and foxes. Standard tests, though, turned up none of the usual suspects.

"Who knows what's in those woods," said Barry, who recovered after being pumped with massive doses of antibiotics. "All I know is that it knocked me so low that even imminent death didn't seem very frightening."

Scientists like Walker point out that suburban plagues--especially those in the Northeast and Midwest--can be as much the product of unbalanced ecosystems as the housing tracts that push into them.

Reforestation of old farmland and a lack of predators, for example, have caused disease-carrying deer and mice populations to soar to unnatural levels.

In Wisconsin, pathologists say the advance of both Lyme and ehrlichiosis can be tracked southward with expanding deer herds, which often move along riverbanks. Yet Illinois, where white tail deer populations have mushroomed over the past century from 1,000 to 600,000 animals, has largely escaped suburban infections. The reason: The woody outskirts of both Milwaukee and Chicago, potentially ideal incubators for microbes, so far lack the infamous Ixodes tick implicated in human transmission.

"It's really only a matter of time before it arrives," said Steve Callister, a researcher on emerging diseases with the Gundersen Medical Foundation in La Crosse. "We already know that more than a hundred species of birds carry the infected ticks, so you could say these diseases are, in a literal sense, spreading through the air."

In the West, where cities like Phoenix are gobbling up an acre of raw desert every hour, suburban homesteaders face a different horde of infectious threats.

The most famous, a lethal airborne hantavirus discovered in 1993 in the fecal matter of mice on a Navajo Indian reservation, has so far made only tentative incursions into the Southwest's booming suburbs. Likewise, flea-transmitted bubonic plague, introduced to San Francisco from the Orient a century ago and now pulsing eastward through the desert's mice, rock squirrel and prairie dog populations, has barely probed the diffuse edges of Sun Belt cities, sweeping handfuls of baffled victims to their deaths.

Ironically, the city dwellers who succumb to these largely rural diseases are often their own worst enemies.

"People out here like to build ornamental rock walls around their homes--perfect rock squirrel habitat," said New Mexico state epidemiologist Mark Sewell, whose office logs some half-dozen plague cases every year. In fast-growing Santa Fe, Sewell said, the disease hits only the affluent neighborhoods where adobe mansions jut into fashionably rural settings--and plague-infected zones.

"This is probably the only city in America where dirt roads are a status symbol," Sewell said.

One of the stranger twists in the story of suburban diseases is that many of these "new" ailments aren't new at all.

Though some pathogens, like recent strains of hantavirus, are probably preying on humans for the first time, others no doubt struck down pioneers who settled the same cities where suburbanites now seek out ersatz, semi-rural lifestyles.

The potentially lethal soil fungus that triggers Valley Fever in California, for example, has been recognized by farmers--and largely forgotten by everyone else--for at least a century. Public concern over the disease flared only after people began dying in the swelling outskirts of cities such as Bakersfield. Fungal spores kicked up by California's massive construction booms, droughts and even earthquakes have killed scores of Central Valley suburbanites in the past four years.

"I thought I was immune because I'm a native," said Lori Gutierrez, 23, a nursing student who contracted Valley Fever last year in one of Bakersfield's newer subdivisions. A biopsy from a lump on her neck showed that the fungus had started multiplying in her lymph nodes. After a year of agonizing drug treatments, she only now feels energetic enough to stay awake past 7 p.m.

"I guess we're paranoid now," Gutierrez said. "My mother closes all the windows when the dust blows up." Those windows frame a banal snapshot of the front line between Bakersfield's two most successful organisms: tidy, shingled houses facing off against a dried-up and possibly fungus-infected orchard.

A host of other diseases, meanwhile, continues to simmer just beyond the last stoplights and off-ramps of inner-city America.

Fleas infected with murine typhus, a grievous sickness usually associated with Third World squalor, have been found on possums roaming the tony outskirts of Los Angeles. Rabies is advancing up the East Coast in infected raccoons. And Equine encephalitis, which has a 50 percent fatality rate, strikes a handful of people every year, especially those whose houses nudge into marshy habitats from Florida to Massachusetts.

But aside from a recent Centers for Disease Control and Prevention plan to establish regional offices in California, Oregon, Minnesota and Connecticut to monitor a broad array of emerging diseases, there are few concerted efforts to study the ultimate perils of living the good life in the zone where city and country meet. Indeed, for many national health officials, the re-emergence of traditional inner-city ills such as tuberculosis far eclipses the threat of many back-yard diseases.

As a result, most local health departments deal with their suburban-type ills piecemeal.

"We plug up tree holes with insulating cement and pick up old tires--both places where mosquitoes breed," said Dave Geskey, a La Crosse County health official who oversees the encephalitis abatement program in Bobbie Bringe's riverside neighborhood. Local researchers are also laying mouse traps in the woods to monitor the southward march of ehrlichiosis from infected forests to the north.

Doris Lien lives in that bucolic northern hot zone.

Though not a suburbanite--home is a family farm 35 miles north of La Crosse and its satellite bedroom communities--she is thinking of becoming one. Last June a tick feeding in the crook of her right arm injected her with ehrlichiosis. Chauffeured by a panicky daughter, she staggered into the La Crosse hospital verging on renal failure and burning with a 106-degree fever. The Midwest's newest emerging disease had wiped out her body's defenses.

"I hate to give up my countryside, but I've already had Lyme twice before catching ehrlichiosis," 71-year-old Lien said as she walked through the deer droppings speckling her pine-shaded yard. "I'm looking into one of those senior houses they're building in town."

Lien said there would be no trouble finding buyers for her farm. Urban folks were already scouting the surrounding landscape of rotting barns, fallow cornfields and infected deer. A family of city slickers from Milwaukee, she noted, just moved in over the hill.

CAPTION: PHOTO (color): Steve Callister, a researcher on emerging diseases, studies ticks, which carry such afflictions as Rocky Mountain spotted fever. He works at the Gundersen Medical Foundation in La Crosse, Wis.

PHOTO (color): Bobbie Bringe's son Jonathan has recovered from his bout with La Crosse encephalitis, a disease that leaves many victims brain-damaged.

PHOTO (color): These ticks aren't a threat, but Steve Callister says it's "only a matter of time before (Lyme disease) arrives" in the Chicago area.

PHOTO (color): Virus-carrying mosquitoes breed in tree holes in the moist hollows of limestone bluffs--prime real estate around La Crosse, Wis. Tribune photo by Nuccio DiNuzzo.

GRAPHIC (color): Symptoms serve as road markers for emerging diseases. As people move away from urban areas and settle near forests, farmlands and deserts, the risk of being exposed to diseases that are carried by insects and animals increases. Nationally, Lyme disease has touched nearly every state while others have been restricted to several regions.

MOSQUITO-BORNE La Crosse encephalitis. The virus is transmitted through a bite of an infected mosquito.

RODENT-BORNE Bubonic and pneumonic plague.

Disease are spread by bites from fleas of rodents and through animal scratches.

TICK-BORNE Rocky Mountain spotted fever

It is caused by an organism transmitted to humans by the bite of an infected tick.

Lyme disease

Lyme disease is a bacterial infection transmitted by tick bites.

Ehrflichiosis

Two strains of disease caused by a bacteria carried by the same tick that transmits Lyme disease.

Sources: Emerging Infections by the Institute of Medicine; Centers for Disease Control and Prevention; American Medical Association Encyclopedia of Medicine; New York State Department of Health; Lyme Disease Network; Lyme Information Resouces. Chicago Tribune.

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