The Littlest Plague : Long a Backpacker’s Woe, Giardia Has Hit the City, Causing Particular Concern for Kids in Day Care
For Yolanda Torres, an experienced manager who runs the day care program at Pasadena’s Huntington Memorial Hospital, it was like being a bus driver whose vehicle is broadsided by a drunk after 50 accident-free years.
On June 9, her 100-child program--where workers washed their hands twice, wore surgical gloves and used sterile paper table liners for diaper changing--was hit with an outbreak of a disease caused by a ubiquitous parasite with an unfamiliar, difficult-to-pronounce name.
The organism is giardia lamblia, and the disease it causes--characterized by diarrhea (often acute), abdominal cramps and pain, gas, bloating, loss of appetite, nausea, vomiting and low-grade fever--is called giardiasis.
Further symptomatic descriptions of it would go beyond the indelicate. It is enough to say giardia (pronounced gee-ARE-dee-uh ) does not kill. But in its most acute form, its victims may wish they were dead.
Becoming Urban Infection
Giardiasis can be treated, most of the time, with common prescription drugs. But its symptoms often can be mild and ambiguous, making it a diagnostic nightmare for doctors. Worse, the ailment, one of the most pervasive infections in human society, is increasingly being detected in urban areas and in day care centers.
About twice the size of a red blood cell and shaped like a stingray with eight tails called flagella, giardia lurks in the digestive tract, holding on to the intestinal lining with a suction-cup-like apparatus that takes up nearly all of the underside of its body.
It has looked and behaved this way probably for at least as long as human society has existed. It was first seen in 1681 by a developer of the microscope. By 1859, it had emerged as a recognized cause of diarrhea in children.
Organism in Bodies
At any one time, 1% to 3% of the people in Southern California--or any urban area--probably carry the organism in their bodies, said Dr. Jerrold Turner, a parasitic-disease expert at Harbor-UCLA Medical Center in Torrance. In high-risk populations, primarily recent immigrants from Southeast Asia and Central America, that rate may be as high as 15%.
Among children, Los Angeles County health officials estimate giardiasis develops into an acute symptomatic disease at a rate of 70 cases in every 100,000 children ages 1 to 4. For those ages 15 to 34, the acute disease develops in 10 to 15 of every 100,000 people.
But, almost as if giardia had retained an image consultant to make it seem upscale and exotic, the organism in the United States has acquired a terribly misleading reputation.
Even well-educated people believe giardia comes from contaminated mountain streams and is only a backpackers’ disease. If campers will just boil, filter or iodine-treat their water, this mistaken reasoning goes, giardia will never be a problem.
Giardia is a problem for campers. Several backpackers appear weekly at Centinela Mammoth Hospital in Mammoth Lakes sick enough with giardiasis to need urgent care, said Dr. Jack Bertman, an emergency physician, who noted, “We publicize it a great deal more in Mammoth.
“In mountain communities, we’re very tuned in to it (giardiasis). In the last 20 years, the organism has become very abundant.”
Besides Torres at Huntington Memorial, Elyssa Nelson, co-director of the day care center serving employees of the Jet Propulsion Laboratory in Pasadena, has also been forced to handle a giardia outbreak. At JPL, it occurred in summer of 1984; a quarter of the 100 children at the center developed acute symptoms.
The JPL case served as the first serious warning to the Los Angeles County Department of Health Services that day care centers had become a giardia hot bed.
“I’m a backpacker so I had heard of it,” Nelson said. “But it was relatively new to day care centers at the time.”
Huntington Outbreak Minor
In contrast to what happened at JPL, the Huntington outbreak, the county’s latest, has been minor. Only two children developed serious diarrhea and both recovered completely, Torres said, noting 13 other tots were found to carry the organism, though they did not have symptoms. No evidence was produced to show all the affected children acquired the organism from the same source.
But the recent Los Angeles outbreaks underscore how the tiny giardia organism can overcome safeguards in even well-run day care programs, said Dr. Stephen Waterman, chief of acute communicable disease control for the county health department.
In 1986, he said, there were two day care outbreaks; there were seven last year; the Huntington Memorial episode is the first outbreak in 1988.
Countywide, in the first four months of 1988, 339 cases of giardiasis were reported, down from 500 in the same period a year earlier when day care center outbreaks were more numerous than they have been this year.
Reported Cases Increased
State health officials say there are between 5,000 and 6,000 cases a year statewide--a figure that increased steadily from the 1980 total of 2,000 until 1984, when the incidence stabilized. (State health officials say the trend probably can be tied to reporting requirements imposed in 1980.)
Giardia, Turner said, is easy to contract. If just 10 of the microscopic organisms enter a person’s body, the disease can develop; if 100 of the parasites are present, the disease is unavoidable.
Prevention must be tailored to fight giardia’s chief means of transmission: oral contact with a fecally contaminated source, which allows the spread of live giardia or the organism in its dormant, protected cyst state.
Giardia has long been a human nuisance, spread mostly in the 1970s through contaminated water. But that “no longer is the most common source of infection,” said Dr. Dennis Juranek, an infectious disease expert at the U.S. government’s Centers for Disease Control in Atlanta.
Hit Day Care in Late ‘70s
“Around the end of the 1970s and beginning of the 1980s, the new entity of day care began to become apparent.”
Giardia’s favorite transmission route is an obvious problem anywhere there are large numbers of children in diapers. Children with diarrhea should be kept out of day care.
Though giardia can usually be treated with drugs--quinacrine (trade name: Atabrine), metronidazole (Flagyl) and furazolidone (Furoxone)--mild cases that go untreated or undiagnosed can be responsible for a childhood syndrome called failure to thrive, a complex of symptoms reflecting a lack of physical or mental development, Turner said.
In adults, mild and moderate untreated cases can turn into a form of chronic fatigue and low-grade gastrointestinal symptoms, he said, adding that adult victims of chronic giardiasis are “the most grateful patients when you come to that conclusion and treat them. The problem just reverses overnight.”
Drug Therapy Uncertain
Turner said there is evidence giardia is growing drug-resistant and some victims cannot be cured with commonly available drugs. Tinidazole--legally available in Mexico and Canada but not in the United States--is effective in some cases. But the economic potential of a giardia drug is so limited, tinidazole may never attract a drug firm willing to obtain U.S. Food and Drug Administration approval to market it, he said.
In the last decade, homosexual men have experienced giardia outbreaks, and a West Hollywood survey two years ago showed 20% of the gay men tested carried the parasite. But campaigns to limit the spread of AIDS have indirectly decreased the giardia threat, too, experts agree.
Giardia often has invaded municipal water supplies because it thrives in water that appears clear and because the organism is unaffected by chemicals like chlorine--an aspect first noted in 1976 when 128 people contracted the disease in Camas, Wash., where the water supply relied on local streams. An outbreak in Reno sickened 324 people in 1982.
Animals, particularly beaver and muskrat, have often been blamed for harboring giardia and spreading it into human water supplies. Several dozen species--including cats but not dogs--can host the parasite that affects humans, said Dr. Ernest Meyer, a giardia authority at the University of Oregon Health Sciences Center in Portland.
Infection Sequence Unknown
“You can’t tell their organisms from ours,” he said. “We don’t know which came first or whether we’re infecting them (through human-contaminated streams) and they’re paying us back. There are a lot of people who say, ‘Don’t give the beaver a bad rap.’ ”
As recently as 1986, 703 giardia cases occurred in Pittsfield, Mass., a city of more than 50,000. Water supplies can usually be made safe by installing filtration equipment to supplement other purification systems. Ironically, Pittsfield’s outbreak occurred as workers installed a filtration system, said Walter Jakubowski, a Cincinnati-based giardia expert with the U.S. Environmental Protection Agency.
In California, municipal water supply contamination has remained rare, with just two small outbreaks affecting 154 people since the EPA began tracking such events in the mid-1970s.
Nationally, between 1965 and 1985, 95 water-supply-related giardia outbreaks occurred, with the number doubling every five years or so in that period, Jakubowski said, noting the EPA hopes to have a draft by year’s end of new, tighter federal rules on filtration of public water supplies.
Organism Has Long Been Around
Giardia appeared on the list of reportable diseases in only eight states before 1980; now 38 states including California require that it be reported to public health officials.
“People have wondered if giardia is more common these days than it used to be. I don’t think there is any way to quantify it. It’s ubiquitous,” Meyer said. “It’s been with us all over the world, whether in civilized or uncivilized, developed or undeveloped countries. . . . It may have been here all the time, just unrecognized.”
The organism also can get out of control in swimming pools. A journal on infectious diseases reported this year on a 60-case outbreak among patrons of a hotel water slide in Winnipeg, Canada. Food-borne outbreaks are rare and are generally traced to food handlers who failed to wash their hands.
Concerned health officials say it is difficult to offer any more specific advice than the tip Torres and Nelson say day care centers have been told to heed: Wash your hands often and hope for the best.
Prevention Strategies Sought
The CDC hopes to develop prevention strategies, though the agency, other than recommending fastidious cleanliness, now has little to tell day care operators or anyone else concerned with ways to impede the disease’s spread, Juranek said.
