Epidemiologic Notes and Reports Gastrointestinal Illness among Scuba
Divers -- New York City


In July 1982, an outbreak of gastrointestinal illness occurred among New
York City's Police and Fire Departments' scuba divers following dives in
sewage-contaminated waters. Although the causes of illness in many divers
were not identified, gastrointestinal parasites were found in 12 divers.

The Fire Department developed a scuba diving program in early 1982 to train
40 firefighters in two rescue companies to respond to pier fires and
water-related emergencies. In July 1982, one company trained primarily along
the Hudson River at 47th Street and the other mainly at the Brooklyn Navy
Yard. The Police Department diving team, which has been in operation since
the mid-1960s with five divers, expanded to 16 divers in January 1982.
Besides responding to water-related emergencies, police divers explore river
beds for evidence and help recover lost or stolen property.

The divers generally use standard scuba masks and wet suits. Despite this
protective gear, they report ingesting small quantities of polluted water
while swimming at the surface or while using mouthpieces that have dangled
in the water before use.

A questionnaire survey of 55 of the Police and Fire Departments' divers was
administered in July 1982. Divers ranged in age from 21 to 52 years (mean
35.5 years). All were male. Approximately 95% were white and the others
black or Hispanic. The survey revealed 21 cases of recent or current
gastrointestinal illness, defined as 2 or more days of any of the following:
(1) diarrhea (watery stool), (2) crampy abdominal pain, or (3) change in
stool consistency. Three cases developed in the spring of 1982, and the
remaining 18 cases in July 1982.

Twenty symptomatic divers had stools cultured for bacterial pathogens, and
all 55 divers had purged stools examined for parasites. No specimens were
obtained for viral studies. One bacterial culture was positive for
Campylobacter. The purged stool examinations revealed 12 cases of
gastrointestinal parasites--five of Entamoeba histolytica and seven of
Giardia lamblia.

To determine if diving in polluted water was an important risk factor for
gastrointestinal illness and parasitic infection, investigators questioned
and examined a comparison group of 116 nondiving firefighters. Study
participants submitted purged stool specimens. The incidence of
gastrointestinal illness in July 1982 among the nondivers was estimated by
reviewing sick-leave records.

During July, the divers had developed gastrointestinal illness more than
four times as frequently as the nondiving firefighters. When symptomatic
firefighters were questioned about possible common sources of exposure, such
as weddings, picnics, camping trips, or other group activities, none except
scuba diving was identified. Neither travel nor sexual orientation, two
additional risk factors for parasites, differed among divers with parasites,
uninfected divers, and nondiving firefighters.

Twenty-three nondiving firefighters had purged stools examined for
parasites; none had G. lamblia or E. histolytica.

At the Fire Department training sites along the Hudson and East Rivers, the
New York City Department of Health tested the water for total coliforms,
pathogenic bacteria (Salmonella, Shigella, Campylobacter, and Yersinia) and
parasites. Relatively few pathogens were found in these highly polluted
waters. However, examination of river water utilizing a high-volume water
filter revealed numerous parasites including G. lamblia and E.
histolytica-like cysts. Reported by A Goodman, MD, S Schultz, MD, E Bell, E
Gumbs, MD, S Friedman, MD, New York City Dept of Health, C Robinson, MD, New
York City Police Dept, C Jones, MD, New York City Fire Dept; C Hibler, PhD,
Dept of Pathology, Colorado State University.

Editorial Note
Editorial Note: In recent years, gastrointestinal illness has been reported
to be associated with swimming in polluted water (1). The causes of these
infections have been somewhat obscure. In some cases, symptoms were probably
caused by viruses; in others, bacterial agents, such as Shigella, have been
isolated. The majority of cases, however, have remained undiagnosed.

More than 188,000,000 gallons of raw sewage are discharged daily into the
Hudson and East Rivers of New York City. Swimming is limited by the
Department of Health to beaches monitored regularly for fecal contamination;
thus, swimming in New York City's coastal waters has never been considered
an important risk factor for illness.

The results of this investigation provide strong evidence that scuba diving
in sewage-contaminated water is associated with gastrointestinal illness.
The data suggest that parasites are an important cause of illness and that
the major health hazard arises from ingesting sewage-contaminted water.
Police and Fire Department scuba divers now practice in waters designated
acceptable by the Department of Health.

Advanced diving equipment, such as high-pressure masks, wireless radio
devices, and dry suits, should be used to minimize exposure; a recent study
of various types of diving suits found that a dry suit in combination with a
full-face mask, afforded the best protection against microbial contamination
(2). The National Oceanic and Atmospheric Administration is continuing this
study.

Routine health surveillance of divers also may minimize the consequences of
diving in contaminated waters. Divers should be questioned as to the nature
of any illness requiring absence from work. Informed police and fire health
officials could then appropriately advise the divers' personal physicians as
to the possibility of water-related infection. Worker education may serve
the same purpose.


Reference

CDC. Water-related disease outbreaks. Annual summary, 1982. Atlanta, Ga.:
Centers for Disease Control, 1983. (HHS Publication No. (CDC) 83-8385.)

Coolbaugh JC, Daily OP, Joseph SW, Colwell RR. Bacterial contamination of
divers during training exercises in coastal waters. J Marine Technology Soc
1982;15:15-21.

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