WATER-BORNE PARASITE AFFLICTING MILWAUKEE COMMON ACROSS U.S.

                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: SATURDAY, April 10, 1993                   TAG: 9304100097
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A2   EDITION: METRO 
SOURCE: Associated Press
DATELINE: ATLANTA                                LENGTH: Medium
WATER-BORNE PARASITE AFFLICTING MILWAUKEE COMMON ACROSS U.S.
Most Americans never will encounter the parasite that contaminated Milwaukee's water. But 21 million people use water systems that aren't protected from the bug, and others swallow it when water plants improperly clean their filters, experts said Friday.
"Just a little lack of rigor can result in one of these outbreaks," said Jack Hoffbuhr of the American Water Works Association, a nonprofit foundation that tracks drinking water. "But I think most people can rest assured this is not common."
Thousands of Milwaukee residents were stricken by cryptosporidium, a protozoan about one-hundredth the size of a speck of dust. It causes severe diarrhea.
Mostly found in developing countries, it's the major cause of travelers' diarrhea. But 2 percent of the diarrhea cases in U.S. hospitals are caused by the bug, which can kill people who have weak immune systems.
"The bad news is there's no treatment for it, but the good news is it runs its course in about 14 days in healthy people," said Dr. Dennis Juranek of the U.S. Centers for Disease Control and Prevention.
Cryptosporidia lives in the intestines of animals and humans and is spread by contact with infected feces - anything from diaper changing to water tainted by farm runoff.
Investigators said Friday that rain and the spring thaw likely washed a parasite from farm pastures and barns into the city's tap water via the Milwaukee River. They focused on how the organism got through the city's water-purification process, and whether it could have been caught at all.
The 800,000 people depending on the municipal water supply continued to boil drinking water, buy bottled water or risk it as health officials worked to cleanse the system.
Officials warned it could be several days before the water is safe.
Milwaukee's is the fourth U.S. outbreak of cryptosporidia in recent years, and all were caused by tainted water, Juranek said.
The largest outbreak was in Carrollton, west of Atlanta, in 1987, when thousands became ill. Residents boiled water for two weeks before the state decided the water plant was filtering properly for the bug.
The other outbreaks were in Braun Station, Texas, in 1984 and Medford and Talent, Oregon, last year.
Filters are the only protection from the parasite, which cannot be killed by chlorine or other chemicals, Juranek said.
The earth naturally filters cryptosporidia before it reaches ground water, which is the primary source for 92 percent of the nation's water systems. Cities that draw drinking water from rivers or lakes - such as Milwaukee - are required to chemically treat their water but not to filter it, Juranek said.
About 21 million Americans drink unfiltered surface water. Most live in mountainous areas where people think the water's safe because it appears so clear, Juranek said. The 1992 Oregon outbreak was caused by an unfiltered spring.

by Bhavesh Jinadra by CNB