Public Health and Drinking Water News Briefs – January 13, 2006

In the News…
Public Health and Drinking Water News Briefs

January 13, 2006

Study Confirms Safe Reduction of Legionella in Hospital Water Supplies

According to a study recently presented at the 45th Interscience Conference on Antimicrobial Agents and Chemotherapy in Washington, DC, the compound chlorine dioxide was safely used to drastically reduce Legionella from hospital water supplies. The study, a continuation of research conducted in 2002, was developed to determine whether chlorine dioxide meets the human health and safety guidelines set by the U.S. Environmental Protection Agency (EPA) for drinking water. Chlorine dioxide is an industrial chemical widely used in the treatment of pulp and paper water.

Hospital-acquired Legionellosis is widespread in the U.S. and around the world. The waterborne pathogen-caused condition particularly affects patients with compromised immune systems and those being treated for post-operative cardiac conditions.

For the study, hospital water samples were evaluated every 2 months between June 2004 and November 2005 from 17 sites at a 437-bed acute care hospital in central Pennsyslvania. After treatment of the water supply, test results showed that concentration levels for chloride dioxide and chlorite, a breakdown product of chlorine dioxide, met EPA drinking water safety standards.

Before disinfection, L. pneumophila, the bacteria that causes Legionnaires’ disease, was detected in 57 percent of water samples at the hospital. After chlorine dioxide disinfection, the Legionella virus was found in only 10 percent of the samples. Additionally, there have been no new cases of Legionella-related hospital-acquired (nosocomial) infections reported since the study was conducted.

To read more about the 2002 chlorine dioxide study, please go to:

For more information about Legionellosis from the CDC, please go to:

Majority of Pakistanis Believe They Drink Risky Water

Approximately 59 percent of Pakistanis believe the water they drink is unsafe, according to a survey conducted by The Network for Consumer Protection (TNCP). Included in the study is the finding that only 19 percent of the populace believed their water sources are safe for consumption. The survey queried approximately 1,500 consumers from 25 cities across Pakistan.

Additionally, the TNCP survey found that 91 percent of Pakistanis believe that contaminated water is the root cause of disease in the country. Almost half of the respondents, 45 percent, believe that the private sector should be allowed to compete with the government in providing safe drinking water, pointing toward a widely held belief that a lack of basic government structure and management is the main factor affecting the development of a safe drinking water supply.

Almost 50 percent of those who were surveyed said they filtered or boiled water before use. Seven percent was not aware of filtration or boiling as a water purification option.

CDC Report Focuses on Petting Zoo E. coli Infections

According to a report in the U.S. Centers for Disease Control & Prevention (CDC) publication, Morbidity & Mortality Weekly Report (MMWR), three outbreaks of Escherichia coli O157:H7 infections occurred among agricultural fair and petting zoo visitors in 2004-2005. The public health incidents occurred in North Carolina, Florida, and Arizona.

Based on the MMWR findings, 108 cases were reported in the North Carolina outbreak, including 15 cases of hemolytic uremic syndrome (HUS); 63 cases were reported in the Florida outbreak, including seven HUS cases; and two E. coli cases were reported in Arizona. The illnesses primarily affected children who visited petting zoos at these events. There were no reports of fatalities.

HUS is an acute condition characterized by microangiopathic hemolytic anemia, renal injury, and low platelet count.

In North Carolina, transmission of the E. coli infection was reportedly due to direct animal contact in an area contaminated with manure, while the Florida illnesses were associated with both touching and feeding animals and indirect animal contact (e.g., touching sawdust or shavings or visibly soiled clothes or shoes). The outbreak in Arizona featured at least one case likely resulting from exposure in the play area adjacent to the petting zoo, where contamination via drainage from the petting zoo was suspected.

E. coli O157:H7 causes approximately 73,000 illnesses annually in the U.S., leading to an estimated 2,168 hospitalizations and 61 deaths. HUS is a principal cause of acute renal failure among children in the United States and occurs in up to 7 percent of E. coli infections.

To read more about the 2004-2005 E. coli outbreaks, please go to:
Outbreaks of Escherichia coli O157:H7 Associated with Petting Zoos
Shipboard Safety Includes Clean Hands, Surfaces

The U.S. Centers for Disease Control and Prevention (CDC) and the cruise ship industry have developed more aggressive sanitation measures to combat the ill effects of noroviruses (Norwalk-like viruses) on board international cruise ship vessels. Noroviruses are common pathogens that cause diarrhea, stomach cramps and vomiting. Transmitted either by tainted water supplies or by eating or drinking food or liquids infected with the bug, norovirus infections have become an increasingly significant public health concern for the cruise ship industry.

The CDC tracked 13 outbreaks of norovirus aboard cruise ships in the first half of 2005. Of the 8 million passengers who cruise from U.S. ports annually, only one in 3,600 comes down with the symptoms, according to the CDC. Additionally, the agency estimates that 23 million Americans — one in every 12 — contract norovirus each year, generally from exposure in close living quarters, including dormitories and nursing homes. Although symptoms generally fade in a day or two, the germs are highly contagious and can survive on surfaces for weeks at a time.

The CDC recommends back-to-basics personal hygiene routines to combat the spread of the Norwalk-like viruses. This includes frequent washing of hands, especially after restroom visits, changing a child’s diapers and before preparing food. In addition, the CDC advises that fruits and vegetables be carefully washed and contaminated surfaces immediately cleaned and disinfected with a bleach-based household cleaner after an episode of illness.

The cruise ship industry has begun to implement approaches to combat norovirus outbreaks. Recent new practices include:

* Using disinfectants, including chlorine-based cleaners, on shipboard counters, bathroom surfaces, door handles, railings, exercise equipment, video arcade equipment, vanities and TV remote controls.

* Sanitizing public-use game items, including individual Scrabble game tiles and poker chips, and the practice of throwing out playing cards after each evening in the casino.

* Cruise ship staff no longer shake hands at cocktail parties.

* Some lines have ceased self-serve buffets. Passengers now point to the food they want and staff members serve them.

To read more about CDC efforts to fight norovirus, please go to:

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