Hospital water may put cancer patients at risk

Avoid tap water during peak immune suppression

The threat of nosocomial infections in highly immunocompromised patients posed by hospital water systems is probably underestimated in many institutions, where opportunistic fungi may be circulating in tap water, a researcher emphasizes.

Infection control professionals in hospitals that treat cancer patients who are highly immunocompromised due to their disease or treatment should consider preventive measures, notes Elias Anaissie, MD, professor of medicine at the University of Arkansas for Medical Sciences in Little Rock.

"We all assume that because the water in the hospital is chlorinated it is safe," says Anaissie, who also is chief of supportive care and oncologic emergencies at the Arkansas Cancer Research Center. "That is not true. I submit that water is a very significant, under-recognized, underestimated source of nosocomial infections."

Anaissie and colleagues documented the presence of several opportunistic fungi in hospital water at a cancer hospital in Houston and at two hospitals in Little Rock.^1,2

The organisms recovered included Fusarium species, an opportunistic fungus that could pose a risk of infections in cancer patients receiving intensive chemotherapy with or without bone-marrow transplantation, he notes. For the typical neutropenic patient, the period of greatest risk would probably be around 20 to 25 days, extending to 100 to 160 days for transplant patients, he says.

In the studies, water samples were taken from sinks, showers, and drains in patient care areas and from water fountains in hallways of the hospitals. After filtration and incubation, fungi and bacteria were recovered from a large number of water samples, sink and shower drains, showerheads, and water tanks. Fungi were recovered from 52% (14/27) of the water samples in the two hospitals in Little Rock. Fusarium was recovered from the water storage, distribution, and drainage systems throughout six hospital floors in two different buildings at the cancer center in Houston. Additional research is ongoing to determine if any nosocomial infections linked to the water systems can be documented. Anaissie stressed that the chlorine concentrations in the hospitals were within the required state and federal regulations, and the water posed no risk of infection to immune-competent people. However, the water-borne pathogens could pose a risk to immune-compromised patients if aerosolized during showers, for example.

Use sterile water for sponge baths, drinking

"The most important thing that we know will work is to prevent high-risk patients from taking showers while in the hospital, and preventing them coming in contact with contaminated water," he says. "We give them sponge baths with sterile water and we allow them only to drink sterile water during the period at risk."

To further minimize the risk of infection in cancer patients in hospitals and at home, Anaissie recommends removing aerators from faucets in patient rooms, inspecting and cleaning contaminated water tanks, and installing inexpensive water sterilization equipment in patient care areas.

References

1. Anaissie EJ, Monson TP, Penzak SR, et al. Opportunistic fungi recovered from hospital water systems. Presented at the 37th Interscience Conference on Antimicrobial Agents and Chemotherapy. Abstract J-93. Toronto; Sept. 28-Oct. 1, 1997.

2. Anaissie EJ, Kuchar R, Rex JH, et al. The hospital water system as a reservoir of Fusarium. Presented at the 37th Interscience Conference on Antimicrobial Agents and Chemotherapy. Abstract J-94. Toronto; Sept. 28-Oct. 1, 1997.