Buller Hospital had to give patients sponge baths, use bottled water and take other precautions for 24 hours after Legionella bacteria were found in its hot water system.
No one contracted the potentially fatal legionnaires' disease.
The bacteria were found during routine testing of the hospital's hot water system in early February, it has just been revealed.
The West Coast District Health Board's general manager, Buller, Kathleen Gavigan, said it was unclear how long the bacteria had been in the system, but it probably wasn't long.
The risk to patients and staff was low, but the hospital had immediately made alternative arrangements for them.
Patients had sponge baths with water from unaffected areas. Bottled water was provided for drinking and brushing teeth. Sterile water was used for flushing naso-gastric tubes.
Staff removed bath toys containing water and used neutral detergent or wipes for cleaning patient equipment. They also used alcohol-based hand rub and scrubbed and disinfected all shower heads.
The precautions continued for 24 hours, while the DHB used hot water to disinfect all outlets/showers and water storage tanks, Ms Gavigan said.
After two consecutive "clear" results, the water system was pronounced free of Legionella on March 3.
Contaminated taps had remained out of use until the all-clear. One tap at a dead end in the reticulation system was still out of use, she said.
Legionella bacteria are found widely in the environment, including in soil and water. Ms Gavigan said maintaining hot water storage temperatures above 70degC helped to control it.
"However, when a water system hasn't been used for a while, multiplication of Legionella can happen in dead ends within pipe work. That's why hot water systems in places like hospitals are monitored for Legionella."
As a result of the contamination, all Buller Hospital's plumbing was now flushed at high temperatures regularly, and sampled three-monthly, Ms Gavigan said.
Legionella causes potentially fatal Legionnaires' disease, a form of pneumonia. About 10% of those infected die.
The disease is usually spread by breathing in mist that contains the bacteria or aspirating contaminated water. It does not usually spread from person to person.
Risk factors for infection include older age, history of smoking, chronic lung disease and poor immune function.
The disease is treated with antibiotics and hospitalisation is often needed. There is no vaccine.
The disease is named after the outbreak where it was first identified, the 1976 American Legion convention in Philadelphia.
- By Lee Scanlon of the Westport News
