Legionnaires outbreak traced to dirty motel spa

By Brendon McMahon

A “small” outbreak of legionnaires disease last year was eventually traced to a dirty spa pool at a Hokitika motel, according to the latest New Zealand Health Surveillance Report.
But it took over six months to trace the Hokitika link after notification in March 2013 of a 79-year-old man with a legionella infection, in Christchurch.
The motel spa only emerged as a suspect after notification six months later of a 65-year-old Hokitika woman with the same disease. Both cases required hospitalisation to treat the potentially fatal disease.
Subsequent investigations by Community and Public Health (CPH) identified that the spa was regularly used by Hokitika residents on a “pay as you go” basis.
CPH found the pool was chlorinated but the motel owner was untrained in basic spa pool maintenance.
Although the outbreak was “small” it could have potentially been more serious given that Hokitika was a tourist town with a steady trickle of out-of-town visitors, the report said.
It was also “possible” that other regular users of the spa had contracted the disease, although no further cases had been notified, despite increased surveillance of the pool. “The motel owner was keen to discover the cause of the illnesses and agreed to the spa pool water being tested,” the report said.
Subsequent tests by ESR found “significant amounts” of a strain of legionella as well as other bacteria, confirming lack of maintenance. The motel owner agreed to close the pool and initiated “a thorough cleaning programme” and took professional advice to improve maintenance and monitoring. Testing since then has found no trace of legionella.
In the first notified case, the sick man told CPH he had been to Hokitika during the incubation period of the illness. CPH investigated the motel where the man had stayed, taking water samples and testing hot water cylinder temperatures, but found no cause for concern.
When the second case emerged, the Hokitika resident with the disease told CPH that she regularly used the spa pool at a nearby motel — the same motel where the first case had stayed in March.
CPH subsequently re-questioned the first man, who admitted he had used the motel spa pool several times during his stay.
It transpired that CPH had not asked the man about the spa pool during its first investigation, and he had not volunteered the information, the report said.