Although there is no confirmed link, YMCA Auckland and the council have treated the pool according to procedures recommended by ARPHS, including a thorough deep clean and additional chlorination.
It will, however, remain closed until the water tests negative for the bacteria, which is likely to take two to three weeks. The rest of the pools are still open.
Council head of active recreation Rob McGee said that after a similar outbreak last year, the council worked closely with ARPHS and the council's environmental health team to improve processes and the YMCA is now working with ARPHS to find out what caused the latest bacterial contamination.
"Auckland Council and YMCA Auckland are now working together to fully investigate this case and understand if further improvements can be made," says McGee.
YMCA Auckland chief operating officer Arvid Ditchburn says the organisation is now testing the other pools in manages.
"Our current operating procedures meet all New Zealand water treatment standards, but we will be undertaking a review to see if any further improvements can be implemented."
McGee says the council believes the risk the public is "very low".
Auckland Council tests its pools daily to ensure water quality remains within New Zealand standards, and also does monthly microbiological testing.
Legionellosis is a respiratory infection caused by legionella bacteria. Early symptoms include muscle aches, headache, tiredness, loss of appetite and coughing followed by high fever, chills and occasionally diarrhoea. The period between exposure and onset of symptoms is usually two to 10 days, but can be up to 14 days.
There are about 50 confirmed cases of legionellosis in the Auckland region every year. Only rarely does contact with the bacteria lead to infection and illness, which is usually the result of breathing in contaminated aerosols or soils dust. It is not contagious, but anyone who is concerned should see a doctor.
