Waikato District Health Board (DHB) is on Friday morning re-starting computers in key locations, such as the emergency department and intensive care unit, after staff pulled an all-nighter battling a computer virus which crippled the organisation.
The Conficker virus was spotted about 2am on Thursday, infecting 3000 computers logged onto the DHB's network and forcing a complete shut down.
DHB spokesperson Mary Anne Gill said Waikato Hospital's emergency department and operating theatre were kept running as usual but all non-urgent patients were asked to stay away.
Gill said information services staff worked through the night and had now cleaned up all the servers in their data centre, set up new complex passwords and begun re-starting desktops in key locations.
The system was being monitored in case the virus reappeared and staff were checking programmes still worked properly, with an "optimistic plan to have systems back up around lunchtime," gill said.
It was not yet known how the virus found its way into the system, but all computers were fully up to date with their anti-virus software, she said.
Conficka is a "computer worm" which targets Microsoft's Windows operating system, using flaws in the software to co-opt machines, allowing a remote user to take control.
A New York Times report said the virus had affected millions of computers in more than 200 countries.
