Anthrax in secret NZ location

26 Oct, 2001 11:42 AM3 mins to read

By TONY WALL

New Zealand's only known samples of anthrax, the deadly disease terrorising the United States, are held at a secret location and have yet to be brought out of storage for comparison testing, despite a string of scares here.

The Ministry of Agriculture and Forestry is refusing to say where its anthrax samples are kept, except that they are freeze-dried and held under "extensive" security at a diagnostic laboratory.

The general manager of MAF's National Centre for Disease Investigation, Dr Hugh Davies, said the location of the samples could not be revealed "because if we have nutters in New Zealand, it makes us a potential target".

The centre is where the suspicious substances seized in the anthrax scares have been tested. The laboratory's 20 staff have been working 24 hours a day, seven days a week since the scares began.

Dr Davies said anthrax was imported from the US several years ago as a reference sample. The last naturally occurring case was in the Waikato in 1954, when 23 cattle died.

The only time humans are thought to have contracted the disease here was in 1895, when three Waikato men contracted anthrax during an outbreak in pigs and cattle. They recovered.

Dr Davies said all the suspicious substances found in New Zealand in the past couple of weeks had been sent to the national centre for disease investigation's state-of-the-art containment laboratory at Wallaceville, near Wellington.

The technicians put the suspicious substances into petri dishes and tried to "grow" them to determine if, like anthrax, they were bacteria.

So far none of the dozens of substances had reacted in that way and the anthrax reference cultures - vaccine strains of the disease which are safe for humans to handle - had not been brought out for comparison.

The laboratory's atmosphere is kept at negative pressure and staff can enter and exit only through air locks. The air is put through a high efficiency particle filter that removes potential bugs.

Staff entering have to strip off, walk through the air lock, then put on gloves, gowns and masks.

They work in "biohazard cabinets" surrounded by air curtains which minimise the chance of organisms escaping into the laboratory.

The air handling, sterilisation and security systems are monitored electronically.

At the end of the day, staff must remove all their clothing and have a three-minute shower in the air lock before they leave. The clothing is sterilised.

Large pieces of equipment that have to be removed for servicing are sterilised with formaldehyde gas.

Waste water from sinks and showers is sterilised before it is released and solid waste is "cooked".

* tony_wall@nzherald.co.nz

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