American experts deployed after the devastating New Orleans floods are working on the Borders anthrax case.
US experts are involved in testing at Mr Norris' home
They are part of the team investigating the home of a Stobs man who is thought to have died as a result of anthrax.
Pascal Norris died in July - but diagnosis took almost a month. After further safety discussions, tests began at his Black Lodge house on Monday.
The US personnel are experts in disposing of the potentially deadly spores of the disease.
NHS Borders has been co-ordinating discussions with acknowledged experts in the field - including the UK's top specialist pathogen laboratory at Porton Down.
It wants to know the source of the disease, whether spores remain in the home and, if so, how they will be dealt with.
Testing at Mr Norris's home is expected to last for a week.
Those involved have estimated it will take four to six weeks to get the results and decide what, if any, decontamination action is necessary.
NHS Borders has stressed there is little risk to the public.
The B6399 Hawick to Newcastleton road has been closed to all vehicles to allow testing to take place.
The road may also be closed on Saturday, if necessary. Diversions will be in place via the A698 and A6088.