The health and safety watchdog has ordered a clean-up at a second company being investigated as a possible source of an outbreak of Legionnaires' disease.
Pharmaceuticals firm Macfarlan Smith, based in Wheatfield Road in south-west Edinburgh where most of the cases originate, was served two improvement notices by the Health and Safety Executive.
There are now 39 confirmed cases and 49 suspected cases of the disease, an increase of two confirmed and four suspected.
So far one man has died, named locally as 56-year-old Robert Air, from Seafield in Edinburgh.
A micrograph picture of the Legionionella pneumophilia bacteria. The bacteria replicates quickly, part of what makes the disease so infectious
The HSE ordered thorough cleaning of one of Macfarlan Smith's cooling towers and ordered provision of access for the same tower so it can be inspected and maintained.
Last week the watchdog served an improvement notice on North British Distillery Company which is also in Wheatfield Road. It was censured for failing to devise and implement a sustained, effective biocide control programme for one cooling tower on its site.
Other companies are being visited as part of the investigation into the outbreak of the disease.
The improvement notices require Macfarlan Smith to improve its management systems, although they do not mean that this cooling tower is the source of the outbreak.
The source may never be conclusively identified, based on experience from previous outbreaks.
Improvement notices were served because the company allegedly failed to maintain control measures for the safe operation of the cooling tower to the required standard.
HSE said the notices do not indicate an immediate risk from Legionella as this was being controlled by the emergency dosing of chemicals and the company's subsequent voluntary shutdown of the cooling towers.
Scottish Health Secretary Nicola Sturgeon said: "Today's developments, which show a slight increase, are in line with expectations. With a 14-day incubation period, we would expect there to be fluctuations over the next week or so.
"It is reassuring however that all those involved are continuing to respond well to being treated.
"NHS Lothian services are coping with the demands and the City of Edinburgh Council and the Health and Safety Executive continue to make significant progress in their investigation to identify the source of this outbreak."
As of noon, of the patients being treated in hospital, 14 are in intensive care and 26 are on general wards, while 18 are being treated in the community.
Seven patients are being treated outside of the NHS Lothian area.
The patients' ages range from between 33 and 76, and more men than women have been infected.
Dr Duncan McCormick, chairman of NHS Lothian's incident management team and consultant in public health medicine, said:
"The number of confirmed and suspected cases have again increased slightly in line with expectations. It is pleasing to see that 22 patients have now recovered and been discharged from hospital.
"Our GPs, out-of-hours services and NHS 24 have been doing an excellent job in reassuring the public and seeing those who have concerns or symptoms.
"The risk to the general public is low but anyone with concerns should contact their GP or NHS 24."
In a statement Macfarlan Smith said: "On Sunday 10th June during a visit by Health and Safety Executive (HSE) inspectors as part of an ongoing investigation into the current legionnaires disease outbreak in South West Edinburgh, we voluntarily shut down a small cooling tower on our site as a precaution.
"Subsequent to the visit, the HSE have today served two Improvement Notices on Macfarlan Smith, one relating to the cleaning of the tower and one relating to improvement of access to the tower.
"As the HSE has stated in their press release, this does not mean that this cooling tower has been identified as the source of the outbreak.
"Macfarlan Smith continues to work closely with the HSE in their investigations into the outbreak. The health and safety of our employees and the local community remains our highest priority.
"Our thoughts are with the individuals and families affected by the current situation."