Aug. 22 (UPI) -- Medical authorities say Legionnaires' disease has killed two British citizens, who were both likely exposed while on vacation to Bulgaria this summer.
Officials said John Cowan, 43, and Brian Taylor, 75, both died of the disease, which is also called legionellosis. The affliction is a type of pneumonia caused by Legionella bacteria.
Investigators suspect the men picked up the disease at a Bulgarian hotel in Sunny Beach, at which they both stayed while vacationing. The resort city is located on the Black Sea.
Officials said Cowan died in mid-June and Taylor in July, after each had returned to Britain.
There are numerous symptoms of Legionnaires' disease and the mortality rate is only about 10 percent, but can be as high as 50 percent under certain conditions. Bacteria is naturally found in water and the disease is generally contracted by inhaling Legionella-contaminated mist.
"We are now investigating how Brian contracted his illness and looking into his stay at the Hotel Kalofer," Jatinder Paul, a senior associate solicitor with London law firm Irwin Mitchell, said in a statement. "It is extremely worrying that other guests who stayed at the same hotel have also contracted this potentially fatal infection.
"Following an outbreak of Legionnaires' disease, it is vital that the source is identified as soon as possible."
Taylor's stepson Martin Farrell said his stepfather was healthy and "fighting fit" before he went to Bulgaria.
Jet2 Holidays, which arranges visits to Sunny Beach, said tests on water samples at the hotel have come back negative.
"Despite these results, we have taken further precautionary measures, like other [British] tour operators at the hotel," the tour company said.
"We have transferred all customers and all bookings for this summer to other hotels."