Saudi Arabia announced another fatality from the MERS virus on Sunday, taking its toll to 53, as neighbouring Oman recorded its first death from the respiratory disease.
The (MERS-CoV) Middle East Respiratory Syndrome Coronavirus had cost 64 lives worldwide by November 4, according to the World Health Organisation (WHO).
In the Gulf region, 53 MERS deaths have been recorded in Saudi, the country most affected by the disease, and two in Qatar, as well as the fatality announced Sunday by Muscat.
The 68-year-old Omani was "suffering from several chronic illnesses including diabetes, blood pressure, and heart failure", the sultanate's health ministry said in a statement.
"The main cause of death was failure in lung function," it said.
Health authorities had announced the infection on October 30 in what was the country's only MERS case reported so far.
The man had been receiving treatment in Nazwa, 150 kilometres (95 miles) west of the capital.
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The ministry said that tests carried out on everyone who had been in contact with the victim returned negative results.
Health authorities in Saudi Arabia, the Gulf nation where the virus first appeared in September 2012, on Sunday announced a new death from MERS.
Experts are struggling to understand the disease, for which there is no vaccine.
It is considered a deadlier but less-transmissible cousin of the SARS virus that erupted in Asia in 2003 and infected 8,273 people, nine percent of whom died.
Like SARS, MERS appears to cause a lung infection, with patients suffering from a temperature, coughing and breathing difficulties.
But it differs in that it also causes rapid kidney failure and the extremely high death rate has caused serious concern.
In August, researchers pointed to Arabian camels as possible hosts of the virus.