Health officials in Saudi Arabia say five more people there have died from MERS, or Middle East Respiratory Syndrome, raising the death toll from the disease to 145. The disease has also sickened more than 500 people.
Here in the United States, doctors confirmed the first case in indiana - and now a second case in Florida. That second patient - a health care worker from Saudi Arabia who flew through several U.S. airports - is now hospitalized.
Two other health care workers where that Saudi patient sought treatment in Florida now are showing MERS symptoms. One is hospitalized, the other is at home.
And to avoid the next step of more infections, two Florida hospitals sent 20 other health care workers home for two weeks.
There is no vaccine for the virus. Doctors believe it's spread through coughing and close, long-lasting exposure to someone who's sick.
Officials have begun posting warnings at 22 of the nation's busiest airports, including Sea-Tac, so travelers know to look out for the early symptoms of MERS.
The disease often starts with flu-like symptoms but can lead to pneumonia, breathing problems and in severe cases, kidney failure and death.
Dr. Keiji Fukuda, an assistant director-general of the World Health Organization, said there wasn't yet proof of the virus' sustained transmission among people.
On Wednesday, the Netherlands' National Institute for Public Health and the Environment announced its first case of MERS, a man who became infected during a visit to Saudi Arabia. He is now in isolation at a hospital in The Hague.
Some experts say the spread of MERS is worryingly similar to the 2003 global outbreak of Severe Acute Respiratory Syndrome or SARS, which infected about 8,000 people in 2003, killing nearly 800. MERS is genetically related to SARS.
Scientists are unsure exactly how people in the Middle East are catching MERS but suspect the disease is linked to camels. WHO recommends that people avoid contact with the animals, skip drinking camel milk or using camel urine in traditional medicines and only eat camel meat that has been well cooked.
Dr. Clemens Wendtner, who treated a German MERS patient in Munich last year, said the current spread of MERS should not set off a global alarm.
"I do not see an international threat or a pandemic (being caused) by MERS," he wrote in an email. He said the spread of MERS to humans was still exceptional and that the disease was mostly affecting animals.