CDC scientist: MERS doesn't present pandemic risk, but other diseases might

Aedes mosquitoes transmit Chikungunya to people.--Courtesy of CDC

BOSTON--Despite its high mortality rate and alarming spread since it was first detected in Saudi Arabia in 2012, a U.S. health official says it's unlikely that Middle East respiratory syndrome coronavirus, or MERS, will turn into a pandemic.

Lyle Petersen, director of the division of vector-borne diseases at CDC's National Center for Emerging and Zoonotic Infectious Diseases, said May 19 at the American Society for Microbiology's General Meeting in Boston that instead, Chikungunya virus poses a bigger threat to Americans.

Petersen said the mosquito-borne virus has been "taking off by leaps and bounds" since it first emerged in October in the Caribbean island of St. Martin. The CDC has since declared the outbreak an epidemic, with cases now confirmed in 12 countries, including three cases that have been imported to the U.S. So far, Petersen said there have been 51,000 total cases of Chikungunya, compared to 614 cases of MERS.

"It will keep spreading and undoubtedly will cause millions of cases before it's all over," said Petersen. Genetic evidence suggests that the virus came from a traveler in Asia, but little else is known about the disease, which is transmitted similarly to dengue.

While Chikungunya does not often cause death, it can cause disabling symptoms, such as headache, muscle pain, joint swelling and rash.

Dr. Ian Lipkin, who directs the Center for Infection and Immunity at Columbia University's Mailman School of Public Health said at the meeting that outbreaks of diseases are increasing in part because human activity, like international travel and farming practices, is enabling the spread of these pathogens.

"There are new opportunities for diseases to spread," Lipkin said.

Lipkin and Petersen said this increase in disease outbreaks is not just due to the fact that scientists have the ability to detect and classify diseases. They said it's also because we're actually seeing new diseases crop up, like Heartland virus, a tick-borne pathogen first detected in 2009 that has infected 8 people in Missouri and Tennessee.

- watch the video of the ASM session