(Story updated at 3:15 p.m. ET.)
Government health officials are defending their response to a suspected third U.S. case of MERS
despite confirming Wednesday they were wrong in announcing that case had been transmitted through contact
in the U.S. Initial test results indicating an Illinois man had contracted the disease from a patient in Indiana were overturned by a third test.
The Centers for Disease Control and Prevention
has confirmed that the Illinois resident who they said on May 17 was the third U.S. case of Middle East respiratory syndrome has tested negative for the virus, raising questions over why the agency did not wait until testing confirmed a positive result before alerting the public.
“We were very concerned about the situation,” said Dr. David Swerdlow, incident manager for the CDC's MERS response, in speaking with reporters in a Wednesday media briefing. “They were preliminary results, but they were positive, and it was our feeling that it was more important to make sure that we were able to contact this gentleman and his family and contact his co-workers to make sure we were protecting the public health.”
The man suspected of being the latest U.S. case of MERS had come in contact with the first known U.S. patient with the disease, who was being treated at an Indiana hospital. That first case involved a healthcare worker who had arrived from Saudi Arabia and who has since been released from Community Hospital in Munster, Ind.
Swerdlow said though two initial tests found the Illinois resident was positive for MERS antibodies, a more definitive third test that takes about five days to get results showed he was negative. The third test, called a neutralizing antibody assay, could not be applied routinely for every suspected case because it is too timely and labor-intensive, he said.
“The neutralization test uses live MERS virus and therefore must be conducted in a highly contained environment,” Swerdlow said. “It is not simple to immediately test all hundreds of samples in that environment.”
MERS is a coronavirus, similar to SARS, which was responsible for more than 700 deaths globally in 2003, more than 600 of which occurred in China. No vaccine exists for MERS; the only treatment option is supportive care for respiratory illness.Follow Steven Ross Johnson on Twitter: @MHsjohnson