More than two dozen different drugs, from old-line chemotherapy drugs to malaria drugs, might work against the baffling new MERS virus, researchers said on Tuesday.
They’ll need to be tested in animals first and then in people after some early promise in the lab, but the discovery offers hope that there might be something available quickly to fight the virus if it does start spreading faster than it has so far, the researchers said.
“It’s a good start," said Dr. Tony Fauci, head of the National Institute for Allergy and Infectious Diseases, which paid for and helped conduct the study. “You try to stay ahead of the game. There’s a host of things we are doing. Hopefully, we will never have to use any of them.”
Middle East respiratory syndrome virus, or MERS, has been spreading in recent weeks. It’s infected at least 614 people and killed 181 of them, which makes for a 29 percent mortality rate.
Three cases have been identified in the United States, including a man who authorities say must have been infected during a meeting with the first known U.S. case last month. Two of the cases were health care workers visiting the U.S. from Saudi Arabia, which has had all but a handful of MERS cases.
It’s concerning that a traveler would show up with MERS, and even more troubling that he infected someone else. But both of the infected travelers have recovered completely and the third man never even got sick – a reassuring sign.
And in more reassuring news, an Orlando hospital said Tuesday that seven health care workers who had been in contact with the second sick man had been cleared of any evidence of infection and could go back to work. “They could be scheduled as early as this afternoon, but most likely will resume their normal schedules tomorrow,” Orlando Health said in a statement.
There is no treatment and no vaccine for MERS, which is a member of the coronavirus family that normally causes little more than a common cold. But in 2003, a new coronavirus called Severe Acute Respiratory Syndrome, or SARS, swept around the world, infecting 8,000 people and killing more than 770 of them before it was stopped.
Matthew Frieman of the University of Maryland school of medicine and colleagues took a look at drugs that might work against MERS. They did this with a common approach — screening compounds in a library of known drugs. Such drugs could be deployed quickly if needed, as opposed to the cumbersome and time-consuming process of first developing and then testing a brand-new drug or vaccine.
“In total, 27 compounds with activity against both MERS and SARS were identified,” they wrote in the journal Antimicrobial Agents and Chemotherapy. “The compounds belong to 13 different classes of pharmaceuticals including inhibitors of estrogen receptors used for cancer treatment and inhibitors of dopamine receptor used as antipsychotics.”
They include the very common cancer drug gemcitabine, the leukemia drugs imatinib and dasatinib, and a breast cancer drug called Fareston that’s also shown possible effectiveness against Ebola virus. Chloroquine, one of the older malaria drugs, also showed promise.
Showing potential in a lab dish doesn’t necessarily mean the drug would work to treat a human being with the virus, however. Two common drugs, the antiviral ribavirin and interferon, have already been tried in MERS patients and they did not work.
“But at least it’s a strong hint about the right direction,” Fauci said.
The team found more drugs that worked against either MERS or SARS alone, but wanted to focus on drugs that attack both in the hope of finding a broadly based coronavirus treatment in case more show up in the future.
SARS was found to originate in an animal called a civet, and MERS has been traced to camels. More research published Tuesday implicates camels as a source. Daniel Chu of the University of Hong Kong and colleagues tested camels being slaughtered for meat in Egypt. Two were actively infected and more than 90 percent of 52 camels had antibodies to the virus, suggesting they had been infected at some point in the past.
“Our findings confirm that MERS infects dromedary camels and that this virus is genetically very similar to a MERS (virus) that is infecting humans,” they wrote in their report published in the journal Emerging Infectious Diseases.
The animals had been imported from Sudan and Ethiopia, something that suggests the virus is also circulating among camels outside the Middle East.
They also tested 179 slaughterhouse workers but found no evidence any of them had even been infected.
“Our findings strengthen the plausibility that dromedaries may be a potential source of human infection and emphasize the need for detailed epidemiologic investigation of the exposure histories of humans with MERS,” Chu’s team wrote.
However, they added, since none of the people they tested appeared to have ever bee infected, it's likely rare that people catch MERS from camels.