MERS Update: Now in the U.S.

Since it was first discovered in a person in mid-2012, MERS (short for Middle East respiratory syndrome) has been a looming viral threat. MERS is a disease caused a type of virus called a coronavirus (CoV), which typically infects the respiratory and gastrointestinal systems. (Many common colds and even cases of pneumonia are caused by coronaviruses.) But unlike common colds, MERS-CoV has a high fatality rate, around 30%. Since its discovery, there’ve been nearly 600 people in the world infected with MERS. While this is a relatively low number of infected individuals, MERS-CoV continues to spread — it’s now been found in 12 different countries, recently including the United States.

The first people infected with MERS-CoV were in Saudi Arabia, and still all known cases of MERS-CoV infections can be traced back to Saudi Arabia and the surrounding countries on the Arabian Peninsula. It’s now thought that the virus came from camels in Saudi Arabia, as camels have been found carrying similar viruses and can be infected with MERS-CoV, but details on any specific cases of transmission between people and camels are unknown. While in people the virus appears to only be spread through close contact, it still continues to spread, crossing country boundaries, and leading to the first two known cases in the U.S.

The first case of a person with MERS-CoV in the U.S. was reported by the Centers for Disease Control and Prevention (CDC) just last month, on May 2, 2014. The individual was a healthcare worker who had flown in from Saudi Arabia to Indiana (through London and Chicago). He started having respiratory problems on April 27, and after receiving isolated treatment in a hospital, he fully recovered and was released. CDC officials have contacted people who were in close contact with him prior to being hospitalized. It was initially thought that an Illinois business associate caught MERS from the Indiana patient, but it’s been since confirmed that the Illinois man did not have MERS-CoV.

The second case of a person with MERS-CoV in the U.S. was reported on May 11. (It was found to be unrelated to the first case.) This individual was also a healthcare worker who’d flown in from Saudi Arabia (to Orlando, Florida, through London, Boston, and Atlanta). He was released from the hospital on May 18 after having fully recovered. The CDC again extensively checked people who may have had contact with the man, screening more than 500 individuals, but still has not found anybody who contracted MERS-CoV from him, which is not surprising since person-to-person transmission is low. There is still not a known case of MERS-CoV being transmitted from person-to-person within the U.S.

Treatments and vaccines for MERS-CoV are being investigated by researchers, but these are still in the early development phases. Most excitingly, on May 29 a group of researchers found a molecule, which they called K22, that can stop coronaviruses — including MERS — in their tracks. However, the experiments were done in human cells grown in a laboratory, and not yet in animals, let alone in humans. With relatively few people infected (about 600), scientists are concerned that drug manufacturers will not be interested in pursuing the drug and funding costly clinical trials that are needed to get it to patients. But at least a potentially effective drug has been identified and is available for study.

While the CDC still thinks the MERS-CoV risk is not significant because transmission from person-to-person remains low, it encourages people to remain vigilant. If traveling through the Arabian Peninsula, the CDC recommends that anybody who gets sick with a fever and respiratory infection within 14 days of being there should talk to a doctor.

For further reading:

• Teisha J. Rowland’s Biology Bytes article “Mysterious MERS: The Next SARS?”
• Tracy Vence’s article “Toward Stopping MERS Spread
• CDC’s webpage “Middle East Respiratory Syndrome (MERS)”
• CDC’s webpage “MERS in the U.S.”
• Tracy Vence’s article “CDC: MERS Has Reached U.S.”
• Tracy Vence’s article “Second Confirmed U.S. MERS Case”
• Tracy Vence’s article “WHO: MERS as Global Health Threat?”
• Ruth Williams’s article “Combating Coronaviruses”
• Anna Lundin et al.’s article “Targeting Membrane-Bound Viral RNA Synthesis Reveals Potent Inhibition of Diverse Coronaviruses Including the Middle East Respiratory Syndrome Virus” in PLOS Pathogens
• Teisha J. Rowland’s book Biology Bytes: Digestible Essays on Stem Cells and Modern Medicine