This article primarily provides information on MERS coronavirus, along with some historical information on SARS coronavirus.
MERS coronavirus is an acute respiratory illness caused by a novel coronavirus, Middle East respiratory syndrome coronavirus (MERS-CoV); cases have been reported since 2012. As of December 2015, more than 1,600 cases (and more than 630 deaths) have been reported. About 40% of these cases were reported since January 2015. Most cases (78%) have occurred in or originated from Saudi Arabia. There is no known effective treatment for coronavirus infection. Entry point screening or travel restrictions are not currently recommended.
SARS coronavirus: Severe acute respiratory syndrome (SARS) was a respiratory illness caused by the SARS coronavirus that first emerged in China in November 2002. The outbreak spread internationally and peaked in April 2003, but by July 2003, all known SARS transmission had ended. A total of 8,096 cases were reported, with 774 deaths.
Mode of Transmission
Viral isolation and antibody studies indicate widespread circulation of MERS-CoV in camels throughout Africa and the Middle East. Camels are considered to be the likely source of MERS-CoV in humans; however, camel-to-human transmission is rare, even with prolonged contact. There has been no direct role for bats in the current outbreak.
In the community, the most implicated risk factors include: direct contact with infected humans, contact with individuals who have had contact with dromedary camels, direct contact with camels, (including carcasses, body fluids, secretions, urine, raw meat, camel droppings), and engaging in animal-related activities (e.g., feeding, cleaning, slaughtering, birthing, milking).
Ongoing low-level circulation of MERS-CoV in human populations may be occurring, but there is currently no evidence of community-based transmission of clinical cases or more than 1 generation of human-to-human transmission within the community.
A lack of high quality infection control measures in health care settings has played a significant if not causal role in nosocomial transmission (transmission within a medical facility). Some degree of persistence in the environment from animal products and excreta is now thought unlikely.
There is no evidence of airborne transmission, but this mode of transmission cannot be ruled out.
Cases of MERS-CoV have been acquired in Saudi Arabia, Qatar, Jordan, Kuwait, Oman, and the United Arab Emirates.
- At least 25 cases have been exported from the Arabian Peninsula and identified in Europe (U.K., Germany, France, Italy, Greece, Netherlands, Austria, and Turkey), Africa (Tunisia and Algeria), Asia (China, Malaysia, Philippines, and South Korea), and the Americas (U.S.).
- Noscomial outbreaks have occurred in Saudi Arabia, Jordan, Europe, and South Korea.
The distribution and extent of MERS-CoV in Saudi Arabia's neighboring countries are unknown at present.
- Travel to areas where cases have been reported
- Direct or indirect contact with camels
- Contact with a person who has had contact with a camel
- Consumption of unpasteurized camel milk, camel urine, or improperly cooked meat
- Close contact with a person diagnosed with MERS-CoV
- Inpatient or outpatient visit to health care facilities in an endemic area
- Underlying medical condition (chronic diseases or immune compromise)
- Elderly persons
- Women who are pregnant
In one study, exposure to cattle was associated with illness.
Most people who have been infected with MERS-CoV developed severe acute respiratory illness with symptoms of fever, cough, and shortness of breath. Pneumonia occurs in about half of all cases and is always present in severe cases. Gastrointestinal symptoms occur in about 30% of cases. About 35-40% of infected persons have died. Some people, especially healthy, younger individuals and secondary cases, are more likely to have a mild respiratory illness.
Travelers to affected countries, especially older individuals and those with underlying health conditions, should:
- Practice good personal hygiene (e.g., handwashing, cough and sneeze etiquette, and keeping distance of at least 1 m (3 ft) from persons with acute febrile respiratory symptoms).
- Avoid physical contact with wild or farm animals and camels.
- Avoid the consumption of camel products (e.g., unpasteurized milk, undercooked meat, and urine).
- Be aware that the presence of infection control standards sufficient to protect travelers presenting to hospitals with unrelated illnesses cannot be assumed
- Any traveler with respiratory symptoms returning from the Arabian Peninsula or neighboring countries should practice cough etiquette (maintain distance from others, cover coughs and sneezes with clothing or disposable tissues, and wash hands frequently), wear a face mask, and seek immediate medical care, informing the provider of his or her travel history.
Entry point screening or travel restrictions are not recommended at this time, but this may change as more information regarding transmission becomes available.
Need for Medical Assistance
Any traveler with respiratory symptoms within 14 days of returning from the Arabian Peninsula or neighboring countries should practice cough etiquette (maintain distance from others, cover coughs and sneezes with clothing or disposable tissues, and wash hands frequently), wear a face mask, and seek immediate medical care (if symptoms appear), informing the provider of his or her travel history.