MERS-CoV Update

MERS-CoV found in camels


The International Health Regulations Emergency Committee held their fourth meeting to discuss the latest developments with MERS-CoV on December 4. The Committee concluded that it saw no reason to change its previous advice to the Director-General that the conditions for a Public Health Emergency of International Concern (PHEIC) have not at present been met. However, the Committee stated that situation continues to be of concern, in view of ongoing cases and of new information about the presence of the virus in camels. The Committee plans to meet again in March.

As of December 17, the WHO states it has been informed of a total of 165 laboratory- confirmed cases of infection with MERS-CoV, including 71 deaths. CIDRAP, the Center for Infectious Disease Research and Policy at the University of Minnesota reports (December 12 - that reports that dromedary camels in Jordan and Saudi Arabia were found to have antibodies to the virus or one closely related to it.

CIDRAP cites two studies published in Eurosurveillance* in which Jordanian and European researchers reported that 11 of 11 camels tested in Jordan had MERSCoV- like antibodies. The second study found that 280 of 310 dromedary camels from various parts of Saudi Arabia had antibodies to MERS-CoV or a very similar virus. In both studies tests in goats, sheep, and cows were negative. Earlier last year researchers found MERS-CoV like antibodies in camels in Oman, Egypt, and the Canary Islands.

The research centre points out, however, that “it remains unclear whether camels are a source of MERS-CoV in humans, because no one has yet demonstrated a close genetic match between a camel MERS-CoV isolate and a human isolate”, but adds that “the new findings seem to strengthen the evidence that many camels in the Middle East have been exposed to the pathogen”. At the December 4 meeting the IHR Emergency Committee emphasized he need for:

- investigative studies, including international case-control, serological, environmental, and animal-human interface studies, to better understand risk factors and the epidemiology;

- further review and strengthening of such tools as standardized case definitions and surveillance and further emphasis on infection control and prevention.

* Reusken CB, Ababneh M, Raj VS, et al. Middle East respiratory syndrome coronavirus (MERS-CoV) serology in major livestock species in an affected region in Jordan, June to September 2013. Eurosurveill 2013 Dec 12;50 (18): pii=20662

Hemida MG, Perera RA, Wang P, et al. Middle East respiratory syndrome (MERS) coronavirus seroprevalence in domestic livestock in Saudi Arabia, 2010 to 2013. Eurosurveill 2013 Dec 12;50(18):pii=2065


The World Health Organisation answers some frequently answered questions about MERS-CoV.

What is coronavirus?

Coronaviruses are a large family of viruses that cause illness in humans and animals. In people, coronaviruses can cause illnesses ranging in severity from the common cold to Severe Acute Respiratory Syndrome (SARS). The novel coronavirus, first detected in April 2012, is a new virus that has not been seen in humans before. In most cases, it has caused severe disease. Death has occurred in about half of cases. This new coronavirus is now known as Middle East respiratory syndrome coronavirus (MERS-CoV). It was named by the Coronavirus Study Group of the International Committee on Taxonomy of Viruses in May 2013.

Where are MERS-CoV infections occurring?

Nine countries have now reported cases of human infection with MERS-CoV. Cases     have been reported in France, Germany, Italy Jordan, Qatar, Saudi Arabia, Tunisia, the United Arab Emirates, and the United Kingdom. All cases have had some connection (whether direct or indirect) with the Middle East. In France, Italy, Tunisia and the United Kingdom, limited local transmission has occurred in people who had not been to the Middle East but who had been in close contact with laboratoryconfirmed or probable cases.

How widespread is MERS-CoV?

How widespread this virus may be is still unknown. WHO encourages Member States to continue to closely monitor for severe acute respiratory infections (SARI) and to carefully review any unusual patterns of SARI or pneumonia. WHO will continue to share information as it becomes available.

What are the symptoms of MERS-CoV?

Common symptoms are acute, serious respiratory illness with fever, cough, shortness of breath and breathing difficulties. Most patients have had pneumonia. Many have also had gastrointestinal symptoms, including diarrhoea. Some patients have had kidney failure. About half of people infected with MERS-CoV have died. In people with immune deficiencies, the disease may have an atypical presentation. It is important to note that the current understanding of illness caused by this infection is based on a limited number of cases and may change as we learn more about the virus.

What is the significance of the recent finding of MERS-CoV in camels?

On 11 November, the Ministry of Health of Saudi Arabia announced that MERSCoV had been detected in a camel linked to a human case in Saudi Arabia. This finding is consistent with previously published reports of MERS-CoV reactive antibodies in camels, and adds another important piece of information to our understanding of MERS-CoV ecology. However, this finding does not necessarily implicate camels directly in the chain of transmission to humans. The critical question that remains about this virus is the route by which humans are infected, and the way in which they are exposed. Most patients who have tested positive for MERS-CoV had neither a human source of infection nor direct exposure to animals, including camels. It is still unclear whether camels, even if infected with MERS-CoV, play a role in transmission to humans. Further genetic sequencing and epidemiologic data are needed to understand the role, if any, of camels in the transmission of MERS CoV to humans.

How do people become infected with this virus?

We do not yet know how people become infected with this virus. Investigations are underway to determine the source of the virus, the types of exposure that lead to infection, the mode of transmission, and the clinical pattern and course of disease.

How is the virus being transmitted to humans?

We still do not know the answer to this question. It is unlikely that transmission of the MERs-CoV to people occurs through direct exposure to an infected camel, as very few of the cases have reported a camel exposure. More investigations are needed to look at the recent exposures and activities of infected humans. WHO is working with partner agencies with expertise in animal health and food safety, including FAO, OIE and national authorities, to facilitate these investigations. Many technical organizations are offering their expertise to assist ministries responsible for human health, animal health, food, and agriculture. Investigation protocols and guidelines for dealing with new cases are available on the WHO website.

Can the virus be transmitted from person to person?

Yes. We have now seen multiple clusters of cases in which human-to-human transmission has occurred. These clusters have been observed in health-care facilities, among family members and between co-workers. However, the mechanism by which transmission occurred in all of these cases, whether respiratory (e.g. coughing, sneezing) or direct physical contact with the patient or contamination of the environment by the patient, is unknown. Thus far, no sustained community transmission has been observed.

Is there a vaccine or treatment for MERS-CoV?

No. No vaccine is currently available. Treatment is largely supportive and should be based on the patient’s clinical condition.

Are health workers at risk from MERS-CoV?

Yes. Transmission has occurred in healthcare facilities, including spread from patients to health-care providers. WHO recommends that health-care workers consistently apply appropriate infection prevention and control measures.

MERS-CoV infections update (WHO)

 Date of upload: 17th Jan 2014


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