Emergencies preparedness, response

Middle East respiratory syndrome coronavirus (MERS-CoV) – update

Disease Outbreak News

On 2 May 2014, the National IHR Focal Point for the United States of America notified WHO about the first laboratory confirmed case of MERS-CoV infection in the United States.

As part of the investigation of contacts of the first confirmed case, testing for MERS-CoV was undertaken on contacts. A contact of the first case initially tested negative for MERS-CoV by PCR based on respiratory tract samples taken 10 days after contact with the first case. However, on 16 May, this contact tested positive for antibodies for MERS-CoV in a blood sample taken 14 days after contact. Currently, this individual is asymptomatic. He is a male in his 70s with comorbidities and has no history of travel to countries outside the United States.

The antibody test result suggests this individual may have been infected with MERS-CoV; however he does not meet WHO's current definition of a laboratory confirmed case of MERS-CoV, which requires positive PCR tests.

Globally, 632 laboratory-confirmed cases of infection* with MERS-CoV have officially been reported to WHO, including 193 deaths. The global total includes all of the case reported in this update, plus 17 laboratory confirmed cases officially reported to WHO from Saudi Arabia between 16 and 18 May. WHO is working with Saudi Arabia for additional information on these cases and will provide further updates as soon as possible.

WHO advice

Based on the current situation and available information, WHO encourages all Member States to continue their surveillance for severe acute respiratory infections (SARI) and to carefully review any unusual patterns.

Infection prevention and control measures are critical to prevent the possible spread of MERS-CoV in health care facilities. Health-care facilities that provide for patients suspected or confirmed to be infected with MERS-CoV infection should take appropriate measures to decrease the risk of transmission of the virus from an infected patient to other patients, health-care workers and visitors. Health-care workers should be educated, trained and refreshed with skills on infection prevention and control.

It is not always possible to identify patients with MERS-CoV early because some have mild or unusual symptoms. For this reason, it is important that health-care workers apply standard precautions consistently with all patients – regardless of their diagnosis – in all work practices all the time.

Droplet precautions should be added to the standard precautions when providing care to all patients with symptoms of acute respiratory infection. Contact precautions and eye protection should be added when caring for probable or confirmed cases of MERS-CoV infection. Airborne precautions should be applied when performing aerosol generating procedures.

Patients should be managed as potentially infected when the clinical and epidemiological clues strongly suggest MERS-CoV, even if an initial test on a nasopharyngeal swab is negative. Repeat testing should be done when the initial testing is negative, preferably on specimens from the lower respiratory tract.

Health-care providers are advised to maintain vigilance. Recent travellers returning from the Middle East who develop SARI should be tested for MERS-CoV as advised in the current surveillance recommendations. All Member States are reminded to promptly assess and notify WHO of any new case of infection with MERS-CoV, along with information about potential exposures that may have resulted in infection and a description of the clinical course. Investigation into the source of exposure should promptly be initiated to identify the mode of exposure, so that further transmission of the virus can be prevented.

People at high risk of severe disease due to MERS-CoV should avoid close contact with animals when visiting farms or barn areas where the virus is known to be potentially circulating. For the general public, when visiting a farm or a barn, general hygiene measures, such as regular hand washing before and after touching animals, avoiding contact with sick animals, and following food hygiene practices, should be adhered to.

WHO does not advise special screening at points of entry with regard to this event nor does it currently recommend the application of any travel or trade restrictions.

* On 23 May 2014, it was noted that this number includes one case that was reported on 7 May, but had not yet been confirmed to WHO.