WHO: Novel coronavirus summary and literature update – as of 17 May 2013

Since April 2012, there have been 40 laboratory-confirmed cases of human infection with novel coronavirus (nCoV). Several countries in the Middle East have been affected, including Jordan, Saudi Arabia, the United Arab Emirates (UAE), and Qatar. Cases have also been reported by three countries in Europe: France, Germany, and the United Kingdom. All of the European cases have had a direct or indirect connection to the Middle East. However, in France and the United Kingdom, there has been limited local transmission among close contacts who had not been to the Middle East but had been in contact with a traveler recently returned from the Middle East.
 
The most recent case reported had onset on 10 May 2013. Most patients are male (79%; 31 of 39 cases with sex reported), and range in age from 24 to 94 years (median 56 years). All of the laboratory confirmed cases had respiratory disease as part of the illness, and most had severe acute respiratory disease requiring hospitalization. Reported clinical features include acute respiratory distress syndrome (ARDS), renal failure requiring hemodialysis, consumptive coagulopathy, and pericarditis. Many patients have also had gastrointestinal symptoms including diarrhea during the course of their illness. One patient, who was immunocompromised, presented with fever, diarrhea and abdominal pain, but had no respiratory symptoms initially; pneumonia was identified incidentally on a radiograph. 20 of the 40 patients have died.

Since 6 April 2013, 21 cases of infection have been confirmed and reported in the region of Al-Ahsa in the Eastern Province of Saudi Arabia (16 males and 5 females, median age 56 years). Nine of these have died, and six remain critically ill. Most patients were reported to have at least one comorbidity. The majority of the initial cases were associated with a single health care facility in Al-Ahsa. Additional cases have subsequently been identified who were not patients at the facility. Three family members of cases linked to the facility and two health care workers not associated with the Al-Ahsa facility but who had contact with laboratory confirmed cases have become infected. Two additional cases have been identified in the community that did not have any links with other cases from the Al-Ahsa healthcare facility. Although investigations are still ongoing into the source of this outbreak, early information indicated that only a small minority of these cases had contact with animals in the time leading up to their illness.

Since 8 May 2013, two cases have been reported by France. The first case became ill after a 9 day vacation to Dubai, UAE. The second case, reported on 12 May, is a patient who shared a room at a health care facility with the first case. Investigations to look for additional cases among fellow travelers of the first case and close contacts of both cases are currently underway, but no further cases have been identified. Of note, the patient’s initial nasopharyngeal swab was negative, but a bronchoalveolar lavage was found to be positive for nCoV.
All clusters reported to date have occurred among family contacts or in a health care setting. Human-to-human transmission occurred in at least some of these clusters, however, the exact mode of transmission is unknown. So far, no evidence of sustained transmission beyond the clusters into the community has been observed.

Recent peer-reviewed papers published since the last update

The Coronavirus Study Group of the International Committee on Taxonomy of Viruses has published a proposed new designation for the novel coronavirus, the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). Reference: De Groot RJ, et al. Middle East Respiratory Syndrome Coronavirus (MERS-CoV): Announcement of the Coronavirus Study Group. J Virol. Published ahead of print 15 May 2013. doi:10.1128/JVI.01244-13.

Summary assessment

The nCoV is thought to be of animal origin and to be sporadically transmitted to humans through an as yet unknown route. However, it is clear that the virus can also be transmitted between humans. So far, human-to-human transmission has only been observed in health care facilities and close family contacts and sustained transmission in the community has not been observed. The continued appearance of cases that are not part of larger clusters, and who do not have a history of animal contact, increases concerns about possible community transmission. This possibility is being investigated by authorities in Saudi Arabia.
The infection of two health care workers who had contact with infected patients and other examples of nosocomial transmission re-emphasize the need for meticulous adherence to appropriate infection control measures when nCoV is suspected, beginning with initial patient triage. Current infection control recommendations can be found at:
http://www.who.int/csr/disease/coronavirus_infections/en/.
 
The large number of cases with reported co-morbidities suggests that increased susceptibility from underlying medical conditions may play a role in transmission. In addition, it has now been demonstrated that nCoV infection may present atypically, and initially without respiratory symptoms, in immunocompromised individuals.
Limited evidence suggests that the use of nasopharyngeal swabs for diagnosis may not be as sensitive as the use of lower respiratory specimens. Lower respiratory specimens should be used for diagnosis in addition to nasopharyngeal swabs when they are available. If an nasopharyngeal swab tests negative, consider retesting using lower respiratory specimens such as sputum, endotracheal aspirate, or bronchoalveolar lavage. Clinicians should take care to follow strict infection prevention and control guidelines when collecting respiratory specimens of any kind.
The recent increase in cases may in part be related to increased awareness among the medical community, however the demonstrated ability of this virus to transmit between humans and to cause large outbreaks, has increased concerns about the possibility of sustained transmission. Countries in the Middle East in particular should maintain a high level of vigilance and a low threshold for testing of suspect cases. Current surveillance recommendations can be found at:
http://www.who.int/csr/disease/coronavirus_infections/en/.
WHO expects that more cases will be identified. Control of the disease will require urgent multisectoral investigations aimed at identifying the source of the virus and the exposures that result in infection. It is critical for member states to report these cases and related information urgently to WHO, as required by the International Health Regulations, to inform effective international alertness, preparedness and response. 

http://www.who.int/csr/disease/coronavirus_infections/update_20130517/en/index.html