Background and summary of novel coronavirus infection – as of 21 December 2012
Over the past three months, WHO has received reports of nine cases of human infection with a novel coronavirus. Coronaviruses are a large family of viruses; different members of this family cause illness in humans and animals. In humans, these illnesses range from the common cold to infection with Severe Acute Respiratory Syndrome (SARS) coronavirus (SARS CoV).
This summary provides the latest information on all reported cases and provides details of a WHO mission to Jordan, which has concluded since the last web update.
Thus far, the laboratory confirmed cases have been reported by Qatar (two cases), Saudi Arabia (five cases) and Jordan (two cases). All patients were severely ill, and five have died.
A total of five confirmed cases have been reported from Saudi Arabia. The first two are not linked to each other and lived in different parts of the country; one of these has died. Three other confirmed cases are epidemiologically linked and occurred in one family living within the same household; two of these have died. One additional family member in this household also became ill, with symptoms similar to those of the confirmed cases. This person has recovered and tested negative, by polymerase chain reaction (PCR) tests, for the virus.
Two confirmed cases have been reported in Jordan. Both of these patients have died. These cases were discovered through testing of stored samples from a cluster of pneumonia cases in health care workers that occurred in April 2012.
In November 2012 staff from WHO Headquarters and the Eastern Mediterranean Regional Office were invited to Jordan to assess severe acute respiratory infection (SARI) surveillance and infection prevention and control measures, and to review the April 2012 outbreak. The mission included hospital site visits, interviews with patients, relatives and caregivers, and review of case files. In addition to the two previously confirmed cases, a number of health care workers with pneumonia associated with the cases were also included in the review and are now considered probable case.
The main findings of this mission are:
- The index case among this cluster could not be determined.
- All patients had significant respiratory disease presenting as pneumonia. Disease was generally milder in the unconfirmed probable cases. One patient who is a probable case had symptoms that were mild enough to be managed at home and was not admitted to hospital.
- No patient in this cluster had renal failure.
- One patient presented with pneumonia and was discovered to also have pericarditis. This patient had laboratory confirmation of infection and has died.
- A second patient developed disseminated intravascular coagulation as a complication of severe respiratory disease. This patient also had laboratory confirmation of infection and has died.
- The method of exposure is uncertain.
- There was no history of travel or contact with animals among confirmed or probable cases.
Most family members and health care workers who were closely exposed to confirmed and probable cases did not develop respiratory disease. However, the appearance of pneumonia in some who provided care and in at least two family members with direct personal contact increases the suspicion that person-to-person transmission may have occurred. The possibility of exposure to a common source has not been definitively excluded. Further investigation with serological testing (when it becomes available) to confirm additional cases may help determine the types of exposures that result in infection.
The current understanding of this novel virus is that it can cause a severe, acute respiratory infection presenting as pneumonia. The additional unconfirmed probable cases in Jordan indicate that milder presentations may also be a part of the clinical appearance associated with infection. Acute renal failure has occurred in five of the nine confirmed cases but was not a prominent feature of the Jordanian cluster. In addition, pericarditis and disseminated intravascular coagulation have now been seen in two confirmed cases.
WHO recognizes that the emergence of a new coronavirus capable of causing severe disease raises concerns because of experience with SARS. Although this novel coronavirus is distantly related to the SARS CoV, they are different. Based on current information, it does not appear to transmit easily or sustainably between people, unlike the SARS virus.
WHO has closely monitored the situation since detection of the first case and has been working with partners to ensure a high degree of preparedness should the new virus be found to be sufficiently transmissible to cause community outbreaks. Some viruses are able to cause limited human-to-human transmission under condition of close contact, as occurs in families, but are not transmissible enough to cause larger community outbreaks.
Actions taken by WHO in coordination with national authorities and technical partners include the following:
- Investigations are ongoing to determine the likely source of infection and the route of exposure. Close contacts of confirmed cases are being identified and followed up.
- An interim surveillance recommendation has been updated to assist clinicians to determine which patients should undergo laboratory testing for the presence of novel coronavirus.
- Laboratory assays for the virus have been developed. Reagents and other materials for testing are available, as are protocols, algorithms and reference laboratory services. WHO has activated its laboratory network to assist in testing and other services. WHO has now issued preliminary guidance for laboratory biorisk management.
- The three affected countries either have already or are in the process of acquiring the capacity to test for the novel coronavirus in national laboratories and have enhanced their surveillance activities according to WHO guidance along with other countries in the area.
- WHO has created a webpage for coronavirus infections, with guidance for surveillance, infection control, biorisk management, and laboratory testing, which can be found at: http://www.who.int/csr/disease/coronavirus_infections/en/index.html
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.
- Further, testing for the new coronavirus of patients with unexplained pneumonias should be considered, especially in persons residing in or returning from the Arabian peninsula and neighboring countries. Any new cases should be promptly reported both to national health authorities and to WHO.
- When collecting specimens for testing, priority should be given to collection of lower respiratory tract specimens such as sputa and endotracheal aspirates (for intubated patients).
- In addition, any clusters of SARI or SARI in health care workers should be thoroughly investigated, regardless of where in the world they occur. These investigations will help determine whether the virus is distributed more widely in the human population beyond the three countries that have identified cases.
- Health care workers should be advised to scrupulously adhere to standard infection control precautions for all patients. Droplet precautions should be added to standard precautions for any patient known or suspected to have an acute respiratory infection, including patients with suspected or confirmed infection with novel coronavirus. Airborne precautions should be used for aerosol-generating procedures, including intubation and related interventions. Details can be found on the website listed above.
- WHO does not advise special screening at points of entry with regard to this event nor does it recommend that any travel or trade restrictions be applied.
WHO continues to monitor this situation closely. Unless information is received that changes our understanding of this virus and the disease it causes, the next web update is expected to be posted during the second week of January 2013.