Novel Diseases





5 dead in Middle East from novel coronavirus


 

The deaths of five people in the Middle East from a novel coronavirus is cause for concern. However, the WHO continues to monitor the situation and says the virus does not appear to transmit easily between people, but nonetheless encourages all Member States, particularly those on the Arabian peninsula to continue their surveillance for severe acute respiratory infections. This is the WHO’s latest report available at the time of going to press.

The WHO issued this report on 30 November 2012: Over the past two 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).

Thus far, the cases reported have come from Qatar, Saudi Arabia and Jordan. All patients were severely ill, and five have died. The two Qatari patients are not linked. Both had severe pneumonia and acute renal failure. Both are now recovering.

A total of five confirmed cases have been reported from Saudi Arabia. The first two are not linked to each other; 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 that occurred in April 2012.

The two clusters (Saudi Arabia, Jordan) raise the possibility of limited human-tohuman transmission or, alternatively, exposure to a common source. On-going investigation may or may not be able to distinguish between these possibilities.

The current understanding of this novel virus is that it can cause a severe, acute respiratory infection presenting as pneumonia. Acute renal failure has also occurred in five 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 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 on-going 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 also issued preliminary guidance for ‘laboratory biorisk management’ (http://tinyurl.com/bq3x9ft).

- Guidance is available for infection control (http://tinyurl.com/bvbl4wf). 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 neighbouring countries. Any new cases should be promptly reported both to national health authorities and to WHO.

- 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.

- 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.

New research shows novel coronavirus could spread easier than SARS

Research on the novel coronavirus that has infected patients from three Middle Eastern countries show that the receptor it uses to infect human cells is different from the one used by its relative the SARS virus and that it can infect cells from a range of animals, and infected hosts may be able to pass on the virus easier than with SARS, according to a study released December 11, 2012.

The study was conducted by researchers from Germany and the Netherlands and appears in mBio, the online journal of the American Society for Microbiology (ASM).

The virus, called hCoV-EMC, has been linked to two illness clusters, including one that involved healthcare workers at a Jordanian hospital. All of the patients with confirmed infections had pneumonia, and several had severe renal complications.

The European Centre for Disease Prevention and Control (ECDC) said recently that though the case clusters raise the possibility of human-to-human transmission, so far there is too little information to confirm or rule it out. Regardless, concerns about transmission risk have prompted intensive monitoring of close contacts of case-patients and reminders about steps to protect healthcare workers.

In a statement from the American Society of Microbiology, Christian Drosten of the University of Bonn Medical Centre in German, a lead author of the study, was quoted as saying: “This virus is closely related to the SARS virus, and looking at the clinical picture, it causes the same pattern of disease.”

Given the similarities, Drosten and his colleagues wanted to know whether hCoV-EMC and SARS might use the same receptor, a sort of molecular “dock” on human cells that the virus latches onto to gain entry to the cell. The SARS receptor, called ACE2, is found mostly on pneumocytes deep within the human lung, so an individual must breathe in many, many SARS viruses for a sufficient number of them to reach this susceptible area and cause an infection. Drosten says this simple fact helped ensure the SARS outbreak didn’t spread like wildfire and was mostly limited to healthcare workers and residents of overcrowded housing in Hong Kong. Also, once a person was infected with SARS in the deep part of their lungs, he or she felt sick almost immediately and therefore was not active in the community and infecting others, another aspect of the receptor that helped curb the outbreak.

“hCoV-EMC does not use the ACE2 receptor,” says Drosten. This leaves open the possibility that hCoV-EMC could use a receptor in the human lung that is easier to access and could make the virus more infectious than SARS, but it is still not known what receptor the virus does use.

He pointed out another fundamental difference between SARS and hCoVEMC. Like SARS, hCoV-EMC is most closely related to coronaviruses from bats, but unlike SARS, this study found that hCoV-EMC can still infect cells from many different species of bats. “This was a big surprise,” says Drosten. “It’s completely unusual for any coronavirus to be able to do that – to go back to its original reservoir.” The virus is also able to infect cells from pigs, indicating that it uses a receptor structure that all these animals have in common. If that receptor is present in mucosal surfaces, like the lining of the lung, it is possible the virus could pass from animals to humans and back again, making animals an ongoing source of the virus that would be difficult or impossible to eliminate.

doi: 10.1128/ mBio.00515-12

 Date of upload: 22nd Jan 2013

 

                                  
                                               Copyright © 2013 MiddleEastHealthMag.com. All Rights Reserved.