Researchers on the offense against deadly coronavirus infections
A new, deadly strain of coronavirus has emerged in Middle East and has caused a handful of infections in three Middle East nations and in the United Kingdom. The virus, discovered last year, is able to infect human cells and cause severe, potentially fatal lung damage. The virus, known as hCoV-EMC, is from the same family of viruses as those that cause common colds and the one that caused the deadly outbreak of Severe Acute Respiratory Syndrome (SARS) that first emerged in Asia in 2003; thus, researchers are concerned that the new strain could cause a similar outbreak to the one caused by SARS.
Last September, the World Health Organization (WHO), issued an international alert about the virus after it was identified in a Qatari man in Britain who had recently been in Saudi Arabia. A study published last month found that hCoV-EMC was well adapted to infecting human cells and may be treatable with medicines similar to the ones used for SARS, which killed a tenth of the 8,000 people it infected. To date, the virus has infected 15 people worldwide, killing nine of them. On a positive note, a breakthrough occurred this week: on March 13, Dutch researchers announced that they have identified a cell surface protein it uses to enter and infect human cells. They published their findings in the journal Nature.
The researchers have found that the key receptor for the disease as a cell surface protein called dipeptidyl peptidase 4 (DPP4). They also found cells containing DPP4 receptors were common in the lower respiratory tract but not in the upper respiratory tract; thus, yielding clues as to why the virus causes illness in the lungs rather than in the nose and throat as a cold virus would. The findings should help scientists determine ways of developing potential drugs or vaccines to block the DPP4 receptors and prevent infection. A few drugs that block DPP4 receptors are currently on the market; interestingly, they are licensed for use in diabetes. However, the researchers tried using those pharmaceuticals on the virus in the laboratory and found that they did not work. Far from being discouraged, the researchers are evaluating other molecules that might block the receptors and could form the basis for developing a potential vaccine.
The researchers note that it will take more than lab work to determine whether the virus is the next SARS or just an exotic pathogen of little broad importance to public health. They note that only epidemiological data can show how efficiently the new coronavirus spreads from person to person and whether it is as deadly as it seems.
The WHO notes that it continues to closely monitor the situation. The organization encourages all Member States to continue their surveillance for severe acute respiratory infections (SARI) and to carefully review any unusual patterns. WHO is currently working with international experts and countries where cases have been reported to assess the situation and review recommendations for surveillance and monitoring. All Member States are reminded to promptly assess and notify WHO of any new case of infection with n hCoV-EMC, together with information about potential exposures that may have resulted in infection and a description of the clinical course. At present, the 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.