Адам коронавирусы NL63: Қасиеттері мен таралуы

Species of virus

Human coronavirus NL63 (HCoV NL63) is a species of coronavirus, specifically a Setracovirus from among the Alphacoronavirus genus. It was identified in late 2004 in patients in the Netherlands by Lia van der Hoek and Krzysztof Pyrc using a novel virus discovery method VIDISCA. Later on the discovery was confirmed by the researchers from the Rotterdam, the Netherlands The virus is an enveloped, positive sense, single stranded RNA virus which enters its host cell by binding to ACE2. Infection with the virus has been confirmed worldwide, and has an association with many common symptoms and diseases. Associated diseases include mild to moderate upper respiratory tract infections, severe lower respiratory tract infection, croup and bronchiolitis. The virus is found primarily in young children, the elderly, and immunocompromised patients with acute respiratory illness. It also has a seasonal association in temperate climates. A study performed in Amsterdam estimated the presence of HCoV NL63 in approximately 4.7% of common respiratory illnesses. The natural reservoirs are palm civets and bats. Estimates of its divergence from another coronavirus (HCoV 229E) are around 1000 years ago; it has likely circulated in humans for centuries. The evolution of HCoV NL63 appears to have involved recombination between an ancestral NL63 like virus circulating in African Triaenops afer bats and a CoV 229E like virus circulating in Hipposideros bats. Recombinant viruses can arise when two viral genomes are present in the same host cell.

The first cases of the infection with HCoV NL63 were found in young children with severe lower respiratory tract infections admitted to hospitals. While the clinical presentation of the virus can be severe, it has also been found in mild cases of respiratory infection. The comorbidity of HCoV NL63 with other respiratory infections, has made the specific symptoms of the virus difficult to pinpoint. A study of clinical symptoms in HCoV NL63 patients without secondary infection, reported the most common symptoms to be fever, cough, rhinitis, sore throat, hoarseness, bronchitis, bronchiolitis, pneumonia, and croup. However, the high frequency of croup is specific to HCoV NL63 infection.

It is believed that the route of HCoV NL63 spread is through direct person to person transmission in highly populated areas. The virus can survive for up to a week outside of the body in aqueous solutions at room temperature and three hours on dry surfaces. Most people will be infected with a coronavirus in their lifetime, but some populations are more susceptible to HCoV NL63. These populations include children under the age of 5, the elderly, and immunocompromised individuals. The virus seems to have seasonal incidence, occurring most frequently in the winter months in temperate climates. In more extreme and tropical climates the virus has no preference toward a particular season. Many studies have reported the co occurrence of HCoV NL63 with other human coronavirus, Influenza A virus, Human orthopneumovirus (RSV), parainfluenza virus, and Human metapneumovirus (hMPV).

It is difficult to distinguish between symptoms caused by infection of the HCoV NL63 virus and those caused by other common human viruses, making diagnosis and detection complex. Reverse transcription polymerase chain reaction of samples collected through nasopharyngeal swab is the most commonly used method for detection of the virus.

Research published in 2005 by Esper, et al. suggested an association of HCoV NL63 infection with Kawasaki disease, a systemic vasculitis in childhood that may result in aneurysms of the coronary arteries. In the developed world, Kawasaki disease is the most common cause of acquired heart disease in children. Further analysis of HCoV NL63 pathogenicity seems warranted, in particular because of recent evidence that this virus uses the same cellular receptor (ACE2) as both SARS CoV (the causal agent of SARS) and SARS CoV 2 (the causal agent of COVID 19), This type of infection is the direct result of the viral invasion of the mucosal lining of the intestines. The role of HCoV NL63 in gastroenteritis is unclear due to typical coinfection with other viruses in this condition. HCoV NL63 is likely under detected due its role in many mild to moderate respiratory infections and comorbidity with other disease. Researchers have suggested that more comprehensive, population based studies are necessary to determine the effects of this virus on systems outside of the respiratory tract.