Tuesday, January 28, 2014

Human Coronavirus HKU1 - The New Common Cold?

More than 200 different viruses are known to cause the common cold.

The most common cold viruses include:

  • Rhinoviruses -- 10-40%
  • Coronaviruses -- 20%
  • Respiratory Syncytial Virus (RSV) -- 10%

I have been seeing a small spike in human coronavirus (HCoV-HKU1) lately (including one of our virologists) and I decided that it would be a good time write a bit about the virus in order to raise awareness among non-virologists out there.
Human coronavirus
HCoV-HKU1 contains the HE gene which distinguishes it as a betacoronavirus, which is the same genus as Severe Acute Respiratory Syndrome Virus (SARS-CoV). It was first identified in January of 2005 in two patients from Hong Kong. The initial patient was a 71-year old man who had been hospitalized with an acute respiratory distress and confirmed bilateral pneumonia. It is possible the man had contracted the virus in nearby (~23 miles) Shenzhen as he had recently (within the incubation period) returned from a trip there.

When I get nasopharyngeal (NP) or throat swabs sent to the health lab, especially during influenza season, our algorithm includes virus culture (Hep-2, Caco-2, HFS, MRC-5, RMK, BGMK, and MDCK cells), influenza PCR, and if influenza negative we use the Luminex Respiratory Virus Panel.
Bio-Rad Bio-Plex 200 Hardware for RVP
HCoV-HKU1 has not been found to be cultureable in any of the above cell lines; however we have noticed some “irregularities” with the cells in these samples. The HCoV-HKU1 samples have been influenza negative, and were identified using the RVP.

HCoV-HKU1 is most closely related to the mouse hepatitis virus (MHV).
Mouse with hepatitis...get it? :)
HCoV-HKU1 is a positive-sense, single-stranded RNA virus. Without getting into too much detail, this means the virus particle is similar to a human mRNA in the sense that its genome can immediately be translated into protein without going through intermediate steps.

A trace back analysis of SARS-CoV negative NP aspirates from patients with respiratory illness during the SARS-CoV pandemic in 2003, identified HCoV-HKU1 RNA in a sample from a 35-year-old woman with pneumonia, as well as 10 patients in northern Australia.

The first identified case in the Western hemisphere was discovered by clinical virologists (good people!) at Yale-New Haven Hospital in Connecticut. They conducted a study of 851 infants and children over a seven-week period from December 2001 to February 2002. The children were also tested for Human respiratory syncytial virus (RSV), parainfluenza viruses (1-3), influenza A and B, adenovirus, and human metapneumovirus. All 851 tested negative, but trace back analysis revealed two of the children tested positive for HCoV-HKU1.

Coronavirus have been very important in the last decade as sources of global emerging disease concerns. SARS-CoV was a pandemic that occurred between winter of 2002 and summer of 2003. Spread to at least 37 countries, there were 8200+ reported cases and at least 775 deaths.
Currently, Middle Eastern Respiratory Syndrome Coronavirus (MERS-CoV) is smoldering. Since spring of 2012 there have been 157 documented cases and 66 deaths. The situation is being closely monitored.

The CDC has put together a very nice FAQ about coronaviruses linked here.

Lance D. Presser has a PhD in Microbiology and Immunology and currently is a Public Health Laboratorian.

Hire Lance as a consultant using Zintro.

No comments:

Post a Comment