New 'Sars-like' coronavirus identified in the UK

A new respiratory illness similar to the Sars virus that spread globally in 2002 and killed hundreds of people has been identified in a man who is being treated in Britain.

The 49-year-old man, who was transferred to a London hospital by air ambulance from Qatar, is the second person confirmed with the coronavirus.

The first case was a patient in Saudi Arabia who has since died.

Officials are still determining what threat the new virus may pose.

The World Health Organization has not recommended any travel restrictions.

Prof John Watson, head of the respiratory diseases department at the UK's Health Protection Agency, said: "In the light of the severity of the illness that has been identified in the two confirmed cases, immediate steps have been taken to ensure that people who have been in contact with the UK case have not been infected, and there is no evidence to suggest that they have.

The SARS coronavirus, sometimes shortened to SARS-CoV, is the virus that causes severe acute respiratory syndrome (SARS). On April 16, 2003, following the outbreak of SARS in Asia and secondary cases elsewhere in the world, the World Health Organization (WHO) issued a press release stating that the coronavirus identified by a number of laboratories was the official cause of SARS. Samples of the virus are being held in laboratories in New York, San Francisco, Manila, Hong Kong, and Toronto.

On April 12, 2003, scientists working at the Michael Smith Genome Sciences Centre in Vancouver, British Columbia finished mapping the genetic sequence of a coronavirus believed to be linked to SARS. The team was led by Dr. Marco Marra and worked in collaboration with the British Columbia Centre for Disease Control and the National Microbiology Laboratory in Winnipeg, Manitoba, using samples from infected patients in Toronto. The map, hailed by the WHO as an important step forward in fighting SARS, is shared with scientists worldwide via the GSC website.

"Further information about these cases is being developed for healthcare workers in the UK, as well as advice to help maintain increased vigilance for this virus."

He said there was no specific evidence of the virus spreading from person to person and he had no advice for the public or returning travellers.

Peter Openshaw, director of the Centre for Respiratory Infection at Imperial College London, told Reuters that at this stage the novel virus looked unlikely to prove a concern, and may well only have been identified due to sophisticated testing techniques.

Coronaviruses, which are about 100nm in diameter, are the largest positive strand RNA viruses (indeed they have the largest genomes of any RNA virus). They infect humans and animals in which they cause respiratory and enteric disease. The coronaviruses, along with the toroviruses and arteriviruses, belong to a group, the nidovirales, that produce a nested set of mRNA with a common 3' end . The coronaviruses and the toroviruses (which together make up the Coronaviridae) have helical nucleocapsids while the arteriviruses have icosahedral nucleocapsids. Coronaviruses have an envelope that is derived from intracellular membranes and not the plasma membrane. In electron micrographs they have spikes sticking out of their surfaces (due to a large glycoprotein), leading to their name (corona = crown).