GENEVA - The World Health Organization said Saturday that there is no evidence so far of person to person transmission of the new type of coronavirus which already killed one and leaves one currently in critical situation.

No additional confirmed cases have been reported till Saturday, WHO said in a written update.

To ensure an appropriate and effective identification and investigation of patients who may be infected with the virus, without overburdening health care systems with unnecessary testing, WHO issued a revised interim case definition Saturday on its website.

The laboratories which were responsible for the confirmation of the presence of the novel coronavirus have been working on the development of diagnostic reagents and protocols and these are now available, according to the organization.

WHO is now seeking to broaden the number of laboratories that will be able to assist member States with the detection or confirmation of this novel virus.

Laboratory testing confirmed the presence of a novel coronavirus in a 49-year-old Qatari man who has been treated in Britain and the British health authority reported it to the WHO on September 22.

The comparison between the sequencing of the virus with that of a virus obtained from lung tissue of a fatal case about three months ago in a 60 year-old Saudi national indicated 99.5 percent identity.

Coronaviruses are a large family of viruses which includes viruses that cause the common cold and severe acute respiratory syndrome (SARS).

A WHO spokesman said earlier that although the novel virus belongs to the same family as what caused SARS in 2002 and 2003, they were distinctly different.