It seems to have begun on September 15 last year, when a doctor at the Dr Soliman Fakeeh Hospital in Jeddah, Saudi Arabia, posted an alert on the international internet-based reporting system ProMED - the Programme for Monitoring Emerging Diseases.
Dr Ali Mohamed Zaki, professor of microbiology at the private hospital, had isolated a human virus that had never been seen before. It had been discovered in the sputum of a 60-year-old patient who in July had died from pneumonia associated with acute kidney failure.
He had tested for all the usual suspects - influenza virus A and B, parainfluenza virus, enterovirus and adenovirus - all with negative results. Then Prof Zaki applied a test that suggested he was dealing with a possibly novel coronavirus.
He sent a sample to a specialist lab in the Netherlands, where the genome of the virus was sequenced and his suspicions were confirmed - the five known human coronaviruses appeared to have been joined by a sixth.
Eight days later, the UK's Health Protection Agency reported that a 49-year-old man from Qatar, who had been travelling in Saudi Arabia, was in intensive care in London infected with the same virus.
The lab in the Netherlands concluded that both victims had been infected with the same novel coronavirus.
The World Health Organisation (WHO) announced four new cases and one death on November 23, "identified as part of the enhanced surveillance in Saudi Arabia (three cases, including a death) and Qatar (one case). This brings the total of laboratory confirmed cases to six".
A week later, it was discovered that the birth of the new virus had taken place months earlier than September last year. On November 30, a WHO team armed with a new test for the virus retested samples from two patients whose deaths in Jordan in April last year had been attributed to pneumonia. They found the deaths had been the first known handiwork of the virus.
Coronaviruses, discovered in the 1960s and named for their crown-like shape when seen under an electron microscope, are common and the majority are responsible for nothing more than the common cold and mild upper-respiratory tract infections.
But in 2003 an outbreak by a new strain, originating in southern China, travelled to 29 countries and killed 774 people. No further cases of Sars - Severe Acute Respiratory Syndrome - have been diagnosed since 2004.
