The window of opportunity to contain a mass global outbreak of the killer coronavirus is "narrowing", the head of the World Health Organisation has warned.  Worried Dr Tedros Adhanom Ghebreyesus has expressed fears of a pattern of infection as countries across the world see hundreds of cases of the virus - with no clear link to source country China.  His comments come as officials in Iran and Italy close schools and offices and cancel events amid a spread of the deadly bug.  Iran today reported two more deaths, bringing the total to four, and said the fatalities were from among 13 new confirmed cases of the virus.  Concerns over the spread of the virus prompted Iran to close all schools and Shiite seminaries in Qom, about 130 kilometres (80 miles) south of Tehran. Read More Related Articles 'Coronavirus' party selling face masks cancelled after being branded 'tasteless'  Officials fear the virus may have spread to "all Iran's cities", the BBC reports.  While Italian authorities said the number of people infected with the new coronavirus from China has more than quadrupled due to an emerging cluster of cases in the country's north.  Many of the new cases represented the first infections in Italy acquired through secondary contagion and brought the country's total to 17.  Dr Tedros said the pattern of infection outside of China was worrying, and the new cases in Iran were "very concerning".  He said: "We are concerned about the number of cases with no clear epidemiological link, such as travel history to or contact with a confirmed case." Read More Related Articles Coronavirus cruise ship Brit couple's extraordinary quarantine diary Read More Related Articles Coronavirus: World Health Organisation debunk 13 myths about how to beat virus  But he insisted there was still a "fighting chance" of stopping the spread of the virus and called on all nations to do more to fight outbreaks.  The first to fall ill in northern Italy met with someone who had returned from China on January 21 without presenting any symptoms of the new virus, called Covid-19, health authorities said.  The 38-year-old Italian man is in hospital in the northern town of Codogno in a critical condition.  The man's wife and a friend of his also tested positive for the virus.  Three patients at the hospital where he went with flu-like symptoms a few days ago also have infections.  Five nurses and doctors contracted the virus as well.  Italian health minister Roberto Speranza said Italy is now seeing the same sort of "cluster" of cases that Germany and France have seen.  The mayor of Codogno has issued a decree ordering the closure of all restaurants, coffee bars, schools and public gathering spots such as discos and gyms.  The Health Ministry advised area residents to stay home as a precaution.  Local officials in another town, Casalpusterlengo, ordered local schools closed until Tuesday.  A third town, Castiglione d'Adda, said its libraries, public offices, gyms and wa