Scientists find ‘cousin to SARS’

Dutch scientists have announced they had uncovered a previously unknown virus, a cousin to SARS, that causes respiratory sickness and is likely to have spread around the world. The virus is only the fourth so-called coronavirus ever to be found in nearly four decades and could explain many cases of respiratory illness that leave doctors baffled. Named HCoV-NL63, the virus causes symptoms similar to a bad cold and does not unleash the pneumonia characterised by severe acute respiratory syndrome (SARS) coronavirus, which killed some 800 people and infected 8,000 in a 2002-03 epidemic. Young children and people whose immune system has been compromised by HIV or other diseases are more at risk although not apparently fatally so. In a study published online by the journal Nature Medicine, the University of Amsterdam team report on their detective work, launched after a seven-month-old girl was to admitted to their hospital last April with bronchiolitis, an inflammation of the lower airways. Tests for the common cold, flu and other well-known viruses all proved negative. “At first, we were worried that the child may have caught the virus from an animal because she had been to the zoo the previous weekend,” the research supervisor, Ben Berkhout, an expert in human retrovirology, told AFP. Those fears proved unfounded, for the team then “did a little amplification trick” of the viral sample and “ended up with a couple of fragments that looked like coronaviruses but not one of the known ones,” he said. Closer examination of its genetic code showed it shares about two-thirds of its nucleotides, the sub-units of a molecule of DNA, with the three established coronavirus types. In other words, it was an independent member of the coronavirus family that had never been spotted before. The team then tested stored samples taken from other admissions and found that another seven patients with respiratory problems – 7 per cent of admissions – had been infected by the same virus. Four of the seven were children less than 12 months old and three were adults. Two of the adults had a damaged immune system – one had had a bone-marrow transplant and the other had AIDS. The findings suggest “the virus is already widely spread within the population,” the research, led by Lia van der Hoek, says. “This virus probably has a worldwide spread, I would say, and it’s causing perhaps the symptoms of common colds but in the younger ones, it’s causing more severe respiratory problems,” Mr Berkhout said. “About 20 to 50 per cent of respiratory problems do not have a viral cause, so we now can fill in a significant fraction of those unknowns.” Mr Berkhout admitted it was “surprising” that this virus had never been found before, but part of the problem was the lack of tools to detect new agents easily. In general, coronaviruses are usually transmitted by airborne droplets, breathed in from someone in proximity who, for instance, sneezes or coughs. (Source: AFP, ABC Health, March 2004)

Dutch scientists have announced they had uncovered a previously unknown virus, a cousin to SARS, that causes respiratory sickness and is likely to have spread around the world. The virus is only the fourth so-called coronavirus ever to be found in nearly four decades and could explain many cases of respiratory illness that leave doctors baffled. Named HCoV-NL63, the virus causes symptoms similar to a bad cold and does not unleash the pneumonia characterised by severe acute respiratory syndrome (SARS) coronavirus, which killed some 800 people and infected 8,000 in a 2002-03 epidemic. Young children and people whose immune system has been compromised by HIV or other diseases are more at risk although not apparently fatally so. In a study published online by the journal Nature Medicine, the University of Amsterdam team report on their detective work, launched after a seven-month-old girl was to admitted to their hospital last April with bronchiolitis, an inflammation of the lower airways. Tests for the common cold, flu and other well-known viruses all proved negative. “At first, we were worried that the child may have caught the virus from an animal because she had been to the zoo the previous weekend,” the research supervisor, Ben Berkhout, an expert in human retrovirology, told AFP. Those fears proved unfounded, for the team then “did a little amplification trick” of the viral sample and “ended up with a couple of fragments that looked like coronaviruses but not one of the known ones,” he said. Closer examination of its genetic code showed it shares about two-thirds of its nucleotides, the sub-units of a molecule of DNA, with the three established coronavirus types.In other words, it was an independent member of the coronavirus family that had never been spotted before. The team then tested stored samples taken from other admissions and found that another seven patients with respiratory problems – 7 per cent of admissions – had been infected by the same virus. Four of the seven were children less than 12 months old and three were adults. Two of the adults had a damaged immune system – one had had a bone-marrow transplant and the other had AIDS. The findings suggest “the virus is already widely spread within the population,” the research, led by Lia van der Hoek, says. “This virus probably has a worldwide spread, I would say, and it’s causing perhaps the symptoms of common colds but in the younger ones, it’s causing more severe respiratory problems,” Mr Berkhout said. “About 20 to 50 per cent of respiratory problems do not have a viral cause, so we now can fill in a significant fraction of those unknowns.” Mr Berkhout admitted it was “surprising” that this virus had never been found before, but part of the problem was the lack of tools to detect new agents easily. In general, coronaviruses are usually transmitted by airborne droplets, breathed in from someone in proximity who, for instance, sneezes or coughs.(Source: AFP, ABC Health, March 2004)