YOUR HEALTH Dr James Le Fanu: 22 November
The viruses responsible for colds and flu are, it is commonly presumed, transmitted by either nasal droplets or physical contact – although it can be difficult to show that even something as infectious as the common cold is transmitted from one person to another.
In a specially designed experiment conducted by the Common Cold Research Unit in the 1960s, 12 volunteers were marooned on a Scottish island for three months; five people with streaming colds then visited them from the mainland. However, not one developed even a sniffle.
It is an observation that no more than one in 10 of those living in closed communities, such as public schools or prisons, will be a ected in any single outbreak. Major flu epidemics can start almost simultaneously in many parts of the country, or in different countries. In the notorious flu pandemic that followed the First World War, which killed 30 million people, the first cases were reported at the same time from cities as far apart as Boston and Bombay.
Even those whose solitary lives mean they have little chance of ‘catching’ a virus from others, are affected by such epidemics. Shepherds in the mountains of Sardinia develop symptoms at the same time as those living in cities many miles away, while sailors who have spent weeks at sea can suddenly be struck down by the same virus.
These observations have prompted two different possible explanations. It could be that many people harbour the common flu and cold viruses throughout the year without knowing it.
Something happens – a change in temperature or the amount of solar radiation – and these latent viruses get activated to cause symptoms. This would explain the seasonality of such illnesses and the tendency for epidemics to start at the same time in different places.
Or, more speculatively, the late, distinguished cosmologist, Sir Fred Hoyle, proposed that viral particles from passing comets are deposited in the upper stratosphere and dispersed around the globe. This could explain the periodicity of viral epidemics and the fact that it is not necessary to be in contact with other humans to catch these illnesses. The existence of such theories only underlies the limits of scientific knowledge in explaining something as apparently simple as the transmission of viral illnesses.
This week’s medical query comes courtesy of a lady from Shropshire who reports, on occasion, dreaming that she is choking, causing her to wake with a feeling of something stuck in her throat. This in turn precipitates a severe bout of coughing and pains in her upper chest. These episodes are very alarming and she wonders what might be the explanation.
The cause of these episodes is most likely to be acid reflux, where acid from the stomach refluxes up into the throat at night and tips over into the larynx, causing it to go into spasm – this can be prevented by taking the acid-suppressant drug omeprazole at night. Other possible causes include postnasal drip from an infection of the sinuses, and the condition known as sleep apnoea. There is a useful article on the internet that explains this more fully: R Thurnheer, Sleep-related Laryngospasm (European Respiratory Journal 1997, vol 10, pp2084-86); but it would certainly be sensible to discuss this further with a GP.
Email drjames@lady.co.uk
In a specially designed experiment conducted by the Common Cold Research Unit in the 1960s, 12 volunteers were marooned on a Scottish island for three months; five people with streaming colds then visited them from the mainland. However, not one developed even a sniffle.
It is an observation that no more than one in 10 of those living in closed communities, such as public schools or prisons, will be a ected in any single outbreak. Major flu epidemics can start almost simultaneously in many parts of the country, or in different countries. In the notorious flu pandemic that followed the First World War, which killed 30 million people, the first cases were reported at the same time from cities as far apart as Boston and Bombay.
Even those whose solitary lives mean they have little chance of ‘catching’ a virus from others, are affected by such epidemics. Shepherds in the mountains of Sardinia develop symptoms at the same time as those living in cities many miles away, while sailors who have spent weeks at sea can suddenly be struck down by the same virus.
These observations have prompted two different possible explanations. It could be that many people harbour the common flu and cold viruses throughout the year without knowing it.
Something happens – a change in temperature or the amount of solar radiation – and these latent viruses get activated to cause symptoms. This would explain the seasonality of such illnesses and the tendency for epidemics to start at the same time in different places.
Or, more speculatively, the late, distinguished cosmologist, Sir Fred Hoyle, proposed that viral particles from passing comets are deposited in the upper stratosphere and dispersed around the globe. This could explain the periodicity of viral epidemics and the fact that it is not necessary to be in contact with other humans to catch these illnesses. The existence of such theories only underlies the limits of scientific knowledge in explaining something as apparently simple as the transmission of viral illnesses.
This week’s medical query comes courtesy of a lady from Shropshire who reports, on occasion, dreaming that she is choking, causing her to wake with a feeling of something stuck in her throat. This in turn precipitates a severe bout of coughing and pains in her upper chest. These episodes are very alarming and she wonders what might be the explanation.
The cause of these episodes is most likely to be acid reflux, where acid from the stomach refluxes up into the throat at night and tips over into the larynx, causing it to go into spasm – this can be prevented by taking the acid-suppressant drug omeprazole at night. Other possible causes include postnasal drip from an infection of the sinuses, and the condition known as sleep apnoea. There is a useful article on the internet that explains this more fully: R Thurnheer, Sleep-related Laryngospasm (European Respiratory Journal 1997, vol 10, pp2084-86); but it would certainly be sensible to discuss this further with a GP.
Email drjames@lady.co.uk