An unexpected summer cold can be just as miserable as the more predictable winter illness. Although we usually associate colds with dark cold winter days we can still fall foul of the ubiquitous common cold viruses in the height of summer. Worse still, the sore throat and headache that herald the start of a cold often start just as we have arrived at our summer holiday destination and are ready for a well deserved break in the sunshine.
What causes a summer cold?
The common cold is caused by around 200 different types of virus which make it the most common illness worldwide. So wherever you plan to go on holiday this year you can be sure that the common cold viruses are already endemic. Unless of course you plan to have a rather lonely holiday in some wilderness resort where you are unlikely to come into contact with other human beings.
Long haul jet flights
Although the chance of getting a cold in summer is only 1 in 4 compared to winter there are some special factors that may increase the risk. Long haul jet flights appear to pose a special risk as there are no other periods when we are likely to be squeezed as tightly together with 400 potential sources of common cold infection. The chances are that several of our fellow passengers will have a cold and the confined space of a jumbo jet is an ideal environment for transmission of airborne disease. Experiments on exposing uninfected volunteers to others with common cold infections have shown that the chances of catching a cold are directly related to the number of hours of exposure to infection. Hence, you are much more likely to get a cold on a long haul flight to the USA compared with a short hop to Europe.
Air conditioning itself may contribute to infection with common cold viruses. The lining of the nose is covered with a thin layer of mucus which protects against infection. Since air conditioners extract moisture from the air they may cause some drying of the protective mucous blanket in the nose and predispose to infection. The cold air may also help viruses to establish a hold in the nose as they reproduce better in a cold nose.
Any form of stress will lower our resistance to infection by depressing the immune response. Although we may take summer holidays as a leisure activity many psychologists classify holidays as a major source of stress. All the worries about last minute parking, holiday insurance, kennels for the dog and home security can take their toll and leave us more susceptible to infection just when we want to be in top form to enjoy ourselves.
Travel to foreign countries
Travel to foreign countries can itself increase the risk of viral infection as we have probably already been exposed to all the current common cold viruses in our home town but are likely to encounter quite new viruses, to which we have no immunity, at our holiday destination. We could ourselves be responsible for introducing new viruses into a foreign country if we arrive at our holiday destination with a cold. With modern jet travel viruses are rapidly spread and this is why influenza spreads so rapidly around the world during an epidemic.
Is there anything we can do to avoid summer colds?
Colds spread in crowded indoor areas so if you can avoid the crowds and spend more time on the beach or in the countryside then you will reduce the risk of infection. Colds are also spread by contaminated surfaces such as door handles, telephone and slot machines. The viruses can survive for hours on a contaminated surface and when we touch the surface we pick up the virus and transfer infection to our nose or eye surface. The tears from the eye drain into the nose and this is a common route of infection from contaminated fingers. We cannot avoid touching contaminated surfaces in public transport and crowded areas, but it is good sense to wash our hands when we sit down to eat or relax. Many other viruses are also spread by finger contact and this simple precaution could also help prevent infection from the many enteroviruses which cause the upset tummy often associated with summer travel.
Is it a cold or hayfever?
Summer is the time for grass pollen to fill the air on warm sunny days and hayfever has some similarities to common cold as both nasal disorders are associated with a blocked and runny nose. However, it is usually easy to distinguish between the two conditions as common cold is associated with a sore throat, headache and nasal irritation whereas hayfever is associated with itching of the nose and eyes.
Those who suffer from hayfever may find that a summer cold is far more bothersome than the winter variety as the nose is already sensitized by the allergic response to pollen and this may exaggerate the response to viral infection and cause more severe symptoms which persist longer than a winter cold.
Medications for the treatment of hayfever such as antihistamines and nasal steroids should be continued during a common cold infection as there is no evidence that they complicate recovery from infection. However, it may be useful to supplement the hayfever medication with paracetamol to control symptoms of sore throat, headache and sinus pain and use a topical nasal decongestant spray to alleviate symptoms of nasal congestion.
(R) thedailystar.net 2005