While the flu is caused by influenza virus the common cold is caused by another virus, the rhinovirus. On the average, each of us catches a cold two to three times a year.
The rhinovirus is spread in the same way that the flu virus is, through the nasal and respiratory secretions. This means that when an individual coughs into their hands or sneezes on an object the virus can be spread to the next person when it is transmitted to their hands in the person and touches their nose, mouth or eyes.
Sometimes the virus is spread directly when an individual sneezes in the area of another person’s face.
Immune System Factors
People become more susceptible to catching a cold, or the virus multiplying at such a rate inside the body that the immune system is not able to contain it before becoming sick, because of several different factors in their life.
The first is an underlying medical condition which adversely affects the immune system, such as diabetes, asthma, HIV or AIDS.
Another factor is rest. When we do not get enough sleep each night are immune system is depressed and we are no longer able to fight off the environmental toxins and waste products which cause illness.
Sugar will depress the immune system as can inappropriate nutritional intake. We truly are what we eat and when we do not provide our body adequate nutritional factors such as vitamins and minerals, we suffer overall poor health.
Rhinovirus Response
Researchers at the University of Calgary confirmed in late 2008 that it is the response of our immune system to the rhinovirus that causes the cold symptoms and not the rhinovirus itself. There are over 100 different types of viruses that can cause the common cold, however, the rhinovirus is a major cause.
The research was published in the American Journal of Respiratory and Critical Care Medicine and was the first time that scientists comprehensively reviewed the gene changes in the rhinovirus.
Rhinovirus is a tiny, nearly round particle. It contains tightly packed genetic material surrounded by a protein shell, or capsid. Details on how the RNA is prepped to exit the capsid and effectively infect us were revealed in a 2013 study from the Max F. Perutz Laboratories in collaboration with groups at the Universities of Barcelona and Madrid.
The researchers looked at how the structure of one of the common cold virus types changes upon infection with the host cell, leading to the release of the RNA and its duplication.
“Interestingly we found that the conformation of the RNA, and in turn its interaction with the inner side of the virus capsid changes”, said Dieter Blaas from the Max F. Perutz Laboratories. “This seems to be crucial to ‘avoid knots’ when the long thread-like RNA molecule is unfolded in order to exit the capsid."
And, while the rhinovirus is the major cause of common cold, it is also an important pathogen in other conditions such as asthma and chronic obstructive pulmonary disease. For instance, researchers have found that children who get recurrent rhinovirus wheezing early in life are 10 times more likely to develop asthma later in life.
Symptoms usually occur within one to three days after being exposed to the virus. They often begin with a burning feeling in the nose or throat.
Many individuals go on to experience sneezing, runny nose and the feeling of being tired and less specifically on well. In the early days nasal secretions or sand and water, but as the cold continues to progress they become sicker and darker.
Color Doesnt Matter
It was once believed that dark mucus or yellow mucus meant you had developed a bacterial infection but researchers today understand that this is not the case.
Some individuals will develop a mild to moderate cough and those who have asthma may find that their control of their disease has suddenly disappeared. Usually there is no fever but sometimes individuals can experience a mild low grade fever of less than 100°F.
After about three days the worst of the symptoms is usually over. However, you can continue to experience congestion for over a week.
During the first three days you have a cold you are contagious to others so it is best to stay home and rest so that you don’t spread the virus to other people and that you will recover much more quickly.
If you continue to feel bad for over a week to 10 days you should seek the advice of your primary care physician who may do sinus x-rays or a nasal swab to determine if you are suffering from another illness.
Complications
Complications can happen in individuals who have a compromised immune system and can include bronchitis, your infection in adults, pneumonia, sinusitis or worsening of their asthma.
Colds are usually seen in young children just before they develop an ear infection because of the drainage of the fluid behind the eardrum and the likelihood that they will develop a bacterial infection.
Preventing a cold is so much easier than suffering through one.
So avoid secondhand smoke, unnecessary antibiotics, drink plenty of water and get enough rest. Some research has found that the bacteria in yogurt has helped in the prevention of colds.
Wash your hands whenever you feel you may have come in contact with the germs and periodically throughout the day. Keep your hands away from your nose, mouth and eyes and use paper towels to dry your hands during cold season instead of sharing a cloth towel.
For More Information:
A. Pickl-Herk, D. Luque, L. Vives-Adrian, J. Querol-Audi, D. Garriga, B. L. Trus, N. Verdaguer, D. Blaas, J. R. Caston.
Uncoating of common cold virus is preceded by RNA switching as determined by X-ray and cryo-EM analyses of the subviral A-particle.
Proceedings of the National Academy of Sciences, 2013; 110 (50): 20063 DOI: 10.1073/pnas.1312128110
L. E. Wickert, M. R. Karta, A. Audhya, J. E. Gern, P. J. Bertics.
Simvastatin attenuates rhinovirus-induced interferon and CXCL10 secretion from monocytic cells in vitro.
Journal of Leukocyte Biology, 2014; 95 (6): 951 DOI:10.1189/jlb.0713413