A variety of pathogens can cause the common cold. Although aspects such as cold weather conditions favor the outbreak of a disease, the real trigger is found in the infection with viruses.
Cold and wet feet in sleet or freezing while waiting for the bus or train: these types of conditions favor the outbreak of a cold. But the real causes for the development of a cold lie in the droplet infection with different viruses.
Viruses as a cause of a cold outbreak
Rhinoviruses cause colds in around 40 percent of cases. This makes them the most common driving force among the various forms of viruses that promote the outbreak of a disease. Respiratory syncytial viruses, also known as RS viruses, cause a cold in around ten to 15 percent of cases, while coronaviruses cause around ten percent of colds.
From the cold to the flu
Adenoviruses, myxoviruses, echoviruses, parainfluenza viruses and influenza viruses are also often responsible for an infection of the upper respiratory tract. The latter are also considered to be the cause of the outbreak of real flu (influenza). About 20 percent of infections with influenza viruses, in contrast to a normal cold, are much more violent flu.
Mixed and super infections
Once the affected person’s body is weakened, bacteria find far fewer obstacles in their spread. If a bacterial infection is added to the typical cold symptoms, one speaks of a mixed or superinfection. In most cases of colds, such superinfections are caused by streptococci, staphylococci and pneumococci. These are often responsible for the complications of colds.