The common cold is probably the most common illness experienced by parents and children, according to MedlinePlus, a website of the National Institutes of Health. Children catch common colds between three and five times a year, often infecting their parents during the contagious phase of the illness. The Merck Manuals Online Medical Library mentions that one group of viruses, the rhinoviruses, cause approximately one-half of all colds. Some different viruses for the common cold are the respiratory syncytial virus, metapneumoviruses, enteroviruses and influenza viruses.
Respiratory Syncytial Virus
The respiratory syncytial virus is among the most common cold-causing viruses, according to the medical text "Essentials of Pathophysiology: Concepts of Altered Health States." That virus can also cause lung diseases, and in American children below the age of one it is the most frequent cause of pnuemonia and bronchiolitis, notes the U.S. Centers for Disease Control and Prevention. Common colds caused by the respiratory syncytial virus occur more frequently and their effect is more severe in children under three. Outbreaks of the common cold due to that virus reach their peak in the winter and spring.
Metapneumovirus
The human metapneumovirus, first identified by Dr. Bernadette van den Hoogen and colleagues in 2001 in the Netherlands, can cause the common cold and other respiratory illnesses. In a 2001 article in the journal "Nature Medicine," Dr. van den Hoogen mentions that the virus spread among humans for more than 50 years before its identification, and that serological studies in the Netherlands showed evidence of previous exposure to the virus in practically every child aged five and over. Pneumonia and severe bronchiolitis join the common cold as illnesses caused by human metapneumovirus.
Enteroviruses
More than 60 types of enteroviruses can cause infections, and those common viruses constitute the second most frequent cause of viral infections in humans after rhinoviruses, notes the CDC. The types of enterovirus include polioviruses, echoviruses and coxsackieviruses. While most enterovirus infections do not cause illnesses, the number of infections that cause diseases with symptoms in the U.S. every year ranges between 10 and 15 million, according to the CDC. Enterovirus infections may present as serious diseases, including polio and meningitis, or as less threatening illnesses such as mild "summer colds."
Influenza Viruses
The CDC notes that influenza types A, B and C can infect humans, and influenza type A can also infect animals, including birds, horses and pigs. Subtypes of influenza type A virus usually exist in wild birds without causing symptoms, but some subtypes can cause illness and death in wild birds and domestic poultry. Presentation of influenza infections range from the common cold, which usually resolves within two weeks, to more serious outbreaks of avian flu or bird flu.
References
- MedlinePlus: Common Cold
- Merck Manuals Online Medical Library: Common Cold
- "Essentials of Pathophysiology: Concepts of Altered Health States"; Carol Mattson Porth; 2006
- U.S. Centers for Disease Control and Prevention: Respiratory Syncytial Virus Infection
- "Nature Medicine"; A Newly Discovered Human Pneumovirus; Bernadette van den Hoogen, et al.: June 2001
