Rhinoviruses
Rhinoviruses are viruses primarily responsible for the common cold, making them the most prevalent cause of respiratory infections. They spread primarily through sneezing and coughing, which release droplets containing the virus into the air. Upon entering the respiratory system, rhinoviruses attach to cells via a receptor called intercellular adhesion molecule-1 (ICAM-1), allowing them to replicate and cause symptoms. Common symptoms include sneezing, coughing, nasal congestion, and in more severe cases, wheezing and pneumonia. While the duration of an infection typically lasts about seven days, some symptoms can persist for two weeks or more.
Currently, there is no cure or vaccine available for rhinovirus infections, which complicates treatment efforts. Instead, approaches to manage symptoms include rest, hydration, and zinc lozenges, although their efficacy is mixed. Preventive strategies, such as frequent handwashing and proper hygiene practices, are vital in reducing the transmission of these viruses. Given the high number of rhinovirus serotypes—ninety-nine in total—developing a universal vaccine remains a challenge. Historically, the common cold has been recognized for centuries and continues to be a focus of research aimed at understanding and combating these infections.
Rhinoviruses
ANATOMY OR SYSTEM AFFECTED: Cells, chest, lungs, nose, respiratory system, throat
DEFINITION: Disease-causing agents that are responsible for more common colds than any other respiratory virus
CAUSES: Transmitted through sneezing and coughing
SYMPTOMS: Sneezing, coughing, nasal and sinus drainage, congestion, fluid in the ears, headache, fever; in more severe cases, wheezing and pneumonia
DURATION: Approximately seven days for infection; two or more weeks for symptoms
TREATMENTS: Zinc lozenges, rest; preventive measures (handwashing with soap or antiseptic such as alcohol-based sanitizer, disinfection of surfaces commonly touched by people, covering coughs and sneezes with tissue or article of clothing)
Causes and Symptoms
Rhinoviruses have been identified as the virus most often responsible for the common cold. Rhinoviruses have also been implicated in complications of asthma. Rhinoviruses are transmitted through sneezing and coughing, which expels droplets of moisture laden with virus. Once introduced into the respiratory system, the virus enters cells by interfacing with the intercellular molecule-1 (ICAM-1) receptor. As its name implies, ICAM-1 provides adhesion between endothelial cells and leukocytes after injury or stress, but it also facilitates the entry of rhinoviruses into cells, where they can replicate. The subsequent is responsible for most of the symptoms of the common cold.
Colds occur more often in winter than in other seasons, although they can occur year-round. This seasonal effect is thought to be the result of an increase in time spent in closer contact with other people who may carry a rhinovirus.
Treatment and Therapy
No cure exists for the treatment of rhinoviruses once contracted, and no exists to against infection with rhinoviruses. However, many strategies exist for reducing the of viruses between infected individuals. Traditional home remedies such as chicken soup, bed rest, and drinking a lot of fluids may increase the comfort level of the sufferer, but they do not shorten the course of the disease. Additionally, while vitamin C and echinacea may help reduce cold symptoms and the length of the cold, there has not been extensive evidence as to their helpfulness in preventing or getting rid of a cold. Antibiotics are not effective against rhinoviruses. Preventive measures are the best methods for reducing infection rate, including breast-feeding of infants and frequent handwashing. Increased vitamin D levels may also be associated with a lowered risk of infection.
Studies conducted on the use of zinc lozenges as a treatment for the have produced mixed results. In test tubes, positively charged zinc inhibits processing of viral proteins by several different mechanisms. One analysis of previous studies suggested that differences in effectiveness of zinc lozenges could be explained by the ligand or ligands bound to the zinc. Zinc lozenges with only one ligand, such as zinc acetate or zinc gluconate lozenges, were observed to be more effective in reducing cold duration than were zinc lozenges with more ligands, though even they were not effective in all studies. The ineffectiveness of intranasal zinc application was hypothesized to result from an electrical potential difference of 60 to 120 millivolts between the nose and mouth, which results in repulsion of charged particles such as ionized zinc.
There are ninety-nine known serotypes of rhinoviruses. This variety of cell surface antigens makes the development of a vaccine that is effective against multiple rhinoviruses difficult. In the first decade of the twenty-first century, a region of a rhinoviral protein called VP4 was shown to be very common between the different serotypes. Future efforts to synthesize a vaccine may focus on this common element.
Perspective and Prospects
The common cold has been known for millenia and was first given this name in the sixteenth century. Evidence exists across cultures demonstrating knowledge of the cold, extending as back as far as ancient Egypt. In the eighteenth century, Benjamin Franklin’s Definition of a Cold (1773) demonstrated insightful speculation about the airborne nature of cold transmission and suggested methods for preventing the disease.
The Rhinovirus was first isolated in 1956 and during successive decades was identified as the virus best associated with the common cold. As technology improved, so did detection and identification of different viruses that could be responsible for the common cold. Simple culturing methods gave way to (RT-PCR) assays, which were more sensitive in detecting and characterizing specific rhinoviruses. In various campaigns to find a treatment for the common cold, antiviral drugs and interferon have been shown to be effective in protecting against rhinoviruses, though attempts to translate these results into a treatment have not been successful.
The Common Cold Research Unit (CCRU), originally established in Great Britain at the outset of World War II as the Harvard Hospital, operated from 1946 to 1989 and was devoted to researching the causes of the common cold as well as possible treatments for the disease. It was there that coronaviruses, which can also be responsible for causing the common cold, were first isolated in 1965.
Bibliography
Carson-DeWitt, Rosalyn, and Brian Randall. "Common Cold." Health Library, Jan. 9, 2013.
"Children and Colds." Healthy Children, 3 Mar. 2022, www.healthychildren.org/English/health-issues/conditions/ear-nose-throat/Pages/Children-and-Colds.aspx. Accessed 8 Aug. 2023.
"Common Cold." MedlinePlus, 2 Feb. 2023, medlineplus.gov/ency/article/000678.htm. Accessed 8 Aug. 2023.
"Common Colds: Protect Yourself and Others." Centers for Disease Control and Prevention, Mar. 11, 2013.
Eccles, Ronald, and Olaf Weber, eds. Common Cold. Birkhäuser Advances in Infectious Diseases. Basel, Switzerland: Birkhäuser Basel, 2009.
"Rhinoviruses." Centers for Disease Control and Prevention, 8 Mar. 2023, www.cdc.gov/ncird/rhinoviruses-common-cold.html. Accessed 8 Apr. 2024.
"Rhinovirus Infections." HealthyChildren.org. American Academy of Pediatrics, May 11, 2013.
Tyrrell, David, and Michael Fielder, Cold Wars: The Fight Against the Common Cold. New York: Oxford University Press, 2002.
Yin-Murphy, Marguerite, and Jeffrey W. Almond. “Picornaviruses—Classification and Antigenic Types.” In Medical Microbiology, edited by Samuel Baron. Galveston: University of Texas Medical Branch, 1996.