SYNONYM OR CROSS REFERENCE: Acute viral rhinitis, acute coryza, common cold virus, RhV.
CHARACTERISTICS: Rhinovirus, part of the Picornaviridae family and discovered in 1956, are small, icosahedral, non-enveloped viruses around 27 nm in diameter, and contain one positive-strand RNA(1,2). Over 100 antigenically distinct serotypes have been identified, which are divided into RhV A and RhV B groups, with RhV A2 and RhV C subclasses, based on their sequence similarity and cell entry receptors(3).
PATHOGENICITY/TOXICITY: Human rhinovirus (HVR) infections are the cause of about 50% of all common colds and asthma, and chronic obstructive pulmonary diseases (COPD) exacerbations(4). Most infections are mild and self-limited, and generally affect the sinuses, although it has been speculated to occur in the middle ear as well(5). Symptoms may include runny nose and nasal congestion, headache, cough, sneezing, sore throat, rhinorrhea, croup in infants, tracheitis, and malaise that may last from 1 - 2 weeks(5-8), and fever may occur in infants and young children. Replication of the virus is optimized at 33° - 35 °C, thus it is commonly found in the upper respiratory tract, where it can cause persistent bronchospastic cough, and can also lead to secondary bacterial infections such as sinusitis and otitis media(8). Although infrequent, it is also the second most recognized means of lower respiratory tract infections such as pneumonia and bronchiolitis in young children and immuno-compromised adults, and can also cause bronchitis and bronchopneumonia(3). Grayish white vesicles may appear in the posterior region of the palate, uvula, and the tonsillar pillars(9). Contracting infection can further exacerbate pre-existing respiratory diseases such as cystic fibrosis(3).
EPIDEMIOLOGY: Worldwide - accounts for more than 80% of common colds during high prevalence seasons in autumn between September to November in temperate climates although it is present in the community year-round and can affect persons of all ages(3,7). Epidemiological studies have shown that children under 7 years of age are more susceptible than adults, with almost all children having experienced this infection by the age of 2 years. Individuals with asthma are more susceptible to infection(10).
HOST RANGE: Humans(11).
MODE OF TRANSMISSION: Airborne transmission of aerosols and droplets is the major route of dissemination of the virus, which can enter the body through the respiratory tract by the nose and mouth(14,15). Transmission through direct and indirect contact also occurs and is most common via the hand-nose-hand route, followed by self-inoculation of nasal/conjunctival mucosa present on one's hands(8).
INCUBATION PERIOD: Generally between 48-72 hours(8).
COMMUNICABILITY: While symptomatic, and while the virus can be detected on their hands and nasal mucosa(16).
DRUG SUSCEPTIBILITY: No single antiviral treatment is effective for Rhinovirus infections as there are a great number of different serotypes; however, a combined antiviral and antimediator treatment may be effective as intranasal interferon-α2b and ipratropium and oral naproxen together can reduce symptoms, rhinorrhea, cough, and malaise . Dextromethorphan and hydrocodone can relieve cough in adults(7). Topical (intranasal), oral nasal decongestants, and topical ipratropium (a prescription anticholinergic) can relieve nasal symptoms in adults. Antihistamines alone or in combination with decongestant therapy are effective but side effects have been observed.
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to disinfectants such as Lysol Disinfectant Spray (0.1% o-phenylphenol and 79% ethanol) after 1 - 10 minutes, domestic bleach (800 ppm free chlorine diluted from 6% sodium hypochlorite) after 10 minutes, 7.05% quaternary ammonium diluted in water, 14.7% phenol diluted in water(20), 2% glutaraldehyde(21), and 1% iodine has virucidal activity for up to 1 hour on hands(22).
PHYSICAL INACTIVATION: Inactivate by heating in a 56°C water bath for 16 minutes(23), and at pH 6 or at pH 3 for rapid and complete inactivation(13). Applying virucides (mixture of 3.5 mg citric acid, 1.7 mg malic acid, and 0.7 mg sodium lauryl sulphate) to paper tissues prevents the virus expelled through the nasal passage from reaching the hands, and thus prevents its spread(15).
SURVIVAL OUTSIDE HOST: Virus can survive on formica, stainless steel, varnished wood, nylon, acetate, orlon, Dacron, wool, and silk for up to 3 hours; on cotton, rayon, facial tissue, and paper towel for up to 1 hour; and in nasal mucous up to 24 hours(24). Drying has little effect on viability.
SURVEILLANCE: Monitor for symptoms. Diagnosis of rhinovirus infections can be done using reverse-transcription polymerase chain reactions (RT-PCR) assay, with probes that target the non-coding region of the virus(3). Identification by cell culture has been utilized traditionally; however, this method is less sensitive compared to RT-PCR.
Note: All diagnostic methods are not necessarily available in all countries.
FIRST AID/TREATMENT: Administer appropriate drug therapy for symptomatic relief if necessary. Humidified air, fluid intake, bed rest, nasal decongestants, cough suppressants, and warm saline gargles can be effective in relieving symptoms(7,8).
IMMUNISATION: No vaccines against rhinovirus are currently available.
PROPHYLAXIS: Studies on human volunteers have shown zinc gluconate lozenges to be an effective treatment in reducing clinical signs of rhinovirus infection(25), as well as human interferon α2 (HuIFN- α2), which is easy to self-administer and can produce a protective effect against infection(26). Antivirals have proven ineffective when used alone, and thus can only be protective when administered with other antimediators(17). Good personal hygiene can limit the risk of infection.
LABORATORY-ACQUIRED INFECTIONS: No incidents have been reported to date.
SOURCES/SPECIMENS: Nasal and throat swabs(27).
PRIMARY HAZARDS: Exposure to particle aerosols or droplets of mucous membranes carrying the infectious virus, contact via hand-to-hand route(16).
SPECIAL HAZARDS: None.
RISK GROUP CLASSIFICATION: Risk Group 2(28).
CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infected or potentially infected materials, animals, or cultures.
PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes(29).
OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities(29).
SPILLS: Allow aerosols to settle. Wear protective clothing and cover spill with absorbent paper towel. Apply appropriate disinfectant, and starting from perimeter and wipe towards the center. Allow sufficient contact time with the detergent before cleaning up(29).
DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration(29).
STORAGE: Properly labelled and sealed containers(29).
REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.
UPDATED: September 2010
PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada
Although the information, opinions and recommendations contained in this Pathogen Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Public Health Agency of Canada, 2010