Rhinovirus

The rhinovirus (from the rhis "nose", ῥινός, romanized: "of the nose", and the vīrus) is the most common viral infectious agent in humans and is the predominant cause of the common cold. Rhinovirus infection proliferates in temperatures of 33–35 °C (91–95 °F), the temperatures found in the nose. Rhinoviruses belong to the genus Enterovirus in the family Picornaviridae. The three species of rhinovirus (A, B, and C) include around 165 recognized types that differ according to their surface antigens or genetics. They are lytic in nature and are among the smallest viruses, with diameters of about 30 nanometers. By comparison, other viruses, such as smallpox and vaccinia, are around ten times larger at about 300 nanometers, while flu viruses are around 80–120 nm. In 1953, when a cluster of nurses developed a mild respiratory illness, Winston Price, from the Johns Hopkins University, took nasal passage samples and isolated the first rhinovirus, which he called the JH virus, named after Johns Hopkins. His findings were published in 1956. Common cold Rhinoviruses may be spread via airborne aerosols, respiratory droplets and from fomites (contaminated surfaces), including direct person-to-person contact. Rhinoviruses are spread worldwide and are the primary cause of the common cold. Symptoms include sore throat, runny nose, nasal congestion, sneezing and cough; sometimes accompanied by muscle aches, fatigue, malaise, headache, muscle weakness, or loss of appetite. Most sinus findings are reversible consistent with a self-limited viral process typical of rhinovirus colds. Fever and extreme exhaustion are more usual in influenza. Children may have six to twelve colds a year. In the United States, the incidence of colds is higher in the autumn and winter, with most infections occurring between September and April. The seasonality may be due to the start of the school year and to people spending more time indoors thereby increasing the chance of transmission of the virus.