Currently, attention is focused on the flu epidemic, which is now in full swing. However, human rhinovirus (HRV) is another virus that can result in serious illness. The virus is responsible for a wide range of human and animal diseases ranging from mild respiratory tract infections (the common cold) to paralytic poliomyelitis. A new study was conducted to evaluate HRV infections in children up to five years of age and factors involved in disease severity. The findings were published online on January 13 in the journal Pediatrics by Brazilian researchers.
The study group comprised 434 children who suffered from a broad range of respiratory infections that varied in severity. Nasopharyngeal aspirates (withdrawal of fluid from the nasal area) were taken from all the subjects. The aspirates were tested for HRV and eight other respiratory viruses. The children were also evaluated for host risk factors and any other health problems.
The investigators detected HRV in 181 (41.7%) samples; in 107 of them. HRV was the only infectious agent present. However, in 74 children, co-infections, primarily with respiratory syncytial virus (RSV; 43.2%) were found. Moderate to severe symptoms were observed in 31/107 (28.9%) single infections and in 38/74 (51.3%) co-infections Statistical analysis found association of co-infections with lower respiratory tract symptoms and some factors of disease severity, such as hospitalization. In co-infections, RSV was the most important virus associated with severe disease. Prematurity, cardiomyopathies (hear disease), and noninfectious respiratory diseases were co-morbidities that also were associated with disease severity.
The researchers concluded that their study showed that HRV was a common pathogen (infectious agent) of respiratory disease in children and was also involved in severe cases, causing symptoms of the lower respiratory tract. Severe disease in HRV infections were primarily due to the presence of RSV in co-infections, prematurity, congenital heart disease, and noninfectious respiratory disease.
The researchers of the present study are affiliated the aLaboratory of Virology, Instituto de Ciências Biomédicas and Hospital de Clínicas, and Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia; all facilies are in Brazil.
There are currently three HRV species: A, B and C. HRVs are the most commonly isolated viruses from individuals with mild upper respiratory tract illness. In otherwise healthy adults this manifests as several minor symptoms such as a runny or blocked nose, sneezing, a sore throat, a dry cough, red eyes, and a general feeling of tiredness. These people generally recover within a week but in some cases symptoms persist for longer periods. HRV can be a much more serious problem for some segments of the population such as infants and the frail elderly. For example, in the USs, 75% of common colds in children under five years are medically attended and HRV has been linked with roughly one third of children with middle ear infections (acute otitis media). HRV is the second most frequently recognized infection associated with pneumonia and bronchiolitis in infants. There is also growing evidence for HRV as the causative agent for severe lower respiratory tract illness in older adults and in highly immunocompromised people, such as bone marrow transplant recipients. These diseases can be fatal.
HRV is a major cause of hospitalization for patients with underlying respiratory conditions, such as asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis, where HRV can aggravate their existing disease. Estimates suggest that HRV is linked to about 70% of all asthma flare-ups and more than 50% of the hospitalized cases. Studies also suggest that more than 35% of acute COPD patients requiring hospitalization, are associated with respiratory viruses, including rhinovirus.
Unlike the flu virus, vaccination is currently not available for HRV. However, the risk of an HRV infection can be reduced by frequent hand-washing and covering your nose and mouth when you sneeze or cough to reduce the spread of the virus. Healthy individuals should avoid close contact with someone who is sick, and those who do become infected should stay home to prevent spreading the virus to others.