This article is more than 5 years old. Information may no longer be current.
Rhinovirus subtypes A2, C aggravated respiratory functions in cystic fibrosis patients
Click Here to Manage Email Alerts
Infection with rhinovirus subtypes A2 and C caused significant respiratory exacerbation in children and adolescents with cystic fibrosis, data from a recent study indicated.
Researchers at the Instituto da Crinaca, Hospital das Clínicas da Faculdade de Midicina da Universidade de Sao Paulo performed microbiologic testing on respiratory specimens to investigate a potential correlation between rhinovirus C infection and worsening lung function in children with cystic fibrosis.
One hundred and three cystic fibrosis patients aged 3.8 months to 17.8 years comprised the study population, according to the researchers. Nasopharyngeal aspirates, nasal mucus specimens, sputum or oropharyngeal samples were collected for microbiologic culturing during 408 patient visits from 2006 to 2007.
The researchers said clinical and lung function data were also recorded. Exacerbation of respiratory disease was defined as a child exhibiting at least two of the following symptoms:
- Fever.
- Increase in the amount of secretion or cough intensity.
- Change in sputum’s color.
- Worsening of dyspnea.
- Loss of appetite.
- Decrease of forced expiratory volume in 1s≥10%.
- Weight loss.
The researchers identified various respiratory infections using individual reverse transcription-polymerase chain reactions or PCRs selective for respiratory syncytial virus; influenza viruses A and B; human parainfluenza viruses 1, 2 and 3; human coronavirus; human metapneumovirus; adenovirus; human bocavirus; picornavirus; and the beta-actin gene. Specimens containing rhinovirus underwent further testing to identify subtypes.
Results indicated the presence of at least one respiratory virus in 49.8% of samples, the researchers reported. Rhinovirus was the most commonly identified agent, appearing in 34.1% of specimens, and was also responsible for the majority of coinfections.
The researchers noted that 93 specimens tested positive for rhinovirus. Thirty-six samples showed evidence of genotype A, and rhinovirus subtypes A2 and C surfaced in 14 samples each.
Acute exacerbation of respiratory disease was observed on 142 occasions, according to the researchers, and patients were hospitalized on 31 occasions. Data did not denote a relationship between respiratory viruses and pulmonary exacerbations.
“Because rhinovirus was the main agent identified among stable patients, we verified the effects of respiratory viruses, excluding rhinovirus from the analysis,” wrote the researchers. “A significant association with respiratory exacerbation was found (OR 1.195, p=0.10).
“In contrast, when looking at rhinovirus subtypes, we noticed that identification of rhinovirus subtypes A2 or C was also significantly associated with respiratory exacerbations (OR 1.213).”
De Almeida MB. Emerg Infect Dis. 2010;16(6): DOI: 10.3201/eid1606.100063.