Detection of influenza, parainfluenza, adenovirus and respiratory syncytial virus during asthma attacks in children older than 2 years old.
BACKGROUND
Viral upper respiratory tract infections (URTI) have been correlated with the onset of asthma attacks in children and viral identification was reported in 14-49 % of nasal samples. The aim of the present study was to detect influenza, parainfluenza, adenovirus and respiratory syncytial virus (RSV) in older children during acute asthma attacks.


METHODS
A total of 104 children (2-14 years) were included in four groups: group I: asthmatics with acute attack and URTI; group II: asthmatics without URTI (group I children, 30 days later); group III: non-asthmatics with URTI; group IV: non-asthmatic, asymptomatic children. A diagnosis of URTI was considered when (3 symptoms (cough and/or sneeze, nasal obstruction, hypertrophy of turbinates, pain and/or retropharynx hyperemia, headache and fever) in asthmatics and at least 2 symptoms in non-asthmatics were present, starting within 7 days. Samples of nasal mucosa cells (n = 123) were collected, and culture and indirect immunofluorescence were carried out to identify respiratory syncytial virus, adenovirus, influenza A and B, parainfluenza 1,2 and 3 and rhinovirus.


RESULTS
Viral identification rates were higher in the asthmatic groups: 13.9 % in group I, 11.1 % in group II; 2.8 % in group III and 0 in group IV. The following viruses were identified: RSV 2/36, rhinovirus 1/36, adenovirus 1/36 and parainfluenzae 1/36 in group I; adenovirus 2/18 in group II; RSV 1/36 in group III.


CONCLUSIONS
The rate of viral identification was higher in asthmatic children, whether symptomatic or not, suggesting a possible susceptibility to viral infections. Virus could also be a triggering factor in attacks, although it is not the most preponderant in older children.
Azevedo
A M N
AM
Medical School, University of São Paulo, Brazil.
Durigon
E L
EL
Okasima
V
V
Queiroz
D A O
DA
de Moraes-Vasconcelos
D
D
Duarte
A J S
AJ
Grumach
A S
AS
D000258:Adenovirus Infections, Human / Q000453:epidemiology; D000260:Adenoviruses, Human / Q000302:isolation & purification; D000293:Adolescent; D001249:Asthma / Q000453:epidemiology* / Q000821:virology; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology; D009980:Influenza A virus / Q000302:isolation & purification; D009981:Influenza B virus / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology; D008297:Male; D010222:Parainfluenza Virus 1, Human / Q000302:isolation & purification; D010223:Parainfluenza Virus 2, Human / Q000302:isolation & purification; D010224:Parainfluenza Virus 3, Human / Q000302:isolation & purification; D018184:Paramyxoviridae Infections / Q000453:epidemiology / Q000821:virology; D012130:Respiratory Hypersensitivity / Q000453:epidemiology; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology; D018113:Respiratory Syncytial Virus, Human / Q000302:isolation & purification; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000821:virology; D012621:Seasons; D014777:Virus Diseases / Q000453:epidemiology* / Q000821:virology