[Studies on respiratory infections in the field of primary care (I). Correlation between viral infection and secondary bacterial infection in patients visiting a doctor in private practice].
We attempted to find out whether there is a correlation between viral infection and secondary bacterial infection on the basis of the analysis of the results of the culture of virus and bacteria in the same specimen from the throat swabs of 95 patients who had an acute upper respiratory inflammation when they visited a doctor in private practice in Sendai city during the epidemic caused by influenza virus. Viral culture was performed by a microplate-method devised originally by Numazaki. The influenza virus was recovered from 56 cases (59%) consisting of 43 cases of type A (Hong-Kong) and 13 cases of type B. From 73 cases, (77%), 79 strains of possibly pathogenic bacteria were recovered, consisting of 43 strains of H. influenzae, 18 strains of S. aureus, seven strains of S. pneumoniae, four strains each of C. freundii and S. liquefaciens and one strain each of beta-haemolytic Streptococcus and B. catarrhalis. The incidence of positive culture of both virus and possibly pathogenic bacteria was high already at the early stage (2-3 days) of the disease. We found no correlation between the type of virus and the species of the microbial isolates. There was no difference in the incidence of positive bacterial culture in relation to age group. We suggest that a secondary bacterial infection occurs already at the early stage of the disease after viral infection because the incidence of positive culture of possibly pathogenic bacteria was high at the above stage.
Watanabe
A
A
Oizumi
K
K
Motomiya
M
M
Shoji
M
M
Tsunoda
A
A
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001419:Bacteria / Q000302:isolation & purification; D001424:Bacterial Infections / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009975:Orthomyxoviridae / Q000302:isolation & purification; D012141:Respiratory Tract Infections / Q000209:etiology*; D014777:Virus Diseases / Q000150:complications*