The use of immunofluorescence in the laboratory diagnosis of influenza type B

Immunofluorescence test with antigen-loaded erythrocytes: detection of influenza virus specific IgG, IgA, and IgM antibodies

An immunofluorescence test (IFT) for the detection of influenza virus antibodies was established to supplement the standard serological diagnostical complement fixation test (CFT). Current strains (A/Philippines/2/82, A/Brazil/11/78, B/Singapore/222/79) were loaded on formalinized chicken erythrocytes. In contrast to CFT, we can distinguish specific immunoglobulin classes against influenza virus. Unlike CFT, IFT is subtype-specific. A recent infection can be distinguished from a past infection by the differentiation of specific immunoglobulin classes. Anticomplementary factors and hemolytic sera do not influence the result of the IFT. IFT does not require cell cultures and is easy to read.

Comparison of direct immunofluorescent staining of clinical specimens for respiratory virus antigens with conventional isolation techniques

Staining of clinical respiratory specimens obtained by nasopharyngeal and throat swabs with direct fluorescein isothiocyanate-conjugated antisera to para-influenza virus types 1, 2, and 3, influenza A virus, respiratory syncytial virus, adenovirus, mumps virus, and measles virus was compared with isolation procedures in routine tissue culture systems. Direct staining of clinical specimens with the commercially available conjugated offered a rapid means of diagnosing respiratory infections on a routine clinical basis when used in conjunction with isolation in tissue culture systems. Of 292 patients who were culture positive for these viruses, 259 were diagnosed by detection of the viral antigen in clinical specimens by direct immunofluorescence. No specimens that subsequently yielded a different respiratory virus by culture were positive by the direct immunofluorescence method. Use of selected antisera based on clinical history of the patient reduced the cost of rapid viral diagnosis.