PFEIFFER'S BACILLUS AND INFLUENZA : A SEROLOGICAL STUDY

Area of Science:

• Microbiology
• Immunology
• Infectious Diseases

Background:

• Pfeiffer's bacillus (Haemophilus influenzae) has been associated with influenza epidemics.
• The role of Pfeiffer's bacillus in the etiology and pathogenesis of influenza requires further elucidation.

Purpose of the Study:

• To investigate the serological responses of influenza patients to Pfeiffer's bacillus.
• To determine the significance of Pfeiffer's bacillus as a causative agent or secondary invader in influenza.

Main Methods:

• Analysis of patient sera for agglutinins, precipitins, and complement-binding bodies against Pfeiffer's bacillus antigens.
• Comparison of Pfeiffer's bacillus strains isolated during different influenza periods.
• Evaluation of serological reaction patterns in relation to disease severity, including postinfluenzal pneumonia.

Main Results:

• Influenza convalescent sera consistently demonstrated immune reactions to Pfeiffer's bacillus antigens.
• These serological reactions peaked in the second week and persisted for 2-4 months.
• Reactions were most pronounced in patients with postinfluenzal pneumonia.
• Pfeiffer's bacillus strains were antigenically similar across different years, with only quantitative differences.
• Serological data supported a parasitic relationship but lacked specificity for influenza causation.

Conclusions:

• Pfeiffer's bacillus elicits a demonstrable immune response in influenza patients.
• The bacillus is a frequent secondary invader in influenza, significantly impacting the disease course.
• Current serological evidence does not confirm Pfeiffer's bacillus as the primary etiological agent of epidemic influenza.