Laboratory Studies on the 1950 Outbreak of Influenza
Year: 1950
Type: article
Abstract: During the first 3 months of 1950, a number of outbreaks of influenza wvere reported in military and civilian populations throughout the world.In the United States during this period, 164,352 patients were diagnosed on clinical grounds as having influenza.The results of serological and isolation procedures performed in different labora- tories established that the infecting agent in a number of these out- breaks was influenza A virus, while, in a few instances, influenza B virus appeared to be of etiological significance (1).The present report is concerned primarily with observations on four strains of virus which were isolated from military patients with an influenza-like disease during January 1950 in Georgia and Wyoming.These agents are closely related antigenically to each other but (liffer somewhat from the so-called A prime strains of influenza A. Materials and MethodsClinical Specimens.These were limited to nasal and pharyngeal washings collected shortly after the onset of clinical influenza and to acute phase and convalescent phase sera collected from persons during the first several days and several weeks, respectively, after initial symptoms.Isolation of Virus.Nasal or pharyngeal washings from patients suffering from a disease clinically diagnosed as influenza were mixed with antibiotics and inoculated into the allantoic and amniotic sacs of embryonated eggs; subsequent passages were made by the allantoic route.After two or three transfers, each strain yielded allantoic fluids which had hemagglutinating titers of 1:320 to 1:1280.These fluids were infective for eggs in dilutions of 10-7 or 10-8.
DOI: 10.2307/4587371
Authors: M. R. Hilleman, R. P. Mason, N. G. Rogers
Institution: United States Army
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W1552437811