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. 2006 Jan;12(1):23–28. doi: 10.3201/eid1201.050965

Table. Key events in the swine influenza A (Hsw1N1) outbreak, Fort Dix, NJ.

Date (1976) Event
January 5 After the holidays, basic training resumed at Fort Dix, NJ; a sudden, dramatic outbreak of acute respiratory disease followed the influx of new recruit trainees (4).
January 19 Earliest hospitalization of a Fort Dix soldier with acute respiratory disease attributed to swine influenza A (Hsw1N1) (identified retrospectively by serologic tests) (7,14)
January 21 Influenza A/Victoria (H3N2) identified away from Fort Dix in NJ civilians (4)
January 23 Fort Dix received reports of adenovirus type 21 isolations from soldiers ill with respiratory disease and reported the outbreak to the local and state health departments (4)
January 28 A NJ Department of Health official suggested the Fort Dix outbreak may be due to influenza and offered to process specimens for virus isolation (4)
January 29–30 19 specimens sent to NJ Department of Health in 2 shipments (4)
February 2–3 NJ Department of Health identified 4 isolates of H3N2-like viruses and 2 unknown hemagglutinating agents in 8 specimens sent on January 29. Fort Dix and NJ Department of Health arranged for the study of deaths possibly due to influenza. NJ Department of Health identified 3 H3N2-like viruses and a third unknown hemagglutinating agent in 11 specimens sent on January 30 (4).
February 4 Fort Dix soldier died with acute respiratory disease (4).
February 5 Tracheal specimens from the soldier who died on February 4 were sent to NJ Department of Health (4).
February 6 NJ Department of Health sent the Fort Dix specimens to Center for Disease Control (CDC), Atlanta, GA; CDC identified a fourth unknown hemagglutinating agent in the Fort Dix specimens (4).
February 9 Specimens from the soldier who died on February 4 yielded a fifth unknown hemagglutinating agent (4). Last hospitalization of an identified Fort Dix soldier with febrile, acute respiratory disease attributed to swine influenza A (Hsw1N1) (identified retrospectively by serologic tests) (7,14).
February 10 Laboratory evidence supported 2 influenza type A strains circulating on Fort Dix; 1 was a radically new strain. Prospective surveillance for cases in the areas around Fort Dix was initiated; only cases of H3N2 were found (4).
February 13 Review of laboratory data and information found that all 5 unknown agents were swine influenza A strains (later named A/New Jersey [Hsw1N1]); 3 laboratories independently identified the swine virus from original specimens (serologic data supporting swine influenza A virus infection was later obtained from 2 survivors with A/New Jersey isolates) (4).
February 14–16 Initial planning meeting between CDC, NJ Department of Health, Fort Dix, and the Walter Reed Army Institute of Research personnel was held in Atlanta, GA. Prospective case finding was initiated at Fort Dix; H3N2 was isolated; Hsw1N1 was not isolated (7). Retrospective case finding was initiated by serologic study of stored serum specimens from Fort Dix soldiers who had been hospitalized for acute respiratory disease; 8 new cases of disease due to Hsw1N1 were identified with hospitalization dates between January 19 and February 9 (7,14).
February 22–24 Prospective case finding was again conducted at Fort Dix; H3N2 virus was isolated but not Hsw1N1 (7).
February 27 Thirty-nine new recruits entering Fort Dix February 21–27 gave blood samples after arrival and 5 weeks later; serologic studies were consistent with influenza immunization but not spread of H3N2 virus. None had a titer rise to Hsw1N1 (11).
March 19 Prospective surveillance identified the last case of influenza in the areas around Fort Dix; only H3N2 viruses were identified outside of Fort Dix (4).