Investigation of Adenovirus and Acute Respiratory Disease (ARD) among Recruits, Fort Jackson, South Carolina November-December 1997.

Abstract : An acute respiratory disease (ARD) outbreak investigation was conducted at Fort Jackson, SC, the largest U.S. Army basic combat training (BCT) center, during November and December 1997. A total of 79 patients were evaluated with throat swabs (on admission and 24 hrs later), acute serum samples and epidemiologic data. Convalescent serum samples for adenovirus (Adv) antibody testing were collected 14 to 21 days later on 49 of the 79 (62%) patients. Adeno-like viruses were isolated in 71 of 79 (90%) throat cultures; 19 of 20 tested were identified as type 4. Anti-adv antibody testing showed a high degree of susceptibility among incoming recruits; 15-22% of them being seropositive upon arrival at Fort Jackson. Review of ARE) surveillance and Adv isolation data revealed that, during the period of June through November 1997, there were 32 and 12 separate military unit clusters, respectively, of ARE) and Adv among recruits. Attack rates for ARE) were found to be higher among recruits of one of the training brigades (0.95% per week, compared to a rate of 0.44% per week in trainees from other units). At least six separate instances of Adv introduction into training units from off-base were documented during the May-September period. Initial results of a case-control study performed among recruits in affected units (66 hospitalized recruit ARE) cases and 189 non-ARE) controls) identified prior smoking as an important risk factor (OR = 1. 89, 95% CI = 1.03 - 3.50, p = 0.03). Females were also found to be at significantly lesser risk than males (OR = 0.47, 95% - CI = 0.25 - 0.87). The impact that Adv had upon training for the period of May-December 1997 was immense; over 2,200 man-days of lost training occurred as a direct result of Adv infections (i.e., admissions to the base military hospital).