1380. Impact of Doxycycline Prophylaxis on Skin and Soft Tissue Infections in Naval Special Warfare Trainees

Abstract

Abstract Background Several severe cases of SSTIs caused by salt-water associated Gram-negative pathogens (mainly Shewanella algae) among U.S. Naval Special Warfare (NSW) trainees prompted introduction of doxycycline prophylaxis during the highest risk portion of training, “Hell Week”. We present analysis of this intervention’s impact on disease incidence and hospital admission for serious SSTI. Necrotizing fasciitis caused by Vibrio harveyi in an NSW trainee during “Hell Week” prior to introduction of doxycycline prophylaxis. Methods We performed a retrospective cohort study examining data from hospital admissions for SSTI in trainees between 2013-2020. We assessed hospital admission rates for SSTIs, hospitalization rates per SSTI diagnosed at the clinic level, overall rates of SSTI, length of hospital stays and blood and wound culture data. We then compared data from pre- and post-intervention cohorts. Results 3371 NSW trainees participated in “Hell Week” training during the study period with 284 SSTIs diagnosed overall, 29 of which led to hospital admission. After introduction of doxycycline prophylaxis, admission rates for SSTI decreased from 1.37 to 0.64 admissions per 100 trainees (p=0.036). Overall SSTI rates diagnosed at the clinic level remained stable from 7.42 to 8.86 SSTI per 100 trainees (p=0.185). Hospitalization rates per diagnosed SSTI decreased from 18.4% to 7.2% (p=0.009). Average length of hospitalization decreased from 9.01 days to 4.33 days (p=0.034). Blood and wound culture data showed a notable decrease in SSTI from salt-water associated Gram-negative rods (Shewanella algae and Vibrio spp.). Total number of SSTI diagnosed at Naval Special Warfare Center (NSWCEN) medical clinic each “Hell Week” training period with corresponding percentage of NSW trainees diagnosed with SSTI in each class. Date of doxycycline prophylaxis initiation labeled for reference. Wound and blood culture (Cx) data from the pre-intervention and post-intervention cohorts Conclusion Doxycycline prophylaxis during “Hell Week” training for NSW trainees was associated with decreased frequency and severity of hospitalization for SSTI, as well as near elimination of infection with invasive salt-water associated pathogens. Disclosures All Authors: No reported disclosures.