Alphavirus/isolation & purification; Arboviruses/isolation & purification; Chikungunya Fever; Dengue; Occupational Exposure; Adult; Animals; Chikungunya Fever/diagnosis; Chikungunya Fever/epidemiology; Chikungunya Fever/physiopathology; Chikungunya Fever/therapy; Chikungunya Fever/virology; Culicidae; Dengue/diagnosis; Dengue/epidemiology; Dengue/physiopathology; Dengue/therapy; Dengue/virology; Disease Outbreaks; Disease Vectors; Female; Humans; Male; Military Personnel; Occupational Exposure/analysis; Occupational Exposure/prevention & control; United States/epidemiology; West Indies/epidemiology