Norwalk-like virus infection in military forces: Epidemic potential, sporadic disease, and the future direction of prevention and control efforts

The impact of Norwalk-like virus (NLV) infection on military forces is eval uated in this report. NLVs were a major cause of both outbreaks and sporadi c disease among crowded US ground troops in the 1991 war with Iraq, NLVs al so have been found to be a cause of acute gastroenteritis in other ground a nd shipboard deployments. Four large outbreaks of acute gastroenteritis wer e investigated aboard US Navy aircraft carriers between 1992 and 1997, In t hese outbreaks, NLVs were identified as the probable cause, and crowding wa s a major risk factor for transmission. An evaluation of a routine shipboar d deployment also suggests that NLVs cause sporadic gastroenteritis, These data indicate that NLV infection is a major cause of acute morbidity in mil itary forces. Because of the limitations of available prevention and contro l methods, development of a vaccine against these viruses may be the best s olution in the military environment.