Epidemiology of Norwalk virus during an outbreak of acute gastroenteritis aboard a US aircraft carrier.
A large outbreak of acute gastroenteritis occurred over a 5-week period aboard an aircraft carrier. The estimated cumulative attack rate was 13% among the 4,500-man crew. Eight percent of the crew sought medical attention, nearly all of whom missed 1 day or more of work. The risk of developing illness was 2 to 3 times greater for individuals living in more crowded sleeping quarters (> 50 persons per compartment). Occurrence of gastroenteritis was associated with a fourfold or more rise in Norwalk virus antibody levels, as measured by an enzyme-linked immunoassay utilizing a baculovirus expressed recombinant antigen. In addition, 27 nm Norwalk virus-like particles were visualized in two of six stools examined by immune electron microscopy. The presence of a low (< 1:50) or a high (> or = 1:6,400) pre-illness antibody level was associated with a lower incidence of illness. This investigation indicates that Norwalk virus can adversely impact operations of a military vessel and that crowding is a major risk factor in transmission.
Sharp
T W
TW
U.S. Navy Environmental and Preventive Medicine Unit No. 7, Naples, Italy.
Hyams
K C
KC
Watts
D
D
Trofa
A F
AF
Martin
G J
GJ
Kapikian
A Z
AZ
Green
K Y
KY
Jiang
X
X
Estes
M K
MK
Waack
M
M
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000473:pathology / Q000635:transmission; D004196:Disease Outbreaks; D005759:Gastroenteritis / Q000453:epidemiology / Q000473:pathology / Q000821:virology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D009326:Naval Medicine; D009663:Norwalk virus / Q000276:immunology; D012307:Risk Factors; D012767:Ships; D014481:United States / Q000453:epidemiology
D000914:Antibodies, Viral