O'nyong-nyong fever in south-central Uganda, 1996-1997: description of the epidemic and results of a household-based seroprevalence survey.
O'nyong-nyong (ONN) fever, an acute, nonfatal illness characterized by polyarthralgia, is caused by infection with a mosquito-borne central African alphavirus. During 1996-1997, south-central Uganda experienced the second ONN fever epidemic ever recognized. During January and early February 1997, active case-finding and a household cluster serosurvey were conducted in two affected and two comparison areas. A confirmed case was defined as an acute febrile illness with polyarthralgia occurring within the previous 9 months plus serologic confirmation or isolation of ONN virus from blood. In affected (n=129) and comparison (n=115) areas, the estimated infection rates were 45% and 3%, respectively, and the estimated attack rates were 29% and 0%, respectively, for an apparent:inapparent infection ratio of nearly 2 in affected areas. In villages sampled near Lake Kijanebalola, Rakai District, the estimated infection and attack rates were 68% and 41%, respectively, and 55% of sampled households had >/=1 case of ONN fever. In conclusion, this epidemic was focused near lakes and swamps, where it was associated with high infection and attack rates.
Sanders
E J
EJ
Division of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA.
Rwaguma
E B
EB
Kawamata
J
J
Kiwanuka
N
N
Lutwama
J J
JJ
Ssengooba
F P
FP
Lamunu
M
M
Najjemba
R
R
Were
W A
WA
Bagambisa
G
G
Campbell
G L
GL
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000524:Alphavirus / Q000276:immunology* / Q000302:isolation & purification; D018354:Alphavirus Infections / Q000453:epidemiology* / Q000821:virology; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016036:Seroepidemiologic Studies; D014454:Uganda / Q000453:epidemiology
D000914:Antibodies, Viral