Risk factors for pandemic (H1N1) 2009 virus seroconversion among hospital staff, Singapore.
We describe incidence and risk factors for pandemic (H1N1) 2009 virus infection in healthcare personnel during the June-September 2009 epidemic in Singapore. Personnel contributed 3 serologic samples during June-October 2009, with seroconversion defined as a ≥4-fold increase in hemagglutination inhibition titers to pandemic (H1N1) 2009. Of 531 participants, 35 showed evidence of seroconversion. Seroconversion rates were highest in nurses (28/290) and lowest in allied health staff (2/116). Significant risk factors on multivariate analysis were being a nurse (adjusted odds ratio [aOR] 4.5, 95% confidence interval [CI] 1.0-19.6) and working in pandemic (H1N1) 2009 isolation wards (aOR 4.5, 95% CI 1.3-15.6). Contact with pandemic (H1N1) 2009-infected colleagues (aOR 2.5, 95% CI 0.9-6.6) and larger household size (aOR 1.2, 95% CI 1.0-1.4) were of borderline significance. Our study suggests that seroconversion was associated with occupational and nonoccupational risk factors.
Chen
Mark I C
MI
Department of Clinical Epidemiology, Tan Tock Seng Hospital, Singapore. mark_ic_chen@ttsh.com.sg
Lee
Vernon J M
VJ
Barr
Ian
I
Lin
Cui
C
Goh
Rachelle
R
Lee
Caroline
C
Singh
Baldev
B
Tan
Jessie
J
Lim
Wei Yen
WY
Cook
Alex R
AR
Ang
Brenda
B
Chow
Angela
A
Tan
Boon Huan
BH
Loh
Jimmy
J
Shaw
Robert
R
Chia
Kee Seng
KS
Lin
Raymond T P
RT
Leo
Yee Sin
YS
D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D015994:Incidence; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000276:immunology; D008297:Male; D016273:Occupational Exposure; D058873:Pandemics; D010564:Personnel, Hospital; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012846:Singapore / Q000453:epidemiology
D000914:Antibodies, Viral