Outbreak of novel influenza A (H1N1-2009) linked to a dance club.
BACKGROUND
This paper describes the epidemiology and control of a community outbreak of novel influenza A (H1N1-2009) originating from a dance club in Singapore between June and July 2009.


METHODS
Cases of novel influenza A (H1N1-2009) were confirmed using in-house probe-based real-time polymerase chain reaction (PCR). Contact tracing teams from the Singapore Ministry of Health obtained epidemiological information from all cases via telephone.


RESULTS
A total of 48 cases were identified in this outbreak, of which 36 (75%) cases were patrons and dance club staff, and 12 (25%) cases were household members and social contacts. Mathematical modelling showed that this outbreak had a reproductive number of 1.9 to 2.1, which was similar to values calculated from outbreaks in naïve populations in other countries.


CONCLUSIONS
This transmission risk occurred within an enclosed space with patrons engaged in intimate social activities, suggesting that dance clubs are places conducive for the spread of the virus.
Chan
Pei Pei
PP
Communicable Diseases Division, Ministry of Health, Singapore. chan_pei_pei@moh.gov.sg
Subramony
Hariharan
H
Lai
Florence Y L
FY
Tien
Wee Siong
WS
Tan
Boon Hian
BH
Solhan
Suhana
S
Han
Hwi Kwang
HK
Foong
Bok Huay
BH
James
Lyn
L
Ooi
Peng Lim
PL
D000293:Adolescent; D000328:Adult; D003132:Commerce; D016358:Contact Tracing / Q000379:methods*; D003615:Dancing; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology*; D007407:Interviews as Topic; D008297:Male; D015233:Models, Statistical; D016133:Polymerase Chain Reaction; D012846:Singapore / Q000453:epidemiology; D014195:Travel; D055815:Young Adult