Trends in importation of communicable diseases into Singapore.
BACKGROUND
Singapore is a transition country in Southeast Asia that is both vulnerable and receptive to the introduction and re-introduction of imported communicable diseases.


METHODS
For a 10-year period between 1998 and 2007 we studied the trend, epidemiological characteristics, proportion of imported versus local transmission of malaria, viral hepatitis (hepatitis A and E), enteric fevers (typhoid and paratyphoid), cholera, chikungunya and SARS.


RESULTS
Of a total of 4617 cases of the above selected diseases notified in Singapore, 3599 (78.0%) were imported. The majority of the imported cases originated from Southeast Asia and the Indian subcontinent. Malaria constituted the largest bulk (of which 95.9% of the 2126 reported cases were imported), followed by hepatitis A (57.1% of 1053 cases imported), typhoid (87.6% of 596 cases imported), paratyphoid (87.6% of 241 cases imported), and hepatitis E (68.8% of 231 cases imported). Furthermore, there were 14 cases of imported cholera, 6 cases of imported severe acute respiratory syndrome (SARS) and 13 cases of imported chikungunya.


CONCLUSIONS
This study underlines that diseases such as malaria, viral hepatitis and enteric fever occur in Singapore mainly because of importation. The main origin of importation was South and Southeast Asia. The proportion of imported diseases in relation to overall passenger traffic has decreased over the past 10 years.
Department of Epidemiology and Public Health, National University of Singapore, 5 Lower Kent Ridge Road, Singapore.
Glenn K M
GK
Lee
Kian Wee
KW
Tan
Kee Tai
KT
Goh
Annelies
A
Wilder-Smith
D003141:Communicable Diseases / Q000453:epidemiology* / Q000209:etiology / Q000635:transmission; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D011159:Population Surveillance; D012846:Singapore / Q000453:epidemiology; D014195:Travel; D055815:Young Adult