Download - Dr Tsang 22 Feb
CUHKSPH/PCAA Inauguration1st Scientific Symposium
Emerging infectious diseases in the past and present decade
Dr Thomas TsangCentre for Health Protection, Department of Health
Feb 22, 2011
Past decade: Observations
1. Pandemics triggered by pathogens with animal link
• SARS Co-V– ? Bats– ?Palm civets as interm
ediate host
• Pandemic H1N1 (2009)– Reassortment with swi
ne flu virus
2. Pandemics travel much faster than anticipated
• Containment difficult despite theoretical possibility
• Present surveillance methods lag behind epidemic progression
• Sharing of epidemic intelligence vital
• Contingency planning must start well before pandemic
3. Epidemics can be halted by public health measures
• SARS– Quarantine & isolation– Hygiene and social
distancing
• Dengue fever– Anti-mosquito
measures
4. Strengthening of infrastructures vital
• Updated legislation
• Capacity building– e.g., surveillance systems, field epidemiology, infection control,
contingency planning
• New programs– vaccination schemes
• Closer public health / clinical interface
• Scientific Committees to pool expertise
• Open channels with Mainland and regional countries
5. Risk communication is all important
New decade: Trends & predictions
1. Another respiratory pandemic??
• Pandemic flu unpredictable– H2? H5? H9? Swine?
• Zoonotic pathogens– Is stopping at source feasible?
• Laboratory leaks
• Bioterrorism– Flu, smallpox, etc.
1997 2003 2009 2015
Avian influenzaH5N1
SARS Human swine influenza
?
2. Multi-drug resistance of increasing concern
• Global trend
• CA-MRSA, C. difficile, Acinectobacter, NDM-1 and other carbapemenase resistant bacteria, etc.
• World Health Day, April 2011
• New antibiotics lag behind due to R&D resource input
Emergence of New Delhi metallo-β-lactamase (NDM-1) producing Enteroba
cteriaceae
Lancet Infect Dis. 2010 Sep;10(9):597-602
Increasing reports of Clostridium difficile infection in UK
Source: Voluntary surveillance of Clostridium difficile in England, Wales and NorthernIreland, 2009. HPA
Source: ECDC, EMEA. The bacterial challenge: time to react. 2009 Sep
3. Climate change may alter pattern of infectious diseases
World Health Organization 2009
4. Some epidemics may flare up from time to time
• Influenza
• EV71 & other enteroviruses
• Norovirus
• HIV
• HEV
• Dengue fever
• Others ???
EV71 periodicity
Number of EV71 infection, 2001 – 2011 (as of Feb 17)
30
5 1
35
8 16 12
98
31
101
50
20
40
60
80
100
120
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Year
Nu
mb
er o
f ca
ses
Voluntary report Statutory report
Source: Department of Health, Hong Kong
HIV epidemic among MSM in Hong Kong (2000-2010)
Source: HIV reporting system, Department of Health, Hong Kong
5. New vaccines ??
• Vaccines under development– Dengue fever, Malaria, HIV, etc.
• Use of existing vaccines– PCV, rotavirus, HPV, etc.
6. Regional accomplishments
• Measles eradication
• Hepatitis B elimination
• Polio-free status
7. Social networks and search engines find increasing use in
disease surveillance
• Powerful GIS systems• How disease spread
through ‘networks’• Rumor filters
Thank you