Transcript Albert Cheung Hoi Yu, Ph.D.

2nd ASEAN China International Bioinformatics Workshop, April 2008
Collaborative Opportunities on Bioinformatics in the
Diagnosis of Infectious Diseases:
Our Preparedness in Battle Against
Avian Influenza？
Albert Cheung Hoi Yu, Ph.D.
Professor
Infectious Disease Center, Peking University
Professor and Vice-director
Neuroscience Research Institute, Peking University
Chairman and CEO
Hai Kang Life Corporation Limited
Beijing Hai Kang DNA Chips Limited
[email protected]
Avian Influenza (AI) – A Global Threat !
Influenza Pandemic Preparedness Plan
 Surveillance–in man & animals
 Stockpiling and logistics
 Emergency responses
 Public health
 Community
 Public communication
 Coordination and command
Phases of Alert
WHO
Inter-pandemic
Phase
Low risk of
human cases
Higher risk of
human cases
Pandemic
Alert
No or very limited
human-to-human
transmission
New virus causes
human cases
Evidence of increased
human-to-human
transmission
Evidence of significant
human-to-human
transmission
Pandemic
Efficient and sustained
human-to-human
transmission
IV
III
Human infection
with no human-tohuman transmission
2
3
4
China
New virus isolated in
humans but triggered
no immune response
OR immune response
triggered but no
symptoms
1
Degree of Response
New virus in
animals, no
human cases
Very similar
Preparatory Stage
II
Human-to-human
Transmission
I
Efficient and sustained
human-to-human
transmission OR
WHO announcement of
outbreak
5
6
Pandemic
Strategy of AI Control In China
National Ministry of Public Health
[ With Provincial Departments of Health, Local Health Bureaus ]
Provide medical
expert teams to
support diagnosis
/ treatment
3. Reporting of
confirmed
diagnostic
result
4.Communication,
feedbacks &
proposed
response
National CDC
National Medical
Expert Team
Direct & Real-time
access to medical
records through
online reporting
system
2. Reporting /
Delivery of sample
for diagnosis &
confirmation
Provincial Medical
Expert Team
Cooperation :
Diagnosis and
Treatment
Provincial CDC
1. Reporting of
suspected
cases
Suspected AI Case identified
in Local Hospital
[by Local Medical Expert Team and Local
CDC]
Surveillance of AI in Animals
During outbreak:
Detection and report of infection by farmers and
volunteer, based on clinical criteria (5% deaths in
flock), to activate pre-emptive culling, confirmed by
lab. (cloacal swab – viral isolation)
After outbreak:
 Maintenance of clinical-based surveillance with lab.
testing to confirm freedom from disease in control
zone around infected area for 21 days, then 5 months
(OIE)
 Proactive countrywide community survey to detect
and destroy infected flocks, then twice a year
Surveillance of AI in Humans
Detection and report of all pneumonia & flulike illnesses with history of exposure to
sick/dead poultry or of contact with pneumonia
cases…
Nasopharyngeal swab of all cases sent for rapid
flu test, and conventional test for H5N1.
Investigations of all reported cases by trained
epidemiology teams.
Daily situation monitoring, daily update on
website .
Pandemic Planning Diagnostic Pyramid
AIV Family Tree
Evolving Viruses
• H5N1 viruses in 1997, 2003, 2004 and 2005 are
genetically and antigenically different
• Different virus clades encountered in countries of the
region:
• Clade 1 (Lao, Thailand, Vietnam, Cambodia, China)
• Clade 2-subclade 3 (China, Thailand, Cambodia,
Vietnam)
• Clade 2-subclade 1 (Indonesia)
• Sequence variation should be considered in diagnostic
development
The Battle Against Infectious Disease
To defeat an infectious disease, you must
control its transmission from infected
people to healthy ones.
The critical issues are planning,
surveillance, and getting an early warning.
It was important to find ways to rapidly
tell people that they are not infected.
AI in China
Outbreaks of AI in Poultry and Human Cases in Thailand
Jan-May 2004
Jun-April 2005
May 2005- Dec 05
Confirmed case
Suspect case
Area of outbreak in poultry
Source: BOE, MOPH
Lab Conditions
• No temperature control nor heating– temp in lab was
about 10oC
• Walls and floors did not have appropriate covering
(tiles and bumpy lino)
• Electricity supply not guaranteed (no generator);
interruptions experienced during testing
• No freezer below about 8oC
Challenges for Diagnostics
from Global Public Health Perspective
As accurate as necessary
– to ensure WHO's public health responsibilities fulfilled
As quick as possible
– to detect the emergence of new variants of human pandemic potential
– to trigger outbreak response, investigation and rapid containment
whenever needed
As simple as possible
– the majority of diagnostic labs in the world does not have advanced
lab settings
– many crucial diagnosis conducted under huge pressure
Symptoms
• Respiratory distress
syndrome
Virus
Current Detection
Methods
Ag / Ab-based method
• X-ray evidence of
lung damage
Microbiological evidence
of virus (virus isolation)
• Fever
Conventional PCR
Real time-PCR
Users
NASBA
•Where?
New Method
•Who? User-friendly?
Modified Enhanced real
time-PCR
•Affordable?
Infection
Amplification Technology of NASBA
Isothermal amplification technique
 comparable results within different test units
Simplified operation process
 reduced contamination, higher reproducibility
PCR’s false
positive result
NASBA Protocol
Step 1. Reagent mixing
Step 2. Isothermal incubation
(can be replaced by a heat block)
Step 3. Probe hybridization
Step 4. Signal detection by ELISA reader
NASBA System
Adapt to regular
instrument
Participation of NASBA-EOC Detection in the
Influenza Surveillance Program
Commissioned by the National AIV Task Force
 NASBA-EOC: Takes part in the project implemented by
National AIV task force
 Surveillance of avian influenza virus (generic and
subtype H5), human influenza virus, parainfluenza
virus, and other selective pneumonia-causing
pathogens in Beijing population
 Beijing Hai Kang DNA Chips Limited provides NASBA
AIV / H5 test kits for the surveillance program
National Task Force for Human AIV
Training on AIV diagnosis using the NASBA EOC method to
the National AIV task force members in Beijing, China
Multiplex NASBA!
Molecular Pneumonia Detection Systems
 Project awarded by the China Ministry of Science and
Technology (a “863” project)
 We collaborated various hospitals in Beijing including
hospitals affiliated Peking University, Chao Yang Hospital,
You An Hospital and Di Tan Hospital of Capital Medical
University
 Development of multiplex NASBA, ERT-PCR and other
detection system/ technology for various pneumoniacausing pathogens (including SARS, AIV, influenza, etc.)
 Development of a Lab-On-A-Chip (LOAC) system
Was it possible to establish
rapid and accurate tests for
Infectious diseases in an
outbreak situation?
Difficulties in Getting Good Diagnostic
Kit Validated!
• Adequate clinical samples
• Well characterized samples are
indispensable for the development and
evaluation of diagnostic test
• Appropriate and adequate specimens
• Good quality
• Adequate clinical information
• Appropriate labeling and storage
• Good data management
Development of Sustainable and Integrated
Management System
1. Development of knowledge management
mechanism during the inter – pandemic period
2. Development of knowledge management
mechanism during pandemic
3. Establishment of a system for coordination and
communication among various organizations
during pandemic
4. Coordination with foreign and international
organizations
5. Monitoring and evaluation
Major success factors for AI control
 Strong leadership and support of the Government
 Close co-operation between public health and animal health authorities, and among partners in
multi – sectors
 Proactive risk communication to the public and strong public involvement
 Extensive international collaborations, especially with WHO, OIE, FAO, APEC,ASEANChina-Korea-Japan,…
 Existing infrastructure (surveillance, laboratories,
disease control, hospital infection, trained personnel)
The influenza epidemic of
1918 killed 20 million in just
18 months. With 25 million
Americans alone infected
during the influenza epidemic, it
was hard to provide care for
everyone. The Red Cross, seen
here with masks over the faces
of the nurses, often worked
around the clock.
Source: Courtesy of the National Library Museum.
CNN - “Businesses brace for pandemic”
3 November 2005