SARS and Avian Influenza: Public Health Priorities

1
SARS and Avian InfluenzaPublic Health Priorities

• Scott F. Dowell, MD, MPH
• International Emerging Infections Program
• Thailand Ministry of Public Health - US CDC
  Collaboration

2
Chest Xray, Day 2
3
Dr. Carlo Urbani
4
Chain of transmission among guests at Hotel
MHong Kong, 2003
2 family members
2 close contacts
Guangdong Province, China
4 family members
10 HCWs
4 HCWs
Hospital 2Hong Kong
Canada
F
A
A
F
G
G
3 HCWs
K
K
Ireland
156 close contacts of HCWs and patients
A
Hospital 3 Hong Kong
H
H
I
Hotel MHong Kong
L
J
I
United States
E
99 HCWs (includes 17 medical students)
J
D
B
Hospital 1 HK
M
C
C
D
E
B
Germany
0 HCWs
HCW
Singapore
HCW
B
Hospital 4 Hong Kong
Vietnam
34 HCWs
2 family members
28 HCWs
37 HCWs
HCW
37 close contacts
4 other Hong Kong Hospitals
Unknown numberclose contacts
HCW
  Health-care workers All guests except G and
K stayed on the 9th floor of the hotel. Guest G
stayed on the 14th floor, and Guest K stayed on
the 11th floor ? Guests L and M (spouses) were
not at Hotel M during the same time as index
Guest A but were at the hotel during the same
times as Guests G, H, and I, who were ill during
this period.
Bangkok
Data as of 3/28/03
5
Airline Transmission of SARS
No illness (person interviewed)
Index Case
Crew
No illness (person not interviewed)
Probable case
Empty seat
0
1
2
3
4
5
6
7
8
9
0
1
2
1
2
3
4
6
7
8
9
1
1
1
1
1
1
1
1
2
2
5
1
1
2
F

E

D
C

B

A
Olsen et al. NEJM 20033492414
6
Measures to Reduce Airline Transmission of SARS
Aircraft Decontamination
Voluntary Use of Masks
Fever Screening
7
Chest Xray, Day 13
8
Clues to the Causative Agent

• Epidemiology highly transmissible respiratory
  pathogen
• Clinical unusually severe disease
• Laboratory generally consistent with virus
• Pathology possibly paramyxovirus
• No known agent could explain all features

9
Coronavirus EM appearance
10
Personal Protective Equipment

• N-95 or better respirator
• Head cover
• Goggles or face shield
• eyeglasses not adequate
• Double gown
• Double gloves
• Double shoe covers

11
SARS on Hospital Surfaces
Surface, Hospital B, Taiwan Positive/ Tested
Patient rooms (71) Patient rooms (71)
Endotracheal tube 3/3
Bedrail 3/4
Ventilator panel 1/3
Other 3/4
Nursing stations (56) Nursing stations (56)
Telephone 1/3
Computer mouse 2/2
Doorknob 1/2
Other 1/2
Public areas of hospital (20) Public areas of hospital (20)
Elevator handrail 1/1
Other 0/4
Total 16/28 (57)
Dowell et al. CID 200439652
12
Intubation of a SARS Patient
13
(No Transcript)
14
(No Transcript)
15
Influenza Drift
16
Influenza Shift
17
US Infectious Disease MortalityThe Impact of
Influenza and AIDS
Armstrong. JAMA 199928161
18
Avian Influenza in Thailand?
19
Avian Influenza in Asia(10 February, 2004)
20
Intensive Pneumonia Surveillance

• Active
• Population-based
• CXR-confirmed
• Laboratory testing
• Influenza
• Other viruses
• Bacterial agents
• Community surveys

Nakorn Phanom
Sa Kaeo
21
Locations of Registered Poultry Farms Sa Kaeo,
Thailand
22
Poultry Exposure is Common

• There are 6 birds to every person in Sa Kaeo
  Province
• 1.3 of poultry is on commercial farms
• 178 farms
• 31,221 poultry
• 98.7 of poultry is in backyards
• 2,410,820 poultry

23
A Cluster of H5 Cases

• Three family members linked coincidentally during
  investigation of another pneumonia case
• Urgent concern about person-to-person
  transmission
• At the time cluster was recognized
• Index case dead, cremated
• Mother dead, body embalmed
• Aunt admitted to hospital
• Interviews rapidly conducted on family, contacts,
  neighbors, and healthcare workers

24
Investigation at Home of Index Patient
25
Timeline of Exposures and Illness
26
Laboratory Investigation

• Immediate and urgent effort to collect specimens
• Specimens promptly shared with WHO network
• Index patient dead, cremated
• 0.5ml serum from day 6 of illness
• Mothers body embalmed
• Lung and other tissues tested by PCR
• Aunt survived
• NP and OP swabs tested by cell culture, RTPCR
• Acute and convalescent serum (neutralization,
  ELISA)

27
Mother Lung Tissue Pathology
Photo courtesy of S. Zaki
28
Mdk/Vietnam/4/2004
Mdk/Vietnam/17/2004
Chicken/Laos/44/2004

• HA Gene Sequence
• Genotype Z
• Resistant to amandatine

Thailand/Kan/353/2004
Thailand/2SP33/2004
Vietnam/3218/2004
Thailand/1KAN1/2004
Thailand/PCBR/6231/2004
Vietnam/HN30262/2004
Thailand/PCB2031/2004
ipGoose/Cambodia/25/2004
Vietnam/1203/2004
Vietnam/1194/2004
Thailand/Pranom5147/2004
Thailand/Pranee5223/2004
Thailand/SP83/2004
Mdk/Vietnam/MDGL/2004
Chicken/Laos/7192/2004
Chicken/Vietnam/ncvd31/2004
Vietnam/3212/2004
Chicken/Vietnam/CM/2004
Vietnam/HN30259/2004
Thailand/16/2004
Thailand/Chai622/2004
serplChicken/Indonesia/11/2003
Chicken/Korea/ES/2003
Duck/China/e3192/2003
hvriDuck/Harbin/15/2004
Hong Kong/213/2002
Duck/Hong Kong/739/2002
RBPochard/Hong Kong/821/2002
Teal/Hong Kong/2978/2002
Chicken/Hong Kong/3175/2001
Hong Kong/156/1997
Goose/Guangdong/96
29
Conclusions from Family Cluster

• Probable person-to-person transmission
• No further spread to contacts
• No significant mutation of virus
• All gene segments were of avian origin
• Critical binding and cleavage sites unchanged
• Isolation precautions needed for H5 patient care
• Future clusters also warrant intensive
  investigation

30
Summary SARS and Avian influenza

• SARS redefined emerging zoonoses
• Broad economic and public health impact
• Avian flu unprecedented unpredictable
• Scale of the epizootic unprecedented
• Ongoing potential for re-assortment event