ly sovann, md, dtmh, mctm philippe buchy, md, phd nic cambodia

Characterization of human influenza virus circulation in

Cambodia 2006-2010 and impact for national public health policies.

Ly Sovann, MD, DTMH, MCTM

Philippe Buchy, MD, PhD

NIC Cambodia

2

ILI and ALRI sites in Cambodia

ILI sentinel sites

ALRI sentinel sites

3

Material and Method

• Naso-pharyngeal specimens obtained from 5-10 patients fulfilling the ILI case definition, each week, from 8 sentinel sites (5 IPC/MoH since 2006, 3 NIPH/US CDC/MoH since 2009) + 1 study site (AFRIMS since 2010)

• >4000 NP specimens obtained from patients hospitalized in Takeo and Kampong Cham provincial hospitals with ALRI symptoms between 2007-2010.

• Specimens tested by RT-PCR at IPC, NIPH/CDC, AFRIMS labs

• Results centralized and analyzed for epidemiological purposes by MoH (CDC department) with support of WHO country office and by IPC (for FluNet reporting)

• Antigenic tests, genomic analysis, phenotypic drug resistance tests performed at IPC before selection of representative strains shipped to WHOCC Melbourne (including NAMRU-2 influenza isolates detected during fever study)

4

Influenza circulation

Year

No. of Specimens

tested

No. of positives

(%)

Type Subtype of influenza A

Influenza A(%)

Influenza B(%)

H1N1(%)

H3N2(%)

H5N1(%)

H1N1pdm09

(%)

2006 81232

(3.9)32

(100)0 0

30(100)

2(6.6)

-

2007 1962104(5.3)

44(41.7)

60(58.3)

14(32.5)

29(67.5)

1(2.3)

-

2008 2873259(9)

171(65.9)

88(34.1)

31(18.2)

139(81.8)

1(0.5)

-

2009 4820743

(15.4)648

(87.2)95

(12.8)2

(0.3)245

(37.8)1

(0.15)400

(61.8)

2010 3455433

(12.5)335

(77.4)98

(22.6)0

151 (45)

1(0.3)

183(54.7)

(93.4)

5

Influenza circulation (2006-2010)

0

50

100

150

200

250

Au

g

Se

p

Oc

t

No

v

De

c

Ja

n

Fe

b

Ma

r

Ap

r

Ma

y

Ju

n

Ju

ly

Au

g

Se

p

Oc

t

No

v

De

c

Ja

n

Fe

b

Ma

r

Ap

r

Ma

y

Ju

n

Ju

ly

Au

g

Se

p

Oc

t

No

v

De

c

Ja

n

Fe

b

Ma

r

Ap

r

Ma

y

Ju

n

Ju

ly

Au

g

Se

p

Oc

t

No

v

De

c

Ja

n

Fe

b

Ma

r

Ap

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Ma

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Ju

n

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ly

Au

g

Se

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No

v

De

c

A(H5N1)

A(H1N1)pdm

B

A(H1N1)

A(H3N2)

1st H1N1pdm 09Case confirmed(imported case)

1st H1N1pdm09 Case detected in the

community

Rainy season Rainy seasonRainy season Rainy seasonRainy season2006 2007 2008 2009 2010

6

Susceptibility to drugs

Virus type and subtype Resistance to neuraminidase inhibitors

Resistance to M2inhibitors

Oseltamivir Zanamivir

# isolatessequenced

Number of resistant

(%)# isolates

tested

Number of resistant

(%)

# isolatestested

Number of resistant

(%)

A(H3N2) 123 0 54 0 51 43 (84.3)

A(H1N1) 10 1 (10) 7 0 18 12 (66.6)

B 90 0 38 0 NA NA

A(H1N1)pdm09 62 0 62 0 34 34 (100)

A(H5N1) 10 0 5 0 5 5 (100)

7

Antigenic analysis

Season A/H1N1 A/H3N2 Influenza B A/H1N1pdm09Vaccine Strains

Cambodian Strains

Vaccine Strain

Cambodian Strains

Vaccine Strain Cambodian Strains


2006(SH*)

A/New Caledonia/20/1999-like

N/AA/California/7/2004-like

A/Wisconsin/67/2005-like

B/Malaysia/2506/2004-like N/A N/A N/A

2006-2007(NH*)



B/Malaysia/2506/2004-like

N/A

2007(SH*)






B/Malaysia/2506/2004-like N/A N/A

2007-2008(NH*)

A/Solomon Islands/3/2006-like


B/Malaysia/2506/2004-like N/A

2008(SH*)


A/Brisbane/59/2007-like



B/Florida/4/2006-like

B/Florida/4/2006-like N/A N/A

2008-2009(NH*)




N/A

2009(SH*)


N/AA/Brisbane/10/2007-like



B/Brisbane/60/2008-like

A/California/7/2009-like


2009-2010(NH*)


A/Brisbane/10/2007



2010(SH*)

N/A N/A

A/Perth/16/2009-like



B/Brisbane/60/2008-likeB/Malaysia/2506/2004-likeB/Florida/4/2006-like



2010-2011(NH*)

N/AA/Perth/16/2009-like



8

Antigenic analysis

Season A/H1N1 A/H3N2 Influenza B A/H1N1pdm09Vaccine Strains

Cambodian Strains

Vaccine Strain

Cambodian Strains



2006(SH*)


N/AA/California/7/2004-like


B/Malaysia/2506/2004-like N/A N/A N/A

2006-2007(NH*)




N/A

2007(SH*)






B/Malaysia/2506/2004-like N/A N/A

2007-2008(NH*)



B/Malaysia/2506/2004-like N/A

2008(SH*)






B/Florida/4/2006-like N/A N/A

2008-2009(NH*)




N/A

2009(SH*)


N/AA/Brisbane/10/2007-like






2009-2010(NH*)


A/Brisbane/10/2007



2010(SH*)

N/A N/A




B/Brisbane/60/2008-likeB/Malaysia/2506/2004-likeB/Florida/4/2006-like



2010-2011(NH*)

N/AA/Perth/16/2009-like



9

H3N2 phylogenetic analysis

2010

2009

2007-2008

2005-2006

10

H1N1pdm09 phylogenetic analysis

11

Influenza B phylogenetic analysis

Victoria/2/87-like lineage

Yamagata/16/88-like lineage

2007

2010

2009

2008

2010

12

Conclusions

• Although Cambodia is geographically located in the Northern hemisphere, influenza circulation has a Southern hemisphere pattern.

• Although the viruses circulating in Cambodia are not always totally matching with those included in the vaccine composition, the use of the Southern hemisphere vaccine should be recommended

• Neuraminidase inhibitors would be the drug of choice for influenza treatment and chemoprophylaxis in Cambodia.

13

Aknowledgements

• Ministry of Health/CDC department

• Dr. Sok Touch, Dr. Ly Sovann, Dr. Seng Heng, Mr. Ieng Vannra & coll.

• Institut Pasteur in Cambodia – Virology & Epi Units

• Dr. Sek Mardy, Dr. Monica Naughtin, Dr. Sareth Rith, Dr. Sirenda Vong, Dr. Sowath Ly, Dr. Arnaud Tarantola & coll.

• National Institute of Public Health

• Dr. Ung Sam An, Dr. Buth Sokhal and coll.

• WHO Cambodia

• Dr. Chea Nora, Dr. Nima Asgari and coll.

• Centres of Disease Control and Prevention USA & Cambodia

• Dr. Paul Kitsutani, Dr. Borann Sar & coll.

• NAMRU2, Cambodia

• Dr. William Rogers, Dr. Chadwick Yasuda

• WHOCC Melbourne, Australia

• Prof. Anne Kelso, Dr. Ian Barr & coll.

• AFRIMS Bangkok & Cambodia

• Dr. Ans Timmermans, Dr. Youry Se, Ms. Nou Samon, Dr. Chanthap Lon, Dr. Stuart Tyner, Dr. David Saunders

ly sovann, md, dtmh, mctm philippe buchy, md, phd nic cambodia

Documents

influenza circulation

influenza isolates

influenza treatment

conclusionsalthough

antigenic analysis

phd nic cambodia

afrims bangkok cambodiadr

genomic analysis