Download ppt - 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

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ILI and ALRI sites in Cambodia

ILI sentinel sites

ALRI sentinel sites

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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)

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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)

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Influenza circulation (2006-2010)

0

50

100

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200

250

Au

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Se

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Oc

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No

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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

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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)

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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



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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



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H3N2 phylogenetic analysis

2010

2009

2007-2008

2005-2006

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H1N1pdm09 phylogenetic analysis

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Influenza B phylogenetic analysis

Victoria/2/87-like lineage

Yamagata/16/88-like lineage

2007

2010

2009

2008

2010

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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.

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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