Pandemic influenza (H1N1) 2009 in Cameroon: Epidemiological, Genetic and Antigenic characterization

Richard Njouom1, Cyrille F. Djoko2, Lucy Ndip3 and Jean-Marc Reynes1 for the Cameroon Network of Laboratories for human influenza surveillance.

1. National Influenza Centre, Centre Pasteur du Cameroun , Yaounde, Cameroon 2. Global Viral Forecasting , Yaounde, Cameroon 3. Laboratory for Emerging Infectious Disease, University of Buea, Buea, Cameroon

Outline of the presentation

1. Geographic situation of Cameroon

2. Cameroon Network of influenza surveillance

3. Virological surveillance of influenza in Cameroon from November 1007 to November 2010

4. Characterization of pandemic influenza A(H1N1) 2009 in Cameroon

5. Conclusions/Challenges/Way forward

WHO Global NIC Meeting, Hammamet, Tunisia Page 1 of 7 30 November 2010 - 3 December 2010 Geographic situation of Cameroon

The World Africa

 20 millions inhab. Age structure  10 regions  475,000 km2  0-14 years (42%)

 Raining season (June to Oct.)  15-64 years (55%)  Dry season (Nov. to May)  65 years and over (3%) Cameroon

Cameroon Network of influenza surveillance 45 sentinel sites located in 8 different regions. Extension in January 2010/UB North West Region Bamenda Extension in January 2009 1 Health Centre North Region Garoua South West Region 2 Health Centres Mutengene, Kumba, Manfe 3 Health Centres Yaounde : November 2007

Centre Region West Region Yaounde Bafoussam, Bandjoun, Foumban 5 Health Centres 3 Health Centres 8 Health Centres

Littoral Region South Region East Region Douala HEVECAM, Kribi Abong Mbang, Bertoua 3 Health Centres 15 Health Centres 5 Health Centres

Extension in January 2010/GVF

WHO Global NIC Meeting, Hammamet, Tunisia Page 2 of 7 30 November 2010 - 3 December 2010 Virological surveillance of influenza in Cameroon Number of samples tested and rate of influenza detection per month from Nov 2007 to Nov 2010

500 60,0% 2008 2009 2010 450 50,0% 400

350 40,0% 300

250 30,0%

200 20,0%

samples tested 150 °

N 100 10,0% % influenza virus detected % influenza 50

0 0,0% 7 8 8 9 9 9 0 0 8 0 9 0 0 0

Nov 0 Jan 08 Mar 0 Mai 08 Juil 0 Sep 08 Nov Jan 09 Mar 0 Mai 09 Juil 0 Sept Nov Jan 10 Mar 1 Mai 10 Juil 1 Sep 10 Nov 1

Seasonality of influenza infection in Cameroon ?

Virological surveillance of influenza in Cameroon Types/subtypes of influenza viruses identify per month from Nov 2007 to Nov 2010 2007 2008 2009 2010 120

100

80

60

40

20 Number of identify Virus

0 7 7 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 08 0 0 -0 0 0 09 0 0 -0 0 10 10 eb juil-0 eb juil-0 eb Juil 10 Nov 0Dec 0 Jan F Mar 0Apr May 08juin Aug Sep 08Oct 0Nov 0Dec Jan F Mar 0Apr May 09juin Aug Sept 09Oct 0Nov 0Dec 0 Jan F Mar 10Apr 10May 10Juin 10 Aout 10Sep 10Oct 10Nov 10 A/H1N1/2009 A/H1N1 A/H3N2 B

WHO Global NIC Meeting, Hammamet, Tunisia Page 3 of 7 30 November 2010 - 3 December 2010 Virological surveillance of influenza in Cameroon Evolution of pandemic influenza H1N1 (2009) from August 2009 to Nov 2010 159 cases in Cameroon since August 2009, Mild and No death

2009: 2010: 152 cases 7 imported cases Community circulation with two periods of high circulation

120

100

80

60

40 of virus identified 20 N °

0 Aug 09 Sept 09 Oct 09 Nov 09 Dec 09 Jan 10 Feb 10 Mar 10 Apr 10 May 10 Juin 10 Juil 10 Aout 10 Sep 10 Oct 10 Nov 10

A/H1N1/2009 A/H1N1 A/H3N2 B

Epidemiological characteristic of the 152 local cases of pandemic influenza A(H1N1) 2009 detected in Cameroon Geographic localization of cases in the country

North West Region North Region 14 cases 4 cases

West Region Centre Region 7 cases 60 cases

South West Region East Region 27 cases 8 cases

Littoral Region South Region 2 cases 10 cases

WHO Global NIC Meeting, Hammamet, Tunisia Page 4 of 7 30 November 2010 - 3 December 2010 Epidemiological characteristic of the 152 local cases of pandemic influenza A(H1N1) 2009 detected in Cameroon Age distribution of the cases

50 45 40 35 30 25 20 15 Number of cases 10 5 0 < 5 5-10 11-20 21-30 31-40 41-50 >50 Age group

Genetic characteristic of pandemic influenza A(H1N1) 2009 detected in Cameroon 10 viruses selected (4 in 2009 and 6 in 2010) and sequenced in NA region

Two main clusters A/Cameroun/353/2009 A/Cameroun/357/2009  Clade 7 was the dominant pH1N1 0.0005 A/NewYork/06/2009 lineage in Cameroon during the IP A/Cameroun/382/2010 A/NewYork/4735/2009 Clade 7 (2009 period) A/CanadaPQ/RV1758/2009 A/CanadaMB/RV1964/2009 A/Cameroun/479/2010  Circulating pH1N1 viruses during A/Cameroun/751/2009 the AP (2010 period) were grouped A/California/14/2009 in a new cluster. A/Amagasaki/1/2009 Clade 4 A/Osaka/1/2009 A/Sakai/1/2009  None of these isolated clustered A/Cameroun/463/2009 97 A/Cameroun/666/2010 Cameroon with the 2010 H1N1 vaccine strain. A/Cameroun/748/2010 Clade A/Cameroun/812/2010 A/Cameroun/813/2010 A/SouthCarolina/09/2009 A/California/06/2009 Clade 2 All 10 NA sequences displayed an A/Colorado/03/2009 H275, the genetic marker for A/NewYork/3177/2009 Clade 3 A/California/04/2009 Clade 1 sensitivity to Oseltamivir. A/California/07/2009

WHO Global NIC Meeting, Hammamet, Tunisia Page 5 of 7 30 November 2010 - 3 December 2010 Antigenic characteristic of pandemic influenza A(H1N1) 2009 detected in Cameroon : Interim Report WHO CC London Good levels of reactivity of all the Cameroonian strains with the panel of antisera used including the current recommended vaccine strain A/California 7/09

Post infection ferret sera

Viruses Collection Passage A/Cal A/Cal A/Eng A/Auck A/Bayern A/Lviv A/HK date History 4/09 7/09 195/09 3/09 69/09 N6/2009 2212/2010 C4/F14/09 F05/10 F06/10 C4/17/09 C4/33/09 C4/34/09 F18/10T/C

A/California/4/2009 C1,E3 1280 1280 2560 2560 1280 2560 1280 A/California/7/2009 E8 640 1280 640 640 1280 2560 640 A/England/195/2009 MDCK5 1280 2560 2560 2560 1280 1280 1280 A/Auckland/3/2009 Ex+3 1280 2560 1280 2560 640 1280 1280 A/Bayern/69/2009 MDCK5 160 160 40 40 320 320 80 A/Lviv/N6/2009 MDCK4/SIAT2 640 320 80 80 640 640 80 A/HK/2212/2010 MDCK5 640 640 640 1280 320 640 640

TEST VIRUSES A/Cameroon/463/2009 09/10/2009 SIAT1 2560 2560 2560 5120 1280 2560 A/Cameroon/566/2009 30/10/2009 SIAT1 1280 1280 1280 2560 640 1280 A/Cameroon/666/2010 2010-03-05 MDCK3 2560 2560 5120 2560 2560 2560 2560 A/Cameroon/812/2010 2010-03-23 MDCK3 640 1280 640 1280 320 640 640 A/Cameroon/381/2010 2010-02-10 C4/MDCK1 1280 1280 1280 2560 640 1280 1280 A/Cameroon/479/2010 2010-02-17 C2/MDCK1 2560 2560 2560 5120 1280 2560 2560 A/Cameroon/748/2010 2010-03-16 C3/MDCK1 1280 1280 2560 2560 1280 1280 1280 A/Cameroon/813/2010 2010-03-23 C2/MDCK1 320 640 160 320 640 1280 320

1. < = 40

Conclusions/Challenges/Way forward

1. Influenza is of public health importance in Cameroon. However, only virological surveillance is effective in Cameroon. Need to develop syndromic surveillance in order to better determine the seasonality of influenza in Cameroon.

2. Only ILI surveillance is effective in Cameroon Need to develop SARI surveillance in order to better determine the disease burden of influenza in Cameroon

WHO Global NIC Meeting, Hammamet, Tunisia Page 6 of 7 30 November 2010 - 3 December 2010 Conclusions/Challenges/Way forward

3. Genetic and antigenic analyses highlight the importance of continuing surveillance and characterization of emerging influenza drift variant in sub-Saharan Africa

Need of training and setup of genetic and antigenic characterization as well as antiviral drug susceptibility monitoring of influenza viruses at the level of NIC in Africa.

Acknowledgments

 All the staff of the different health centres for assistance in sample collection.

 Collaboration 1) The WHO Global Influenza Surveillance Network and the WHO AFRO, 2) WHO Collaborative Centre of London UK and the CDC Atlanta 3) NIC of the Pasteur Institute in Paris

 Financial support 1) The French Ministry of Health 2) The American Department of Health and Human Services. 3) The Global Emerging Infectious Surveillance and Response System (GEIS) a division of the Armed Forces Health Surveillance Centre (AFHSC) 4) The SANOFI-PASTEUR Laboratory

Contact : Dr Richard Njouom, Head National Influenza Centre Cameroon E.mail: [email protected]; Tel: 00237 79 87 36 04

WHO Global NIC Meeting, Hammamet, Tunisia Page 7 of 7 30 November 2010 - 3 December 2010