F. Moura, Influenza in the tropics, Current Opinion in Infectious Diseases, vol.23, issue.5, pp.415-420, 2010.
DOI : 10.1097/QCO.0b013e32833cc955

P. Hanvoravongchai, W. Adisasmito, P. Chau, A. Conseil, D. Sa et al., Pandemic influenza preparedness and health systems challenges in Asia: results from rapid analyses in 6 Asian countries, BMC Public Health, vol.364, issue.10, p.322, 2010.
DOI : 10.1093/heapol/czp066

P. Vongphrachanh, J. Simmerman, D. Phonekeo, V. Pansayavong, and T. Sisouk, An early report from newly established laboratory-based influenza surveillance in Lao PDR, Influenza and Other Respiratory Viruses, vol.39, issue.111, pp.47-52, 2010.
DOI : 10.1016/S1473-3099(05)01305-8

W. Lao and P. D. , Human infections of influenza A (H1N1): Perspective from, WHO, 2009.

W. Lao and P. D. , Influenza Update: Perspective from, WHO, 2010.

N. Lapidus, D. Lamballerie, X. Salez, N. Setbon, M. Ferrari et al., Integrative study of pandemic A/H1N1 influenza infections: design and methods of the CoPanFlu-France cohort, BMC Public Health, vol.10, issue.1, p.417, 2012.
DOI : 10.1186/1471-2334-10-301

URL : https://hal.archives-ouvertes.fr/inserm-00730688

K. Dellagi, O. Rollot, S. Temmam, N. Salez, and V. Guernier, Pandemic Influenza Due to pH1N1/2009 Virus: Estimation of Infection Burden in Reunion Island through a Prospective Serosurvey, Austral Winter 2009, PLoS ONE, vol.6, issue.2, p.25738, 2009.
DOI : 10.1371/journal.pone.0025738.t004

URL : https://hal.archives-ouvertes.fr/halsde-00724649

O. Koita, L. Sangare, B. Poudiougou, B. Aboubacar, and Y. Samake, A seroepidemiological study of pandemic A/H1N1(2009) influenza in a rural population of Mali, Clinical Microbiology and Infection, vol.18, issue.10, pp.976-981, 2012.
DOI : 10.1111/j.1469-0691.2011.03725.x

J. Vallée, A. Dubot-pérès, P. Ounaphom, C. Sayavong, and J. Bryant, Spatial distribution and risk factors of dengue and Japanese encephalitis virus infection in urban settings: the case of Vientiane, Lao PDR, Tropical Medicine & International Health, vol.4, issue.9, pp.1134-1142, 2009.
DOI : 10.1186/1742-7622-4-6

J. Vallée, M. Souris, F. Fournet, A. Bochaton, and V. Mobillion, Sampling in health geography: reconciling geographical objectives and probabilistic methods. An example of a health survey in Vientiane (Lao PDR), Emerging Themes in Epidemiology, vol.4, issue.1, p.6, 2007.
DOI : 10.1186/1742-7622-4-6

J. Vallée, T. Thaojaikong, C. Moore, R. Phetsouvanh, and A. Richards, Contrasting Spatial Distribution and Risk Factors for Past Infection with Scrub Typhus and Murine Typhus in Vientiane City, Lao PDR, PLoS Neglected Tropical Diseases, vol.80, issue.6, p.909, 2010.
DOI : 10.1371/journal.pntd.0000909.s001

J. Delangue, N. Salez, L. Ninove, A. Kieffer, and C. Zandotti, Serological study of the 2009 pandemic due to influenza A H1N1 in the metropolitan French population, Clinical Microbiology and Infection, vol.18, issue.2, pp.177-183, 2011.
DOI : 10.1111/j.1469-0691.2011.03545.x

J. Nauta, Eliminating bias in the estimation of the geometric mean of HI titres, Biologicals, vol.34, issue.3, pp.183-186, 2006.
DOI : 10.1016/j.biologicals.2005.09.001

I. Stephenson, Reproducibility of Serologic Assays for Influenza Virus A (H5N1), Emerging Infectious Diseases, vol.15, issue.8, pp.1251-1259, 2009.
DOI : 10.3201/eid1508.081754

J. Wood, R. Gaines-das, J. Taylor, and P. Chakraverty, Comparison of influenza serological techniques by international collaborative study, Vaccine, vol.12, issue.2, pp.167-174, 1994.
DOI : 10.1016/0264-410X(94)90056-6

E. Broberg, A. Nicoll, and A. Amato-gauci, Seroprevalence to influenza A(H1N1) 2009 virus -where are we? Clinical and vaccine immunology 18, pp.1205-1212, 2011.

C. Achonu, R. L. Gubbay, J. Deeks, S. Rebbapragada, and A. , Seroprevalence of Pandemic Influenza H1N1 in Ontario from January 2009???May 2010, PLoS ONE, vol.6, issue.11, p.26427, 2009.
DOI : 10.1371/journal.pone.0026427.s003

J. Wu, E. Ma, C. Lee, D. Chu, and P. Ho, The Infection Attack Rate and Severity of 2009 Pandemic H1N1 Influenza in Hong Kong, Clinical Infectious Diseases, vol.51, issue.10, pp.1184-1191, 2010.
DOI : 10.1086/656740

D. Chao, K. Cheng, T. Li, T. Wu, and C. Chen, Serological Evidence of Subclinical Transmission of the 2009 Pandemic H1N1 Influenza Virus Outside of Mexico, PLoS ONE, vol.361, issue.27, p.14555, 2011.
DOI : 10.1371/journal.pone.0014555.t002

S. Riley, K. Kwok, K. Wu, D. Ning, and B. Cowling, Epidemiological Characteristics of 2009 (H1N1) Pandemic Influenza Based on Paired Sera from a Longitudinal Community Cohort Study, H1N1) Pandemic Influenza Based on Paired Sera from a Longitudinal Community Cohort Study, p.1000442, 2009.
DOI : 10.1371/journal.pmed.1000442.s009

P. Yang, L. Zhang, W. Shi, G. Lu, and S. Cui, Seroprevalence of pandemic (H1N1) 2009 influenza and effectiveness of 2010/2011 influenza vaccine during 2010/2011 season in Beijing, China, Influenza and Other Respiratory Viruses, vol.37, issue.6, pp.381-388, 2010.
DOI : 10.1016/S0531-5565(01)00210-8

J. Kok, K. Tudo, C. Blyth, H. Foo, and L. Hueston, Pandemic (H1N1) 2009 Influenza Virus Seroconversion Rates in HIV-Infected Individuals, JAIDS Journal of Acquired Immune Deficiency Syndromes, vol.56, issue.2, pp.91-94, 1999.
DOI : 10.1097/QAI.0b013e318204a1c3

M. Chen, V. Lee, W. Lim, I. Barr, and R. Lin, 2009 Influenza A(H1N1) Seroconversion Rates and Risk Factors Among Distinct Adult Cohorts in Singapore, JAMA, vol.303, issue.14, pp.1383-1391, 2009.
DOI : 10.1001/jama.2010.404

M. Chen, V. Lee, I. Barr, C. Lin, and R. Goh, Risk Factors for Pandemic (H1N1), Virus Seroconversion among Hospital Staff, Singapore. Emerging Infectious Diseases Available, vol.16, 2009.

J. Kok, D. Dwyer, and D. Dywer, How common was 2009 pandemic influenza A H1N1? The Lancet infectious diseases 11, pp.423-424, 2011.

A. Park and K. Glass, Dynamic patterns of avian and human influenza in east and southeast Asia, The Lancet Infectious Diseases, vol.7, issue.8, pp.543-548, 2007.
DOI : 10.1016/S1473-3099(07)70186-X

P. Blair, T. Wierzba, S. Touch, S. Vonthanak, and X. Xu, Influenza epidemiology and characterization of influenza viruses in patients seeking treatment for acute fever in Cambodia, Epidemiology and Infection, vol.18, issue.02, pp.199-209, 2010.
DOI : 10.1016/S0140-6736(04)15595-5

J. Simmerman and T. Uyeki, The burden of influenza in East and South-East Asia: a review of the English language literature, Influenza and Other Respiratory Viruses, vol.39, issue.Suppl. 8, pp.81-92, 2008.
DOI : 10.7883/yoken1952.49.77

D. Bandaranayake, Q. Huang, A. Bissielo, T. Wood, and G. Mackereth, Risk Factors and Immunity in a Nationally Representative Population following the 2009 Influenza A(H1N1) Pandemic, PLoS ONE, vol.7, issue.10, p.13211, 2010.
DOI : 10.1371/journal.pone.0013211.s001

G. Dowse, D. Smith, H. Kelly, I. Barr, and K. Laurie, Incidence of pandemic (H1N1) 2009 influenza infection in children and pregnant women during the 2009 influenza season in Western Australia -a seroprevalence study, The Medical journal of Australia, vol.194, pp.68-72, 2011.

G. Gilbert, M. A. Cretikos, L. Hueston, G. Doukas, O. Toole et al., Influenza A (H1N1) 2009 Antibodies in Residents of New South Wales, Australia, after the First Pandemic Wave in the 2009 Southern Hemisphere Winter, PLoS ONE, vol.375, issue.9, p.12562, 2010.
DOI : 10.1371/journal.pone.0012562.t004

E. Miller, K. Hoschler, P. Hardelid, E. Stanford, and N. Andrews, Incidence of 2009 pandemic influenza A H1N1 infection in England: a cross-sectional serological study, The Lancet, vol.375, issue.9720, pp.1100-1108, 2010.
DOI : 10.1016/S0140-6736(09)62126-7

G. Mak, P. Choy, W. Lee, A. Wong, and K. Ng, Sero-immunity and serologic response to pandemic influenza A (H1N1) 2009 virus in Hong Kong, Journal of Medical Virology, vol.101, issue.11, pp.1809-1815, 2010.
DOI : 10.3201/eid1605.091678

B. V. Tandale, S. Pawar, Y. Gurav, M. Chadha, and S. Koratkar, Seroepidemiology of pandemic influenza A (H1N1) 2009 virus infections in Pune, India, BMC Infectious Diseases, vol.49, issue.5, p.255, 2010.
DOI : 10.1086/644775

K. Waalen, . Kilander-a, S. Dudman, G. Krogh, and T. Aune, High prevalence of antibodies to the 2009 pandemic influenza A(H1N1) virus in the Norwegian population following a major epidemic and a large vaccination campaign in autumn 2009, Euro surveillance Available, vol.15, pp.1-6, 2010.

C. Xu, T. Bai, A. Luliano, M. Wang, and L. Yang, The Seroprevalence of Pandemic Influenza H1N1 (2009) Virus in China, PLoS ONE, vol.49, issue.4, p.17919, 2011.
DOI : 10.1371/journal.pone.0017919.s004

S. Zimmer, C. Crevar, D. Carter, J. Stark, and B. Giles, Seroprevalence Following the Second Wave of Pandemic 2009 H1N1 Influenza in Pittsburgh, PA, USA, PLoS ONE, vol.324, issue.7, p.11601, 2010.
DOI : 10.1371/journal.pone.0011601.t002

R. Xu, D. Ekiert, J. Krause, R. Hai, and J. Crowe, Structural Basis of Preexisting Immunity to the 2009 H1N1 Pandemic Influenza Virus, Science, vol.106, issue.48, pp.357-360, 2010.
DOI : 10.1073/pnas.0911580106

P. Hardelid, N. Andrews, K. Hoschler, E. Stanford, and M. Baguelin, Assessment of baseline age-specific antibody prevalence and incidence of infection to novel influenza A/H1N1, Health Technology Assessment, vol.14, pp.115-192, 2009.

H. Maltezou, P. Katerelos, M. Mavrouli, A. Lourida, and J. Routsias, Seroepidemiological study of pandemic influenza H1N1 following the 2009???2010 wave in Greece, Vaccine, vol.29, issue.38, pp.6664-6669, 2011.
DOI : 10.1016/j.vaccine.2011.06.098

K. Smith, P. Warner, L. Williams, W. Adamson, and S. Katikireddi, Prevalence of influenza A (H1N1) seropositivity in unvaccinated healthcare workers in Scotland at the height of the global pandemic, Journal of environmental and public health, pp.10-1155407505, 2011.

J. Mccullers, L. Van-de-velde, K. Allison, K. Branum, and R. Webby, Recipients of Vaccine against the 1976 ???Swine Flu??? Have Enhanced Neutralization Responses to the 2009 Novel H1N1 Influenza Virus, Clinical Infectious Diseases, vol.50, issue.11, pp.1487-1492, 2010.
DOI : 10.1086/652441

J. Mcvernon, L. K. Nolan, T. Owen, R. Irving, and D. , Seroprevalence of 2009 pandemic influenza A(H1N1) virus in Australian blood donors, Euro surveillance: 15. Available, 2009.

C. Rizzo, M. Rota, A. Bella, V. Alfonsi, and S. Declich, Cross-reactive antibody responses to the 2009 A/H1N1v influenza virus in the Italian population in the pre-pandemic period, Vaccine, vol.28, issue.20, pp.3558-3562, 2010.
DOI : 10.1016/j.vaccine.2010.03.006

R. Allwinn, J. Geiler, A. Berger, J. Cinatl, and H. Doerr, Determination of serum antibodies against swine-origin influenza A virus H1N1/09 by immunofluorescence, haemagglutination inhibition, and by neutralization tests: how is the prevalence rate of protecting antibodies in humans?, Medical Microbiology and Immunology, vol.29, issue.3, pp.117-121, 2010.
DOI : 10.1016/S0140-6736(09)62026-2

D. Huang, P. Shao, K. Huang, C. Lu, and J. Wang, Serologic Status for Pandemic (H1N1) 2009 Virus, Taiwan, Serologic status for pandemic (H1N1) 2009 virus, pp.76-78, 2011.
DOI : 10.3201/eid1701.100014

K. Hancock, V. Veguilla, X. Lu, W. Zhong, and E. Butler, Cross-Reactive Antibody Responses to the 2009 Pandemic H1N1 Influenza Virus, New England Journal of Medicine, vol.361, issue.20, pp.1945-1952, 2009.
DOI : 10.1056/NEJMoa0906453

N. Ikonen, M. Strengell, L. Kinnunen, P. Osterlund, and J. Pirhonen, High frequency of cross-reacting antibodies against 2009 pandemic influenza A(H1N1) virus among the elderly in Finland. Euro surveillance 15, Available, 2010.

C. Chi, C. Liu, C. Lin, H. Wang, and Y. Cheng, Preexisting Antibody Response against 2009 Pandemic Influenza H1N1 Viruses in the Taiwanese Population, Clinical and Vaccine Immunology, vol.17, issue.12, pp.1958-1962, 2010.
DOI : 10.1128/CVI.00212-10

H. Chen, Serologic Survey of Pandemic (H1N1), Virus Emerging Infectious Diseases, vol.15, pp.3-4, 2009.

J. Tang, P. Tambyah, A. Wilder-smith, K. Puong, and R. Shaw, Cross-Reactive Antibodies to Pandemic (H1N1), Virus Emerging Infectious Diseases, vol.16, pp.2009-2011, 2009.
DOI : 10.3201/eid1605.091678

URL : https://wwwnc.cdc.gov/eid/article/16/5/pdfs/09-1678.pdf

S. Cauchemez, A. Bhattarai, T. Marchbanks, R. Fagan, and S. Ostroff, Role of social networks in shaping disease transmission during a community outbreak of 2009 H1N1 pandemic influenza, Proceedings of the National Academy of Sciences, vol.10, issue.1, pp.2825-2830, 2011.
DOI : 10.1145/99902.99903

S. Cauchemez, C. Donnelly, C. Reed, A. Ghani, and C. Fraser, Household Transmission of 2009 Pandemic Influenza A (H1N1) Virus in the United States, New England Journal of Medicine, vol.361, issue.27, pp.2619-2627, 2009.
DOI : 10.1056/NEJMoa0905498

B. Yee, The Social and Cultural Context of Adaptive Aging by Southeast Asian Elders. Web Book available at: www, 1997.