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Masahiko HACHIYA, MD, MPH, PhD

 As of April 2023

Deputy Director General,
Department of Healthl Planning and managment


Area of expertise

Vaccine preventable diseases, Infectious disease epidemiology, Pediatrics

Long-term overseas experiences

Jul  2003-
Aug 2005  
Harvard School of Public Health (Visiting Scientist), Massachusetts State Laboratory (Epidemiologist)
May 2007-
May 2009
JICA Vaccine Preventable Diseases Surveillance and Control Project,
PR China (EPI Advisor, Chief Advisor)

Publication list

  1. Nozaki I, Hachiya M, Ikeda C. COVID-19 vaccination program in Cambodia: Achievements and remaining challenges. Glob Health Med. 2023 Apr 30;5(2):92-98. doi: 10.35772/ghm.2023.01002. PMID: 37128223; PMCID: PMC10130549.
  2. Do AD, Pham TTP, Nguyen CQ, Van Hoang D, Fukunaga A, Yamamoto S, Shrestha RM, Phan DC, Hachiya M, Van Huynh D, Le HX, Do HT, Mizoue T, Inoue Y. Different associations of occupational and leisure-time physical activity with the prevalence of hypertension among middle-aged community dwellers in rural Khánh Hòa, Vietnam. BMC Public Health. 2023 Apr 19;23(1):713. doi: 10.1186/s12889-023-15631-w. PMID: 37076854; PMCID: PMC10116664.
  3. Manandhar Shrestha R, Mizoue T, Pham TTP, Fukunaga A, Hoang DV, Nguyen CQ, Phan DC, Hachiya M, Huynh DV, Le HX, Do HT, Inoue Y. Association between parental absence during childhood and metabolic syndrome during adulthood: A cross-sectional study in rural Khanh Hoa, Vietnam. PLoS One. 2023 Mar 9;18(3):e0282731. doi: 10.1371/journal.pone.0282731. PMID: 36893153; PMCID: PMC9997891.
  4. Van Hoang D, Fukunaga A, Nguyen CQ, Pham TTP, Shrestha RM, Phan DC, Le HX, Do HT, Hachiya M, Mizoue T, Inoue Y. Eating speed and abdominal adiposity in middle-aged adults: a cross-sectional study in Vietnam. BMC Public Health. 2023 Mar 7;23(1):443. doi: 10.1186/s12889-023-15328-0. PMID: 36882714; PMCID: PMC9993665.
  5. Miyano S, Vynnycky E, Pattamavone C, Ichimura Y, Mori Y, Nouanthong P, Phounphenghack K, Tengbriacheu C, Khamphaphongphane B, Franzel L, Yang TU, Raaijimarkers H, Komada K, Ota T, Funato M, Takeda M, Hachiya M. Comparison of population-based measles-rubella immunoglobulin G antibody prevalence between 2014 and 2019 in Lao People's Democratic Republic: Impacts of the national immunization program. Int J Infect Dis. 2023 Apr;129:70-77. doi: 10.1016/j.ijid.2023.01.044. Epub 2023 Feb 8. PMID: 36758852.
  6. Do AD, Pham TTP, Nguyen CQ, Hoang DV, Fukunaga A, Stickley A, Yazawa A, Phan DC, Hachiya M, Jimba M, Huynh DV, Le HX, Do HT, Mizoue T, Inoue Y. Individual-level social capital is associated with depressive symptoms among middle-aged community dwellers in rural Vietnam: a cross-sectional study. BMJ Open. 2022 Dec 6;12(12):e064998. doi: 10.1136/bmjopen-2022-064998. PMID: 36600355; PMCID: PMC9730365.
  7. Miyano S, Pathammavong C, Ichimura Y, Sugiyama M, Phounphenghack K, Tengbriacheu C, Khamphaphongphane B, Nouanthong P, Franzel L, Yang TU, Raaijimakers H, Ota T, Funato M, Komada K, Hachiya M. Prevalence of hepatitis B and C virus infections in Lao People's Democratic Republic: The first national population-based cross-sectional survey. PLoS One. 2022 Dec 30;17(12): e0278933. doi: 10.1371/journal.pone.0278933. PMID: 36584043; PMCID: PMC9803141.
  8. Komada K, Ichimura Y, Shimada M, Funato M, Do HT, LE HX, Hoang TT, Nguyen TB, Huynh MK, Hoang HTH, Tran NAT, LE TH, Ngo QT, Miyano S, Sugiyama M, Mizoue T, Hachiya M. Impact of hepatitis B vaccination programs in Vietnam evaluated by estimating HBsAg prevalence. J Virus Erad. 2022 Dec 10;8(4):100309. doi: 10.1016/j.jve.2022.100309. PMID: 36582474; PMCID: PMC9792882.
  9. Ichimura Y, Yanagisawa N, Thandar MM, Pathammavong C, Phounphenghuk K, Nouanthong P, Tengbriacheu C, Khamphaphongphane B, Franzel-Sassanpour LE, Yang TU, Raaijmakers H, Ota T, Komada K, Hachiya M, Miyano S. The determinants of immunization coverage among children aged between 12 and 35 months: a nationwide cross-sectional study in Lao People's Democratic Republic. BMC Public Health. 2022 Dec 3;22(1):2259. doi: 10.1186/s12889-022-14522-w. PMID: 36463130; PMCID: PMC9719255.
  10. Yazawa A, Kawachi I, Shrestha RM, Fukunaga A, Pham TTP, Nguyen CQ, Hoang DV, Phan DC, Hachiya M, Huynh DV, Le HX, Do HT, Mizoue T, Inoue Y. Parental absence during childhood and weight status in adulthood among middle-aged community dwellers in rural Vietnam. Am J Hum Biol. 2023 Mar;35(3):e23827. doi: 10.1002/ajhb.23827. Epub 2022 Nov 7. PMID: 36345160.
  11. Okawa S, Komada K, Ichimura Y, Sugiyama M, Do HT, Le HX, Hoang TT, Nguyen TB, Huynh MK, Hoang HTH, Tran NAT, Le TH, Ngo QT, Miyano S, Yokobori Y, Inoue Y, Mizoue T, Hachiya M. Comparison between a rapid diagnostic test and dried blood spot-based immunoassay for hepatitis B surface antigen testing: Performance and cost implications in a population-based serosurvey in Vietnam. Int J Infect Dis. 2022 Dec;125:51-57. doi: 10.1016/j.ijid.2022.10.011. Epub 2022 Oct 12. PMID: 36241163.
  12. Ichimura Y, Yamauchi M, Yoshida N, Miyano S, Komada K, Thandar MM, Tiwara S, Mita T, Hombhanje FW, Mori Y, Takeda M, Hachiya M. Effectiveness of immunization activities on measles and rubella immunity among individuals in East Sepik, Papua New Guinea: A cross-sectional study. IJID Reg. 2022 Mar 3;3:84-88. doi: 10.1016/j.ijregi.2022.03.001. PMID: 35755474; PMCID: PMC9216679.
  13. Nguyen CQ, Pham TTP, Fukunaga A, Hoang DV, Phan TV, Phan DC, Huynh DV, Hachiya M, Le HX, Do HT, Mizoue T, Inoue Y. Red meat consumption is associated with prediabetes and diabetes in rural Vietnam: a cross-sectional study. Public Health Nutr. 2023 May;26(5):1006-1013. doi: 10.1017/S1368980022001422. Epub 2022 Jun 20. PMID: 35722988.
  14. Inoue Y, Fukunaga A, Stickley A, Yazawa A, Pham TTP, Nguyen CQ, Hoang DV, Shrestha RM, Phan DC, Hachiya M, Huynh DV, Le HX, Do HT, Mizoue T. Association between parental absence during childhood and depressive symptoms in adulthood in rural Vietnam. J Affect Disord. 2022 Aug 15;311:479-485. doi: 10.1016/j.jad.2022.05.102. Epub 2022 May 20. PMID: 35598745.
  15. Tsuboi M, Hachiya M, Ohtsu H, Akashi H, Miyoshi C, Umeda T. Epidemiology and Risk of Coronavirus Disease 2019 Among Travelers at Airport and Port Quarantine Stations Across Japan: A Nationwide Descriptive Analysis and an Individually Matched Case-Control Study. Clin Infect Dis. 2022 May 3;74(9):1614-1622. doi: 10.1093/cid/ciab659. PMID: 34318872; PMCID: PMC8406868.
  16. Kitamura T, Bouakhasith V, Phounphenghack K, Pathammavong C, Xeuatvongsa A, Kobayashi A, Norizuki M, Okabayashi H, Miyano S, Mori Y, Takeda M, Sugiyama M, Mizokami M, Machida M, Hachiya M. Vaccine temperature management in Lao People's Democratic Republic: A nationwide cross-sectional study. Heliyon. 2021 Jun 17;7(6):e07342. doi: 10.1016/j.heliyon.2021.e07342. PMID: 34307926; PMCID: PMC8258653.
  17. Norizuki M, Hachiya M, Motohashi A, Moriya A, Mezaki K, Kimura M, Sugiura W, Akashi H, Umeda T. Effective screening strategies for detection of asymptomatic COVID-19 travelers at airport quarantine stations: Exploratory findings in Japan. Glob Health Med. 2021 Apr 30;3(2):107-111. doi: 10.35772/ghm.2020.01109. PMID: 33937574; PMCID: PMC8071686.
  18. Matsuoka S, Kawakatsu Y, Koga S, Ayeola N, Iwayemi V, Saito C, Murakami H, Hachiya M. Underlying causes of underutilization of maternal, neonatal and child health (MNCH) services in Africa: A survey from Lagos State, Nigeria. Glob Health Med. 2020 Jun 30;2(3):184-189. doi: 10.35772/ghm.2020.01012. PMID: 33330805; PMCID: PMC7731355.
  19. Tsuboi M, Hachiya M, Noda S, Iso H, Umeda T. Epidemiology and quarantine measures during COVID-19 outbreak on the cruise ship Diamond Princess docked at Yokohama, Japan in 2020: a descriptive analysis. Glob Health Med. 2020 Apr 30;2(2):102-106. doi: 10.35772/ghm.2020.01037. PMID: 33330785; PMCID: PMC7731102.
  20. Fujita M, Matsuoka S, Kiyohara H, Kumakura Y, Takeda Y, Goishi N, Tarui M, Inaba M, Nagai M, Hachiya M, Fujita N. "Staying at home" to tackle COVID-19 pandemic: rhetoric or reality? Cross-cutting analysis of nine population groups vulnerable to homelessness in Japan. Trop Med Health. 2020 Nov 23;48(1):92. doi: 10.1186/s41182-020-00281-0. PMID: 33292830; PMCID: PMC7680823.
  21. Vynnycky E, Miyano S, Komase K, Mori Y, Takeda M, Kitamura T, Xeuatvongsa A, Hachiya M. Estimating the immunogenicity of measles-rubella vaccination administered during a mass campaign in Lao People's Democratic Republic using multi-valent seroprevalence data. Sci Rep. 2019 Aug 29;9(1):12545. doi: 10.1038/s41598-019-49018-y. PMID: 31467441; PMCID: PMC6715652.
  22. Norizuki M, Kitamura T, Komada K, Sugiyama M, Mizokami M, Xeuatvongsa A, Som-Oulay V, Vongphrachanh P, Machida M, Wada K, Ishii K, Kiyohara T, Wakita T, Hachiya M. Serologic testing of randomly selected children after hepatitis B vaccination: a cross-sectional population-based study in Lao People's Democratic Republic. BMC Infect Dis. 2019 Jun 10;19(1):507. doi: 10.1186/s12879-019-4086-0. PMID: 31182043; PMCID: PMC6558699.
  23. Okabayashi H, Komada K, Kidokoro M, Kitamura T, Miyano S, Ito T, Phounphenghak K, Pathammavong C, Murano K, Nagai M, Mori Y, Komase K, Xeuatvongsa A, Takeda M, Hachiya M. Seroprevalence of mumps before the introduction of mumps-containing vaccine in Lao PDR: results from a nationwide cross-sectional population-based survey. BMC Res Notes. 2019 Mar 19;12(1):155. doi: 10.1186/s13104-019-4194-3. PMID: 30890154; PMCID: PMC6425695.
  24. Nozaki I, Hachiya M, Kitamura T. Factors influencing basic vaccination coverage in Myanmar: secondary analysis of 2015 Myanmar demographic and health survey data. BMC Public Health. 2019 Feb 28;19(1):242. doi: 10.1186/s12889-019-6548-0. PMID: 30819127; PMCID: PMC6394082.
  25. Kitamura T, Bouakhasith V, Phounphenghack K, Pathammavong C, Xeuatvongsa A, Norizuki M, Okabayashi H, Mori Y, Machida M, Hachiya M. Assessment of temperatures in the vaccine cold chain in two provinces in Lao People's Democratic Republic: a cross-sectional pilot study. BMC Res Notes. 2018 Apr 27;11(1):261. doi: 10.1186/s13104-018-3362-1. PMID: 29703228; PMCID: PMC5924473.
  26. Hachiya M, Miyano S, Mori Y, Vynnycky E, Keungsaneth P, Vongphrachanh P, Xeuatvongsa A, Sisouk T, Som-Oulay V, Khamphaphongphane B, Sengkeopaseuth B, Pathammavong C, Phounphenghak K, Kitamura T, Takeda M, Komase K. Evaluation of nationwide supplementary immunization in Lao People's Democratic Republic: Population-based seroprevalence survey of anti-measles and anti-rubella IgG in children and adults, mathematical modelling and a stability testing of the vaccine. PLoS One. 2018 Mar 29;13(3):e0194931. doi: 10.1371/journal.pone.0194931. PMID: 29596472; PMCID: PMC5875789.
  27. Miyakawa M, Shimizu T, Van Dat N, Thanh P, Thuy PT, Anh NT, Chau NH, Matsushita Y, Kajio H, Mai VQ, Hachiya M. Prevalence, perception and factors associated with diabetes mellitus among the adult population in central Vietnam: a population-based, cross-sectional seroepidemiological survey. BMC Public Health. 2017 Apr 5;17(1):298. doi: 10.1186/s12889-017-4208-9. PMID: 28381223; PMCID: PMC5382364.
  28. Xeuatvongsa A, Hachiya M, Miyano S, Mizoue T, Kitamura T. Determination of factors affecting the vaccination status of children aged 12-35 months in Lao People's Democratic Republic. Heliyon. 2017 Mar 21;3(3):e00265. doi: 10.1016/j.heliyon.2017.e00265. PMID: 28367510; PMCID: PMC5362045.
  29. Komada K, Sugiyama M, Vongphrachanh P, Xeuatvongsa A, Khamphaphongphane B, Kitamura T, Kiyohara T, Wakita T, Oshitani H, Hachiya M. Seroprevalence of chronic hepatitis B, as determined from dried blood spots, among children and their mothers in central Lao People's Democratic Republic: a multistage, stratified cluster sampling survey. Int J Infect Dis. 2015 Jul;36:21-6. doi: 10.1016/j.ijid.2015.04.020. Epub 2015 May 6. PMID: 25957815.
  30. Xeuatvongsa A, Komada K, Kitamura T, Vongphrachanh P, Pathammavong C, Phounphenghak K, Sisouk T, Phonekeo D, Sengkeopaseuth B, Som-Oulay V, Ishii K, Wakita T, Sugiyama M, Hachiya M. Chronic hepatitis B prevalence among children and mothers: results from a nationwide, population-based survey in Lao People's Democratic Republic. PLoS One. 2014 Feb 28;9(2):e88829. doi: 10.1371/journal.pone.0088829. PMID: 24586408; PMCID: PMC3938412.
  31. Murakami H, Kobayashi M, Hachiya M, Khan ZS, Hassan SQ, Sakurada S. Refusal of oral polio vaccine in northwestern Pakistan: a qualitative and quantitative study. Vaccine. 2014 Mar 10;32(12):1382-7. doi: 10.1016/j.vaccine.2014.01.018. Epub 2014 Feb 1. PMID: 24492016.
  32. Kitamura T, Komada K, Xeuatvongsa A, Hachiya M. Factors affecting childhood immunization in Lao People's Democratic Republic: a cross-sectional study from nationwide, population-based, multistage cluster sampling. Biosci Trends. 2013 Aug;7(4):178-85. PMID: 24056168.
  33. Hanafusa S, Muhadir A, Santoso H, Tanaka K, Anwar M, Sulistyo ET, Hachiya M. A surveillance model for human avian influenza with a comprehensive surveillance system for local-priority communicable diseases in South sulawesi, indonesia. Trop Med Health. 2012 Dec;40(4):141-7. doi: 10.2149/tmh.2012-10. Epub 2012 Dec. PMID: 23532690; PMCID: PMC3598071.
  34. Hachiya M, Sakurada S, Mizuno T, Sugiura Y. Poliovirus eradication. Lancet Infect Dis. 2012 Jun;12(6):433. doi: 10.1016/S1473-3099(12)70103-2. PMID: 22632185.
  35. Hachiya M, Kikuchi H, Mizoue T. Descriptive epidemiology of travel- associated diarrhea based on surveillance data at Narita International Airport. J Travel Med. 2010 Mar-Apr;17(2):105-10. doi: 10.1111/j.1708-8305.2009.00386.x. PMID: 20412177.
  36. Rentsen T, Enkhtuya B, Nymadawa P, Kobune F, Suzuki K, Yoshida H, Hachiya M. Measles outbreak after a post-honeymoon period in Mongolia, 2001. Jpn J Infect Dis. 2007 Jul;60(4):198-9. PMID: 17642531.
  37. Hachiya M, Osborne M, Stinson C, Werner BG. Human eastern equine encephalitis in Massachusetts: predictive indicators from mosquitoes collected at 10 long-term trap sites, 1979-2004. Am J Trop Med Hyg. 2007 Feb;76(2):285-92. PMID: 17297037.
  38. Takeuchi K, Kyoko H, Hachiya M, Ohara A, Tsukimoto I, Kanto H, Hatano M. Pyoderma gangrenosum of the skin and respiratory tract in a 5-year-old girl. Eur J Pediatr. 2003 May;162(5):344-5. doi: 10.1007/s00431-002-1084-8. PMID: 12784795.
  39. Hachiya M, Hachiya Y, Mitsui K, Tsukimoto I, Watanabe K, Fujisawa T. Solid, cystic and vanishing tumors of the pancreas. Clin Imaging. 2003 Mar-Apr;27(2):106-8. doi: 10.1016/s0899-7071(02)00482-5. PMID: 12639776.
  40. Hachiya M, Nara C, Tsukimoto I, Yamada S. Massive gastrointestinal bleeding in a 14-year-old boy. Eur J Pediatr. 2002 Jan;161(1):61-2. doi: 10.1007/s004310100846. PMID: 11808882.
  41. Sato M, Yokoya S, Hachiya Y, Hachiya M, Fujisawa T, Hoshino K, Saji T. Two hyperandrogenic adolescent girls with congenital portosystemic shunt. Eur J Pediatr 160: 307-11; 2001.
  42. Hachiya M, Watanabe H, Tsukimoto I, Fujisawa T. Hereditary hemochromatosis not associated with common HFE gene mutation in Japanese siblings. J Pediatr Gastroenterol Nutr 32: 501-3; 2001.
  43. Hachiya M, Matsui M, Sanogo M, Oseto M, Morooka K, Ushijima H. Genetic variation in the capsid region of human astrovirus serotype 4 isolated in Japan. Microbiol Immunol 43: 1067-1070; 1999.
  44. Matsui M, Ushijima H, Hachiya M, Kakizawa J, Wen L, Oseto M, Morooka K, Kurtz B. Determination of serotypes of astroviruses by reverse transcription-polymerase chain reaction and homologies of the types be the sequencing of Japanese isolates. Microbiol Immunol 42: 539-547; 1998.