Volume 96, Issue 5
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



Rickettsial infections are recognized as important causes of fever throughout southeast Asia. Herein, we determined the seroprevalence to rickettsioses within rural and urban populations of northern Vietnam. Prevalence of individuals with evidence of prior rickettsial infections (IgG positive) was surprisingly low, with 9.14% (83/908) testing positive to the three major rickettsial serogroups thought to circulate in the region. Prevalence of typhus group rickettsiae (TG)–specific antibodies (6.5%, 58/908) was significantly greater than scrub typhus group orientiae (STG)– or spotted fever group rickettsiae (SFG)–specific antibodies ( < 0.05). The majority of TG seropositives were observed among urban rather than rural residents ( < 0.05). In contrast, overall antibody prevalence to STG and SFG were both very low (1.1%, 10/908 for STG; 1.7%, 15/908 for SFG), with no significant differences between rural and urban residents. These results provide data on baseline population characteristics that may help inform development of serological testing criteria in future clinical studies.

[open-access] This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


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  1. Acestor N, Cooksey R, Newton P, Menard D, Guerin PJ, Nakagawa J, Christophel E, Gonzalez IJ, Bell D, , 2012. Mapping the aetiology of non-malarial febrile illness in southeast Asia through a systematic review: terra incognita impairing treatment policies. PLoS One 7: e44269.[Crossref] [Google Scholar]
  2. Aung AK, Spelman DW, Murray RJ, Graves S, , 2014. Rickettsial infections in southeast Asia: implications for local populace and febrile returned travelers. Am J Trop Med Hyg 91: 451460.[Crossref] [Google Scholar]
  3. Richards AL, , 2012. Worldwide detection and identification of new and old rickettsiae and rickettsial diseases. FEMS Immunol Med Microbiol 64: 107110.[Crossref] [Google Scholar]
  4. Dittrich S, Rattanavong S, Lee SJ, Panyanivong P, Craig SB, Tulsiani SM, Blacksell SD, Dance DAB, Dubot-Pérès A, Sengduangphachanh A, Phoumin P, Paris DH, Newton PN, , 2015. Orientia, Rickettsia, and Leptospira pathogens as causes of CNS infections in Laos: a prospective study. Lancet Glob Health 3: e104e112.[Crossref] [Google Scholar]
  5. Dumler JS, Barbet AF, Bekker CP, Dasch GA, Palmer GH, Ray SC, Rikihisa Y, Rurangirwa FR, , 2001. Reorganization of genera in the families Rickettsiaceae and Anaplasmataceae in the order Rickettsiales: unification of some species of Ehrlichia with Anaplasma, Cowdria with Ehrlichia and Ehrlichia with Neorickettsia, descriptions of six new species combinations. Int J Syst Evol Microbiol 51: 21452165.[Crossref] [Google Scholar]
  6. Elisberg B, Campbell J, Bozeman F, , 1968. Antigenic diversity of Rickettsia tsutsugamushi: epidemiologic and ecologic significance. J Hyg Epidemiol Microbiol Immunol 12: 1825. [Google Scholar]
  7. Azad AF, , 1990. Epidemiology of murine typhus. Annu Rev Entomol 35: 553570.[Crossref] [Google Scholar]
  8. Hamaguchi S, Cuong NC, Tra DT, Doan YH, Shimizu K, Tuan NQ, Yoshida L-M, Mai LQ, Duc-Anh D, Ando S, Arikawa J, Parry CM, Ariyoshi K, Thuy PT, , 2001. Clinical and epidemiological characteristics of scrub typhus and murine typhus among hospitalized patients with acute undifferentiated fever in northern Vietnam. Am J Trop Med Hyg 92: 972978.[Crossref] [Google Scholar]
  9. Lim C, Paris DH, Blacksell SD, Laongnualpanich A, Kantipong P, Chierakul W, Wuthiekanun V, Day NPJ, Cooper BS, Limmathurotsakul D, , 2015. How to determine the accuracy of an alternative diagnostic test when it is actually better than the reference tests: a re-evaluation of diagnostic tests for scrub typhus using Bayesian LCMs. PLoS One 10: e0114930.[Crossref] [Google Scholar]
  10. Dao TT, Liebenthal D, Tran TK, Ngoc Thi Vu B, Ngoc Thi Nguyen D, Thi Tran HK, Thi Nguyen CK, Thi Vu HL, Fox A, Horby P, Van Nguyen K, Wertheim HFL, , 2014. Klebsiella pneumoniae oropharyngeal carriage in rural and urban Vietnam and the effect of alcohol consumption. PLoS One 9: e91999.[Crossref] [Google Scholar]
  11. Chuc N, Diwan V, , 2003. FilaBavi, a demographic surveillance site, an epidemiological field laboratory in Vietnam. Scand J Public Health Suppl 62: 37.[Crossref] [Google Scholar]
  12. Graf PCF, Chretien J-P, Ung L, Gaydos JC, Richards AL, , 2008. Prevalence of seropositivity to spotted fever group rickettsiae and Anaplasma phagocytophilum in a large, demographically diverse US sample. Clin Infect Dis 46: 7077.[Crossref] [Google Scholar]
  13. Richards AL, Soeatmadji D, Widodo M, Sardjono T, Yanuwiadi B, Hernowati TE, Baskoro AD, , 1997. Seroepidemiologic evidence for murine and scrub typhus in Malang, Indonesia. Am J Trop Med Hyg 57: 9195. [Google Scholar]
  14. Thiga JW, Mutai BK, Richards AL, Waitumbi JN, , 2015. High seroprevalence of antibodies against in patients with febrile illness, Kenya. Emerg Infect Dis 21: 688691.[Crossref] [Google Scholar]
  15. Vallée J, Thaojaikong T, Moore CE, Phetsouvanh R, Richards AL, Souris M, Fournet F, Salem G, Gonzalez JPJ, Newton PN, , 2010. Contrasting spatial distribution and risk factors for past infection with scrub typhus and murine typhus in Vientiane city, Lao PDR. PLoS Negl Trop Dis 4: 110.[Crossref] [Google Scholar]
  16. Blacksell SD, Kantipong P, Watthanaworawit W, Turner C, Tanganuchitcharnchai A, Jintawon S, Laongnuanutit A, Nosten FH, Day NPJ, Paris DH, Richards AL, , 2015. Underrecognized arthropod-borne and zoonotic pathogens in northern and northwestern Thailand: serological evidence and opportunities for awareness. Vector Borne Zoonotic Dis 15: 285290.[Crossref] [Google Scholar]
  17. Maude RR, Maude RJ, Ghose A, Amin MR, Islam MB, Ali M, Bari MS, Majumder MI, Tanganuchitcharnchai A, Dondorp AM, Paris DH, Bailey RL, Faiz MA, Blacksell SD, Day NP, , 2014. Serosurveillance of Orientia tsutsugamushi and Rickettsia typhi in Bangladesh. Am J Trop Med Hyg 91: 580583.[Crossref] [Google Scholar]
  18. Tay S, Kamalanathan M, Rohani M, , 2003. Antibody prevalence of Orientia tsutsugamushi, Rickettsia typhi and TT118 spotted fever group rickettsiae among Malaysian blood donors and febrile patients in the urban areas. Southeast Asian J Trop Med Public Health 34: 165170. [Google Scholar]
  19. Strickman D, Tanskul P, Eamsila C, Kelly D, , 1994. Prevalence of antibodies to rickettsiae in the human population of suburban Bangkok. Am J Trop Med Hyg 51: 149153. [Google Scholar]
  20. Duong V, Mai TTX, Blasdell K, Lo LV, Morvan C, Lay S, Anukool W, Wongprompitak P, Suputtamongkol Y, Laurent D, Richner B, Ra C, Chien BT, Frutos R, Buchy P, , 2013. Molecular epidemiology of Orientia tsutsugamushi in Cambodia and central Vietnam reveals a broad region-wide genetic diversity. Infect Genet Evol 15: 3542.[Crossref] [Google Scholar]

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  • Received : 18 May 2016
  • Accepted : 17 Jan 2017
  • Published online : 06 Mar 2017

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