1887

Abstract

Japanese encephalitis remains the most important cause of viral encephalitis in humans in several southeast Asian countries, including Cambodia, causing at least 65 000 cases of encephalitis per year. This vector-borne viral zoonosis – caused by Japanese encephalitis virus (JEV) – is considered to be a rural disease and is transmitted by mosquitoes, with birds and pigs being the natural reservoirs, while humans are accidental hosts. In this study we report the first two JEV isolations in Cambodia from human encephalitis cases from two studies on the aetiology of central nervous system disease, conducted at the two major paediatric hospitals in the country. We also report JEV isolation from mosquitoes and from pig samples collected in two farms, located in peri-urban and rural areas. Out of 11 reverse-transcription polymerase chain reaction-positive original samples, we generated full-genome sequences from 5 JEV isolates. Five additional partial sequences of the JEV NS3 gene from viruses detected in five pigs and one complete coding sequence of the envelope gene of a strain identified in a pig were generated. Phylogenetic analyses revealed that JEV detected in Cambodia belonged to genotype I and clustered in two clades: genotype I-a, mainly comprising strains from Thailand, and genotype I-b, comprising strains from Vietnam that dispersed northwards to China. Finally, in this study, we provide proof that the sequenced JEV strains circulate between pigs, and humans in the Phnom Penh vicinity.

Loading

Article metrics loading...

/content/journal/jgv/10.1099/jgv.0.000892
2017-09-01
2024-12-06
Loading full text...

Full text loading...

/deliver/fulltext/jgv/98/9/2287.html?itemId=/content/journal/jgv/10.1099/jgv.0.000892&mimeType=html&fmt=ahah

References

  1. Campbell GL, Hills SL, Fischer M, Jacobson JA, Hoke CH et al. Estimated global incidence of Japanese encephalitis: a systematic review. Bull World Health Organ 2011; 89:766–774 [View Article][PubMed]
    [Google Scholar]
  2. Tarantola A, Goutard F, Newton P, de Lamballerie X, Lortholary O et al. Estimating the burden of Japanese encephalitis virus and other encephalitides in countries of the mekong region. PLoS Negl Trop Dis 2014; 8:e2533 [View Article][PubMed]
    [Google Scholar]
  3. Solomon T, Ni H, Beasley DW, Ekkelenkamp M, Cardosa MJ et al. Origin and evolution of Japanese encephalitis virus in southeast Asia. J Virol 2003; 77:3091–3098 [View Article][PubMed]
    [Google Scholar]
  4. Schuh AJ, Ward MJ, Leigh Brown AJ, Barrett AD. Dynamics of the emergence and establishment of a newly dominant genotype of Japanese encephalitis virus throughout Asia. J Virol 2014; 88:4522–4532 [View Article][PubMed]
    [Google Scholar]
  5. Solomon T. Control of Japanese encephalitis–within our grasp?. N Engl J Med 2006; 355:869–871 [View Article][PubMed]
    [Google Scholar]
  6. Ghosh D, Basu A. Japanese encephalitis-a pathological and clinical perspective. PLoS Negl Trop Dis 2009; 3:e437 [View Article][PubMed]
    [Google Scholar]
  7. Chheng K, Carter MJ, Emary K, Chanpheaktra N, Moore CE et al. A prospective study of the causes of febrile illness requiring hospitalization in children in Cambodia. PLoS One 2013; 8:e60634 [View Article][PubMed]
    [Google Scholar]
  8. Chhour YM, Ruble G, Hong R, Minn K, Kdan Y et al. Hospital-based diagnosis of hemorrhagic fever, encephalitis, and hepatitis in Cambodian children. Emerg Infect Dis 2002; 8:485–489 [View Article][PubMed]
    [Google Scholar]
  9. Srey VH, Sadones H, Ong S, Mam M, Yim C et al. Etiology of encephalitis syndrome among hospitalized children and adults in Takeo, Cambodia, 1999-2000. Am J Trop Med Hyg 2002; 66:200–207 [View Article][PubMed]
    [Google Scholar]
  10. Touch S, Hills S, Sokhal B, Samnang C, Sovann L et al. Epidemiology and burden of disease from Japanese encephalitis in Cambodia: results from two years of sentinel surveillance. Trop Med Int Health 2009; 14:1365–1373 [View Article][PubMed]
    [Google Scholar]
  11. Horwood PF, Duong V, Laurent D, Mey C, Sothy H et al. Aetiology of acute meningoencephalitis in Cambodian children, 2010-2013. Emerg Microbes Infect 2017; 6:e35 [View Article][PubMed]
    [Google Scholar]
  12. Schuh AJ, Ward MJ, Brown AJ, Barrett AD. Phylogeography of Japanese encephalitis virus: genotype is associated with climate. PLoS Negl Trop Dis 2013; 7:e2411 [View Article][PubMed]
    [Google Scholar]
  13. Gao X, Liu H, Li M, Fu S, Liang G. Insights into the evolutionary history of Japanese encephalitis virus (JEV) based on whole-genome sequences comprising the five genotypes. Virol J 2015; 12:43 [View Article][PubMed]
    [Google Scholar]
  14. Wang HY, Takasaki T, Fu SH, Sun XH, Zhang HL et al. Molecular epidemiological analysis of Japanese encephalitis virus in China. J Gen Virol 2007; 88:885–894 [View Article][PubMed]
    [Google Scholar]
  15. Nitatpattana N, Dubot-Pérès A, Gouilh MA, Souris M, Barbazan P et al. Change in Japanese encephalitis virus distribution, Thailand. Emerg Infect Dis 2008; 14:1762–1765 [View Article][PubMed]
    [Google Scholar]
  16. Nam JH, Chung YJ, Ban SJ, Kim EJ, Park YK et al. Envelope gene sequence variation among japanese encephalitis viruses isolated in Korea. Acta Virol 1996; 40:303–309[PubMed]
    [Google Scholar]
  17. Ma SP, Yoshida Y, Makino Y, Tadano M, Ono T et al. Short report: a major genotype of Japanese encephalitis virus currently circulating in Japan. Am J Trop Med Hyg 2003; 69:151–154[PubMed]
    [Google Scholar]
  18. Tsuchie H, Oda K, Vythilingam I, Thayan R, Vijayamalar B et al. Genotypes of Japanese encephalitis virus isolated in three states in Malaysia. Am J Trop Med Hyg 1997; 56:153–158 [View Article][PubMed]
    [Google Scholar]
  19. Do LP, Bui TM, Hasebe F, Morita K, Phan NT. Molecular epidemiology of Japanese encephalitis in northern Vietnam, 1964-2011: genotype replacement. Virol J 2015; 12:51 [View Article][PubMed]
    [Google Scholar]
  20. Fulmali PV, Sapkal GN, Athawale S, Gore MM, Mishra AC et al. Introduction of Japanese encephalitis virus genotype I, India. Emerg Infect Dis 2011; 17:319–321 [View Article][PubMed]
    [Google Scholar]
  21. Chen YY, Fan YC, Tu WC, Chang RY, Shih CC et al. Japanese encephalitis virus genotype replacement, Taiwan, 2009-2010. Emerg Infect Dis 2011; 17:2354–2356 [View Article][PubMed]
    [Google Scholar]
  22. Lindahl JF, Ståhl K, Chirico J, Boqvist S, Thu HT et al. Circulation of Japanese encephalitis virus in pigs and mosquito vectors within Can Tho city, Vietnam. PLoS Negl Trop Dis 2013; 7:e2153 [View Article][PubMed]
    [Google Scholar]
  23. Cappelle J, Duong V, Pring L, Kong L, Yakovleff M et al. Intensive circulation of Japanese encephalitis virus in peri-urban sentinel pigs near Phnom Penh, Cambodia. PLoS Negl Trop Dis 2016; 10:e0005149 [View Article][PubMed]
    [Google Scholar]
  24. Kuwata R, Nga PT, Yen NT, Hoshino K, Isawa H et al. Surveillance of Japanese encephalitis virus infection in mosquitoes in Vietnam from 2006 to 2008. Am J Trop Med Hyg 2013; 88:681–688 [View Article][PubMed]
    [Google Scholar]
  25. Gingrich JB, Nisalak A, Latendresse JR, Sattabongkot J, Hoke CH et al. Japanese encephalitis virus in Bangkok: factors influencing vector infections in three suburban communities. J Med Entomol 1992; 29:436–444 [View Article][PubMed]
    [Google Scholar]
  26. Lindahl J, Chirico J, Boqvist S, Thu HT, Magnusson U. Occurrence of Japanese encephalitis virus mosquito vectors in relation to urban pig holdings. Am J Trop Med Hyg 2012; 87:1076–1082 [View Article][PubMed]
    [Google Scholar]
  27. Ricklin ME, García-Nicolás O, Brechbühl D, Python S, Zumkehr B et al. Vector-free transmission and persistence of Japanese encephalitis virus in pigs. Nat Commun 2016; 7:10832 [View Article][PubMed]
    [Google Scholar]
  28. Hegde NR, Gore MM. Japanese encephalitis vaccines: Immunogenicity, protective efficacy, effectiveness, and impact on the burden of disease. Hum Vaccin Immunother 2017; 13:1320–1337 [View Article][PubMed]
    [Google Scholar]
  29. Gould DJ, Edelman R, Grossman RA, Nisalak A, Sullivan MF. Study of Japanese encephalitis virus in Chiangmai Valley, Thailand. IV. Vector studies. Am J Epidemiol 1974; 100:49–56 [View Article][PubMed]
    [Google Scholar]
  30. Stojanovich CJ, Scott HG.Communicable Disease Center Illustrated Key to Mosquitoes of Vietnam. Communicable Disease Center Atlanta: Communicable Disease Center; 1966
    [Google Scholar]
  31. Reuben R, Tewari SC, Hiriyan J, Akiyama J. Illustrated keys to species of culex (Culex) associated with Japanese encephalitis in Southeast Asia (Diptera: Culicidae). Mosquito Systematics 1994; 26:75–76
    [Google Scholar]
  32. Rattanarithikul R, Harbach RE, Harrison BA, Panthusiri P, Jones JW et al. Illustrated keys to the mosquitoes of Thailand. II. Genera Culex and Lutzia. Southeast Asian J Trop Med Public Health 2005; 36:1–97[PubMed]
    [Google Scholar]
  33. Shirato K, Miyoshi H, Kariwa H, Takashima I. Detection of West Nile virus and Japanese encephalitis virus using real-time PCR with a probe common to both viruses. J Virol Methods 2005; 126:119–125 [View Article][PubMed]
    [Google Scholar]
  34. Tanaka M. Rapid identification of flavivirus using the polymerase chain reaction. J Virol Methods 1993; 41:311–322 [View Article][PubMed]
    [Google Scholar]
  35. Vong S, Khieu V, Glass O, Ly S, Duong V et al. Dengue incidence in urban and rural Cambodia: results from population-based active fever surveillance, 2006-2008. PLoS Negl Trop Dis 2010; 4:e903 [View Article][PubMed]
    [Google Scholar]
  36. Edgar RC. MUSCLE: a multiple sequence alignment method with reduced time and space complexity. BMC Bioinformatics 2004; 5:113 [View Article][PubMed]
    [Google Scholar]
  37. Gouy M, Guindon S, Gascuel O. SeaView version 4: a multiplatform graphical user interface for sequence alignment and phylogenetic tree building. Mol Biol Evol 2010; 27:221–224 [View Article][PubMed]
    [Google Scholar]
  38. Posada D. Selection of models of DNA evolution with jModelTest. Methods Mol Biol 2009; 537:93–112 [View Article][PubMed]
    [Google Scholar]
  39. Tamura K, Peterson D, Peterson N, Stecher G, Nei M et al. MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol 2011; 28:2731–2739 [View Article][PubMed]
    [Google Scholar]
/content/journal/jgv/10.1099/jgv.0.000892
Loading
/content/journal/jgv/10.1099/jgv.0.000892
Loading

Data & Media loading...

Supplements

Supplementary File 1

PDF
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error