Intensive Circulation of Japanese Encephalitis Virus in Peri-urban Sentinel Pigs near Phnom Penh, Cambodia

PLoS Negl Trop Dis. 2016 Dec 7;10(12):e0005149. doi: 10.1371/journal.pntd.0005149. eCollection 2016 Dec.

Abstract

Despite the increased use of vaccination in several Asian countries, Japanese Encephalitis (JE) remains the most important cause of viral encephalitis in Asia in humans with an estimated 68,000 cases annually. Considered a rural disease occurring mainly in paddy-field dominated landscapes where pigs are amplifying hosts, JE may nevertheless circulate in a wider range of environment given the diversity of its potential hosts and vectors. The main objective of this study was to assess the intensity of JE transmission to pigs in a peri-urban environment in the outskirt of Phnom Penh, Cambodia. We estimated the force of JE infection in two cohorts of 15 sentinel pigs by fitting a generalised linear model on seroprevalence monitoring data observed during two four-month periods in 2014. Our results provide evidence for intensive circulation of JE virus in a periurban area near Phnom Penh, the capital and most populated city of Cambodia. Understanding JE virus transmission in different environments is important for planning JE virus control in the long term and is also an interesting model to study the complexity of vector-borne diseases. Collecting quantitative data such as the force of infection will help calibrate epidemiological model that can be used to better understand complex vector-borne disease epidemiological cycles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Viral / blood
  • Cambodia / epidemiology
  • Cohort Studies
  • Culex / virology
  • Encephalitis Virus, Japanese / genetics
  • Encephalitis Virus, Japanese / immunology
  • Encephalitis Virus, Japanese / isolation & purification*
  • Encephalitis, Japanese / blood
  • Encephalitis, Japanese / epidemiology
  • Encephalitis, Japanese / veterinary*
  • Encephalitis, Japanese / virology
  • Female
  • Insect Vectors / virology
  • Seasons
  • Seroepidemiologic Studies
  • Swine
  • Swine Diseases / blood
  • Swine Diseases / epidemiology
  • Swine Diseases / transmission
  • Swine Diseases / virology*

Substances

  • Antibodies, Viral

Grants and funding

This study was undertaken in the framework of the ComAcross project with the financial support of the European Union (EuropeAid, INNOVATE contract 315-047). The study was also supported by the SouthEast Asia Encephalitis project which is funded by Aviesan Sud and Fondation Total. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.