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Japanese EncephalitisNCT01163123

Seroepidemiology of Japanese Encephalitis Virus Infection in Hualien, Taiwan

An observational study of Japanese Encephalitis, run by Mennonite Christian Hospital.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
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Trial summary

Japanese encephalitis (JE) is one of important zoonotic infectious diseases in Taiwan. JE caused by Japanese encephalitis virus (JEV) which transmitted by Culex tritaeniorhynchus and used swine as amplifying host. Infections leading to overt encephalitis are estimated to be 1 in 1000 cases. Read more about this study

Who is it for?
Ages 18 to 85 yearsHealthy volunteers can take part
Conditions the study is for
Japanese Encephalitis
How many people
312 participants
Where
No sites listed yet
Study dates
May 2010to Dec 2010
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 85 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: Volunteers were recruited from 2 villages in Hualien county Taiwan. There were at least one patient who had confirmed diagnosis of Japanese virus encephalitis in past 2 years. Many pig farms were located in these 2 villages also. The volunteers are either living or working in the villages during 2010 summer. We had blood test for IgM, IgG for Japanese virus encephalitis before and after the summer season to identify possible subclinical infection. At the same time, mosquito were analyzed by RT-PCR periodically to identify possible virus in the community.

Who may be able to join

  • Living in the specific 2 villages in Hualien county
  • Aged 18-85

Who cannot join

  • 1. Difficulty to have blood test due to coagulopathy or small blood vessels

About this study

Japanese encephalitis (JE) is one of important zoonotic infectious diseases in Taiwan. JE caused by Japanese encephalitis virus (JEV) which transmitted by Culex tritaeniorhynchus and used swine as amplifying host. Infections leading to overt encephalitis are estimated to be 1 in 1000 cases. Among JE confirmed cases, approximately 25 percent of cases die and 50 percent of the survivals develop permanent neurologic and/or psychiatric sequelae. JEV circulated in Taiwan are belonged to genotype III and the vaccine strain selected from same genotype. Genotype I JEV was first detected in northern Taiwan in 2008 by CDC, and the same genotype JEV were detected in mosquito collected in central Taiwan by our group. In order to study the genotypic shift of JEV in Taiwan areas, and the effects of the replacement of genotype on vaccine, we will conduct the JEV seroepidemiology in Hualien county which was the highest incidence of JEV in Taiwan. The aims of this study were: (1) study the circulating of genotype I JEV in Hualien county; (2) determine the virulence of genotype I JEV in human; (3) differential diagnosis of JEV genotype I or III infection among confirmed cases; (4) measure the cross neutralizing activity, after immunized with genotype III JEV vaccine, against genotype I JEV; (5) determine the age-specific seroprevalence of JEV antibody; (6) estimate the annual risk of infection for JEV.

Read the detailed description

According to CDC Taiwan epidemiology data, Hualien county had 6 confirmed JEV infection patients in 2009 witch was the highest county in Taiwan. Since mass vaccination was arranged since 45 years ago in Taiwan, most of the JEV infection was happened on the elderly, possible due to aging and immune compromised. However, from Mennonite Christian Hospital and CDC records, most of the confirmed JEV patients in Hualien county were aboriginal people. The youngest patient in 2009 is around 30-year-old who lived in the mountain side aboriginal village. Whether aboriginal people are at more risk for JEV infection or Genotype I JEV was appeared in Hualien with more virulent, resistent to vaccine protection is unknown.

In order to understand the risk of JEV infection and environmental (mosquito, swine) surveillance, we had arranged a small cohort study in 2 villages. The 2 villages are located at middle Hualien with direct distance around 20 KM between each other. Both villages had several pig farms and mosquito numbers in summer were very high. Both villages had document JEV infection resident in past 2 years. The first village was near the river ready to entrance the sea (wetlands) and many migrate birds appeared in the summer every year. The residence were mostly Han people. The seconds village was located very closed to the central mountain Taiwan and the residence were almost aboriginal people.

In this year 2010, we plan to do the following research:

  1. Collect mosquito in 2 villages since May.2010 with RT-PCT method to identify the JEV genotype
  2. Collect sera from swine in 2 villages to identify the JEV genotype
  3. Collect sera from 312 residency in 2 villages at May and Sep 2010 to detect sub-clinical infection rate. ( estimated sub-clinical infection rate = 2.5%)
  4. Identify the JEV from new diagnosed patient in 2010.

Since virus was hardly detected by RT-PCR or virus isolation from JEV infected patient, the virus identified from mosquito or swine in the nearby may show indirect evidence of the JEV genotype.

After comparing the 2 sera from the same person during the summer in these 2 villages, we can identify:

  1. The subclinical infection rate of the JEV (genotype I or III, depends on JEV isolated from mosquito)
  2. Whether aboriginal people near the central mountains are at more risk then people near the wetlands.
Keywords
Subclinical infection of Japanese encephalitis virus
Medical subject headings
Encephalitis, Japanese

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Measure the subclinical infection rate in the cohort population during the summer ( May 2010 ~ Sep 2010)

    We exam 2 sera from volunteer collected seperately on May and October 2010 to estimate the subclinical infection rate. Subclinical infection rate was defined by one of the following

    1. 4 times increased in IgG titer
    2. Appearance of IgM in the second sera
    3. Apperance of Anti-NS1 antibody in the second sera

    Measured: May 2010 - Oct 2010

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted15 Jul 2010 (estimated)
  2. Study startMay 2010
  3. Primary completionDec 2010 (estimated)
  4. Study completionDec 2010 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
312 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01163123
Sponsor's protocol ID
D9902
Status last verified
Jul 2010
First submitted
14 Jul 2010
Last updated
16 Jul 2010
Results posted
No
Data monitoring committee
No

Questions about this trial

What is this clinical trial studying?

An observational study of Japanese Encephalitis, run by Mennonite Christian Hospital.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: status not confirmed, as of the sponsor's last update on 16 Jul 2010. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Results are not available in the source record.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Measure the subclinical infection rate in the cohort population during the summer ( May 2010 ~ Sep 2010) (time frame: May 2010 - Oct 2010). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Jul 2010.

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