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Investigating Vector-Borne Determinants of Aedes Transmitted Arboviral Infections in Cambodia: An Observational Longitudinal Cohort Study in Children

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ClinicalTrials.gov Identifier: NCT03534245
Recruitment Status : Active, not recruiting
First Posted : May 23, 2018
Last Update Posted : July 17, 2019
Sponsor:
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute of Allergy and Infectious Diseases (NIAID) )

Tracking Information
First Submitted Date May 22, 2018
First Posted Date May 23, 2018
Last Update Posted Date July 17, 2019
Actual Study Start Date May 16, 2018
Estimated Primary Completion Date September 30, 2021   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures
 (submitted: May 14, 2019)
  • Prevalence of symptomatic and inapparent dengue infection (serotypes 1-4) as detected semiannually via ELISA assay (binary outcome present/absent) over a three-year period in Kampong Speu in children aged 2-9 years old [ Time Frame: Semi-Annual visits and sick/convalescent visits throughout study enrollment ]
    Detailed knowledge of dengue seroprevalence and transmission season variability will help establish an epidemiological foundation to prepare for larger future studies such as disease incidence studies or vector interventional trials.
  • Prevalence of Aedes aegypti salivary gland homogenate reactivity as detected by ELISA assay (binary outcome present/absent) during wet and dry seasons over a three-year period in Kampong Speu in children aged 2-9 years old [ Time Frame: Semi-annual visits and sick/convalescent visits throughout study enrollment ]
    Characterizing the Ae. aegypti salivary protein reactivity profile in Cambodians is the first step prior to assessing how Ae. aegypti saliva exposure modulates disease in humans.
Original Primary Outcome Measures
 (submitted: May 22, 2018)
  • Prevalence of symptomatic and inapparent dengue infection (serotypes 1-4) as detected semiannually via ELISA assay (binary outcome present/absent) over a three-year period in Kampong Speu in children aged 2-9 years old [ Time Frame: Semi-Annual visits and sick/convalescent visits throughout study enrollment ]
  • Prevalence of Aedes aegypti salivary gland homogenate reactivity as detected by ELISA assay (binary outcome present/absent) during wet and dry seasons over a three-year period in Kampong Speu in children aged 2-9 years old [ Time Frame: Semi-annual visits and sick/convalescent visits throughout study enrollment ]
Change History Complete list of historical versions of study NCT03534245 on ClinicalTrials.gov Archive Site
Current Secondary Outcome Measures
 (submitted: May 14, 2019)
  • Western blot analysis of sera from participants with strongest ELISA positivity to Ae. aegypti whole salivary gland homogenate compared to Anopheles and Culex to assess cross-reactive immunogenicity to mosquito saliva versus specific Aedes marke... [ Time Frame: Semi-annual visits and sick/convalescent visits throughout study enrollment ]
  • Positive RT-PCR result for diagnosis of dengue, chikungunya, and Zika viruses (or IgM capture ELISAs for dengue as needed) [ Time Frame: Semi-annual visits and sick/convalescent visits throughout study enrollment ]
  • Geographic information system with all data components (mosquito catch sites, houses, schools) referenced by latitude and longitude in addition to a series of map layers (point maps, smoothed maps) to evaluate relationships between IgG intensity... [ Time Frame: Semi-annual visits and sick/convalescent visits throughout study enrollment ]
  • Seroconversion to Ae. aegypti salivary homogenate in relationship to season (wet versus dry) and collected time-dependent variables defined as mean and maximum rainfall, te,perature and humidity [ Time Frame: Semi-annual visits and sick/convalescent visits throughout study enrollment ]
  • Capture a minimum of 25 female Aedes aegypti mosquitoes for transcriptional comparison to LMVR-reared Aedes aegypti mosquitoes [ Time Frame: Duration of study enrollment ]
Original Secondary Outcome Measures
 (submitted: May 22, 2018)
  • Positive RT-PCR result for diagnosis of dengue, chikungunya, and Zika viruses (or IgM capture ELISAs for dengue as needed) [ Time Frame: Semi-annual visits and sick/convalescent visits throughout study enrollment ]
  • Geographic information system with all data components (mosquito catch sites, houses, schools) referenced by latitude and longitude in addition to a series of map layers (point maps, smoothed maps) to evaluate relationships between IgG intensity... [ Time Frame: Semi-annual visits and sick/convalescent visits throughout study enrollment ]
  • Seroconversion to Ae. aegypti salivary homogenate in relationship to season (wet versus dry) and collected time-dependent variables defined as mean and maximum rainfall, te,perature and humidity [ Time Frame: Semi-annual visits and sick/convalescent visits throughout study enrollment ]
  • Capture a minimum of 25 female Aedes aegypti mosquitoes for transcriptional comparison to LMVR-reared Aedes aegypti mosquitoes [ Time Frame: Duration of study enrollment ]
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
 
Descriptive Information
Brief Title Investigating Vector-Borne Determinants of Aedes Transmitted Arboviral Infections in Cambodia: An Observational Longitudinal Cohort Study in Children
Official Title Investigating Vector-Borne Determinants of Aedes-Transmitted Arboviral Infections in Cambodia: an Observational Longitudinal Cohort Study in Children
Brief Summary

Background:

Some mosquitos carry viruses that can cause disease. Some examples are dengue and Zika. The mosquitos spread disease by biting people and infecting them with the virus. Children, elderly people, and people who are already sick are especially likely to get infected. Researchers want to learn more to help make new medicines to treat these viral infections.

Objective:

To learn more about how mosquitos infect people, and why young children are more likely to get sick than other people.

Eligibility:

Healthy children 2-9 years old who live near the study site. This is Kampong Speu District Referral Hospital in Chbar Mon, Cambodia.

Design:

At visit 1, participants will have a physical exam. A small amount of blood will be taken from their arm or finger. Parents will answer questions about the participant s general health and medical history.

Participants will come back to the study site every wet season and every dry season for the next 3 years. The visits will be the same as visit 1 and take about 1 hour.

If at any time during the study the participant gets a fever and has other symptoms that could be caused by these viral diseases, they should be brought to the study site. These symptoms might include headache, pain behind the eyes, muscle pain, or joint pain. They can also include a rash that lasts longer than 12 hours.

Participation ends after the final study visit in late 2021.

...

Detailed Description Mosquito-borne viruses continue to cause significant global morbidity and mortality, particularly in Southeast Asia. When mosquitoes deliver the virus into the skin of humans while probing for a blood meal, they deposit also saliva, which contains a myriad of pharmacologically active compounds that modulate the host immune system. Most vaccines against vector-borne diseases under development ignore the importance of the complex infectious inoculum delivered by the mosquito vector and the subsequent host immune response to mosquito salivary proteins. Many studies of vector-borne disease do not evaluate what role vector-derived factors play in the host immune response of these infections. A cumulative body of evidence from animal models and limited retrospective human data demonstrates that a variety of vector-derived components, including salivary components, are codelivered with the pathogen and may play an important role in the establishment and dissemination of arboviral infection. Knowledge of the effect of these vector-derived factors on the development of arboviruses in the human is limited. Here, we will establish and follow a longitudinal pediatric cohort study to describe the burden of dengue virus and to carefully examine the immune response to exposure of the salivary proteins of Aedes aegypti, the mosquito vector of dengue, Zika and chikungunya viruses. This study will serve as a foundation so that future studies may contribute to further understanding how saliva immunity impacts arboviral disease development i Cambodia, a country endemic to these viruses.
Study Type Observational
Study Design Observational Model: Cohort
Time Perspective: Prospective
Target Follow-Up Duration Not Provided
Biospecimen Not Provided
Sampling Method Non-Probability Sample
Study Population Community-based cohort of children from the town of Chbar Mon in Kampong Speu, Cambodia, who live within 5.5 km to the Kampong Speu District Referral Hospital.@@@
Condition Dengue Fever
Intervention Not Provided
Study Groups/Cohorts 1
Healthy children aged 2 - 9 years
Publications *

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status Active, not recruiting
Actual Enrollment
 (submitted: May 14, 2019)
775
Original Estimated Enrollment
 (submitted: May 22, 2018)
1200
Estimated Study Completion Date September 30, 2021
Estimated Primary Completion Date September 30, 2021   (Final data collection date for primary outcome measure)
Eligibility Criteria
  • INCLUSION CRITERIA:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

  1. Provision of signed and dated informed consent form
  2. Stated willingness to comply with all study procedures and availability for the duration of the study
  3. Male or female, aged 2-9 years
  4. Live within approximately 5.5 km of study site
  5. In good general health as evidenced by medical history
  6. Willing to allow biological samples to be stored for future research.

EXCLUSION CRITERIA:

  1. Current or prior use within last 6 months of any immunosuppression (e.g. intravenous immunoglobulin, steroids, interferon therapy)
  2. Treatment with another investigational drug, vaccine, or other intervention within six months of screening
Sex/Gender
Sexes Eligible for Study: All
Ages 2 Years to 9 Years   (Child)
Accepts Healthy Volunteers No
Contacts Contact information is only displayed when the study is recruiting subjects
Listed Location Countries Cambodia
Removed Location Countries  
 
Administrative Information
NCT Number NCT03534245
Other Study ID Numbers 999918100
18-I-N100
Has Data Monitoring Committee Not Provided
U.S. FDA-regulated Product
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
IPD Sharing Statement Not Provided
Responsible Party National Institutes of Health Clinical Center (CC) ( National Institute of Allergy and Infectious Diseases (NIAID) )
Study Sponsor National Institute of Allergy and Infectious Diseases (NIAID)
Collaborators Not Provided
Investigators
Principal Investigator: Jessica E Manning, M.D. National Institute of Allergy and Infectious Diseases (NIAID)
PRS Account National Institutes of Health Clinical Center (CC)
Verification Date July 11, 2019