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Sylvatic Transmission of Zika, Dengue, and Chikungunya Viruses in Thailand and Cambodia

Investigating the Sylvatic Transmission and Reservoir Potential of Zika, Dengue, and Chikungunya Viruses of Co-located Humans and Long-tailed Macaques of Thailand and Cambodia

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT04434846
Enrollment
300
Registered
2020-06-17
Start date
2021-02-08
Completion date
2021-05-07
Last updated
2024-04-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Chikungunya, Dengue Fever, Vector-Borne Diseases, Zika

Keywords

Vector-Borne Diseases, Arbovirus, Serological Survey, Seroprevalence, Southeast Asia, Natural History

Brief summary

Background: Zika, dengue, and chikungunya are spread by mosquitos. These diseases have a major impact on public health. This is especially true in in Southeast Asia. Non-human primates (such as macaques) could play an essential role in spreading these diseases. Researchers want to further understand the relationship between humans and these primates. They want to see how this affects how mosquito-borne viruses are spread in Southeast Asia. Objective: To describe the prevalence of Zika virus, dengue virus, and chikungunya virus in the blood of people who live close to long-tailed macaques in Thailand and Cambodia. Eligibility: Healthy people aged 18-55 who have lived or worked within approximately 10 kilometers of the Wat Amphae Phnom monkey habitat in Kampong Speu, Cambodia, for a minimum of 2 years Design: Participation will last 1 day. Participants will be screened in person through an interview. Their medical history will be reviewed. Participants will give information about themselves. This will include sex, age, and behaviors related to the spread of mosquito-borne disease. For example, they will be asked about the number of water containers at their home. They will be asked about recent travel. They will be asked about the extent of their contact with the macaques. Participants will give a blood sample....

Detailed description

Arboviral epidemics continue to emerge suddenly and spread of disease is unpredictable. The 2015-16 Zika epidemic resulted in a high case number in Thailand, but not in neighboring Cambodia. It is known that nonhuman primates (NHPs) are important reservoirs of arboviruses, but the importance of their epidemiological role in the transmission of arboviruses is not clearly understood. While transmission dynamics are complex and require consideration of many variables, primate reservoirs are not routinely sampled, particularly in Southeast Asia, because of the level of operational complexity and skill required. Here, we propose a serological survey for evidence of Zika virus (ZIKV), dengue virus (DENV), and chikungunya virus (CHIKV) exposure in long-tailed macaques and human adults who live or work in close proximity to these monkeys in Thailand and Cambodia. We hypothesize that ZIKV seroprevalence in both humans and macaques will be higher in Thailand than Cambodia. With the current rise of arboviral diseases around the world, we hope the results of this study contribute to better understanding of the epidemiology and burden of arboviral diseases in this region.

Interventions

None listed

Sponsors

National Institute of Allergy and Infectious Diseases (NIAID)
Lead SponsorNIH

Study design

Observational model
COHORT
Time perspective
CROSS_SECTIONAL

Eligibility

Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
No

Inclusion 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 ICF 2. Able to provide informed consent 3. Stated willingness to comply with study procedures 4. Male or female, aged 18-55 years 5. Live/work within approximately 10 km of the Wat Amphae Phnom monkey habitat for minimum of 2 years 6. In good general health as evidenced by screening medical history 7. Willing to allow biological samples to be stored for future research

Exclusion criteria

1\. Any underlying, chronic, or current medical condition that, in the opinion of the investigator, would interfere with participation in the study (e.g., inability or great difficulty in drawing blood)

Design outcomes

Primary

MeasureTime frameDescription
Assessment of DENV, ZIKV, CHIKV Seroprevalence Via Screening PRNT50 Titers in Cambodian Adults.300 at day 0Proportion of Participants with DENV, ZIKV, CHIKV Seroprevalence Via Screening PRNT50. Outcome will be analyzed unadjusted and adjusted for age, location, vector exposure, and sylvatic reservoir exposure.

Secondary

MeasureTime frameDescription
Comparative Assessment of Seroprevalence Via PRNT50 Titers for ZIKV, DENV, and CHIKV in Cambodian Adults to That of Thai Adults.Day 0Understanding how the prevalence of these Aedes transmitted viruses differs across the Mekong region is critical for cross-border disease detection and management, particularly given the high level of human migration in the Greater Mekong Subregion.
Assessment of Reactivity to Salivary Gland Homogenate of Aedes Aegypti as Detected by ELISA or Western Blot in Human Sera.Day 0Characterizing vector salivary protein reactivity profiles (mosquitos, ticks, fleas) in Cambodians with vector- borne disease is the first step to better understanding transmission patterns, responsible vectors, and Cambodians' risk of exposure to these vectors.

Countries

Cambodia

Participant flow

Participants by arm

ArmCount
Cross Sectional Enrollment of 300 Adults
Adults of ages 18-55 with ZIKV, DENV, and/or CHIKV seroprevalence living near Amphae Phnom, Cambodia
300
Total300

Baseline characteristics

CharacteristicCross Sectional Enrollment of 300 Adults
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
0 Participants
Age, Categorical
Between 18 and 65 years
300 Participants
Age, Continuous44 years
STANDARD_DEVIATION 8
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
300 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Region of Enrollment
Cambodia
300 participants
Sex: Female, Male
Female
173 Participants
Sex: Female, Male
Male
127 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
0 / 300
other
Total, other adverse events
0 / 300
serious
Total, serious adverse events
0 / 300

Outcome results

Primary

Assessment of DENV, ZIKV, CHIKV Seroprevalence Via Screening PRNT50 Titers in Cambodian Adults.

Proportion of Participants with DENV, ZIKV, CHIKV Seroprevalence Via Screening PRNT50. Outcome will be analyzed unadjusted and adjusted for age, location, vector exposure, and sylvatic reservoir exposure.

Time frame: 300 at day 0

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Cross Sectional Enrollment of 300 AdultsAssessment of DENV, ZIKV, CHIKV Seroprevalence Via Screening PRNT50 Titers in Cambodian Adults.300 Participants
Secondary

Assessment of Reactivity to Salivary Gland Homogenate of Aedes Aegypti as Detected by ELISA or Western Blot in Human Sera.

Characterizing vector salivary protein reactivity profiles (mosquitos, ticks, fleas) in Cambodians with vector- borne disease is the first step to better understanding transmission patterns, responsible vectors, and Cambodians' risk of exposure to these vectors.

Time frame: Day 0

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Cross Sectional Enrollment of 300 AdultsAssessment of Reactivity to Salivary Gland Homogenate of Aedes Aegypti as Detected by ELISA or Western Blot in Human Sera.300 Participants
Secondary

Comparative Assessment of Seroprevalence Via PRNT50 Titers for ZIKV, DENV, and CHIKV in Cambodian Adults to That of Thai Adults.

Understanding how the prevalence of these Aedes transmitted viruses differs across the Mekong region is critical for cross-border disease detection and management, particularly given the high level of human migration in the Greater Mekong Subregion.

Time frame: Day 0

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Cross Sectional Enrollment of 300 AdultsComparative Assessment of Seroprevalence Via PRNT50 Titers for ZIKV, DENV, and CHIKV in Cambodian Adults to That of Thai Adults.300 Participants

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026