Red TideNCT07091058
Harmful Algal Blooms
An observational study of Red Tide, run by University of Central Florida at 1 site in United States.
Trial summary
The purpose of this study is to compare the frequency of symptoms, exposure and health impacts in persons living in areas where they are exposed to bloom and non-bloom periods of cyanobacteria and red tide in Florida. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Red Tide
- How many people
- 400 participants
- Where
- 1 siteUnited States
- Study dates
- 13 Nov 2024to 30 Jun 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: The study population will include up to 400 individuals who are 18yrs of age or older, visit, live or work in specific Florida counties and who read and understand English and consent to participation.
Who may be able to join
- 18 years or older
- live, visit, and/ or work in the following Florida counties: Indian River, St. Lucie, Charlotte, Collier, Hendry, Hillsborough, Lee, Manatee, Martin, Monroe, Okeechobee, Palm Beach, Pasco, Pinellas, Indian River, and/or Sarasota
- able to read and understand English
Who cannot join
- unable to independently consent
- younger than 18 years old
- prisoner
- pregnant women
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Central Florida
Multiple Locations, Florida, 00000
Amoy Fraser, PhD, CCRP, PMP, 4072668742, Amoy.Fraser@ucf.edu
Britney-Ann, BS, CTBS, CCRP, 4072668742, britney-ann.wray@ucf.edu
About this study
Official title: Health Outcomes Associated With Algal Blooms of Cyanobacteria and Red Tide in in Florida: Long-Term Health Impacts of Harmful Algal Bloom Exposure, Phase 2
The purpose of this study is to compare the frequency of symptoms, exposure and health impacts in persons living in areas where they are exposed to bloom and non-bloom periods of cyanobacteria and red tide in Florida.
Read the detailed description
Florida has experienced multiple harmful algal blooms during the past several years of two predominant types of Florida red tides occur in the Gulf of Mexico and are due to proliferation of the dinoflagellate Karenia brevis which produces a suite of highly irritative compounds known as brevetoxins. Human illness is primarily due to inhalation of aerosols, which results in a well-characterized syndrome of respiratory tract symptoms due to the irritative effects of brevetoxin.
The proposed study will utilize a case-control approach to compare symptom frequency during bloom and non-bloom period sampling to compare exposures and health impacts. In addition, for the exposed group, comparison of bloom cell density will be examined. As in our previous study, sampling locations will include Fort Myers region, Stuart, and communities around Lake Okeechobee (for example Clewiston and Indiantown). Continuing data collection sites will include: The Volunteers in Medicine Clinic (VIM) in Stuart, Public Health Department in Clewiston, Florida Public Works Department in Cape Coral, and FAU Clinical Research Unit in Boca Raton, FL.
- Conditions
- Red Tide
- Keywords
- algae, Cyanobacteria, red tide, cyanotoxin, Harmful Algal Blooms (HABs), microcystins, brevetoxin
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Questionnaire A | Participants will be assigned to complete Questionnaire A based on if they are new or returning participants and on the status of bloom at consent. | |
| Questionnaire B | Participants will be assigned to complete Questionnaire B based on if they are new or returning participants and on the status of bloom at consent. |
What is being measured
The primary outcome is the main question the study is designed to answer.
To correlate self- reported symptom occurrence with recreational/occupational cyanotoxin exposure (measured in air and water environmental samples) and cyanotoxin levels in blood, nasal swab
These data will be linked to determine if and how much contact the participant may have had with Florida waters, presence of cyanotoxin in the bio samples (blood, nasal swabs, and urine) and self-reported health issues to determine the impact of harmful algal blooms (HABs) on human health. In addition, this study will explore a potential link between self-reported COVID-19 exposure/infection and susceptibility to cyanotoxins and establish a HAB biorepository.
Measured: 2 years
Secondary outcomes (4)
Continue the study of previously enrolled cohort participants prospectively to determine whether long-term effects can be attributed to exposure to microcystins and brevetoxins (Florida Red Tide).
Previously enrolled cohort participants will be screened, consented and enrolled, complete a questionnaire, self- collect nasal swab and urine sample and collection of blood.
Measured: 1 year
Recruit and establish new study participants on the West Coast of Florida (coastal Lee County) to further study the health effects of exposure to Red Tide.
New participants will be screened, consented and enrolled, complete a questionnaire, self- collect nasal swab and urine sample and collection of blood.
Measured: 1 year
Apply novel approaches to measure biomarkers in samples included in the biobank repository and maintained in the FAU Health Clinical Research Unit using using logistic regression and Generalized Linear Mixed Models (GLMM).
Access is granted through our continued relationship with FAU and Dr. McFarland as Co-PI. The concentrations of inflammatory biomarkers will be compared between 30 participants reporting dry cough, and/or wheezy respirations and 30 who reported neither of these symptoms and for whom serum samples are stored in the biobank. The data will be analyzed using parametric statistics with adjustment for potential confounders. Statistical analyses of the relationships between environmental concentrations of HAB toxins and concentrations in human tissues will be performed initially using standard regression techniques. Multivariable modelling of the relationships between environmental concentrations, tissue concentrations, symptom frequency and biomarkers will be conducted using logistic regression and Generalized Linear Mixed Models (GLMM) as appropriate for the data form.
Measured: 2 years
Analysis of data collected during our previous studies in 2016, 2018, and 2020-2023 to explore risk factors that potentially increase the susceptibility to the respiratory impacts of harmful algal bloom toxin exposure.
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jul 2025
- Study start13 Nov 2024
- Primary completion30 Jun 2026 (estimated)
- Study completion30 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Red TideStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Case-control
- Time perspective
- Prospective
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Central Florida
- Sponsor type
- University, hospital or other
- Collaborators
- Florida Atlantic University, Florida Department of Health
- Responsible party
- Sponsor
- Investigators
- Rebecca Koszalinski, PhD, MS, RN, FIEL, CRRN, FARN, Principal investigator, University of Central Florida
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07091058
- Sponsor's protocol ID
- STUDY00007298
- Status last verified
- Jul 2025
- First submitted
- 21 Jul 2025
- Last updated
- 29 Jul 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Health Outcomes Associated With Algal Blooms of Cyanobacteria and Red Tide in in Florida: Long-Term Health Impacts of Harmful Algal Bloom Exposure, Phase 2
- ClinicalTrials.gov ID
- NCT07091058
- Acronym / sponsor ID
- STUDY00007298
- Conditions
- Red Tide
- Keywords
- algae, Cyanobacteria, red tide, cyanotoxin, Harmful Algal Blooms (HABs), microcystins, brevetoxin
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- University of Central FloridaUniversity, hospital or other
- Collaborators
- Florida Atlantic University, Florida Department of Health
- Study start
- 13 Nov 2024 (actual)
- Primary completion
- 30 Jun 2026 (estimated)
- Study completion
- 30 Jun 2026 (estimated)
- First posted
- 29 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to compare the frequency of symptoms, exposure and health impacts in persons living in areas where they are exposed to bloom and non-bloom periods of cyanobacteria and red tide in Florida.
Detailed description
Florida has experienced multiple harmful algal blooms during the past several years of two predominant types of Florida red tides occur in the Gulf of Mexico and are due to proliferation of the dinoflagellate Karenia brevis which produces a suite of highly irritative compounds known as brevetoxins. Human illness is primarily due to inhalation of aerosols, which results in a well-characterized syndrome of respiratory tract symptoms due to the irritative effects of brevetoxin.
The proposed study will utilize a case-control approach to compare symptom frequency during bloom and non-bloom period sampling to compare exposures and health impacts. In addition, for the exposed group, comparison of bloom cell density will be examined. As in our previous study, sampling locations will include Fort Myers region, Stuart, and communities around Lake Okeechobee (for example Clewiston and Indiantown). Continuing data collection sites will include: The Volunteers in Medicine Clinic (VIM) in Stuart, Public Health Department in Clewiston, Florida Public Works Department in Cape Coral, and FAU Clinical Research Unit in Boca Raton, FL.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Questionnaire A | – | –Participants will be assigned to complete Questionnaire A based on if they are new or returning participants and on the status of bloom at consent. |
| Questionnaire B | – | –Participants will be assigned to complete Questionnaire B based on if they are new or returning participants and on the status of bloom at consent. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- The study population will include up to 400 individuals who are 18yrs of age or older, visit, live or work in specific Florida counties and who read and understand English and consent to participation.
Key inclusion criteria (3 listed)
- 18 years or older
- live, visit, and/ or work in the following Florida counties: Indian River, St. Lucie, Charlotte, Collier, Hendry, Hillsborough, Lee, Manatee, Martin, Monroe, Okeechobee, Palm Beach, Pasco, Pinellas, Indian River, and/or Sarasota
- able to read and understand English
Key exclusion criteria (4 listed)
- unable to independently consent
- younger than 18 years old
- prisoner
- pregnant women
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
To correlate self- reported symptom occurrence with recreational/occupational cyanotoxin exposure (measured in air and water environmental samples) and cyanotoxin levels in blood, nasal swab
Time frame: 2 years
These data will be linked to determine if and how much contact the participant may have had with Florida waters, presence of cyanotoxin in the bio samples (blood, nasal swabs, and urine) and self-reported health issues to determine the impact of harmful algal blooms (HABs) on human health. In addition, this study will explore a potential link between self-reported COVID-19 exposure/infection and susceptibility to cyanotoxins and establish a HAB biorepository.
4 secondary outcomes
Continue the study of previously enrolled cohort participants prospectively to determine whether long-term effects can be attributed to exposure to microcystins and brevetoxins (Florida Red Tide).
Time frame: 1 year
Recruit and establish new study participants on the West Coast of Florida (coastal Lee County) to further study the health effects of exposure to Red Tide.
Time frame: 1 year
Apply novel approaches to measure biomarkers in samples included in the biobank repository and maintained in the FAU Health Clinical Research Unit using using logistic regression and Generalized Linear Mixed Models (GLMM).
Time frame: 2 years
Analysis of data collected during our previous studies in 2016, 2018, and 2020-2023 to explore risk factors that potentially increase the susceptibility to the respiratory impacts of harmful algal bloom toxin exposure.
Time frame: 2 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Jul 2025.
Related trials for Red Tide
RecruitingObservational study
Investigating Health Impacts of Exposure to Harmful Algal Blooms
Red Tide, Neurologic Disorder
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Rebecca Koszalinski, PhD, MS, RN, FIEL, CRRN, FARN principal investigator
University of Central Florida
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Red Tide, run by University of Central Florida at 1 site in United States.
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 3 inclusion and 4 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: looking for participants now, as of the sponsor's last update on 29 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Amoy Fraser, PhD, CCRP, PMP (14072668742, Amoy.Fraser@ucf.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To correlate self- reported symptom occurrence with recreational/occupational cyanotoxin exposure (measured in air and water environmental samples) and cyanotoxin levels in blood, nasal swab (time frame: 2 years). 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 29 Jul 2025.