Conjunctivitis, BacterialMACHONCT03987178
Microbiologic Alterations of the Conjunctiva of Hot Tub-soaking Ophthalmologists
A study testing Dunk and Exposure to Hot Tub in people with Conjunctivitis, Bacterial and Keratitis Bacterial, run by University of California, San Francisco at 1 site in United States.
Trial summary
The purpose of this study is to determine if there are microbiologic alterations of the ocular surface after hot tub exposure. The study will evaluate the number of microbes before and after hot tub use in order to find out whether hot tub exposure has any change on the organisms present on the ocular surface. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Conjunctivitis, Bacterial, Keratitis Bacterial
- What is being tested?
- Dunk and Exposure to Hot Tub
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 36 participants
- Where
- 1 siteUnited States
- Study dates
- 27 May 2019to 26 Mar 2020
- Phase
- Interventional
- 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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- greater of 18 years of age
- a willing participant
- healthy
Who cannot join
- pregnancy
- high or low blood pressure
- active diarrhea
- lymphedema
- heart disease
- seizure disorder.
Trial locations and contacts
1 site in 1 country.
About this study
The purpose of this study is to determine if there are microbiologic alterations of the ocular surface after hot tub exposure. The study will evaluate the number of microbes before and after hot tub use in order to find out whether hot tub exposure has any change on the organisms present on the ocular surface. Participants will be randomized to dunk or not to dunk their head during their time in the hot tub.
Read the detailed description
Keratitis is a rare destructive cause of blindness. It typically affects young and healthy individuals, is excruciatingly painful, and difficult to treat. With 60% of cases mis-diagnosed at presentation, acanthamoeba keratitis carries a far worse visual prognosis compared to other cornea infections. Exposure to hot tubs is a widely accepted risk factor. However, the mechanism of infection and prediction of who is at risk is unknown as the vast majority of hot tub users do not become infected.In vivo changes to ocular microbiology after hot tub exposure has never been described.
Changes to ocular microbiology after exposure to hot tubs have not been described. The purpose of this study is to investigate whether there are significant alterations in the microbiology of the conjunctiva after hot tub exposure that may contribute to these changes.
This study will recruit at least 34 subjects, who will be randomized to head submersion versus no head submersion, using at least three different hot tubs. A conjunctival swab, a minimal-risk test performed routinely in the eye clinic, will be performed before and after 15 minutes of hot tub exposure on one eye (randomized) per subject. The swabs will be plated on blood agar (bacterial cultures) and non-nutrient agar (acanthamoeba cultures).
In this prospective study, healthy subjects will be recruited. The study will be Health Insurance Portability and Accountability Act compliant and approved by the Institutional Review Board. All subjects will review and sign an informed consent form.
Each patient will have the conjunctiva of one eye (randomized) cultured. This practically no-risk technique entails touching a polyester-tip swab to the lining of the lower eyelid. Each subject will be randomized to head submersion or no head submersion; this exposure will be masked by the study coordinator. After 15 minutes of hot tub exposure, the subject will have the same eye swabbed for cultures.
Each sample (pre- and post-hot tub) will be randomly assigned a study number. One study coordinator will record and mask data. Water from each tub will be cultured.
The culture plates will be sent to our microbiology facility at UCSF and identification of organisms on the blood agar plates will be performed on our MALDI (mass spectrometry to identify bacteria and fungi). Non-nutrient agar plates will be plated with E. coli overlay and incubated for up to 7 days. The plates will be randomized and the microbiologists will be masked to exposures.
- Conditions
- Conjunctivitis, Bacterial, Keratitis Bacterial
- Being tested
- Dunk, Exposure to Hot Tub
- Keywords
- hot tub, conjunctival cultures, bacterial keratitis
- Medical subject headings
- Conjunctivitis, Bacterial
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DunkBehavioural
If randomized to "Dunk," the subject is asked to submerge his or her head in the hot tub at least up to brow level.
Exposure to Hot TubOther
Subjects will be asked to sit in a hot tub for 15 minutes (with an individual timer).
| Study group | Role | What they receive |
|---|---|---|
| Head Dunk | Experimental | Subjects who are assigned to be in this arm are asked to sit in a hot tub for 15 minutes and instructed to submerge his or her head in the hot tub at least once and at least up to the eyebrows during his or her time in the hot tub. Receives: Behavioral: Dunk; Other: Exposure to Hot Tub |
| No Head Dunk | Placebo comparator | Subjects assigned to this arm are asked to sit in a hot tub for 15 minutes but to keep his or her chin above water during the entire time. Receives: Other: Exposure to Hot Tub |
What is being measured
The primary outcome is the main question the study is designed to answer.
Quantity of organisms
Genus-species will be identified for each sample, and quantified with an ordinal scale (0-4). The total of this score will be the quantity for that person-time. The primary analyses will be a Wilcoxon Rank Sum test (Mann-Whitney) between the two arms at the follow-up time point (randomized comparison of dunk vs no-dunk), and a Wilcoxon Signed Rank test between pre-hot-tub and post-hot-tub (longitudinal comparison of all cases).
We estimate that a total of 20 subjects will provide 80% power to detect a 1.25 SD difference in the total quantity score between randomization arms at the post (f/u) time point. We estimate 80% power to detect a .9 SD difference between pre (baseline) and post (f/u) time points in a paired longitudinal analysis.
Measured: 1 year
Secondary outcomes (6)
Richness (number of species per sample) of organisms found in the conjunctiva with hot tub use (post-test comparison)
The investigators will assess whether organism diversity (richness) changes between arms (post-test comparison) using Simpson's Diversity, expressed in units of effective number (see Jost). We will also assess using Shannon's Diversity.
Measured: 1 year
Richness (number of species per sample) of organisms found in the conjunctiva with hot tub use (pre versus post)
The investigators will assess whether organism diversity (richness) changes longitudinally (pre vs post-test comparison).
Measured: 1 year
Difference in organism profile with hot tub use (pre versus post)
The investigators will determine whether the organism profile differs longitudinally (pre vs post-test comparison) using L-2 norm (Euclidean distance) and PERMANOVA. We will also assess using L-1 norm (Manhattan distance)
Measured: 1 year
Difference in organism profile with hot tub use (between arms)
The investigators will determine whether the organism profile differs between arms (post-test comparison) using L-2 norm (Euclidean distance) and PERMANOVA. We will also assess using L-1 norm (Manhattan distance)
Measured: 1 year
Quantity comparing pre-hot tub and post-hot tub swabs
We will compare quantity of organisms (amount and type) before and after hot tub use in both arms. We will used a paired t-test for analysis.
Measured: 1 year
Specific organisms found in the conjunctiva with hot tub use
The investigators will compare specific organisms (Staphylococcus epidermidis, Corynebacterium species) between arms (post-test only) and longitudinally between time points (pre vs post-test) with Bonferroni correction
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jun 2019
- Study start27 May 2019
- Primary completion26 Mar 2020
- Study completion26 Mar 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Conjunctivitis, BacterialStudies of the same condition, open and under way.
- More trials run by University of California, San FranciscoThe sponsor's other registered studies.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, San Francisco
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Gerami D Seitzman, MD, Principal investigator, UCSF/Proctor Foundation
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03987178
- Sponsor's protocol ID
- 18-26141
- Acronym
- MACHO
- Status last verified
- Sep 2020
- First submitted
- 5 Jun 2019
- Last updated
- 10 Sep 2020
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Sep 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Microbiologic Alterations of the Conjunctiva of Hot Tub-soaking Ophthalmologists
- ClinicalTrials.gov ID
- NCT03987178
- Acronym / sponsor ID
- MACHO / 18-26141
- Conditions
- Conjunctivitis, Bacterial, Keratitis Bacterial
- Keywords
- hot tub, conjunctival cultures, bacterial keratitis
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 36 participants (actual)
- Lead sponsor
- University of California, San FranciscoUniversity, hospital or other
- Study start
- 27 May 2019 (actual)
- Primary completion
- 26 Mar 2020 (actual)
- Study completion
- 26 Mar 2020 (actual)
- First posted
- 14 Jun 2019 (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 determine if there are microbiologic alterations of the ocular surface after hot tub exposure. The study will evaluate the number of microbes before and after hot tub use in order to find out whether hot tub exposure has any change on the organisms present on the ocular surface. Participants will be randomized to dunk or not to dunk their head during their time in the hot tub.
Detailed description
Keratitis is a rare destructive cause of blindness. It typically affects young and healthy individuals, is excruciatingly painful, and difficult to treat. With 60% of cases mis-diagnosed at presentation, acanthamoeba keratitis carries a far worse visual prognosis compared to other cornea infections. Exposure to hot tubs is a widely accepted risk factor. However, the mechanism of infection and prediction of who is at risk is unknown as the vast majority of hot tub users do not become infected.In vivo changes to ocular microbiology after hot tub exposure has never been described.
Changes to ocular microbiology after exposure to hot tubs have not been described. The purpose of this study is to investigate whether there are significant alterations in the microbiology of the conjunctiva after hot tub exposure that may contribute to these changes.
This study will recruit at least 34 subjects, who will be randomized to head submersion versus no head submersion, using at least three different hot tubs. A conjunctival swab, a minimal-risk test performed routinely in the eye clinic, will be performed before and after 15 minutes of hot tub exposure on one eye (randomized) per subject. The swabs will be plated on blood agar (bacterial cultures) and non-nutrient agar (acanthamoeba cultures).
In this prospective study, healthy subjects will be recruited. The study will be Health Insurance Portability and Accountability Act compliant and approved by the Institutional Review Board. All subjects will review and sign an informed consent form.
Each patient will have the conjunctiva of one eye (randomized) cultured. This practically no-risk technique entails touching a polyester-tip swab to the lining of the lower eyelid. Each subject will be randomized to head submersion or no head submersion; this exposure will be masked by the study coordinator. After 15 minutes of hot tub exposure, the subject will have the same eye swabbed for cultures.
Each sample (pre- and post-hot tub) will be randomly assigned a study number. One study coordinator will record and mask data. Water from each tub will be cultured.
The culture plates will be sent to our microbiology facility at UCSF and identification of organisms on the blood agar plates will be performed on our MALDI (mass spectrometry to identify bacteria and fungi). Non-nutrient agar plates will be plated with E. coli overlay and incubated for up to 7 days. The plates will be randomized and the microbiologists will be masked to exposures.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Head Dunk | Experimental | Behavioral: Dunk, Other: Exposure to Hot TubSubjects who are assigned to be in this arm are asked to sit in a hot tub for 15 minutes and instructed to submerge his or her head in the hot tub at least once and at least up to the eyebrows during his or her time in the hot tub. |
| No Head Dunk | Placebo comparator | Other: Exposure to Hot TubSubjects assigned to this arm are asked to sit in a hot tub for 15 minutes but to keep his or her chin above water during the entire time. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- greater of 18 years of age
- a willing participant
- healthy
Key exclusion criteria (6 listed)
- pregnancy
- high or low blood pressure
- active diarrhea
- lymphedema
- heart disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| DunkIf randomized to "Dunk," the subject is asked to submerge his or her head in the hot tub at least up to brow level. | Behavioural | Head Dunk |
| Exposure to Hot TubSubjects will be asked to sit in a hot tub for 15 minutes (with an individual timer). | Other | Head Dunk, No Head Dunk |
Primary outcome
Quantity of organisms
Time frame: 1 year
Genus-species will be identified for each sample, and quantified with an ordinal scale (0-4). The total of this score will be the quantity for that person-time. The primary analyses will be a Wilcoxon Rank Sum test (Mann-Whitney) between the two arms at the follow-up time point (randomized comparison of dunk vs no-dunk), and a Wilcoxon Signed Rank test between pre-hot-tub and post-hot-tub (longitudinal comparison of all cases). We estimate that a total of 20 subjects will provide 80% power to detect a 1.25 SD difference in the total quantity score between randomization arms at the post (f/u) time point. We estimate 80% power to detect a .9 SD difference between pre (baseline) and post (f/u) time points in a paired longitudinal analysis.
6 secondary outcomes
Richness (number of species per sample) of organisms found in the conjunctiva with hot tub use (post-test comparison)
Time frame: 1 year
Richness (number of species per sample) of organisms found in the conjunctiva with hot tub use (pre versus post)
Time frame: 1 year
Difference in organism profile with hot tub use (pre versus post)
Time frame: 1 year
Difference in organism profile with hot tub use (between arms)
Time frame: 1 year
Quantity comparing pre-hot tub and post-hot tub swabs
Time frame: 1 year
Specific organisms found in the conjunctiva with hot tub use
Time frame: 1 year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Sep 2020.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Gerami D Seitzman, MD principal investigator
UCSF/Proctor Foundation
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Dunk and Exposure to Hot Tub in people with Conjunctivitis, Bacterial and Keratitis Bacterial, run by University of California, San Francisco 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 6 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: finished, as of the sponsor's last update on 10 Sep 2020. 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. Some participants in this study may receive a placebo. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Quantity of organisms (time frame: 1 year). 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 10 Sep 2020.