Clinical trial NCT03987178: Microbiologic Alterations of the Conjunctiva of Hot Tub-soaking Ophthalmologists
Official title: Microbiologic Alterations of the Conjunctiva of Hot Tub-soaking Ophthalmologists
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Conjunctivitis, Bacterial
Keratitis Bacterial
Keywords: hot tub
conjunctival cultures
bacterial keratitis
Lead sponsor: University of California, San Francisco
Sponsor class: OTHER
First posted: 2019-06-14
Enrollment: 36
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief 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. 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.

Eligibility criteria: Inclusion criteria:

* greater of 18 years of age
* a willing participant
* healthy

Exclusion criteria:

* pregnancy
* high or low blood pressure
* active diarrhea
* lymphedema
* heart disease
* seizure disorder.

Primary outcomes:
measure: Quantity of organisms
timeFrame: 1 year
Secondary outcomes:
measure: Richness (number of species per sample) of organisms found in the conjunctiva with hot tub use (post-test comparison)
timeFrame: 1 year
measure: Richness (number of species per sample) of organisms found in the conjunctiva with hot tub use (pre versus post)
timeFrame: 1 year
measure: Difference in organism profile with hot tub use (pre versus post)
timeFrame: 1 year
measure: Difference in organism profile with hot tub use (between arms)
timeFrame: 1 year
measure: Quantity comparing pre-hot tub and post-hot tub swabs
timeFrame: 1 year
measure: Specific organisms found in the conjunctiva with hot tub use
timeFrame: 1 year
Other outcomes:
Locations:
city: San Francisco
country: United States
facility: UCSF
state: California
Study officials:
affiliation: UCSF/Proctor Foundation
name: Gerami D Seitzman, MD
role: PRINCIPAL_INVESTIGATOR
References: