Determining the Complete Protection Time of an Insect Repellent With 30% Citriodiol® Against Three Species of Ticks.
Condition: Tick Bites
MeSH terms: Tick Bites
Study type: Interventional

Summary: 
      This study evaluates the length of time an insect repellent product can protect against three
      species of ticks. Participants will have one arm treated with the repellent, and throughout
      the next 10 hours, ticks will be given the opportunity to crawl up the treated arm. The test
      will stop after 10 hours or when the repellent stops working whichever occurs sooner.
    

Detailed description: 
      This is a single group trial with the participants acting as their own controls. The study is
      split into two parts; the first to determine a typical consumer dose when applied to repel
      ticks, and the second to evaluate the longevity of that consumer dose against three tick
      species.

      To determine the typical consumer dose, twenty-five volunteers will be required to apply the
      repellent product from final consumer ready pump spray bottle to their forearm. Each
      volunteer will be asked to read the label and apply the repellent according to the
      instructions to their forearm. They will repeat the application three times. The amount
      applied by each subject across the three applications will be averaged, and then the average
      amount applied by each subject will be averaged to arrive at a "typical consumer dose". This
      typical consumer dose will be used as the application rate for the tick repellent efficacy
      trial. Three species are required by the EPA to demonstrate the effectiveness of a repellent.
      The following tick species have been chosen from the list of five species recommended by the
      EPA.

      Ixodes scapularis - Also known as blacklegged ticks or deer ticks, this species is one of the
      principal vectors of Lyme disease. They are found in eastern and northern Midwest of the
      United States. The lifecycle takes approximately two years during which the tick develops
      from egg to larva, to nymph and finally adult. Larvae, nymphs and adults will all blood feed.
      Larvae usually feed from smaller mammals and birds, whilst nymphs and adults feed on larger
      mammals such as deer and humans.

      Amblyomma americanum - The Lone Star Tick is found in the eastern United States and in
      Mexico. This species of hard tick can be a vector of human ehrlichiosis, tularaemia, and may
      trigger an allergy to the carbohydrate alpha gal found in mammalian meat.

      Dermacentor variabilis - The American dog tick is usually found in central and eastern areas
      of the United States. Adults preferentially feed on large mammals such as dogs and humans,
      however immature stages will also feed on humans if the opportunity arises. They are the most
      common vector of Rocky Mountain spotted fever, and can also transmit tularaemia.

      Rhipicephalus sanguineus - The brown dog tick is distributed worldwide, including across the
      United States. It is the vector of many pathogens, including Rickettsia rickettsia, the
      causative agent of Rocky Mountain spotted fever, Coxiella burnetii, causative agent of Q
      fever, Ehrlichia canis, and Rickettsia conorii. Dogs are the primary host for the brown dog
      tick in each of its life stages, but the tick may also bite humans or other mammals.

      Ticks will be sourced from disease-free colonies at Oklahoma State University and housed at
      the London School of Hygiene & Tropical Medicine, United Kingdom, under optimal environmental
      conditions of 25 ± 3 °C and greater than or equal to 80% Relative Humidity with a 16:8 hour
      photoperiod.

      Single ticks will be exposed to participants' forearms following standardised treatment of
      one of the participant's forearms with repellent, in a laboratory setting. The treatment will
      be based on the dose derived from the dosimetry phase of the study, which will be submitted
      to EPA for review before proceeding to the repellency phase of testing. The treatment will be
      randomised to either the left or right arm of each participant for each test. There is no
      blinding employed since the outcome measures are based on tick behaviour. Twenty-five
      participants will be required for the consumer dose evaluation and to test the repellent
      against each of the tick species (preferably with a 50:50 ratio of males to females).
      Participants will test the product at a single dose against at least one of the three
      species.
    

Intervention name(s): Citrepel (Insect Repellent) EPA Reg. No. 84878-2
Intervention type(s): Other
Intervention description(s): Citrepel (Insect Repellent) EPA Reg. No. 84878-2 is a pump spray formulation containing the active ingredient Citriodiol®, a tradename for Oil of Lemon Eucalyptus (OLE, Chemical Abstracts Service (CAS) No.: 1245629-80-4). Citriodiol® is derived from Eucalyptus citriodora leaves and contains a minimum of 65% p-Menthane-3,8-diol (PMD, CAS: 42822-86-6) and other constituents occurring naturally in the essential oil source material. The repellent is manufactured by Citrefine International Ltd and will be supplied by them in the pump spray bottle the manufacturer intends to use when the product is marketed with instructions for use on the product label.
Other intervention name(s): Citrapel; Coleman botanicals Insect Repellent
Intervention MeSH terms: Insect Repellents
Intervention model: Single Group Assignment
Intervention model description: This is a single group trial with the participants acting as their own controls, one arm will be treated with insect repellent, and the other left untreated.
Masking: None (Open Label)
Primary purpose: Basic Science