5 Clinical Trials for Various Conditions
Background: Each year, the number of cases of tick-borne diseases increases. The deer tick (Ixodes scapularis) is the vector of at least 7 pathogens that cause human diseases, including Lyme disease. Researchers want to learn more to help them develop vaccines against ticks in the future. Objective: To learn how people s bodies, particularly the skin, respond to tick bites. Eligibility: Healthy adults aged 18 years and older who have no known history of a tick-borne disease or tick bite exposure. Design: Participants will be screened with a medical history, physical exam, and blood tests. Participants will have 2 skin punch biopsies of healthy skin. For this, a sharp instrument will be used to remove a round plug of skin about the size of a pencil eraser. Participants will then have 10 clean laboratory-bred ticks placed at 2 different sites on their skin (20 ticks total). The ticks will be removed from the first site 1 day after placement and from the second site 2-4 days after placement. Participants will complete symptom diary cards. They will answer questions about itching at the tick feeding sites. They will give blood samples. Photos will be taken of the tick feeding sites. Skin punch biopsies will be collected at the sites of the tick bites. Participants will repeat the tick feeding procedures 2 times, each 2-8 weeks apart. For the 2nd and 3rd procedures, 10 clean laboratory-bred ticks will be placed at 1 site. The ticks will be removed 2-3 days after tick placement. They will have telephone follow-up visits after each procedure. After the final tick removal, participants will have follow-up visits in 4-6 weeks and again in 3 months. They will give blood samples and discuss how they are feeling. Participation will last about 5-7 months.
The goal of this work is to evaluate the use of ecological momentary assessments as a tool to assess risk and risk factors for tick encounters and tick-borne diseases. This study will be conducted across the United States, with a focus the upper Midwest and Northeast and with a focus on Wisconsin and will enroll up to 1000 people.
Lyme and other tick-borne diseases pose a significant health threat to outdoor workers. This study is a double-blind randomized controlled trial of outdoor workers in Rhode Island and the surrounding area that will address the following study aims: 1) Evaluate the effectiveness of LLPI clothing in preventing tick bites among outdoor workers in Lyme endemic areas; 2) Measure the urine levels of permethrin metabolites in study subjects; and 3) Measure the loss over time of knockdown activity against ticks and of permethrin in LLPI clothing.
The high risk of acquiring tick-borne diseases by outdoor workers is well documented. Workers most at risk include, foresters, park rangers, land surveyors and other outdoor workers have frequent exposure to tick-infested habitats. Many North Carolina state employees with outdoor occupations report multiple tick bites each year, which indicates that existing tick preventive strategies may be ineffective. The principal goal of this study is to assess whether the use of long-lasting permethrin impregnated uniforms can reduce the number of tick bites sustained by North Carolina outdoor workers.
Background: The most common tick-borne illness in the United States, Lyme disease is caused by Borrelia burgdorferi bacteria that are transmitted to people by Ixodes scapularis ticks. Most cases of Lyme disease are cured by antibiotics, but some patients continue to experience symptoms despite the absence of detectable Lyme bacteria. Xenodiagnosis uses a vector to detect the presence of a disease-causing microbe. Researchers will use live, laboratory-bred ticks to see if Lyme disease bacteria can be detected in people after completing antibiotic therapy and if that is more common in people who continue to experience symptoms such as fatigue and joint pain. Objectives: - To see if ticks can be used to detect B. burgdorferi in people who have had Lyme disease and received antibiotic therapy and if it correlates with persistent symptoms. Eligibility: * Adults at least 18 years old who have: * Untreated erythema migrans (the Lyme disease rash); OR * Untreated Lyme arthritis; OR * Continuing symptoms after treatment for Lyme disease; OR * Had Lyme disease and antibiotic treatment within the past 12 months. * Healthy volunteers Design: * Participants will be screened with medical history, physical exam, and blood tests. * Visit 1: * Blood and urine tests, health questionnaire. * Up to 30 laboratory-bred, pathogen-free, larval ticks (each smaller than a poppy seed) will be placed under a dressing. * Participants may have two small biopsies of skin . * 4 6 days later, Visit 2: * Dressing will be removed and ticks will be collected. * Participants will answer symptom questions. * If many ticks are still attached, participants will have to come back the next day. If not enough ticks feed successfully, the procedure may be repeated. * Participants will keep a diary of symptoms for 30 days. Over 3 months, they will be return to the clinic 3 times to see how they feel and answer questionnaires. Test results will be discussed.