Immune Responses After Human Subject Challenge With Sand Fly Bites

NCT ID: NCT01289977

Last Updated: 2018-02-19

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 68 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2010-10-31
• Study Completion Date: 2016-04-15

Brief Summary

Sand flies can carry the infection leishmaniasis (a parasite). The purpose of this study is to evaluate the human immune response to uninfected laboratory raised sand fly bites and select from the immune response to sand fly saliva, possible substances to use for a future vaccine to protect against the parasite leishmaniasis.

Detailed Description

Based on travel history and possible exposure, subjects were entered into one of 2 arms, Ph. dubosqui or Lu. lutzomyia controlled sand fly repeated feedings. At baseline a pheresis was done to collect baseline cells. Subjects received sand fly bites on a q2 week schedule for 2 months followed by a q2 months schedule for one year. They had an option to extend for a late recall feeding at 18 months, when a skin biopsy was performed 48 hours after sand fly bites. Currently the study is fully enrolled and all human subject contact is complete. We (laboratory at NIAID) are studying the humoral, cellular immune responses using blood samples, and cytokine expression in the skin biopsy samples.

Conditions

Healthy

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Phlebotomus group

Those in the Phlebotomus group will have exposure to P. duboscqui sand fly

No interventions assigned to this group

Lutzomyia group

Those placed in this group will receive exposure to L. longipalpis sand fly bites.

No interventions assigned to this group

Eligibility Criteria

Inclusion Criteria

• Age 18-50
• Plans to remain in DC area for at least one year
• willingness to participate in all study procedures
• general good health
• military health care beneficiary
• able to provide informed consent

Exclusion Criteria

• Prior travel to geographic areas where leishmania transmitting sand flies are common
• positive antibody to sand fly saliva on screening blood test
• pregnancy
• elevated serum IgE
• history of chronic medical illness
• adult history of treatment requiring anemia
• large reactions to insect bites
• history of multiple vasovagal reactions to phlebotomy
• difficult venous access for phlebotomy
• Taking medications that could interfere with immune responses

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

National Institute of Allergy and Infectious Diseases (NIAID)

NIH

Sponsor Role: collaborator

Uniformed Services University of the Health Sciences

FED

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Naomi E Aronson, MD

Role: PRINCIPAL_INVESTIGATOR

Uniformed Services University of the Health Sciences

Locations

Walter Reed National Military Medical Center

Bethesda, Maryland, United States

Countries

United States

Other Identifiers

Y1-AI-0744-01

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

G183ZU

Identifier Type: -

Identifier Source: org_study_id