A Clinical Study to Develop an Uninfected Sand Fly Biting Protocol

NCT03999970 | Completed DMC

• 1 other identifier: RE19_030_266151
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

The disease leishmaniasis mainly occurs in hot and tropical countries, affects millions of people and causes around 20,000 deaths across the world every year. Leishmaniasis is caused by the Leishmania parasite and is transmitted by sand flies. The parasite is tiny and not visible to the naked eye, whereas the particular sand fly is visible but small and inconspicuous. There are different types of leishmaniasis around the world and some can be very serious. They affect the skin (cutaneous leishmaniasis) or the internal organs of the body (visceral leishmaniasis). Some of the milder forms will produce skin problems which will be localised, whilst other forms of leishmaniasis will cause widespread skin changes. The skin lesions of cutaneous leishmaniasis can be disfiguring if left untreated. There are some treatments for leishmaniasis available but many of them are not easy to use or don't work well. Therefore new treatments and vaccines are needed that prevent or work against leishmaniasis. A solution being adopted for other diseases, which the investigators now wish to adopt for leishmaniasis is to develop a 'Controlled human infection model' (CHIM). These models involve deliberate exposure of individuals to an infection, in order to better understand how the disease works and to test potential vaccines and treatments. They have contributed vital scientific knowledge that has led to advances in the development of drugs and vaccines. This is an initial study using uninfected (disease-free) sand flies, taking place at the University of York. The information from this study will help us to develop a model in the future using infected sand flies so that the investigators can assess any future vaccines against Leishmaniasis. The investigators will also hold a focus group after the sand fly biting study to explore the experiences of individuals taking part in this study.

Conditions

Leishmaniasis, Cutaneous; Insect Bites

Keywords

Cutaneous Leishmaniasis; Controlled Human Infection Model; Sand Fly; Human Challenge

Outcome Measures

Primary Outcomes (1)

• Percentage of participants who successfully undergo sand fly bite during a 30 minute exposure determined by visual dermatoscopy

  Development of a sand fly biting protocol using pathogen-free sand flies which is effective and safe for volunteers: Volunteers aged between 18-65 years will receive a bite or bites by sand flies using a watch-like biting chamber placed on the arm. The investigators will initially evaluate the use of biting chambers containing up to 5 sand flies maintained on the arm for 30 minutes, and evaluate the two sand fly species Phlebotomus papatasi and Phlebotomus duboscqi fed on blood twice in the laboratory prior to human exposure.

  21 days

Secondary Outcomes (7)

• Percentage of participants with visual changes following sand fly bite using photography.

  21 days

• Percentage of participants with visual changes following sand fly bite using dermatoscopy.

  21 days

• Percentage of participants with demonstrable serological evidence of sand fly bite. To determine human immunological response to sand fly bite using serology and cellular response measurement.

  21 days

• Percentage of participants with demonstrable cellular response evidence of sand fly bite.

  21 days

• Percentage of participants with demonstrable evidence of change in IgE (immunoglobulin E) following sand fly bite.

  21 days

Study Arms (2)

Phlebotomus papatasi sand fly bite

ACTIVE COMPARATOR

Volunteers aged between 18-65 years will receive a bite or bites by sand flies using a watch-like biting chamber placed on the arm. The investigators will initially evaluate the use of biting chambers containing up to 5 sand flies maintained on the arm for 30 minutes, and evaluate the sand fly species Phlebotomus papatasi fed on blood twice in the laboratory prior to human exposure.

Other: Sand fly bite

Phlebotomus duboscqi sand fly bite

ACTIVE COMPARATOR

Volunteers aged between 18-65 years will receive a bite or bites by sand flies using a watch-like biting chamber placed on the arm. The investigators will initially evaluate the use of biting chambers containing up to 5 sand flies maintained on the arm for 30 minutes, and evaluate the sand fly species Phlebotomus duboscqi fed on blood twice in the laboratory prior to human exposure.

Other: Sand fly bite

Interventions

Sand fly bite OTHER

Comparison between sand fly bites from two different species (Phlebotomus papatasi and Phlebotomus duboscqi)

Phlebotomus duboscqi sand fly bite; Phlebotomus papatasi sand fly bite

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy adults aged 18 to 65 years on the day of screening
• Willing and able to give written informed consent
• Willing to undergo an Hepatitis B, Hepatitis C \& HIV test
• Willing to undergo a pregnancy test during screening and follow-up visits and must not be breastfeeding (female volunteers)
• Willing to refrain from blood donation during the study
• Using a reliable and effective form of contraception (female volunteers)
• Judged, in the opinion of a medically qualified Clinical Investigator, to be able and likely to comply with all study requirements as set out in the protocol
• Without any other significant health problems as determined by medical history, physical examination, results of screening tests and the clinical judgment of a medically qualified Clinical Investigator
• Available for the duration of the study
• Willing to refrain from travel to regions where Leishmania-transmitting sand flies are present, from recruitment until the last study visit.
• Willing to consent to a report from the volunteer's GP (General Practitioner) confirming medical eligibility, to be provided before study entry

You may not qualify if:

• The volunteer may not enter the study if any of the following apply:
• Receipt of a live attenuated vaccine within 30 days or other vaccine within 14 days of screening
• Administration of immunoglobulins and/or any blood products within the three months preceding the planned study.
• History of allergic disease/atopy or reactions or a history of severe or multiple allergies to drugs or pharmaceutical agents
• Any significant chronic skin condition as judged by the medical team
• Any history of Leishmaniasis
• Any history of travel within the last 30 days to regions where Leishmania major-transmitting sand flies are endemic\*.
• Any past history of more than 30 contiguous days stay in regions where Leishmania major-transmitting sand flies are endemic\*.
• Any history of severe local or general reaction to insect bites, defined as
• Local: extensive, indurated redness and swelling involving most of the antero-lateral thigh or the major circumference of the arm, not resolving within 72 hours
• General: fever ≥ 39.5°C within 48 hours, anaphylaxis, bronchospasm, laryngeal oedema, collapse, convulsions or encephalopathy within 48 hours
• Any history of anaphylaxis Females - pregnancy, less than 12 weeks postpartum, lactating or willingness/intention to become pregnant during the study and for 3 months following the study.
• Any clinically significant abnormal finding on screening biochemistry or haematology blood tests or urinalysis
• Total IgE levels \>81 Kilo-units/L Any confirmed or suspected immunosuppressive or immunodeficient state, including HIV infection; asplenia; recurrent, severe infections and chronic (more than 14 days) immunosuppressant medication within the past 6 months
• Tuberculosis, leprosy, or malnutrition

Sponsors & Collaborators

• University of York: lead
• Medical Research Council: collaborator

Study Sites (1)

Translational Research Facility, Department of Biology, University of York

York, North Yorkshire, United Kingdom

Location

Related Publications (2)

• Parkash V, Ashwin H, Sadlova J, Vojtkova B, Jones G, Martin N, Greensted E, Allgar V, Kamhawi S, Valenzuela JG, Layton AM, Jaffe CL, Volf P, Kaye PM, Lacey CJN. A clinical study to optimise a sand fly biting protocol for use in a controlled human infection model of cutaneous leishmaniasis (the FLYBITE study). Wellcome Open Res. 2021 Jun 30;6:168. doi: 10.12688/wellcomeopenres.16870.1. eCollection 2021.

  PMID: 34693027 RESULT

• Parkash V, Jones G, Martin N, Steigmann M, Greensted E, Kaye P, Layton AM, Lacey CJ. Assessing public perception of a sand fly biting study on the pathway to a controlled human infection model for cutaneous leishmaniasis. Res Involv Engagem. 2021 May 30;7(1):33. doi: 10.1186/s40900-021-00277-y.

  PMID: 34053461 DERIVED

MeSH Terms

Conditions

Leishmaniasis, Cutaneous; Insect Bites and Stings

Condition Hierarchy (Ancestors)

Leishmaniasis; Euglenozoa Infections; Protozoan Infections; Parasitic Diseases; Infections; Skin Diseases, Parasitic; Vector Borne Diseases; Skin Diseases, Infectious; Skin Diseases; Skin and Connective Tissue Diseases; Bites and Stings; Poisoning; Chemically-Induced Disorders; Wounds and Injuries

Study Officials

• Charles Lacey, BMBS, MD

  University of York

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor Paul Kaye

Model Details: Clinical study

Study Record Dates

• First Submitted: May 23, 2019
• First Posted: June 27, 2019
• Study Start: October 3, 2019
• Primary Completion: December 23, 2019
• Study Completion: January 10, 2020
• Last Updated: October 31, 2022

Record last verified: 2022-10

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)