Evaluation of a Diagnostic Device, CL Detect™ Rapid Test, for the Diagnosis of Cutaneous Leishmaniasis in Peru

Evaluation of a Diagnostic Device, CL Detect™ Rapid Test, for the Diagnosis of Cutaneous Leishmaniasis in Peru

Determine the sensitivity and specificity of the FDA-cleared CL Detect™ Rapid Test in Peru, using a test procedure that was modified from that described in the device instructions to optimize these parameters for the detection of Leishmania species identified in Peru.

Observational study of a FDA cleared device, the CL Detect™ Rapid Test. Data for the 510(K) was supported by a sensitivity study conducted in Tunisia, Old world Leishamania major and a specificity study conducted in the United Sates. Sensitivity and specificity data collected recently in Peru (2014-2015), by the Instituto de Medicina Tropical Alexander von Humbolt, supports the idea that the sensitivity of the CL Detect™ Rapid Test can be drastically increased for New World Leishmania species. The study is a single trial, with two clinical sites, NAMRU-6, Puerto Maldonado and the Alexander von Humboldt Tropical Medicine Institute in Lima. The objective of the study is to determine the sensitivity and specificity of the FDA-cleared CL Detect™ Rapid Test, using an optimized test procedure determined from a pilot study conducted in Peru. Two modifications to the test procedure (marketed device instructions) are included in this study: 1) increase in extraction time in lysis buffer from 5 to 10 minutes to 20 to 30 minutes and 2) a 20 μl increase in the volume of the sample to add to the test strip, from 20 μl to 40 μl. The gold standard for Leishmania diagnosis, which is microscopic identification of amastigotes in stained lesion sample, will be used as a control.

Participants will be patients who present for medical consultation due to a suspected CL lesion. After obtaining informed consent and screening the participant for eligibility, we will collect and test at most 4 samples from the index lesion in the following order:

1. one sample obtained with a dental broach for use with the CL Detect™ Rapid Test;
2. one sample obtained by scraping for microscopic identification of amastigotes; and
3. one sample obtained by scraping for Leishmania speciation by PCR; and
4. when possible, (depending on the size of the lesion), one sample from a different site of the same lesion, obtained by scraping for use with the CL Detect™ Rapid Test. PCR analysis will be performed by NAMRU-6 for possible exploratory analyses including species identification. If the etiologies of the lesions that are negative for Leishmania are known, they will be reported. Participants with a positive diagnosis of leishmaniasis by microscopy or other methods will be referred for standard of care treatment in Peru by the attending physician of the Peruvian Ministry of Health. Treatment is not part of this study. If a participant's lesions are negative for Leishmania, standard of care follow-up testing will be performed, either at the study site, or (when indicated) in another hospital.

Inclusion Criteria:

• At least 18 years of age and generally healthy.

• Able to provide written informed consent.

• Index lesion present that is suspicious for CL, as defined by the following criteria for an index lesion:

  1. less than 2 months in age
  2. primarily ulcerative, i.e. not purely verrucous or nodular
  3. no clear clinical evidence of cellulitis
  4. location suitable for collecting samples by dental broach and scraping.

• Capable of understanding and complying with the protocol, in the opinion of the evaluator

Exclusion Criteria:

• Received treatment for leishmaniasis within the last 2 months prior to evaluation.
• In the opinion of the investigator, evidence of manipulation of the lesion.