Evaluation of the reference value for the Montenegro skin test

Area of Science:

• Tropical medicine
• Infectious diseases
• Diagnostic immunology

Background:

• The Montenegro skin test (MST) is a cost-effective tool for diagnosing American tegumentary leishmaniasis (ATL).
• The established 5mm cut-off for MST results lacks comprehensive validation.
• This study aimed to evaluate MST performance with varying cut-off points.

Purpose of the Study:

• To validate the diagnostic accuracy of the Montenegro skin test (MST) for American tegumentary leishmaniasis (ATL).
• To compare the performance of different cut-off values for the MST.
• To provide evidence-based recommendations for MST interpretation.

Main Methods:

• Analysis of laboratory test results from 4,256 patients with suspected ATL.
• Formation of two groups: 769 patients with positive direct parasite search (PCL) and 413 with negative results (NCL).
• Receiver-operating characteristic (ROC) curve analysis to determine optimal cut-off points.

Main Results:

• The mean MST induration was 12.62mm in the PCL group and 1.43mm in the NCL group.
• A 5mm cut-off yielded 97.4% sensitivity and 93.9% specificity.
• A 6mm cut-off demonstrated 95.8% sensitivity and 97.1% specificity.

Conclusions:

• Both 5mm and 6mm cut-off values are suitable for diagnosing ATL using the MST.
• These cut-offs offer high sensitivity and specificity, supporting their clinical utility.
• The findings support the reliable use of MST in ATL diagnosis.