Evaluation of two screening tests for human leptospirosis

Area of Science:

• Medical Microbiology
• Infectious Diseases
• Diagnostic Immunology

Background:

• Leptospirosis is a significant public health concern in Thailand, with diagnosis often relying on clinical suspicion.
• Current serodiagnosis, microagglutination (MA), is slow and not ideal for early detection.
• A need exists for rapid, sensitive serological tests for early leptospirosis diagnosis.

Purpose of the Study:

• To evaluate the sensitivity and specificity of Latex agglutination (LA) and indirect hemagglutination (IHA) tests for leptospirosis diagnosis.
• To compare the performance of LA and IHA with the conventional MA test, particularly in early disease stages.

Main Methods:

• LA and IHA tests were developed and initially evaluated using 100 MA-positive sera and 200 blood donor samples.
• Further comparison involved 30 patients with clinical signs of leptospirosis, assessing LA, IHA, and MA performance.

Main Results:

• LA and IHA demonstrated high sensitivities (98% and 94%, respectively) in MA-positive sera.
• Specificities for IHA and LA were high (99% and 100%, respectively) in blood donors.
• In early-stage patients (within two weeks of fever onset), LA and IHA were significantly more sensitive than MA.

Conclusions:

• Latex agglutination (LA) and indirect hemagglutination (IHA) are rapid and sensitive diagnostic tools for leptospirosis.
• These tests can improve the accuracy and timeliness of human leptospirosis diagnosis in Thailand.
• Wider adoption of LA or IHA could lead to earlier and more effective patient management.