Indirect Hemagglutination Test for Anti-Leptospira Screening Test

Leptospirosis, which is caused by Leptospira interrogans, is a zoonotic disease. Diagnosis of leptospirosis in humans and animals is almost entirely dependent on laboratory findings. The microscopic agglutination tests (MAT) is most often used and is generally accepted as the standard reference test for demonstration of leptospiral antibodies. The problems encountered in laboratory confirmation of the disease are varied and complex. This study is a search for a simple, rapid and reliable test for screening purpose in routine serological laboratory. An indirect hemagglutination test (IHA), which is a simple screening test, was compared with MAT in sensitivity and specificity. Specimens were collected from lower north eastern part of Thailand. All 456 sera from patients with a clinical picture compatible with leptospirosis and 100 sera from blood donors were tested by IHA and MAT. In the group of patient, 39 sera were positive by IHA , while only 26 sera were positive by MAT. 2 of 100 sera from blood donors were positive by IHA but all were negative by MAT. It was found that the sensitivity and specificity of IHA is 96.2 and 96.9%, respectively. IHA is suitable for using as a screening test for anti-Leptospira. Keywords : Leptospirosis, Hemagglutination, Microscopic agglutination.