Validation of the modified Faine’s Criteria in the diagnosis of leptospirosis in children using the Microscopic Agglutination Test as the gold standard

ABSTRACT

Objective@#This study aimed to validate the modified Faine’s criteria (Parts A and B) proposed by Brato in the early diagnosis of leptospirosis in children using the microscopic agglutination test (MAT) as gold standard. @*Methodology@#This diagnostic validity study was conducted at the Philippine General Hospital. It included all pediatric patients who were admitted between September 2009 to December 2010 and who satisfied the presumptive and suggestive criteria in the diagnosis of leptospirosis based on the modified Faine’s criteria. A fourfold or greater rise in paired MAT titers was used as the gold standard. Calculations for sensitivity, specificity, positive and negative predictive values, and likelihood ratios of positive and negative tests were computed. Results Thirty-three patients satisfied the diagnosis of leptospirosis based on the criteria; however, only 20 of these had paired MAT titers and were included. The modified Faine’s criteria had a sensitivity of 60%, specificity of 73%, positive predictive value (PPV) of 43%, negative predictive value (NPV) of 85%, positive likelihood ratio of 2 and negative likelihood ratio of 0.4 . Modifying the clinical criteria by revision of the point allocation to create a “Pediatric Locally Modified Criteria” increased the sensitivity to 80%, PPV to 50%, NPV to 92%, positive likelihood ratio to 3 and negative likelihood ratio to 0.3. @*Conclusion@#The Modified Faine’s criteria had poor sensitivity and low positive predictive value and cannot be recommended as a screening test for the early diagnosis of leptospirosis in children. A proposed modification of the clinical criteria for local application increased diagnostic accuracy but must be further validated in a larger number of pediatric patients in the Philippines.