Evaluation of a Commercial Latex Agglutination Assay for Serological Diagnosis of Leptospirosis

Abstract

Leptospirosis is a febrile zoonosis of worldwide distribution. A latex agglutination assay was evaluated in two studies, the first using a panel of well-characterized sera from patients with leptospirosis and from patients with other disease states and the second, a prospective hospital-based study, evaluating sera from 186 consecutive patients admitted to hospital with acute febrile illness. The confirmed leptospirosis serum panel included paired acute-and convalescent-phase specimens from 40 cases, of which 34 gave positive latex tests (case sensitivity, 85%; 95% confidence interval [95% CI], 70 to 94%). The other diseases represented in the panel of 112 specimens from nonleptospirosis patients included autoimmune diseases, brucellosis, dengue, melioidosis, malaria, syphilis, toxoplasmosis, viral hepatitis, and a number of other viral infections. The specificity of latex agglutination using this panel was 81% (95% CI, 73 to 87%). Among the patients with acute febrile illness, there were 25 cases of leptospirosis and 161 patients with other diagnoses. The sensitivity and specificity of latex agglutination in this group were 88% (95% CI, 72 to 97%) and 98% (95% CI, 95 to 100%), respectively. In this evaluation, the two distinct groups of specimens gave similar results for sensitivity, but specificity was different in each study. The sensitivity and specificity observed for the hospital study were similar to those obtained in evaluations of other rapid tests in the same population. The results of this study suggest that multiple evaluations of new diagnostic assays should be performed, because performance characteristics may vary in different populations.

Leptospirosis Outbreak in 2005: L.T.M.G. Hospital Experience

“…[1][2][3] The sensitivity of these tests ranges from 88-100% and specificity from 95-99.8%. [1,8,9] Gupta et al, have reported sensitivity of IHA to be 100% and specificity 94% as compared to MAT. [10] LeptoTek Dri-dot assay has shown an overall sensitivity of 90% and specificity of 92%.…”

“…[1] Traditionally considered an occupational risk among persons exposed to contaminated water or infected animal urine, it is becoming recognized as a major public health problem, particularly in the tropics. [2,3] In tropical and subtropical regions, the disease is endemic and exposure is widespread.…”

“…[2,3] In tropical and subtropical regions, the disease is endemic and exposure is widespread. [1] Clinical recognition of leptospirosis is difficult, due to its multisystem involvement. It presents with varied clinical manifestations and is often misdiagnosed as influenza, aseptic meningitis, encephalitis, dengue fever, hepatitis, or gastroenteritis.…”

Evaluation of Leptospiral Recombinant Antigens MPL17 and MPL21 for Serological Diagnosis of Leptospirosis by Enzyme-Linked Immunosorbent Assays

“…Due to the broad spectrum of symptoms, the disease largely remains underdiagnosed. If it is not treated in due course, patients may develop renal damage or liver failure, and in some cases death may occur (2,5,22). Although leptospirosis can be treated, early diagnosis is critical for the establishment of effective antibiotic therapy.…”

Epidemiology, Surveillance and Laboratory Diagnosis of Leptospirosis in the WHO South-East Asia Region

“…These assays have been used as alternatives to MAT but have low sensitivity especially during the acute phase (Smits et al, 2001;Effler et al, 2002;Hull-Jackson et al, 2006;McBride et al, 2007). Furthermore, the diagnostic accuracies of these techniques are poor in some areas where leptospirosis is endemic (Blacksell et al, 2006;Myint et al, 2007).…”