» Indexing and Archiving | More Bacteriology & Parasitology Journals Journal of Bacteriology & Parasitology Download Journal Flier JBP Editorial Board Scientific Associations Ann Albihn 2010- Governmental commission on climate change and infectious diseases 2009 Commission on climate change and animal inf. diseases to the governmental investigation on the handling of animal inf. diseases(Djursmittoutredningen), Agricult. Ministry 2007- 2010 The trend surveillance and analysis Group (omvärldsråd) at

Abstract

Laboratory case definition of leptospirosis is scarcely defined by a solid evaluation that determines cut-off values in the tests that are applied. This study describes the process of determining optimal cut-off titers of laboratory tests for leptospirosis for a valid case definition of leptospirosis. In this case the tests are the microscopic agglutination test (MAT) and an in-house IgM enzyme-linked immunosorbent assay (ELISA) both on single serum and paired samples using a positive culture as the reference test in the Dutch population. The specificity was assessed using panels of sera from healthy donors, cases with known other diseases and non-leptospirosis cases with symptoms compatible with leptospirosis. Cases were divided into three periods corroborating the acute phase (1-10 days post onset of illness (DPO)), the early convalescent (11-20 DPO) and the late convalescent phase (>20 DPO). Cut-off titers for MAT and IgM ELISA were determined as 1:160 and 1:80 respectively for all three periods. These cut-off titers combined 100% specificity with a sensitivity that changed according to the stage of disease for both tests. The low sensitivities in the early acute phase are consistent with the dynamics of the humoral immune response. IgM ELISA yielded higher sensitivities compared to MAT in the acute and early convalescent stages. Moreover, the optimal sensitivity of MAT, the gold standard was < 82%, implying that a significant part of global cases is missed by this recommended test. MAT and IgM ELISA manifested partly complementary, resulting in a higher sensitivity when combining the results of these two tests. The availability of paired samples and of adequate clinical and epidemiological data are other parameters that will significantly increase the sensitivity of laboratory confirmation. This study enables fine-tuning of the current laboratory definition towards an improved case finding and implies that solid validation of laboratory parameters for case definition will improve both the diagnosis for individual patient care and for estimating the disease burden at a worldwide scale.

Development of a Recombinase Polymerase Amplification Assay for the Detection of Pathogenic Leptospira

“…The study sample consisted of 19 samples that yielded a positive culture and 44 samples that were negative by culture. From all 19 patients who had a positive culture, leptospirosis was also confirmed by serology on paired samples, consistent with our case definition [17]. From eight of the 44 cases that scored as culture negatives, a follow up sample was received that showed negative results in the serodiagnosis.…”

IgM ELISA for leptospirosis diagnosis: a systematic review and meta-analysis

“…Whereas molecular tests, such as the polymerase chain reaction (PCR), that demonstrate the presence of the causative agent in a clinical sample mainly during the first 5 days after the onset of the disease (DPO), serological tests depend on the accumulation of detectable amounts of anti-Leptospira antibodies in the late acute to convalescent samples [74][75][76] . Rapid diagnostic tests should ideally be accurate, simple to use, relatively inexpensive, easy to interpret, stable under extreme conditions, require little or no processing, and give the results within 1-2 hours 70 .…”

“…The rapid diagnosis is highly useful at the peripheral facilities and might be integral for early outbreak warning and useful for monitoring outbreaks if a rapid unusual accumulation of cases might provide an early alert, provided that specimens are collected, transported, and stored in an adequate manner 76 . This review, which included retrospective and prospective studies, had the following limitations: i) high heterogeneity found between studies; ii) use of selected samples and the choice of case definition may be a source of bias; and iii) it is a misunderstanding that rapid tests are easy and therefore do not require experience; iv) it may reflect population-related differences, such as past exposure to leptospirosis, exposure to environmental leptospires, or infection with other infectious agents.…”

In-house ELISA screening using a locally-isolated Leptospirain Malaysia: determination of its cut-off points

“…The AUC reflects how good of the test to distinguish between patients with and without disease [14]. In the ROC curve analysis, it showed that the AUC for serum dilutions 1:80 and 1:160 were 0.953 (95% Confidence Interval, CI =0.928-0.978) and 0.927 (95% CI =0.896-0.958) respectively (Figures 1 and 2).…”

“…The protocol of preparing antigen and coating plate was according to the protocol described by Goris et al . [14]. Briefly, the culture was grow in EMJH medium, killed by formalin (final concentration 0.2% v/v), heated in a boiling water bath for 30 min and centrifuged for 30 min at 10,000 g. The 100 μl supernatant was pipetted into the well and left to be evaporated.…”