Serological Evaluation of Clinically Suspected Leptospirosis Cases in a Tertiary Care Hospital

Leptospirosis is a zoonotic infection caused by the spirochaete Leptospira, which has worldwide distribution. Laboratory diagnosis is routinely performed by serological tests like dipstick assay, lateral flow assay and latex agglutination which are rapid tests recommended for screening the disease. Microscopic Agglutination Test (MAT) is the standard test for serological diagnosis of leptospiral infection which is not included in the test panel in most of the peripheral laboratories as the procedure is laborious and it requires to maintain live leptospira. Therefore, one of the rapid tests is routinely employed for demonstration of leptospiral antibodies. Our objective was to screen the acute cases of leptospirosis by Leptochek WB IgM and PanBio IgM Elisa and compare the findings with the MAT and correlate the clinical findings with the serological tests.METHODSThis study was conducted in a tertiary care hospital in Mangalore from August 2010 to September 2013. A total of 314 cases of clinically suspected leptospirosis were included based on the Faine’s criteria. Patients’ serum was screened for leptospiral antibodies by Leptochek WB IgM, PanBio IgM ELISA and Microscopic Agglutination Test (MAT).RESULTSOut of 314 clinically suspected cases screened, seropositivity for leptospirosis by Leptochek WB-IgM, PanBio IgM ELISA and MAT was found to be 49 (15.6%), 65 (20.7%) and 78 (24.8%) respectively. Thus, an overall prevalence rate of leptospirosis was 24.8% (78/314) based on the MAT test. Sensitivity, specificity, positive predictive value and negative predictive value of Leptocheck WB IgM was 53.8%, 97%, 85.7 and 86.4% with MAT while the comparative values of PanBio-ELISA IgM with respect to MAT test was 74.5%, 97 %, 89.2% and 92% respectively. Common clinical features among MAT positive cases were fever, chills and rigors, oliguria, vomiting, jaundice and headache.CONCLUSIONSMAT is a standard serological test for Leptospirosis. This test is not always available for peripheral health centres, as the test is time consuming and cumbersome. Thus, screening tests are now being employed for screening the patients. Rapid tests like Leptocheck -WB can be supplemented with an ELISA test for screening of clinically suspected cases of Leptospirosis and later confirmed with the MAT at reference centres.

Fluorescence of Candida in diagnosis of oral candidiasis.

Background: Many pathogenic fungi fluoresce in hematoxylin and eosin stained sections, and Papanicolaou (PAP)‑stained smears under ultraviolet illumination. In theory, this phenomenon could aid in the diagnosis of common fungal infections without the delay which is usually associated with special stains. Objective: To evaluate the role of fluorescence as a rapid screening technique for oral infections caused by Candida organisms in exfoliative smears of oral candidiasis. Materials and Methods: Two smears and one swab were collected from each of 62 clinically diagnosed cases of oral candidiasis. Smears were stained with (PAP) and periodic acid–Schiff stain (PAS). Both smears were evaluated under light microscopy (LM). Later, PAP smears were observed under fluorescent microscopy (PAP‑FM). The swab was inoculated on Sabouraud’s agar plate. Each technique was evaluated for sensitivity and specificity. Results: It was found that the PAS‑stained smears were more reliable for detection of Candida species than other methods (sensitivity = 100%; specificity = 66.7%). The PAP‑LM and PAP‑FM showed less sensitivity (67.9% and 85.7%) and specificity (66.7% and 33.3%), respectively. Combined results of both light and fluorescent microscopy of PAP (LM + FM) showed increased sensitivity (89.3%) but reduced specificity (16.7%). Conclusion: PAP autofluorescence is less sensitive than PAS, still it accentuates the distinct morphological features of Candida.

Determination of phenotypic expression of the fimbriae and hemolysin of uropathogenic Escherichia coli (UPEC).

The bacterial strains that cause symptomatic urinary tract infections possess diverse distinctive properties that enable them to overcome the local host defences. In Escherichia coli, virulence results from the cumulative impact of several virulence factors, which can vary according to the patient populations. The study was undertaken to assess the prevalence of the virulence factors by phenotypic assays in the E. coli isolates which were isolated from patients with UTI from a tertiary care hospital in Kerala. Methods: A total of 300 E. coli isolates were obtained from symptomatic cases of urinary tract infections and 30 E. coli faecal isolates were obtained from apparently healthy individuals and they were tested for phenotypic properties like haemolysin production, mannose resistant hemagglutination to indicate P fimbriae, cell surface hydrophobicity. Results: Among the 300 E. coli isolates from the cases group, 135 (43.5%) were hemolytic, 106 (35.5%) were MRHA positive, 123 (41%) were hydrophobic. Among the 30 controls, 2 (6%) were hemolytic, 02 (6%) were MRHA positive and 04 (10%) were hydrophobic. The difference between the cases and the control group was significant (P <0.001). Multiple virulence factors were observed in 51% of the isolates. Conclusion: The present study showed varied phenotypic expression of the virulence factors in the urinary isolates as compared to the fecal isolates.