Evaluation Of Diagnostic Utility Of Modified Faine’s Criteria In Leptospirosis- Experience From A Tertiary Care Hospital.

Abstracts: Background & Objective: Leptospirosis is an emerging infectious disease, for the diagnosis of which clinical, epidemiological and laboratory parameters may be evaluated as per modidified Faine’s criteria suggested by several authors. The objective of this study was to validate the utility of modified Faine’s criteria in the diagnosis of leptospirosis. Methodology: This study was carried out at a tertiary care hospital in Bengaluru, India from January 2011 to April 2012. Blood, urine and paired sera from one hundred patients with clinical suspicion of leptospirosis were collected. Relevant clinical and epidemiological details of these patients were also obtained as per modified Faine’s criteria. Blood and urine samples of these patients were subjected to Dark Field Microscopy (DFM) and culture, whereas, their sera were subjected to Immuno chromatography (IgM Leptocheck), IgM Enzyme Linked Immuno Sorbent Assay (IgM ELISA) and Macroscopic Slide Agglutination Test (MSAT). All the leptospira seropositive samples were subjected to Microscopic Agglutination Test (MAT) which was also used as the gold standard to validate all the aforementioned serological tests and modified Faine’s criteria. Results: Positive Predictive Values (PPV) of all the aforementioned serological screening tests and modified Faine’s criteria were calculated. PPV of IgM Leptocheck, MSAT, IgM ELISA and modified Faine’s criteria were found to be 14.3%, 6.5%, 8.7% and 21% respectively. Conclusion: The diagnosis of leptospirosis (both laboratory & clinical) is an uphill task. A high index of suspicion is needed in endemic areas & leptospirosis must be considered when a patient presents with acute onset of fever, headache & myalgia. From the results obtained in our study, it seems that modified Faine’s criteria may not be as useful a diagnostic tool as it has traditionally been thought to be. More studies should be carried out to evaluate its diagnostic utility.

An evaluation of dark field microscopy, culture and commercial serological kits in the diagnosis of leptospirosis.

Context: This study was conducted to analyze the clinical utility of various leptospira diagnostic modalities. Aims: To evaluate the role of dark field microscopy (DFM), culture, immunochromatography (IgM Leptocheck), IgM enzymelinked immunosorbent assay (IgM ELISA), macroscopic slide agglutination test (MSAT) and microscopic agglutination test (MAT) in diagnosing leptospirosis in febrile patients. Settings and Design: Descriptive study conducted in a tertiary care hospital from January 2011 to April 2012. Subjects and Methods: Blood, urine and paired sera from 100 patients with clinical suspicion of leptospirosis (study group) were collected and subjected to DFM, culture, IgM Leptocheck, IgM ELISA and MSAT. Fifty randomly selected sera from febrile patients tested positive for infections other than leptospirosis (control sera) were also subjected to the aforementioned serological assays. All the leptospira seropositive samples were subjected to MAT. Statistical Analysis Used: Positive predictive values (PPV) and coefficient of agreement (kappa). Results: None of the clinical samples showed positivity by DFM. Leptospira inadai was isolated from a urine sample. The seropositivity of IgM Leptocheck, IgM ELISA and MSAT was 16%, 46% and 47%, respectively. The PPV of these assays was 14.3%, 8.7% and 6.5%, respectively. Poor agreement was obtained among these assays. Only four study group leptospira seropositive samples were confirmed by MAT with Australis being the predominant serovar. None of the leptospira-positive control sera were confirmed by MAT. Conclusions: DFM and culture have limited utility in diagnosing leptospirosis with serology being the mainstay. The present study shows discordant results with the commercially available serological kits. Further studies should be done to evaluate the various diagnostic modalities.

A preliminary study on metallo-beta-lactamase producing Pseudomonas aeruginosa in hospitalized patients.

Metallo beta-lactamase (MBL) producing Pseudomonas aeruginosa is an emerging threat and a cause of concern for the physicians treating such infections. The present study was undertaken to know the resistance pattern of P. aeruginosa to beta-lactamase inhibitors and carbapenems, and to detect the presence of MBL among resistant isolates to both groups of antibiotics. Between June-November 2001, 50 P. aeruginosa isolates from clinical specimens were tested for susceptibility to beta-lactamase inhibitors and carbapenems by Kirby-Bauer disc diffusion method. Isolates resistant to both groups of antibiotics were screened for the presence of MBLs by disc diffusion method using 2-mercaptoethanol. Of the 50 isolates, 6 (12%) were resistant to both beta-lactamase inhibitors and carbapenems. All 6 isolates were MBL producers were resistant to all the antibiotics tested. Resistance to piperacillin-tazobactam, cefoperazone-sulbactam and ticarcillin-clavulanic acid was 12, 20 and 36 per cent respectively. Resistance of 12 per cent each was noted to imipenem and meropenem respectively. This is to the best of our knowledge the first report of MBL producing P. aeruginosa from India and suggests the need for early detection, notification and control of spread.

Antibiotic resistance among gram-negative bacteria of lower respiratory tract secretions in hospitalized patients.

Data on antibiotic resistance pattern of gram-negative bacterial isolates of lower respiratory tract secretions of hospitalized patients were fed into WHONET computer and analyzed for the year 1999. Out of 860 samples, 269 (31.2%) were culture positive. Gram-negative bacteria (GNB) accounted for 238 (88.4%) positive samples. Non-fermenting gram-negative bacteria (NFGNB) were found in 34% samples, the other common ones being Klebsiella spp (29.8%) and Pseudomonas spp (17.2%). GNB isolates from tracheal aspirates and sputum were 132 (55.4%) and 106 (44.5%) respectively. Adults (32.7%) and elderly patients (24.3%) recorded higher isolation of GNB as compared to pediatric patients (1.6%). The highest mean resistance among predominant GNB in both tracheal aspirate (96.6%) and sputum (86.9%) was noted to ampicillin while the lowest mean resistance in tracheal aspirate (28%) and sputum (14.3%) was to amikacin. NFGNB of tracheal aspirates and sputum showed highest resistance of 50% and 32% to amikacin, respectively. Pseudomonas spp showed the highest variation in the resistance pattern between tracheal aspirates and sputum samples. Overall mean resistance was highest among tracheal aspirate isolates compared to sputum isolates.

Prevalence of beta hemolytic streptococci carrier rate among schoolchildren in Salem.

A preliminary study was conducted to identify the carriers of beta hemolytic streptococci (BHS) among school children. BHS were identified, grouped by latex agglutination test and tested for susceptibility to penicillin, erythromycin and cefazolin from their throat swabs. Prevalence of BHS was found to be 21.6% with group G (43.2%) as the predominant group followed by group A (28.8%). All the isolates were sensitive to the antibiotics tested. Health cards were issued to the carriers of group A beta hemolytic streptococci.