Medicine
Permanent URI for this communityhttp://repository.kln.ac.lk/handle/123456789/12
This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
Browse
2 results
Search Results
Item The usefulness of rapid screening tests in discriminating normal and infected urine specimens under Sri Lankan conditions(Sri Lanka College of Microbiologists, 2003) Athhukorala, G.I.D.D.A.D.; Nilaweera, T.H.W.T.; Sunil-Chandra, N.P.INTRODUCTION: Tropical climate and improper specimen collection can lead to contamination of urine by the commensal flora and their rapid multiplication prior to the culture. In Sri Lanka, some laboratories use the centrifuged urine for estimating pus cell counts whilst others use the un-centrifuged urine. OBJECTIVE: To assess the usefulness of rapid and simple screening tests for UTI currently available in Sri Lanka STUDY DESIGN: A prospective study over a three months period. SETTINGS: Urine specimens referred to University laboratory from wards of the Teaching Hospital, Ragama. METHODS: Midstream urine specimens from 100 patients presenting with a history of UTI, collected prior to antibiotic therapy were examined within one hour of collection for the determination of urine pus cell and organism counts, nitrate reduction (NR) and leukocyte esterase (LE) activity and the significant bacteriuria. Organism and pus cell counts of un-centrifuged and centrifuged urine using a Neubauer haemocytometer and per high power field (PHF) were examined by microscopy. RESULTS: 28 out of 100 patients enrolled in the study, had significant bacteriuria (>105 colony forming units (CFU) /ml) whilst 17/100 had 'may be significant1 (104'105 CFU/ml) and 55/100 had <104 CFU/ml bacteriuria. The sensitivity and specificity of using the pus cell count /ml of un-centrifuged urine using a Neubauer haemocytometer, compared to the culture positive samples was 71.42%(20/28) and 89.09% (49/55) respectively, at the cut off point of 10s pus cells/ml. The sensitivity and specificity of pus cell count /HPF in un-centrifuged urine was 14.3% (4/28) and 96.4% (53/55) respectively whilst the counts /HPF in centrifuged urine was 57% (16/28) and 91% ( 50/55) respectively. The sensitivity and specificity of the presence of both NR and LE activity in relation to culture was 82.1% and 27.3 % respectively. CONCLUSIONS: The pus cell count/ml of un-centrifuged urine is a better indicator of UTI at the cut off point of 105 pus cells/ml compared to the count per HPF or urine NR and LE activity. Pus cell counts/HPF or organism counts in both un-centrifuged and centrifuged urine were found to have a lower co-relation with the culture positive samples. However, amongst the screening tests assessed, the pus cell count/ml of un-centrifuged urine is superior in terms of sensitivity, specificity and the reliability.Item Comparison of laboratory techniques for diagnosis of hookworm infections(Sri Lanka College of Microbiologists, 2011) Manamperi, N.H.; Anjalee, K.G.C.; Gunawardena, N.K.; Sudusinghe, H.; Nilaweera, T.H.W.T.; de Silva, N.R.INTRODUCTION: Hookworm infection may be diagnosed by detection of eggs or culturing of larvae from stools. OBJECTIVE: To compare the efficacy of modified Kato-Katz (K-K) technique, saline smears, Harada-Mori (H-M) and nutrient agar culture plate (NACP) methods in diagnosis of hookworm infections. METHODOLOGY: A total of 324 stool samples, from the plantation sector families in Ratnapura district were examined by modified Kato-Katz technique and saline smears, and cultured by Harada-Mori and on NACP according to standard protocols, at the Faculty of Medicine, Ragama. Harada-Mori and NACP were maintained for 7-10 days and larvae or larval tracts observed by a stereomicroscope. Positivity in any two of the four techniques was considered the gold standard positive. Statistical analysis was done using SPSS version 16. RESULTS: A total of 172 (53.1%) samples were positive by at least one method. The positivity rates with K-K, H-M, NACP and saline smears were 42.3% (137/324), 37.7% (122/324), 23.5% (76/324) and 22.2% (72/324) respectively. The highest sensitivity (89.8%) and lowest specificity (88.3%) was seen in modified K-K, the lowest sensitivity (50.4%) in saline smears and the highest specificity in NACP (98.5%). Detection rates with saline smears, H-M and NACP rose with increasing intensity of infection as determined by K-K technique. Harada-Mori had the highest detection rate (70.7%) in light infections. It also detected 11.8% of K-K negative samples. CONCLUSIONS: The modified K-K technique is a reasonably good diagnostic method for detection of hookworm infections. A combination of methods will increase the diagnostic accuracy in hookworm infections.