Community acquired bacterial pneumonia: aetiology, laboratory detection and antibiotic susceptibility pattern

This cross sectional study was conducted to identify the common bacterial causes of community acquired pneumonia (CAP) from sputum and blood by culture and polymerase chain reaction (PCR) and to evaluate the effectiveness of these tests. A total of 105 sputum and blood samples were collected from patients with pneumonia on clinical suspicion. Common causative bacterial agents of pneumonia were detected by Gram staining, cultures, biochemical tests and PCR. Among 55 sputum culture positive cases, a majority (61.82%) of the patients were in the age group between 21-50 years and the ratio between male and female was 2.5:1. Most (61.90%) of the cases were from the lower socio-economic group. Out of 105 samples, 23 (37.12%) were positive by Gram stain, 29 (27.62%) yielded growth in culture media and 37 (35.24%) were positive by PCR for Streptococcus pneumoniae and Haemophilus influenzae. Streptococcus pneumoniae was the most common aetiological agent (19.05%) followed by Klebsiella pneumoniae (13.33%), Haemophilus influenzae (8.57%) and Pseudomonas aeruginosa (5.71%). Multiplex PCR is a useful technique for rapid diagnosis of bacterial causes of pneumonia directly from sputum and blood. Considering culture as a gold standard, the sensitivity of PCR was 96.55% and specificity was 88.15%. More than 80% of Streptococcus pneumoniae isolates were found to be sensitive to ampicillin, amoxycillinclavulanate, and ceftriaxone. Susceptibilities to other antimicrobials ranged from 65% for azithromycin to 70% for levofloxacin. On the other hand, the Gram negative organisms were more sensitive to meropenem, ceftriaxone, amoxycillin-clavulanate and amikacin.

Quality assessment of sputum for Acid Fast Bacilli(AFB) test in microbiology laboratories before and after implementation of Standard Operating Procedure (SOP): a comparative study.

Aims: To evaluate the present status of microbiology laboratory by comparing the test results of investigator with that of laboratory staff for sputum for Acid Fast Bacilli (AFB) withZiehl-NeelsenStaining (Z-N Staining) at primary and secondary level andto assess the present status of a microbiology laboratory for sputum for Acid Fast Bacilli (AFB) withZiehl-NeelsenStaining (Z-N Staining) at tertiary level. Material and Methods: Type of study : Cross sectional, descriptive type of study. Place of study: Department of Microbiology of Dhaka Medical College,Narsingdi Sadar Hospital,Narsingdi,PolashUpzilla Health Complex ,Polash, Narsingdi andDOTS centers. Duration of study: From July, 2007 to June,2008 Method of sampling: Non probability, purposive and convenient sampling Sample Size: Sputum for AFB: 300 sputum samples were collected for detection of AFB by direct Z-N staining, Z-N staining after bleach centrifugation and Auramine phenol staining before implementing SOP. After following SOP 150 sputum samples were collected and tested in direct Z-N method. Results: In the present study, before SOP out of 100 sputum smear at each level, discrepancy was found in 3% cases at primary level, 2% cases at secondary level and 1% case at tertiary level.After following SOP out of 50 sputum smear at each level, discrepancy was reduced to 2% cases at primary level and no discrepancy was found at secondary and tertiary level. Conclusion: Each laboratory must have SOP for laboratory testing to set the minimum acceptable standard for every test in order to improve and maintain the quality of laboratory services.

Comments on Evaluation of Endoscopic Findings and Detection of H. pylori Antibody by Serum IgG ELISA.

Bangladesh is a developing country with high prevalence of peptic ulcer disease and H. pylori infection. During the period of January 2007 to December 2007, a cross sectional study was conducted. In this study, serum samples were collected from 86 dyspeptic patients undergoing upper GIT endoscopy to determine anti-H. pylori IgG antibody by serum ELISA and was evaluated with endoscopic findings. Out of 86 study patients, gastro-duodenal mucosa was found normal in 58.14%, gastritis in 11.63%, duodenitis 2.33%, reflux oesophagitis 4.65%, peptic ulcer 17.44% and carcinoma of stomach 5.81%. Among 86 study population, 68 were serum IgG ELISA positive and 20 were negative.

Prevalence of Bacterial Vaginosis among the PID Patients in Bangladesh.

A cross sectional study was conducted on patients attending at the outpatient department of Gynaecology and Obstetrics of Dhaka Medical College Hospital, Dhaka during the period of July, 2007 to December, 2007. Two hundred sexually active female in the age group of 15-45 years, with vaginal discharge and itching, were selected for the study. Among them 143 having only vaginal discharge and itching without PID (Pelvic inflammatory disease) and 57 patients having vaginal discharge and itching with PID. A detailed history and a thorough clinical examination of all the cases were done. After making the clinical diagnosis of BV (Bacterial vaginosis) by Amsels criteria, diagnosis also carried out with Acridine orange staining, Gram stain Nugent criteria. Out of 200 women, 48 (24%) cases were diagnosed as having bacterial vaginosis by applying Amsel's clinical criteria. The rate of detection of bacterial vaginosis was 23% by Gram stain Nugent criteria and 24.5% by acridine orange staining. In this study BV was diagnosed in 31(54.39) cases among the PID patients and 17(11.89) among the women having only vaginal discharge and itching. This study shows the increased association of BV in PID patients of Bangladesh.

A Comparative Study Among Different Invasive Methods For The Diagnosis Of Helicobacter Pylori.

H. pylori infection occurs worldwide. Approximately 50% of the world population is infected with this organism. A cross-sectional study was conducted on 81 dyspeptic patients attending at Dhaka Medical College Hospital, for diagnostic endoscopy. H. pylori infection was measured by three invasive methods: culture, rapid urease test & histopathology. Among study patients maximum (34.57%) H. pylori infected were in 21-30 years age group, bearing male female ratio 1: 92.86. Forty four (54.32%) out of 81 were culture positive, 61 (75.31%) were rapid urease test positive and 62 (76.54%) were histopathology positive. By using ‘gold standard’ definition, 64 (79.02%) were H. pylori infected, 17 were un-infected. Finally comparing among three invasive methods, all are highly sensitive and specific to diagnose H. pylori infection.

Comparison between ELISA and ICT- MycoDot in adult pulmonary tuberculosis.

The present study was conducted to see the diagnostic efficacy of serum anti-TB IgG antibody detection in adult pulmonary tuberculosis (TB) by ELISA and Immunochromatography test (ICT) method using commercially available diagnostic kit (Pathozyme TB complex and MycoDot test respectively). This case-control study included 48 cases of adult pulmonary TB within the age range of 15-65 years. Among them, 22 (45.9%) were AFB positive confirmed cases, 12 (25.0%) were AFB negative clinically diagnosed cases before treatment and 14 (29.1%) were clinically diagnosed cases on treatment. Age and sex matched 33 controls were also included, of which 19 (57.6%) were healthy and 14 (42.4%) were sick with non-specific pulmonary infection. Overall sensitivity and specificity of ELISA were 60.42% & 96.97% (p<0.001) and those of MycoDot as 72.92% & 93.94% (p<0.001). Rate of both ELISA and MycoDot positive were higher among clinically diagnosed cases on treatment with respective values as 71.42% and 85.71%. Respective values among AFB positive confirmed TB cases were 68.18% and 72.72%. As, both ELISA and MycoDot yielded be used as a confirmatory test for TB.

Comparison between ELISA and ICT-MycoDot in childhood tuberculosis.

Diagnosis of childhood tuberculosis (TB) is a difficult job. Keeping this fact in mind, the present study was designed to detect serum anti-TB IgG antibody in childhood TB cases by Enzyme Linked Immunosorbent Assay (ELISA) and Immunochromatography test (ICT) method using commercially available diagnostic kit (Pathozyme TB complex and MycoDot test respectively). This case-control study, were done on 52 cases of childhood TB within the age range of 4(+)-14 years. Among them, 15 (28.8%) were AFB positive confirmed cases, 25 (48.1%) were AFB negative clinically diagnosed cases before treatment and 12 (23.1%) were clinically diagnosed cases on treatment. Age and sex matched 36 controls were also included of which 21 (58.3%) were healthy children and 15 (41.7%) were sick children with non-specific pulmonary infection. Overall sensitivity and specificity of ELISA were 34.62% and 97.20% (p<0.001) and those of MycoDot as 48.08% and 96.92% (p<0.001). Rate of both ELISA and MycoDot positive were higher among. clinically diagnosed cases on treatment with respective values as 71.42% and 85.71%. Respective values among AFB positive confirmed TB cases were 40% and 72.72%. Different aspects of immune response in TB were discussed. Since, both method yielded negative results in confirmed TB cases, so none of the methods should be considered as a confirmatory test method for TB.

Socioeconomic status, clinical features, laboratory and parasitological findings of hepatic amebiasis patients--a hospital based prospective study in Bangladesh.

Socioeconomic status, clinical, laboratory and parasitological features of 31 hospitalized amebic liver abscess (ALA) and 8 amebic hepatitis (AH) patients were studied. Thirty-seven (94.9%) of the total 39 cases were from low socioeconomic class and 2 (5.1%) were from middle class (p<0.001). Sixteen (51.6%) ALA and 5 (62.5%) AH patients were admitted with duration of disease for 3 weeks or more. Twenty-one (67.7%) ALA and 3 (37.5%) AH cases gave no previous history of diarrhea or dysentery. Epigastric pain was the predominant symptoms in 71% patients compared to high fever (19.4%), nausea and vomiting (9.7%). Neutrophilic leukocytosis was found in 9 (29.0%) ALA and 2 (25%) AH cases. Raised alkaline phosphatase was the predominant abnormal liver function test found elevated in 22 (71.0%) ALA and 5 (62.5%) AH cases. Three (7.7%) of the 5 (12.8%) microscopy positive stool samples yielded growth of Entamoeba histolytica in culture. The right lobe was involved in 28 (90.3%) ALA cases; 29 (93.5%) patients had single abscess. Bacterial super infection was observed in 1 (12.5%) abscess, reactive changes in right lung was observed in 6 (19.4%) ALA and 1 (12.5%) AH cases. Ascaris lumbricoides was the predominant associated intestinal parasite.

Cost effectiveness in the discrimination of leishmania species causing anthroponotic leishmaniases in Asia using selective enzymes.

In this study, an attempt was made to evaluate the usefulness of selective enzymes in the identification of Leishmania spp causing anthroponotic leishmaniasis in Asia, especially from a cost effectiveness point of view. For this purpose cellulose acetate electrophoresis was carried out to identify the Leishmania species of the Old World. After analyzing 11 enzymes 6PGDH was found to be the most polymorphic enzyme which could distinguish the WHO reference strains of the Leishmania species endemic in Asian countries like L.(L.) donovani (DD8), L. (L.) infantum (IPT-I), L.(L.) major (5ASKH), and L.(L.) tropica (K-27). Addition of another enzyme G6PDH improved the quality of diagnosis. Cost could be reduced manifold to discriminate the Asian Leishmania parasites by analyzing these two enzymes.