Frequency of tuberculous cervical lymphadenitis detection at a single laboratory in islamabad.

OBJECTIVE: To determine the frequency of tuberculous cervical lymphadenitis and to evaluate the diagnostic efficacy of microscopy and conventional Lowenstein Jensen (LJ) culture technique in the diagnosis of cervical lymphadenitis caused by M. tuberculosis (MTB) Study Design: A descriptive, cross-sectional study. Place and Duration of the Study: Department of Mycobacteriology, Public Health Laboratories Division, National Institute of Health, Islamabad, from January 2003 to December 2004. PATIENTS AND METHODS: A total of 220 patients from Pakistan Institute of Medical Sciences (PIMS), Islamabad, Federal Government Services Hospital (FGSH), Islamabad and Rawalpindi General Hospital (RGH), Rawalpindi, presenting with enlarged cervical lymph nodes (for at least six months), pain/ weight loss and low grade fever were studied for the presence of MTB from 142 lymph node biopsies, 60 FNA samples and 18 discharge fluids/swabs. All the samples were examined at NIH by ZN staining smear and culture on conventional LJ medium as well as on Bactec 12B medium using Bactec 460 TB system. The drug susceptibility testing of the isolates was performed on Bactec 460 TB system. NAP test on Bactec 460-TB system, Accuprobe and biochemical tests were employed to identify the mycobacterial isolates. RESULTS: M. tuberculosis accounted for 173 out of 220 cases of cervical lymphadenopathy. Maximum incidence was found to be in the age group 10-30 years with male to female ratio of 1:1.7. Discharge sinuses and abscess formation were uncommon. Biopsy tissue samples gave the maximum yield of positive mycobacterial cultures as all 142 biopsy samples being positive while only 50% (30/60) of FNA and 5.5% (1/18) of discharge fluids/swabs were positive. All the isolates were identified as M. tuberculosis. No atypical mycobacteria were recovered from the samples examined. All isolates were found to be susceptible to first line anti-tuberculous drugs i.e. Streptomycin, Isoniazid, Rifampicin and Ethambutol (SIRE). CONCLUSION: Tuberculosis was the major cause of cervical lymphadenopathy in the referral area. Culture of the biopsy tissue from the affected lymph nodes is a method of choice for laboratory diagnosis of tuberculous cervical lymphadenopathy.

Trend of blood groups and Rh factor in the twin cities of Rawalpindi and Islamabad.

OBJECTIVE: To determine the prevalence of different blood groups and Rh factors in a random population sample from urban and rural areas of Rawalpindi and Islamabad region of Pakistan. METHODS: Blood group and Rh factor determination was carried out by the antigen-antibody agglutination test from October 2003 to October 2004, and encompassed 2518 subjects. RESULTS: The percentages of various groups among male and female subjects, respectively, were recorded as 27.01% and 24.02% (for blood group A), 33.75% and 32.87% (for blood group B), 8.93% and 11.20% (for blood group AB) and 30.31% and 31.91% (for blood group O). The Rh positive and negative distribution in the studied population was 92.45% and 7.55% respectively. CONCLUSION: The determination of the frequency of blood groups in the region would not only help in blood transfusion services, but also eliminate the risk of erythroblastosis foetalis in the neonates.

Penetration and activity of antibiotics in brain abscess.

Penetration of antimicrobial agents into the cerebrospinal fluid is dependent on numerous factors, including their serum protein binding, molecular size and lipid solubility, and degree of local inflammation. The choice of an appropriate agent is further complicated by diverse bacterial flora involved in brain abscess, local resistant patterns and activity of the drug in abscess environment. This update examines the conventional and newer agents in the above context for their role in the management of brain abscess.

Genus and species-specific IgG and IgM antibodies for pulmonary tuberculosis.

OBJECTIVE: To evaluate three different enzyme immunoassays for serological diagnosis of pulmonary tuberculosis and to compare their diagnostic accuracy in different combinations. DESIGN: A non-interventional comparative study. PLACE AND DURATION OF STUDY: The study was carried out at the Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi between April and September 2001. SUBJECTS AND METHODS: Sera from patients suffering from pulmonary tuberculosis (n=94) with sputum positive for acid fast bacilli (AFB) and sera from control group of healthy individuals (n=90) with sputum negative for AFB were tested by Pathozyme-Myco G EIA, Pathozyme-TB Complex Plus EIA and Pathozyme Myco M EIA kits for the genus-specific IgG and IgM, and the species-specific IgG antibodies against antigens of Mycobacterium tuberculosis. RESULTS: The detection of IgG against genus-specific antigens by Pathozyme-Myco G had a sensitivity of 46% and a specificity of 93%, of IgG against species-specific antigens by Pathozyme-TB Complex Plus had a sensitivity of 64% and specificity of 97% and of IgM against genus-specific antigens by Pathozyme Myco M had a sensitivity of 67% and specificity of 98%. When the results of these immunoassays were evaluated in combination, their sensitivity improved. Combination of genus-specific IgM and species-specific IgG yielded best results with a sensitivity of 87% and specificity of 93%. CONCLUSION: The sensitivity of serological diagnosis of tuberculosis is low, but it can be increased by utilizing a combination of several antigens.

Diagnosis of beta-thalassaemia major in previously transfused patients.

OBJECTIVE: The study was conducted to evaluate the effects of blood transfusion(s) on the haematological picture of b-thalassaemia major. DESIGN: Retrospective case control study. PLACE AND DURATION OF STUDY: Department of Haematology, Armed Forces Institute of Pathology, Rawalpindi from January 1999 to December 2000. SUBJECTS AND METHODS: A total of 280 consecutive patients of beta-thalassaemia major were studied. They were diagnosed by haematological parameters, and Hb-F estimation. Parent's study and PCR was also used when required. RESULTS: Out of the 280 patients 109 (39%) had received one or more blood transfusions (cases). The remaining 171 patients who did not receive any transfusion served as controls. The mean MCV, MCH and Hb-F in cases were significantly higher than in the controls (p<0.05). The mean Hb-F in 95 cases, which had received occasional ( <4) transfusions, was higher (33%) than in the 14 cases who had received >4 transfusions (17%) (p=0.016). In the occasionally transfused patients Hb-F level was directly related to the time since last transfusion. In 44/109 (40%) transfused patients (Hb-F >30%) the diagnosis of thalassaemia was not difficult. In 54/109 (50%) patients (Hb-F: 5-30%) the diagnosis was aided by parent's study, while PCR for thalassaemia mutations was required in 11/109 (10%) patients (Hb-F <5%). CONCLUSION: In most transfused patients of thalassaemia major MCV and MCH were significantly higher while Hb-F was lower than in the un-transfused patients. There was a linear correlation between Hb-F level and time since last transfusion in the occasionally transfused patients. However, the reduction in Hb-F level was more marked and sustained in multipally transfused patients. Parent's study and PCR are useful aids in establishing the correct diagnosis in these patients.