BCG vaccination and active tuberculosis prevention: a three-year study

Six to eight million people are infected with tuberculosis [TB] annually throughout the world, out of which 2 to 3 million die. BCG vaccination and its efficacy are always used in tuberculosis control planning. There are different rates of BCG vaccination efficacy in the world from 0 to 80%. BCG vaccine has different efficacy in endemic and non-endemic areas. The prevalence of tuberculosis in Iran is high; therefore it was necessary to perform a study in this regard. This was a case-control descriptive study conducted from 2001- 2003. There were 50 cases of active pulmonary tuberculosis [according to WHO definitions], and 100 controls without tuberculosis admitted for other reasons. Vaccination was done in 10 [20%] people in the case group and 36 [36%] people in the control group [OR: 43%].Thus vaccine efficacy was calculated to be 57% in this study from the equation VE=1-OR [CI: 95% between 0.04-0.81]. Twenty percent of vaccinated people have been protected from active tuberculosis in this study. In this study vaccine efficacy was 57% [CI: 95% between 4-81%], and protection rate of vaccinated people against active tuberculosis was 20%. The effectiveness of BCG vaccine is not constant in all situations and old age and past history of contact with TB patients are confounding factors causing the low efficacy of the vaccine. While case control studies have limitations; thus, similar studies should be planned in different parts of our country for more accurate results

Antibiotic resistant patterns in MRSA isolates from patients admitted in ICU and infectious ward

Background: Methicillin- Resistant Staphylococcus Aureus [MRSA] has become one of the highest - ranking hospital acquired pathogens throughout the world, capable of causing a wide range of hospital infections. Staphylococcus aureus is a major nosocomial pathogen that causes a range of diseases, including endocarditis, osteomyelitis, pneumonia, toxic shock syndrome, food poisoning, carbuncles, and boils

Materials and Methods: One hundred S. aureus isolates recovered from patients in Loghman Hakim hospital were included in this study. Minimum inhibitory concentration [MIC] of strains for methicillin was determined by broth macrodilution method as recommended by NCCLS. Antibiotic susceptibility was tested by using the "disk diffusion technique on Mueller-Hinton Agar". Nineteen antibiotics were tested including Ampicillin, Penicillin, Cephalexin, Cefepime, Gentamicin, Doxycycline, Erythromycin, Chloramphenicol, Tetracycline, Nitrofurantoin, Kanamycin, Amikacine, Cefotaxime, Clindamycin, Cefazolin, Amoxicillin, Sulfamethoxazole-trimethoprim, Vancomycin, and Ciprofloxacin

Results: The MIC range for methicillin was from 1microg/ml to 1024microg/ml. Ninety percent of the isolated strains had methicillin MIC >/= 16microg/ml and were designated as resistant. Vancomycin and Chloramphenicol were the most effective antibiotics and only 7% and 14% of the isolates were resistant respectively. Forty-four percent hospital acquired MRSA strains were resistant to Co-trimoxazole. The high antibiotic resistance among MRSA strains could be originated due to widespread use of antibiotics

Conclusion: Out of 90 MRSA isolates characterized in this study, approximately half of them displayed resistance to one or more antimicrobial agents, including Penicillin, Cephalosporins, Tetracycline and aminoglycosides. These data are in accord with previous study suggesting use of these drugs was important in the emergence of antimicrobial resistance in MRSA. In addition, 66% of MRSA isolates were sensitive to Trimethoprim-Sulfamethoxazole [Co-Trimoxazole]. Since this drug combination is recommended for treating a range of human infections, S.aureus isolates should be monitored for further emergence of Co-Trimoxazole resistance