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Showing 11 results for Tuberculosis
Farhad Salehzadeh , Shahnam Arshi ,
Volume 2, Issue 3 (9-2002)
Abstract
Background & Objective: Control of TB is regarded as a health priority program in underdeveloped countries, and Iran in no exception in this regard. Annual risk of infection (ARI) is an important index in this program. This index shows the percentage of people in a society who have been contaminated, and consequently their skin test has changed from negative to positive. In this study, Tuberculin skin test is conducted on Ardabil primary school students and its changes, if any, after one year have been regarded using renewed skin test in order to show ARI in this age group. Methods: 780 students were selected from among 17 primary schools using simple random sampling method. They were 8-14 years old, (mean 9.92). Tuberculin skin test was performed on all subjects two times with a one- year interval (May 1998-1999). The test results were recorded and analyzed. In this study PPD over 10 mm was considered positive. Results: In 55 (7.1%) students the test was positive in both tests, and in 33 (4.2%) students, PPD changed from negative (first time) to positive (second time) and in 78 subjects the results were doubtful. 765 students (98.1%) had history of BCG vaccination. Conclusions: This study indicated that, firstly, over the time, BCG has little effect on Tuberculin skin test, and secondly, the high rate of tuberculin skin test changes from negative (first time) to positive (second time) represents probability of severe contamination in this area.
Mohammadhasan Namaei , Mohammad Nazem , Ali Sadeghian , Mahboobeh Naderinasab,
Volume 3, Issue 1 (4-2003)
Abstract
Background & Objective: Tuberculosis is a diseases which is severely threatening the individuals health and is spreading quickly. Moreover, the appearance of new strains resistant to drugs has complicated the issue. Since there is no information available regarding the present drug-resistance situation of patients suffering from tuberculosis in Mashhad, this study was conducted to determine the prevalence of this resistance in this city. Methods: To determine prevalence of anti-tuberculosis drug resistance in Mashhad, drug sensitivity of 75 M. tuberculosis strains isolated from patients with pulmonary and extra-pulmonary tuberculosis from 20 Feb. 2002 to 20 Aug. 2002 was studied using the indirect proportion method. Every strain was tested against Rifampicin (RMP), Isoniazid (INH), Ethambutol (ETM), and Streptomycin (STM). Medical records of the patients were reviewed. Patients with no or less than 1 month treatment were defined as new cases and those previously treated for more than 1 month were defined as previously treated cases. Results: Of 75 isolates, 70(93.33%) were from new and 5(6.66%) from previously treated cases. 68 patients (90.66%) were suffering from pulmonary and 7(9.33%) from extra-pulmonary tuberculosis. Of 75 isolates, 23(36%) were resistant to at least one anti-tuberculosis drug. The highest rate of resistance was observed to streptomycin. Three of the 75 strains (4%) were resistant to all four drugs. 1.43% and 40% of strains isolated from newly and previously treated patients respectively were multidrug resistant. Conclusions: In this study new cases with MDR-TB were less prevalent compared to other studies. Most drug resistance and MDR-TB were associated with previous treatment. Continual evaluation of drug resistance following DOTS implementation seems to be necessary.
Shahram Habibzadeh, Latif Gachcar, Mohammad Reza Masjedi, Ali Akbar Velayati ,
Volume 5, Issue 2 (6-2005)
Abstract
Background & Objectives: Some special characteristics of mycobacterium tuberculosis such as long time incubation period in culture media needed for colony appearance, unavailability of serologic methods for diagnosis, along with necessity of starting treatment in the patients with severe conditions as well as isolation limitations requires the introduction of rapid and innovative diagnostic tests. On the other hand, some diagnostic tests such as Polymerase Chain Reaction (PCR) require special experimental conditions which are not easily available to clinicians. This study was designed to determine the diagnostic value of serum adenosine deaminasae in pulmonary tuberculosis and evaluate its efficacy in pulmonary tuberculosis diagnosis. Methods:This cross-sectional study started in spring 2002. Continuous sampling was done and admitted patients were observed, examined and interviewed using a diagnotic test. All patients admitted with a suspected pulmonary tuberculosis diagnosis based on physical examination, history and chest X-Ray results were followed up for six months to ensure that mycobacterium tuberculosis infection was appropriately diagnosed. Blood samples were taken for serum ADA and complementary diagnostic tests. Following certain necessary tests and work-ups patients with or without tuberculosis were identified. Results: 131 Patients were evaluated completely. 103 had tuberculosis and 28 patients had other diseases. No statistically significant difference was found between mean level of serum ADA in two groups. But a serum level of ADA greater than 51 U/L was associated with 90% positive predictive value and specificity in differentiating two groups. Conclusion: Serum ADA is not a suitable test for pulmonary tuberculosis diagnosis.
Shahram Habibzadeh, Zahra Tazacori , Firooz Amani , Uoones Sheshgellani, Khadige Khodapanahi ,
Volume 5, Issue 4 (12-2005)
Abstract
Background & Objectives: Since 1985 because of increasing incidence of tuberculosis (TB) in HIV background, the outbreaks of TB have been reported in different parts of the world. From 1985 to 1991 the incidence of TB increased by 18% in United States and Europe. In Multi Drug Resistant outbreaks of TB in United States 18 to 35% of heath care workers (HCW) who had exposure to TB patients had PPD Converted to positive test (Seroconversion). That is why the risk of TB incidence in health care workers has been put forward again. This study was designed to determine the rate of Buali hospital HCW exposure to mycobacterium tuberculosis. Methods: All 96 HCW of Buali hospital took part in this cross-sectional and analytical study. No PPD test was performed for HCW in this hospital in the beginning of their employment. For this reason 30 officers who had not previously worked in hospital wards and 60 medical students who had not started their clinical course were selected to obtain an estimation of PPD test before starting professional nursing. Results: Out of 96 subjects, 72 were female and 24 were male. Rate of positive PPD was 50% in general. Data analysis showed that PPD positivity was in direct relationship with number of working years in hospital. In 60 university students whose mean age was 21.6± 0/2.9 PPD positivity rate was 13.3%. I the third group consisting of 30 office workers (mean age=333±6.5) it was 23.3%. Conclusion: This study shows that HCW with 50% of PPD positivity are in exceeding probability of mycobacterium tuberculosis exposure, which is almost twice as much as the other office workers, possibility of exposure.
Mohammadyousef Alikhani , Mohammad Mahdi Aslani , Hadi Peeri Dogaheh , Mohammadhosein Dehghan ,
Volume 8, Issue 2 (6-2008)
Abstract
Background & Objective: Tuberculosis is more prevalent in developing countries and death from tuberculosis meningitis is strongly associated with delays in diagnosis and treatment. Polymerase chain reaction (PCR) has been incorporated as a diagnostic tool for the diagnosis of tuberculosis. The rapid results and greater sensitivity compared to traditional microbiological methods makes PCR a suitable technique in tuberculosis, especially in tuberculosis meningitis, when diagnosis is difficult or when rapid diagnosis is needed. However, the possibility of false positive and false negative results must be considered. The aim of this study was to compare the conventional bacteriology (culture Ziehl- Neelsen staining) with polymerase chain reaction (PCR) technique for rapid diagnosis of tuberculosis meningitis. Methods: This study included 25 clinically diagnosed patients that were suspected to have tuberculosis meningitis and 10 other bacterial or viral meningitis patients were investigated. DNA was extracted from CSF and the NESTED PCR using specific primers were done. Results: In 25 samples, Mycobacterium tuberculosis DNA was detected in 9 (36%) by PCR, 2(8%) and 1(4%) with culture and direct smear was obtained, respectively. whereas no DNA bands were detected in patient with the other 10 meningitis. The entire procedure was repeated and the same result was obtained. Conclusion: The findings of this study indicated that PCR is a powerful method for rapid and sensitive diagnosis of tuberculosis meningitis. In a way that it decreases obtaining the results from several weeks in bacteriological methods to one to two days, especially in smear negative patients. This is very important in tuberculosis meningitis because it is a medical urgency and needs rapid diagnosis and early treatment.
Mirmehdi Chinifroush Asl , Mohammad Bagher Sootode , Amir Jameeii , Samira Shahbazzadegan,
Volume 9, Issue 2 (6-2009)
Abstract
Background & Objectives: Lymphadenopathy refers to the disease of lymphatic nodes. Any immune response against foreign antigens is often associated with lymph node enlargement (lymphadenopathy) and lymphadenitis. Most pathologic studies of neck lymph nodes indicated TB as the most common cause of cervical lymphadenopathy. Approach to a neck lymphadenopathy as the main complaint of the patients or the only clinical finding is usual events which physicians encounters frequently during their practice. M anagement of these patients depends on the physician experience and knowledge. This study aimed to investigate etiology of cervical lymphadenopathies in admitted patients. Methods : In this cross-sectional study, one hundred patients with cervical lymphadenopathy who referred to Fatemi hospital from 2002-2006 and underwent excisional biopsy with pathologic results were included. Demographic data ' age and sex', and pathologic findings were obtained using the patients' file . FNA results and non lymphoid samples were excluded . All findings were analyzed by SPSS. Results: A total number of 100 subjects were studied of whom, 52 (52%) were male and 48 (48%) were female. On the basis of pathologic findings, tuberculosis was the most common cause of lymphadenopathy (36%) . Reactive changes including follicular hyperplasia, sinus histiocytosis and other forms of lymphadenitis, metastatic carcinoma, Hodgkin and non Hodgkin lymphoma were found in 34%, 13%, 9% and 8% respectively. In patients aged under 15, reactive changes were seen in 11cases (57%), and in age group of 16- 55 years tuberculosis was found in 31 cases (44.2%), and metastatic carcinoma was diagnosed in subjects aged over 55 years with 5 cases (45.4%). Conclusion: In our study tuberculosis is the most common cause for cervical lymphadenopathies in both sexes (especially between 15 to 55 years). This findings emphasis about the TB prevalence in Ardabil. Under the 15 years old reactive change of lymph nodes and over the 55 years metastatic carcinoma were the most common causes.
Farideh Ebrahimi Taj, Abdolhasan Mohammadi Khangah, Mojdeh Ramezani, Khatereh Anbari,
Volume 9, Issue 3 (9-2009)
Abstract
Background and Objective: Intradermal Purified Protein Derivative PPD test is a reliable test assessment of primary mycobacterial infection. In this test the specific antigen is Purified Protein Derivative (PPD). The reaction were assessed by touching, the induration's diameter after 48 &48hours. We compared the induration's size 48 and 72 hour in this study. Methods: At this semi experimental study a 5 unit PPD was administered to 120 healthy medical students. Results: The measurements made at 72 h were significantly (4.22 mm) (p<0.001) higher than those made at 48h (2.79 mm). The reading taken at 72 h were 1.47mm larger than at 48 h recovery. There were significant differences between induration size of 48 and 72h between male and female. Conclusion: This study demonstrates that, in adults, the size of the 5 U Monteux reaction is significantly larger at 72h compared to the reaction at 48h. We suggest to read PPD after 72 hours if the PPD is negative after 48 hours.
Parisa Tahmasebi, Fatemeh Maryam Sheikolslami , Parisa Farnia , Majid Sadeghizadeh, Rashid Ramazanzadeh, Mahdi Kazempoor, Mohammadreza Masjedi , Ali Akbar Velayati,
Volume 11, Issue 4 (12-2011)
Abstract
Background & objectives : Amikacin is one of the key second-line drugs for treatment of tuberculosis. Mutations at the codons 1400, 1401and1483 of the 16srRNA gene are associated with resistance to amikacin. The purpose of this study was to detect these mutations using PCR-RFLP method in multi-drug resistant (MDR) strains of Mycobacterium tuberculosis showing resistance to amikacin. Methods : Susceptibility of strains (n=100) against first and second–line anti-tuberculosis drugs was performed by proportional method. Based on antimicrobial resistance pattern 97 strains were analyzed by PCR-RFLP method. rrs1096 and rrs1539 primers were used to amplify a 460bp region of the rrs gene. Then, the PCR products were digested using Tai 1 and Dde1 restriction enzymes. The results were analyzed by the SPSS software using Chi-square test. Results : Based on results from proportional method, 63 strains (64.9%) were MDR (Multiple Drug Resistant), 26 (26.8%) and 8 (8.2%) strains were susceptible and non-MDR, respectively. Also, 13.4% and 6.1% of the strains were XDR (Extensively Drug Resistant) and TDR ( Totally drug resistant ) respectively. Using PCR-RFLP method, 7 (7.2%) strains were resistant and 90 (92.7%) strains were susceptible to amikacin respectively. Moreover, we found that the mutation at the codon 1400 was the most frequent mutations responsible for resistance to amikacin. Conclusion : The PCR-RFLP method can be used as a supplemental method to detect resistance to amikacin however to increase our knowledge, mutatuions in several number of codons in rrs gene need to be studied.
Zahra Derakhshani Nezhad, Fatemeh Maryam Sheikolslami, Parisa Farnia, Zahra Deilami Khiabani, Rashid Ramazanzadeh, Mahdi Kazempoor, Mohammad Reza Masjedi , Ali Akbar Velayati,
Volume 12, Issue 3 (9-2012)
Abstract
Background & Objectives: Ethambutol is one of the four main drugs in treatment of tuberculosis. The most common mutation associated with this drug resistance usually occurs in codon 306 of embB. The aim of this study was to detect ethambutol resistance using Allele-Specific PCR and Spoligotyping in various subtypes of Mycobacterium tuberculosis. Methods : 140 sputum specimens were collected from suspected TB patients. They were digested and decontaminated using Pettrof method before culturing them on LJ medium. Drug susceptibility testing was performed on 106 culture positive specimens using proportional method. DNA was extracted from the isolated organisms and subsequently subjected to Allele-Specific PCR to detect any mutationin embB306. Spoligotyping was then used to determine the subtypes. Results: Out of 106 cultures positive samples, 36 samples (33.9%) showed resistance to ethambutol using proportional method. Allele-Specific PCR assay identified 93 as sensitive and 13 (27.6%) as resistant strains. The results of PCR were in agreement with result of proportional method. The PCR method revealed that 61.5% of mutation occurred in the first and 38.5% in third nucleotides. Spoligotyping differentiated Mycobacterium tuberculosis strains into Beijing (10 9.4%), Bovis (2 1.8%), CAS (24 22.6%), EAI (1 0.9%), Haarlem (27 25.4%), LAM (5 4.7%), Manu (5 4.7%), T (27 25.4%) and U( 2 1,8%) families. The high frequency of mutation in embB gene was belonged to Haarlem, CAS and T subfamilies. Conclusion: Based on results current study, mutations in the genes other than embB might have occurred in the resistant strains that gave negative result in Allele-Specific PCR assay. Therefore other mechanisms of resistance to this antibiotic should be investigated.
Jalil Rashedi, Mohammad Asgharzadeh, Seyed Reza Moaddab, Mojtaba Amani, Mohammad Mazani,
Volume 13, Issue 4 (1-2013)
Abstract
Background & Objectives: It is estimated that one third of the world’s population is infected by M. tuberculosis. Because of differences in immune system activity against the invasive microorganisms, the disease is developed only among 10% of them. Vitamin D metabolism and its receptor activity are important factors in human native immune system against tuberculosis. In the present study we investigated ApaI polymorphism of vitamin D receptor (VDR) gene and association with susceptibility to tuberculosis. Method: This study was performed on 84 cases with tuberclosis (male =50, female =34) and 90 controls (male =49, female = 41). DNA was extracted from cases and controls leucocytes and elected sequences amplified in polymerase chain reaction (PCR) procedure by using specific primers. ApaI polymorphism of VDR gene evaluated by RFLP technique on PCR products. Finally statistical analysis performed using Chi- square to compare genotype frequencies between cases and controls. Results: In case and control groups, AA genotype frequency were 34.5% and 33.3% respectively (OR=0.905, 95% CI 0.469-1.747, p = 0.766) and a genotype frequency in patients and control group were 15.47% and 13.3% respectively (OR=0.808, 95% CI 0.333 –1.961, p=0.637). Conclusion: In the present study we could not find any significant relationship between genotype frequency of ApaI (A/a) polymorphism in VDR gene and susceptibility to tuberculosis.
Samira Sheikh Ghomi , Parisa Farnia , Mojtaba Darbouy ,
Volume 14, Issue 2 (7-2014)
Abstract
Background & objectives: The rapid identification of patients carrying resistant Mycobacterium tuberculosis (M.TB) isolates is important for effective tuberculosis therapy. Unfortunately, during the recent years considerable numbers of isolates showed resistant to Rifampin (RIF) and Isoniazid (INH). The aim of this study was to rapidly identify resistant MTB isolates using molecular method. For this reason, the comparison between real-time PCR based on Taqman and HRM AssayS in detection of rpoB, inhA and katG genes mutation in clinical isolates were performed and analyzed. Methods: The study carried out on Mycobacteriology Research Center (MRC) from 2012-2013. Classical susceptibility testing i.e., proportional method against INH and RIF was performed on eighty three M.TB isolates. Thereafter, multiplex and real-time PCR were performed on extracted DNA sample. The real-time PCR was based on Taqman and HRM assays. Mutation in genes rpoB, inhA and katG were detected. Results: In overall, based on proportional and multiplex PCR method, 47 and 35 isolates were resistant to RIF and INH, respectively. Thirty of strains were resistant to both RIF and INH. The agreement of real-time PCR using Taqman was 88% for resistant and 84% for susceptible isolates, whereas the agreement of HRM was 96% and 30%, respectively. The sensitivity and specificity of Taqman in comparison to multiplex were 84% and 88%, respectively. In addition, the sensitivity and specificity of HRM were 30% and 96%, respectively. Conclusion: Results documented that real-time PCR based on Taqman assay is more sensitive than HRM assay. Additionally, real-time PCR based on Taqman assay is a rapid, accurate and cost effective method in detection of Mycobacterium tuberculosis resistance.
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