Evaluation of tuberculosis transmission in Tehran: using RFLP and spoligotyping methods

OBJECTIVES: To evaluate the DNA polymorphism among Mycobacterium tuberculosis (MTB) strains isolated from new smear positive tuberculosis (TB) patients residing in Tehran capital city of Iran, during the year 2001. METHODS: IS6110-restriction fragment length polymorphism (RFLP) and spoligotyping analyses were performed on 129 M. tuberculosis strains. Additional patient's information was collected for further epidemiological analyses. Patients whose isolates had identical RFLP and spoligotyping patterns were considered a cluster. RESULTS: The results show that the IS6110 were polymorphic and the strains with 8 or 9 IS6110 copy number were more frequently defected (42%). Out of 129 available isolates, 56 (43%) belonged to clusters and 72 (57%) did not. The risk factors like age, sex, family history or close contact and intravenous drug abuse were associated with clustering. Whereas, unemployment (61%) and poor living conditions (83%) contributed to diseases development in both groups. Spoligotyping of M. tuberculosis strains resulted in 46 different patterns, out of which 38 patterns were unique and reported for the first time. We found one M. tuberculosis strains with a pattern characteristic of the Beijing family. CONCLUSION: In the studied time period both reactivation (57%) and recent transmission (43%) were contributing to annual new TB cases in Tehran.     

Study of resistance to anti-tuberculosis drugs in five districts of Equatorial Guinea: rates, risk factors, genotyping of gene mutations and molecular epidemiology.

SETTING: Five districts in Equatorial Guinea, March 1999 to February 2001. OBJECTIVES: To determine tuberculosis drug resistance among new and previously treated cases, the risk factors associated with resistance, and the mutations associated with isoniazid and rifampicin (katG, inhA and rpoB genes) resistance, and to genotype resistant strains. RESULTS: A positive culture identified as Mycobacterium tuberculosis complex was obtained in 240/499 patients. Susceptibility testing was performed in 236 strains. The overall resistance rate in new cases was 16.9% compared to 41.6% in previously treated cases. Isoniazid resistance was the most frequent (respectively 12.5% and 16.6%) in the two groups, while multidrug resistance was observed in 1.7% and 25% of new and previously treated cases, respectively. Female sex was statistically associated with resistance in new cases. Of 41 isoniazid-resistant strains, 33 (80.5%) had mutations in the inhA gene; none had mutations in the katG gene and eight had no mutations in either gene. All strains had low-level isoniazid resistance. Of eight strains resistant to rifampicin, six had mutations in the rpoB gene. Genotyping defined seven clusters. CONCLUSIONS: Moderate resistance was found in new cases. Low-level isoniazid resistance predominated among mutations in the inhA gene, with a high percentage of clustering in resistant strains.     

Clustering of tuberculosis among senegalese immigrants in Italy.

OBJECTIVE: To study clustered Mycobacterium tuberculosis isolates as an indicator of recent TB transmission in a small urban setting in Italy, and to determine associated risk factors. METHODS: M. tuberculosis strains isolated between 1991 and 1997 were characterised by IS6110 restriction fragment length polymorphism (RFLP) analysis. RESULTS: One hundred and ninety-five isolates were available for RFLP analysis, which revealed 163 different patterns. Available cases were represented by 137 Italians (70%), 32 Senegalese (17%), and 26 other foreign-born cases (13%). A unique fingerprint pattern was found in 143 cases (73.3%), while 52 strains (26.7%) were grouped into 20 clusters. Nineteen cases (10%) were resident in the same quarter of Brescia with a high density of Senegalese immigrants (Area A). An increased probability of yielding clustered M. tuberculosis strains was associated with residence in Area A (OR 3.87, 95%CI 1.42-10.56; P = 0.02) and being Senegalese (OR = 5.96, 95%CI 1.48-23.97; P = 0.005). In the logistic regression analysis, being Senegalese was independently associated with yielding a clustered M. tuberculosis strain. CONCLUSIONS: Our results demonstrate a clustering of TB cases among Senegalese immigrants and suggest that RFLP analysis may be used to identify geographical areas where efforts can be targeted to interrupt TB transmission.     

人类免疫缺陷病毒阳性肺结核患者临床分析

目的 提高人类免疫缺陷病毒（ＨＩＶ）阳市肺结核（ＰＴＢ）的认识。方法 对赤道几内亚巴塔医院１９９６年１月～１９９９年１１月确诊的１６８例ＨＩＶ阳性ＰＴＢ进行分析。结果 ＨＩＶ在ＰＴＢ患的感染率由１９９６年的１１．４％升至１９９９年的２２．７％。患多急骤起病（９４．６％）,以近期消瘦（８２．１％）、全身关节酸痛（７８．６％）、皮肤瘙痒（４２．９％）、慢性腹泻（２３．２％）、浅表淋巴结肿大（２０．     

Transmission of tuberculosis in an endemic urban setting in Brazil.

SETTING: Two out-patient facilities in S?o Paulo, Brazil. OBJECTIVE: To study the transmission pattern of tuberculosis (TB) among human immunodeficiency virus (HIV) infected and uninfected persons in a setting endemic for TB. DESIGN: A prospective study comparing HIV-seropositive and -seronegative TB patients identified consecutively between 1 March 1995 and 1 April 1997. The patients were stratified according to their Mycobacterium tuberculosis isolate IS6110 RFLP patterns. Risk factors were sought for infection with an RFLP cluster pattern strain, inferred to represent recent transmission. RESULTS: Fifty-eight (38%) of 151 HIV-seropositive patients and 36 (25%) of 142 HIV-seronegative patients were infected with M. tuberculosis isolates that belonged to cluster patterns (OR 1.84, 95% CI 1.08-3.13). Multidrug-resistant (MDR) strains were isolated from 19 patients, all of whom were HIV seropositive; 12 (63%) of these, and 46 (35%) of 132 drug-susceptible isolates had cluster patterns (OR 3.20, 95% CI 1.08-9.77). CONCLUSION: In a TB-endemic urban setting in Brazil, the proportion of cases resulting from recent transmission appears to be greater among HIV-seropositive than among HIV-seronegative patients. A large proportion of MDR-TB (63%) cases was caused by strains that had cluster RFLP patterns, suggesting recent transmission of already resistant organisms. This type of knowledge regarding TB transmission may help to improve locally appropriate TB control programs.     

Control of tuberculosis in Uganda: a tale of two districts.

SETTING: Rakai and Mbarara districts, south-western Uganda. OBJECTIVE: To compare compliance and other treatment outcomes with tuberculosis (TB) treatment for Rakai and Mbarara districts, and to elucidate factors associated with the disparity. DESIGN: A retrospective cohort analysis of tuberculosis treatment outcomes for the period 1992-1996. Predictors for compliance were examined for 1995 using univariate and multivariate methods. RESULTS: Of the surviving patients, 57% finished treatment in Mbarara compared to 92% in Rakai. Enhanced compliance on univariate analysis was associated with being smear positive; previous TB treatment; use of short-course chemotherapy; return for repeat smear; no change of health unit; no change of district; registration in Rakai; and not being hospitalised. On multivariate analysis, being smear positive, previous TB treatment, hospitalisation and registration site were not significant. The highest risk for default was unit change after the intensive phase of treatment, with an adjusted odds ratio of 17.53. The highest differences in the two districts were for the hospitalisation and unit change rates, with corresponding odds ratios of 52 and 0.06. CONCLUSIONS: Initial hospitalisation of TB patients is not necessary for subsequent completion of treatment. Use of one health unit for both the intensive and continuation phase of treatment may improve compliance.     

Determinants of drug-resistant tuberculosis: analysis of 11 countries.

SETTING: Eleven countries/territories. OBJECTIVES: Global information on the determinants of drug-resistant tuberculosis (TB) based on representative data is not available. We therefore studied the relationship between demographic characteristics, prior TB treatment, and human immunodeficiency virus (HIV) infection with anti-tuberculosis drug resistance. METHODS: Population-based representative data on new and previously treated patients with TB collected within an international drug resistance surveillance network. RESULTS: Of 9,615 patients, 8,222 (85.5%) were new cases of TB and 1,393 (14.5%) were previously treated cases. Compared with new cases, previously treated cases were significantly more likely to have resistance to one (OR = 2.5,95% CI 2.1-3.0; P < 0.001), two (OR = 4.6, 95%CI 3.7-5.6; P < 0.001), three (OR = 11.5, 95%CI 8.6-15.3; P < 0.001), and four (OR = 18.5, 95% CI 12.0-28.5; P < 0.001) drugs. An approximately linear increase in the likelihood of having multidrug-resistant tuberculosis (MDR-TB) was observed as the total time (measured in months) of prior anti-tuberculosis treatment increased (P < 0.001, chi2 for trend). In multivariate analysis, prior TB treatment for 6-11 months (OR = 7.6, 95% CI 2.6, 22.4; P < 0.001) and > or = 12 months (OR 13.7, 95% CI 4.5-41.6; P < 0.001), but not HIV positivity, was associated with MDR-TB. CONCLUSION: This study shows that prior but ineffective treatment is a strong predictor of drug resistance, and that HIV is not an independent risk factor for MDR-TB. The association between length of treatment and drug resistance may reflect longer treatment as a result of treatment failure in patients with drug resistance; it may also reflect irregular prior treatment for TB, leading to drug resistance.     

Identifying pulmonary tuberculosis in patients with negative sputum smear results

BACKGROUND: Clinicians need to decide whether to begin empiric therapy for patients who are suspected of having tuberculosis (TB) but have negative sputum smear results. Culture results may take weeks, and delaying treatment may allow further transmission of disease. Study objective: To identify the clinical, demographic, and radiographic characteristics that identify smear-negative patients who have TB, and to create a TB prediction rule. DESIGN: Retrospective chart review. SETTING: University-affiliated public hospital in San Francisco, CA, between 1993 and 1998. PATIENTS: Forty-seven patients with TB and 141 control patients who were hospitalized with a suspicion of pulmonary TB; all had negative sputum smear results. Measurements and results: Demographic, clinical, and radiographic variables were determined by chart review. In multivariate analysis, a positive tuberculin skin test result (odds ratio [OR], 4.8; 95% confidence interval [CI], 2.0 to 11.9) was independently associated with an increased risk of a positive TB culture finding. A radiographic pattern not typical of pulmonary tuberculosis (OR, 0.3; 95% CI, 0.1 to 0.7) and expectoration with cough (OR, 0.3; 95% CI, 0.1 to 0.6) were predictive of a decreased risk. An interaction between HIV seropositivity and mediastinal lymphadenopathy on the chest radiograph was also associated with a positive TB culture result (OR, 7.2; 95% CI, 1.4 to 36.0). The TB prediction score (TPS) was created with widely ranging likelihood ratios that could affect the posterior probability of TB by 30-fold. CONCLUSION: The TPS put into context with the overall prevalence of TB in a given area may help clinicians decide if a patient with negative sputum smear results should start empiric antituberculous therapy or wait for culture results. These results need prospective validation.     

Genetic analysis of mycobacterium tuberculosis strains isolated in Ural region, Russian Federation, by MIRU-VNTR genotyping.

SETTING: The Ural region in Russia is one of the areas most affected by a high incidence of tuberculosis (TB). Molecular epidemiological studies able to trace Mycobacterium tuberculosis transmission are of particular significance. OBJECTIVE: To characterize the population of M. tuberculosis strains circulating in the Ural region, to detect the predominant genotypes and to evaluate their phylogenetic relationship and epidemiological significance. DESIGN: Ninety-two M. tuberculosis clinical samples originating from the Ural region were genotyped using the MIRU-VNTR method. RESULTS: Two major phylogenetically distinct groups of isolates were identified: the W-Beijing family (54.3%) and a previously unreported cluster, named the Ural group (15.2%). Forty-seven different MIRU profiles were identified, including 38 unique (41.3%) and 54 isolates grouped into nine clusters (from 2 to 28 isolates in each cluster). Genetic diversity within the clusters was shown by additional sub-typing of M. tuberculosis isolates in nine additional QUB-VNTR loci. CONCLUSION: W-Beijing family isolates are associated with multiresistance to anti-tuberculosis drugs. It is possible that the strains of this family play a significant role in the spread of multidrug-resistant TB over the Ural region.     

Implementation and evaluation by a population-based RFLP analysis in an urban area, Shinjuku city, Tokyo--the possibility of application for contact investigations

OBJECTIVES: The objectives were to examine Mycobacterium tuberculosis transmission patterns by RFLP analysis in Shinjuku city, and to elucidate more effective methods of contact investigations. METHODS: We applied RFLP analysis to 389 M. tuberculosis isolates from 402 TB patients registered in Shinjuku city from September 2002 though August 2006. RESULTS: Forty-six clusters consisting of 155 TB patients (average 3.4 people per cluster) were identified (proportion of clustering: 39.8%). The clustering rates were 34.5% among general patients, and 57.8% among homeless patients, and the latter was higher than that of non-homeless patients (odds ratio: 2.6, 95% CI; 1.6-4.1, p < 0.001). On the other hand, the clustering rates were only 19.4% among foreigners (odds ratio: 0.5, 95% CI; 0.2-1.2, p = 0.090). Twenty-eight of 46 clusters (60.9%) were consisted of mixture of general patients, homeless patients and foreigner patients. Thus, RFLP analysis can detect the transmission route which can not be identified by the routine contact examination, thus enabling contact investigations extended to the appropriate persons. DISCUSSION: The homeless clustering rate was significantly high. This suggests that the proportion of transmission among the homeless patients might be high. However, many clusters were composed of a mixture of homeless patients and non-homeless patients, so transmission patterns are not easy to identify. It is not always true that transmission of tuberculosis to non-homeless patients took place from homeless patients. Clustering rates among homeless patients are high, therefore taking countermeasures for the homeless patients is an effective way to prevent the spread of tuberculosis. Introduction of RFLP analysis is a practical epidemiological methodology to investigate the source of infection and transmission route of infection, and can be applied to contact investigations. If RFLP analysis can be applied in a larger area, yearly changes of notification rates and molecular epidemiological clustering rates will provide indices for preventive measures against tuberculosis.     

Impact of sputum gross appearance and volume on smear positivity of pulmonary tuberculosis: a prospective cohort study

ABSTRACT: BACKGROUND: Although checking specimen quality upon sputum collection for acid-fast smear of suspected tuberculosis (TB) cases is recommended, this procedure is based on expert opinion. The purpose of this study was to elucidate the impact of sputum gross appearance and volume on smear positivity among patients with suspected pulmonary TB, according to sex. METHODS: From November 2010 through June 2011, we enrolled consecutive patients suspected to have active pulmonary TB. The association of sputum gross appearance and volume with smear positivity, along with other variables possibly affecting smear positivity such as symptoms, disease extent, and cavity on chest radiograph, were investigated. RESULTS: Among 2,439 patients undergoing TB examination, 170 (113 men, 57 women) with active pulmonary TB were enrolled in the final analysis. They submitted 492 sputa. There were 73 smear-positive patients (42.9%) and 164 smear-positive sputa (33.3%). While gross appearance was associated with smear positivity in both sexes (purulent or blood-tinged sputum (rather than mucoid sputum or saliva); odds ratio (OR), 2.05, 95% confidence interval (CI), 1.21-3.47 in men; OR, 2.78, 95% CI, 1.23-6.26 in women), the amount of sputum specimens was associated with smear positivity in only female patients (4 ml or more versus less than 4 ml; OR, 4.96, 95% CI, 1.98-12.37). CONCLUSIONS: Sputum gross appearance and volume were associated with smear positivity. A volume of 4 ml seems to be the the minimum sputum volume acceptable for smear microscopy in females suspected of TB. Those suspected of TB should be encouraged to expectorate grossly qualified sputum specimens.     

Predictors of persistent airway stenosis in patients with endobronchial tuberculosis.

SETTING: The university and municipal hospitals in Seoul, Korea. OBJECTIVE: To evaluate the predictors of persistent airway stenosis following anti-tuberculosis chemotherapy in patients with endobronchial tuberculosis (TB). DESIGN: Diagnosis of TB was confirmed by microbiology or histopathology. Bronchoscopic examinations revealed that patients had endobronchial lesions compatible with endobronchial TB. Study subjects had at least one follow-up bronchoscopy to evaluate their treatment response. Treatment response was determined by changes in the degree or extent of airway stenosis between the first and last bronchoscopic examinations. RESULTS: Sixty-seven subjects were recruited retrospectively from Seoul National University Hospital and Seoul National University Boramae Hospital. Persistent bronchostenosis occurred in 41.8% of the patients. In multivariate regression analysis, age >45 years (OR 3.65), pure or combined fibrostenotic subtype (OR 5.54) and duration from onset of chief complaint to the initiation of anti-tuberculosis chemotherapy >90 days (OR 5.98) were identified as independent predictors of persistent airway stenosis. Oral corticosteroids (prednisolone equivalent >or=30 mg/d) did not reduce the frequency of persistent airway stenosis. CONCLUSION: Early diagnosis and early administration of anti-tuberculosis chemotherapy before involvement of the deeper airways is important to prevent the development of unwanted sequelae of bronchostenosis.     

Tuberculosis control of urban areas in Japan

The rates of tuberculosis remain high in urban areas. The declining speed of tuberculosis incidence rate in urban areas has been slower than other areas. Efforts and resources to tuberculosis control must be concentrated on urban locations to eradicate tuberculosis in Japan. 1. Tuberculosis control in a public health center of urban area: Teru OGURA and Chiyo INOGUCHI (Toshima City, Ikebukuro Public Health Center, Tokyo Metropolitan) A wide range of TB control measures is implemented by public health centers, such as a patient registration, home-visit guidance, contact examination in urban areas. Directors of every health center have the direct responsibility for tuberculosis control measures in their jurisdiction. Ikebukuro is urban areas where there are many offices, shopping and amusement facilities. Urban people is often on the move looking for job, so public health centers are often not easy to carry out contact examinations as planned. In recent years, homelessness has been recognized as a growing urban social problem. Their incidence of tuberculosis is high. Special TB control program must be carried out in urban areas. 2. Tuberculosis Control in Tokyo Metropolitan: Kazumasa MATSUKI (Department of Infectious Diseases and Tuberculosis, Bureau of Public Health, Tokyo Metropolitan) There has been a steady decline in the TB wards. The beds for TB patients are running short and even smear positive TB cases cannot be put in a hospital without waiting several days. Staffs of an urban emergency department must protect tuberculosis infection by environmental controls of emergency room. Tokyo Metropolitan government supports the engineering improvements of emergency room to hospitals. Directly observed therapy for tuberculosis patients at a district has been implemented to complete their therapy. On DOT, a trained health worker observes the patient take anti-TB medication. 3. Usefulness of Molecular Epidemiologic approach on Tuberculosis Control: Atsushi HASE (Osaka City Institute Laboratory of Health and Environment) DNA fingerprinting establishes the genetic relatedness of Mycobacterium tuberculosis isolates and has become a powerful tool in tuberculosis epidemiology. To use DNA fingerprinting to assess the efficacy of current tuberculosis infection-control practices. Combining conventional epidemiologic techniques with DNA fingerprinting of M. tuberculosis can improve the understanding of how tuberculosis is transmitted. Patients were assigned to clusters based on mycobacterial isolates with identical DNA fingerprints. Clusters were assumed to have arisen from recent transmission. We analyzed M. tuberculosis isolates from patients reported to the tuberculosis registry by RFLP techniques. These results were interpreted along with demographic data. Patients infected with the same strains were identified according to their RFLP patterns, and patients with identical patterns were grouped in clusters. RFLP patterns of high incidence districts have more variations than other areas. This suggests that the source of tuberculosis infection are quite diverse and complicated. Tuberculosis patients may accumulate to high incidence districts from other places after infection. 4. Structure of High Incidence of Tuberculosis and Control Plan in Osaka City: Yoichi TATSUMI (Bureau of Infection Control, Osaka City Office) The case notification rate in Osaka City is the highest in Japan. That of all TB cases and smear positive TB cases was 1573 and 216 per 100,000 population in 1997 at Airin District in Osaka City. The main reason for this highest incidence rate is that there are many homeless people and it is a mobile population. Most of residents are daily laborers. They come from all over Japan and stay there, mainly in rented rooms, to look for jobs. Thousands of homeless people also live in tents on streets or in parks. We are making to new strategic plan to intensify tuberculosis control measures throughout the city. Osaka city government h     

Drug resistance of Mycobacterium tuberculosis in selected urban and rural areas in Bangladesh

The magnitude of anti-tuberculosis drug resistance in Bangladesh is not precisely known. We studied the drug resistance patterns of Mycobacterium tuberculosis in an urban and a rural area of Bangladesh. A tuberculosis (TB) surveillance system has been set up in a population of 106,000 in rural Matlab and in a TB clinic in urban Dhaka. Trained field workers interviewed all persons > or =15 y at Matlab to detect suspected cases of tuberculosis (cough >21 d) and sputum samples were examined for acid-fast bacilli (AFB). The first 3 AFB positive patients daily from the urban clinic were included. AFB positive cases diagnosed between June 2001 and June 2003 from both settings were cultured and drug susceptibility tests were performed. Of 657 isolates, resistance to 1 or more drugs was observed in 48.4% of isolates. Resistance to streptomycin, isoniazid, ethambutol and rifampicin was observed in 45.2%, 14.2%, 7.9% and 6.4% of isolates, respectively. Multidrug resistance was observed in 5.5% of isolates. It was significantly higher among persons who previously had received tuberculosis treatment of > or =1 month (15.4% vs 3.0%, adjusted OR: 6.12, 95% CI: 3.03-12.34). The magnitude of anti-tuberculosis drug resistance in Bangladesh is high. Further evaluation is needed to explain the high proportion of streptomycin resistant M. tuberculosis. Appropriate measures to control and prevent drug resistant tuberculosis in Bangladesh to reduce mortality and transmission are warranted.     

An alarming rate of drug-resistant tuberculosis at Ngwelezane Hospital in northern KwaZulu Natal, South Africa.

OBJECTIVE: To obtain a profile of tuberculosis (TB) cases caused by Mycobacterium tuberculosis in northern KwaZulu Natal (KZN) for 2001. METHOD: The demographic and drug resistance characteristics were determined. A total of 251 smear and culture confirmed cases was obtained and the resistance of three major anti-tuberculosis drugs was tested using the proportion method. RESULTS: The patients were mainly from Ngwelezane (57.8%), Stanger (23.5%) and Manguzi (18.7%); 59.0% were male; 54.2% of the isolates were obtained from new TB patients. The mean age of the TB patients was 29.6 years, with the maximum notification age range at 25-34 years. A high prevalence of drug-resistant and multiresistant TB was observed in this region. At least 55% of previously treated and 19% of new cases from all areas were resistant to at least one of the drugs tested. New patients from Ngwelezane and Manguzi area had a high prevalence of any rifampicin resistance (11.0%) and ethambutol resistance (3.9%), respectively. CONCLUSION: Our results indicate that the TB epidemic in northern KZN, especially in Ngwelezane, is severe. An infrastructure to educate stakeholders about the need to ensure consistency in treatment is needed.     

Management of pulmonary tuberculosis in Tajikistan: which factors determine hospitalization?

Objective To assess predictors for tuberculosis hospitalization and treatment outcome in Tajikistan. Methods Stratified, single stage cluster sample survey of 1495 adult patients with pulmonary TB during 2 calendar years (2005–2006) from the registries of 10 TB centres chosen by simple random sampling. The primary outcome was referral to hospital. Logistic regression was conducted to test associations with the study outcome using linearization and a variance formula. Results Prevalence of hospitalization for tuberculosis was 58%. The odds of patients with smear‐positive tuberculosis being referred were three times those of smear‐negative patients [OR 2.99 (95% CI 1.81–4.96)]. Other predictors for hospitalization were the availability of TB hospital beds within the same district [OR 2.15 (95% CI 1.22–3.76)] and male gender [OR 1.46 (95% CI 1.07–2.48)]. The overall treatment success was 80%. Conclusions Hospitalization of patients with pulmonary tuberculosis was determined by positive sputum smear, supply of hospital beds, and gender. Reducing hospitalization with support of national guidelines is not expected to have a negative impact on treatment outcome and spread of disease, but could lead to improved efficiency and effectives of health service delivery for pulmonary tuberculosis in Tajikistan.     

河南省第二轮结核病耐药监测及耐药趋势研究

目的掌握河南省2001年结核病耐药水平,评价1996—2001年耐药趋势,为结核病控制决策提供参考。方法采用整群抽样随机抽取30个监测点,各监测点连续入选43个新涂阳病人,同时纳入其间的复治涂阳病例。痰涂片镜检采用Ziehl-Neelsen法,培养用L-J培养基。对培养阳性的菌株用TCH和PNB进行菌型鉴定。对四种抗结核药物:INH,RFP,EMB和SM采用比例法进行药敏试验。结果总耐药率、初始耐药率及获得性耐药率分别为35.3%,29.8%和60.8%;总MDR率、初始MDR率和获得性MDR率分别为:12.9%,7.8%和36.6%。2001年河南省总耐药率、初始耐药率及总MDR率、初始MDR率较之1996年有所下降,但获得性耐药率及获得性MDR率变化不明显。结论河南省结核病耐药率仍处于全国5个监测省份之首和全球前几位,应引起高度重视。同时提示河南省需采取得力措施落实DOTS策略。     

Control of anti-tuberculosis drug resistance in Botswana.

SETTING: Botswana, where in 2000 the prevalence of human immunodeficiency virus (HIV) infection among adults was 38%, and the tuberculosis (TB) rate was 591/100,000. A 1995-1996 survey demonstrated low levels of anti-tuberculosis drug resistance. OBJECTIVE: Because TB drug resistance may increase rapidly in HIV-infected populations, a second survey was undertaken in 1999 to determine any increase in anti-tuberculosis drug resistance. DESIGN: Sputum specimens positive for acid-fast bacilli from patients without prior TB treatment (new patients), and all sputum specimens from patients reporting prior TB treatment (retreatment patients) were collected nationwide. Specimens were cultured for Mycobacterium tuberculosis and tested for resistance to isoniazid, rifampicin, ethambutol, and streptomycin. RESULTS: From January to May 1999, 783 patients were consecutively enrolled from all districts. Of these, 483 (61.7%) were male, the median age was 33 years, and 82% were new patients. Drug resistance occurred in 6.3% of new patients (95 % confidence interval [CI] 4.6-8.6) and 22.8% of retreatment patients (95% CI 16.5-30.1). Resistance to at least isoniazid and rifampicin was found in 0.5% of new (95% CI 0.1-1.3) and 9.0% of retreatment patients (95% CI 5.1-14.5). CONCLUSION: Anti-tuberculosis drug resistance remains relatively low in Botswana, probably as a result of a well-functioning TB program. Periodic surveys will be essential to adequately determine any significant trend.     

Tuberculosis in Calgary, Canada, 1995-2002: site of disease and drug susceptibility.

SETTING: A centre managing all tuberculosis (TB) cases in the population of the Calgary region in Canada. OBJECTIVE: To facilitate the diagnosis and management of TB by examining the distribution of TB by site of disease and the prevalence and pattern of drug-resistant Mycobacterium tuberculosis in a north American setting. DESIGN: A retrospective analysis of data collected at the time of diagnosis of all TB cases recorded during the 8-year period 1995-2002. Data collected included demographic information, site of disease, method of diagnosis and M. tuberculosis drug susceptibility. RESULTS: During the 8-year period, 435 cases of TB were diagnosed: 49% had exclusively extra-pulmonary disease. Lymph node disease (usually cervical) accounted for 44% of the extra-pulmonary cases. A culture of M. tuberculosis resistant to at least one first-line anti-tuberculosis drug was detected in 16% of the initial isolates. All of the resistant strains were found in foreign-born patients and resistance was more common in patients from Asia (19%) and in previously treated patients (26%). CONCLUSION: Extra-pulmonary TB is common in the foreign-born population in the Calgary region, and this pattern may be more widespread than is realised. Drug-resistant strains of TB were more common in foreign-born and previously treated patients.     

Prevalence of intestinal parasite infections with special reference to Entamoeba histolytica on the island of Bioko (Equatorial Guinea)

The prevalence of intestinal parasitic infections was assessed (1993 through 1995) among two different groups of persons on the island of Bioko, Equatorial Guinea. In the first group, parasitologic examinations were performed on stool specimens from a household-based sample of 557 dwellers from the rural area of the island. In the second group, 1,633 inpatients and outpatients at the General Hospital of Malabo (the capital of the country) were studied. All age groups were represented in both groups. The average prevalence of the most common protozoan and helminthic intestinal infections in rural and urban areas, respectively, was as follows: Entamoeba histolytica/E. dispar (14.9% and 32.7%, respectively), Giardia lamblia (7.2% and 8.6%), Ascaris lumbricoides (45.8% and 31.4%), and Trichuris trichiura (25.7% and 36.4%). Seventy-nine sera from patients with amebic liver abscess (suspected by ultrasonography) were studied by an immunohemagglutination assay, with 44 (56%) showing anti-E. histolytica titers > or = 1:32. Of these 79 sera, 71 were studied by an enzyme immunoassay, 86% of which were positive with titers > or = 1:64. This study showed that parasitic infections in Equatorial Guinea represent a major health problem.