Prevalence and risk factors associated with tuberculin skin test positivity among household contacts of smear-positive pulnionary tuberculosis cases in Umerkot, Pakistan.

STUDY POPULATION AND SETTING: Household contacts of acid-fast bacilli (AFB) sputum smear-positive tuberculosis patients in the Umerkot Taluka, Sindh, Pakistan. OBJECTIVE: To estimate the prevalence of and identify risk factors associated with tuberculin skin test (TST) positivity among household contacts of acid-fast bacilli (AFB) sputum smear-positive pulmonary tuberculosis cases. DESIGN: A cross-sectional study of household contacts of AFB sputum smear-positive tuberculosis cases, registered at the Umerkot Anti-Tuberculosis Association clinic from August 1999 to September 1999. The contact's Mycobacterium tuberculosis infection status was assessed using TST. On the day of the TST, a pre-designed questionnaire was administered to collect data on putative risk factors for TST positivity among contacts. The data were analysed using a marginal logistic regression model by the method of generalised estimating equations (GEE) to determine risk factors independently associated with TST positivity. RESULTS: The prevalence of TST positivity among household contacts of AFB sputum smear-positive index patients was 49.4%. The final multivariate GEE model showed that contact's age and sleeping site relative to the index case, the intensity of the index case's AFB sputum-smear positivity and the contact's BCG scar status were independent predictors of TST positivity among household contacts of AFB sputum smear-positive index cases. CONCLUSIONS: The results suggest that the household contacts of AFB sputum smear-positive tuberculosis patients in a poor neighbourhood of rural Sindh had a high prevalence of M. tuberculosis infection as determined by TST. Poor housing conditions seem to contribute to the spread of M. tuberculosis infection. Early diagnosis of pulmonary TB through evaluation of TST-positive household contacts, followed by appropriate therapy, may prevent further spread of M. tuberculosis infection. We recommend an awareness programme to prevent household contacts from acquiring M. tuberculosis infection from smear-positive pulmonary TB cases.     

A comparative study of clinico-radiological spectrum of tuberculosis among HIV seropositive and HIV seronegative patients

BACKGROUND: A study to determine the prevalence of human immunodeficiency virus (HIV) infection among tuberculosis patients and to compare the clinico-radiological spectrum of tuberculosis among HIV seropositive and seronegative patients was carried out in the Department of TB and Chest Diseases, CSM Medical University, Lucknow (Uttar Pradesh), India. METHODS: A total of 1105 radiologically and/or bacteriologically confirmed patients of tuberculosis were screened for HIV infection during the years 1995 to 1997 and from 2000-2001. RESULTS: Out of a total 1105 patients screened, 31(2.8%) were found to be HIV seropositive. Tuberculin positivity was less among HIV seropositive patients as compared to HIV seronegative patients (22.6% vs 76.4%; p < 0.001). There was no statistically significant difference in sputum smear positivity for acid-fast bacilli (AFB) among HIV seropositive and seronegative patients. Among HIV seropositive patients, mid and lower zone involvement, exudative lesions and mediastinal lymphadenopathy was more common as compared to the seronegative patients. CONCLUSION: HIV seropositivity rates among tuberculosis patients was 2.8 percent. The presentation of tuberculosis was more often atypical among these patients.     

Number of negative acid-fast smears needed to adequately assess infectivity of patients with pulmonary tuberculosis

STUDY OBJECTIVES: To investigate the relationship between the number of negative acid-fast bacilli (AFB) smear results and infectivity of pulmonary tuberculosis (TB). DESIGN: Retrospective analysis. METHODS AND SUBJECTS: We examined 122 index cases in Harris County, TX, reported in 1998 and 1999. All cases had only negative AFB smear results during the infectious period and were categorized in two groups: group A consisted of cases with only one or two sputum specimens collected and processed, and group B consisted of cases with at least three sputum specimens or at least one bronchoscopic specimen. Tuberculin skin test (TST) results of contacts were ascertained from the results of contact investigations performed by the City of Houston Department of Health and Human Services, Tuberculosis Control Division. Univariate and multivariate analyses were done to explore index case and contact attributes associated with tuberculosis (TB) transmission using positive TST results of contacts as a measure of recent transmission. RESULTS: We found male gender and younger age of index cases along with Hispanic ethnicity of contacts to be independently associated with positive TST results, while younger contacts were less likely to be TST positive. Smear category of the index case (group A vs group B) was not independently associated with transmission. We also found that the first two sputum specimens in cases where three or more were performed yielded 90% of all positive culture results for Mycobacterium tuberculosis (MTB). CONCLUSIONS: We conclude that two sputum specimens negative for AFB stain are adequate for both assessing infectivity and for isolating MTB from patients with pulmonary TB.     

某监测哨点住院结核患者人类免疫缺陷病毒(HIV)感染状况

目的通过哨点监测住院结核患者中HIV感染和发病状况。方法对住院结核病连续病例常规采用HIV血清抗体ELISA法初筛,阳性者抽血复验,并送省疾病控制中心HIV检测中心进行免疫印迹试验(WB)确认。结果本哨点3年间共对3345例住院结核患者进行了HIV筛查,其中男性2 257例(67.5%),女性1 088例(32.5%);平均年龄(41.1±13.0)岁;职业以农民为主,占64.5%,其次是行政管理、技术人员,占24.6%,商业服务者占10.1%,学生占0.8%。入院时肺结核患者3274例,其中涂阳肺结核患者598例(18.3%),涂阴肺结核患者2676例(81.7%)。初治结核患者1 057例(32.3%),复治2 217例(67.7%)。共检出HIV血清阳性者2例,均为男性;年龄分别为49和40岁;2人均为性传播感染,HIV感染率为0.06%。结论住院结核病患者中HIV感染率接近全国平均0.05%的感染水平。     

Treatment results of DOTS in 1797 Sudanese tuberculosis patients with or without HIV co-infection.

SETTING: Consecutive new tuberculosis (TB) patients, from eight states in Sudan, who had never been previously treated for as much as 1 month between 1998 and 2000. OBJECTIVE: To determine the impact of human immunodeficiency virus (HIV) co-infection on tuberculosis treatment outcome. DESIGN: All patients presenting with symptoms suggestive of tuberculosis underwent sputum microscopy for acid-fast bacilli (AFB). Treatment is free of charge, and directly observed for all smear-positive patients. Treatment outcomes were those defined by the World Health Organization. All patients were tested anonymously for human immunodeficiency virus (HIV) using the Bionor test. RESULTS: Of 10 494 patients suspected of TB and referred for sputum microscopy, 1797 were TB cases; 983 had smear-positive pulmonary tuberculosis, 521 smear-negative pulmonary tuberculosis, and 293 extra-pulmonary tuberculosis. Smear-positive cases showed a cure rate of 77.2% and a failure rate of 1%. Smear-negative and extra-pulmonary patients had a completion rate of 79.4%. Cure rates for the smear-positive cases were 68.3% for HIV-positive and 77.6% for HIV-negative patients (P = 0.164). Case fatality was significantly higher among HIV-positive (12%) than among HIV-negative cases (1.8%) (OR 7.7, 95% CI 3.51-16.8). CONCLUSION: To date, a relatively low proportion of tuberculosis patients in Sudan also have HIV infection. These patients are substantially more likely to die while on treatment for their tuberculosis, a fact that underlines their need for more comprehensive care if their lives are to be prolonged. In addition, every effort is required to diminish the transmission of HIV infection to prevent the tragedy this infection represents to the community.     

Induced sputum improves the diagnosis of pulmonary tuberculosis in hospitalized patients in Gaborone, Botswana

SETTING: Low sensitivity of acid-fast bacilli (AFB) sputum smears and absence of productive cough are obstacles to the diagnosis of pulmonary tuberculosis (PTB) in hospitals that lack access to bronchoscopy. OBJECTIVES: To evaluate induced sputum, gastric content, blood and urine specimens to improve PTB diagnosis in patients not diagnosed by expectorated sputum AFB smears. DESIGN: Patients admitted to the medical wards of a large public hospital in Gaborone, Botswana, were prospectively enrolled if they had symptoms consistent with PTB, an abnormal chest radiograph, were treated empirically with anti-tuberculosis chemotherapy or had no improvement on antibiotics, and had a non-productive cough or AFB smear-negative sputum. Induced sputum was stained for AFB and Mycobacterium tuberculosis cultures were performed on induced sputum, gastric contents, urine and blood. RESULTS: Of 140 patients meeting the enrollment criteria, 113 (81%) were human immunodeficiency virus (HIV) positive. Fifty-seven (41%) had PTB based on positive cultures from one or more sites, including 48 (84%) from induced sputum, 17 (30%) urine, 13 (23%) gastric contents and 7 (12%) blood. AFB smears were positive in only 18 (32%) culture-proven PTB cases. CONCLUSION: Induced sputum cultures greatly enhanced M. tuberculosis detection in patients with a high prevalence of HIV/AIDS in a hospital without access to bronchoscopy.     

The value of bronchial lavage in patients with radiologically suggestive pulmonary tuberculosis with no sputum production and gastric lavage smear negativity

We assessed whether acid-fast bacilli (AFB) investigation in bronchial lavage (BL) contributes to diagnosis in patients with gastric lavage smear negative and radiologically suggestive of pulmonary tuberculosis. Eighty-three patients were recruited for the study, five cases were excluded due to diagnosis of inactive disease or non-tuberculosis disease. The remaining 78 patients were evaluated. All patients were unable to expectorate sputum and their gastric lavages were negative for AFB. BL was performed for the detection of Mycobacterium tuberculosis in all patients. Bronchial lavage smear were positive in 15.4%(12 patients). BL culture positivity was 58.3%(42 patients) and gastric lavage culture positivity was 33.3%(26 patients). Eighteen cases had both gastric lavage and BL culture positivity. BL culture was positive in 24 cases who had gastric lavage culture negativity. We suggest that in cases who do not produce sputum and whose gastric lavage smears are negative; BL should be performed for diagnosis of pulmonary tuberculosis.     

Delayed diagnosis of tuberculosis in patients with human immunodeficiency virus infection

PURPOSE: To determine the frequency with which the diagnosis of tuberculosis is delayed in patients with concomitant human immunodeficiency virus (HIV) infection, and to identify reasons for such delays. PATIENTS AND METHODS: We reviewed medical records of 52 consecutive HIV-infected patients with culture-proven tuberculosis seen at a 1,900-bed general hospital serving a predominantly indigent population in Los Angeles, where the prevalences of HIV infection and tuberculosis are high. The late-treatment (LT) group consisted of 25 patients in whom tuberculosis was untreated prior to death (n = 6) or treated more than 22 days after presentation (n = 19). The early-treatment (ET) group comprised 27 patients in whom antituberculous therapy was begun less than 16 days after presentation. RESULTS: Symptoms, physical and laboratory findings, chest roentgenographic abnormalities suggestive of tuberculosis (hilar adenopathy, pleural effusion, miliary pattern, cavitation, predominant upper lobe infiltrate), and frequencies of concomitant nontuberculous disease were similar in LT and ET groups. Delayed diagnosis of tuberculosis was attributable to errors in management in 21 (84%) of 25 LT group patients. The most common error was failure to obtain at least three sputum samples for acid-fast smear and mycobacterial culture in patients with clinical and chest roentgenographic findings compatible with tuberculosis (15 cases). Acid-fast sputum smears were positive in 25 (61%) of 41 cases of pulmonary tuberculosis. Acid-fast smears of stool were positive in eight (42%) of 19 cases. Blood cultures yielded Mycobacterium tuberculosis in 18 (38%) of 48 cases. CONCLUSIONS: Delayed therapy of tuberculosis in HIV-infected patients at our medical center was common and was not due to atypical manifestations of tuberculosis. In most cases, delays could have been avoided if adequate numbers of sputum samples for acid-fast smear and mycobacterial culture had been obtained, and if empiric antituberculous therapy had been given to symptomatic patients in whom chest roentgenographic findings were suggestive of mycobacterial disease.     

A study on family infection of tuberculosis

The guideline for contacts examination and chemoprophylaxis for tuberculosis was revised in 1993. Secondary cases and chemoprophylaxis cases found by the contacts examination of family members were analyzed in Sapporo City. The average age of index cases and of secondary cases has become higher. Many secondary cases were found among spouse of the index case and children of male index case. Chemoprophylaxis cases were found mostly among children of male or female index cases and grandchildren of male index cases. The results of family contacts examination carried out during the period from 1994 to 1999 were compared with those from 1987 to 1992. The incidence of family infection of tuberculosis and the number of newly infected persons and of secondary cases have decreased in the latter period. The time interval from the registration of the index case to the detection of secondary cases has become shorter, and the ratio of sputum smear positive cases among secondary cases has also decreased. Male to female ratio of the index cases was 2:1, that of secondary cases was 3:5, and that of children indicated chemoprophylaxis was 4:5. All secondary cases found by the contacts examination carried out within 6 months after the previous examination were sputum smear negative for tubercle bacilli, and there were a few smear positive cases among secondary cases who were found by the examination with longer interval with the previous examination. Such cases with longer interval from the last periodic examination was found often among younger cases below 40 years of age. Most smear negative tuberculosis cases were found by the family contacts examination, while most smear positive cases were found by symptomatic visit to doctors.     

肺结核患者痰抗酸杆菌检出阳性率的影响因素

目的探讨肺结核患者痰涂片抗酸杆菌阳性检出率的影响因素。方法 79803份痰标本、3750份纤支镜灌洗液标本分别采用直接涂片镜检法和液基集菌法检出的阳性率进行分析。结果采用液基集菌法涂片后痰液的抗酸杆菌阳性检出率提高2.94%,纤支镜灌洗液的抗酸杆菌阳性检出率提高8.22%。同样方法获取的标本使用液基集菌法对纤支镜灌洗液涂片中抗酸杆菌阳性检出率的提高明显大于痰标本。结论痰涂片阳性检出率的提高,除与标本检测方法有关外,合格的痰液标本是提高抗酸杆菌阳性检出率的重要影响因素。     

117例HIV／AIDS病人合并肺结核的临床特点

目的分析艾滋病病毒（HIV）感染者／艾滋病（AIDS）病人合并肺结核的临床特点,提高诊疗水平。方法对1997年7月至2011年7月间,住院的HIV／AIDS合并肺结核的病人,回顾分析其末梢血CD＋T淋巴细胞（简称CD4细胞）计数与结核菌素纯蛋白衍生物试验（PPD试验）、痰涂片、结核抗体以及纤维支气管镜灌洗液涂片的关系。结果117例病人中,cD。细胞计数〈50个／mm3时,PPD试验无阳性反应,痰涂片阳性率为20．0％（3／15）,结核抗体阳性率为26．7％（4／15）;CD4细胞计数在50～200个／mm3时,PPD试验阳性率为25．0％（16／64）,痰涂片阳性率为40．6％（26／64）,结核抗体阳性率为35．9％（23／64）;CD4细胞计数在200～500个／mm3时,PPD试验阳性率为55．3％（21／38）,痰涂片阳性率为60．5％（23／38）,结核抗体阳性率为52．6％（20／38）,其中65例痰涂片阴性患者经纤维支气管镜灌洗液涂片有29例（44．6％）抗酸杆菌阳性;CD4细胞计数〉500个／mm3时,痰涂片阳性率为71．4％（5／7）,结核抗体阳性率为57．1％（4／7）。结论CD4细胞计数在500个／mm3以上时,痰涂片阳性率、结核抗体阳性率与HIV阴性肺结核检测相近,CD4细胞计数在200个／mm3以下时,临床表现较为复杂,数值越低合并肺结核症状越重,PPD试验反应、痰涂片、结核抗体以及纤维支气管镜灌洗液涂片阳性率越低。     

Use of mycobacterial smears in the diagnosis of pulmonary tuberculosis in AIDS/ARC patients

Pulmonary tuberculosis in AIDS/ARC patients is an increasing problem. To assess the utility of acid-fast smears of pulmonary secretions in this patient population, we evaluated 38 AIDS/ARC patients with culture-positive pulmonary infection. A control group consisted of 57 non-AIDS/ARC patients, who also did not belong to an AIDS risk group, diagnosed during the same period. The number of culture-positive sputum samples evaluated per patient was similar in both groups (3.82 +/- 3.11 AIDS/ARC vs 4.47 +/- 2.83 control group). Significantly fewer AIDS/ARC patients, 45 percent, however, had a positive acid-fast smear compared with the control group, 81 percent (p less than 0.001). The initial sputum smear submitted was positive in only 29 percent of the AIDS/ARC group compared with 61 percent of control subjects (p less than 0.01). Further, greater than or equal to 5 negative smears were found in 60 percent of the evaluable AIDS/ARC patients compared with just 13 percent of control subjects (p less than 0.01). More extensive findings on chest roentgenograms were not associated with a significantly higher yield of smear positivity in the AIDS/ARC group. We conclude that acid-fast smears on sputum specimens are a relatively insensitive test for pulmonary tuberculosis in AIDS/ARC patients.     

Yield of bronchoscopy for the diagnosis of tuberculosis in patients with human immunodeficiency virus infection.

The efficacy of bronchoscopy for the diagnosis of tuberculosis in patients infected with human immunodeficiency virus (HIV) has not been systematically evaluated. We therefore compared the diagnostic yield of bronchoscopy in 67 HIV-infected and 45 non-HIV-infected patients with culture-proven pulmonary tuberculosis. In all cases, acid-fast smears of sputum were negative or not obtained prior to bronchoscopy. Prebronchoscopic sputum culture yielded Mycobacterium tuberculosis in 34 (89 percent) of 38 HIV-infected patients and 26 (93 percent) of 28 non-HIV-infected patients from whom specimens were obtained. Bronchoscopy provided an early diagnosis of tuberculosis (positive acid-fast smear or granulomata on biopsy) in 23 (34 percent) of the HIV-infected patients and 20 (44 percent) of the patients without HIV infection. The sensitivities of the acid-fast smear and of mycobacterial culture of bronchoscopic specimens and postbronchoscopic sputum were similar in patients with or without HIV infection. In HIV-infected patients, granulomatous inflammation was noted on transbronchial biopsy in 11 (19 percent) of 59 patients with HIV infection, compared to 16 (43 percent) of 37 patients without HIV infection (p = 0.01). Nevertheless, transbronchial biopsy provided the exclusive means for an early diagnosis of tuberculosis in six (10 percent) of 59 HIV-infected patients. We conclude that the yield of bronchoscopy for the diagnosis of pulmonary tuberculosis in HIV-infected patients is similar to that in patients without HIV infection, and that transbronchial biopsy provides incremental diagnostic information not available from evaluation of sputum or bronchoalveolar lavage fluid.     

HIV/AIDS合并非结核分枝杆菌肺病97例临床分析

目的 探讨HIV/AIDS合并非结核分枝杆菌(nontuberculosis mycobacteria, NTM)肺病的临床特点,以提高诊疗水平. 方法 对我院2009—2012年97例HIV/AIDS合并NTM肺病患者进行回顾性分析. 结果 97 例中咳嗽 93 例(95.88%),咳痰88例(90.72%),气喘71例(73.20%),发热70例(72.16%),消瘦69例(71.13%),乏力58例(59.79%),胸痛 47 例(48 . 45%),腹泻36例(37.11%). HIV感染途径为性乱史64例(65.98%),静脉吸毒史26例(26.80%),输血史2例(2.06%),不详5例(5.15%). 胸部影像学表现以双肺中下叶多见,多为左下肺受累,形态多种多样,并容易形成空洞及支气管扩张样改变,可见胸膜病变. 结论 HIV/AIDS合并NTM肺病的临床症状、胸部影像学表现、痰涂片、PPD试验和结核抗体检查酷似肺结核,在痰培养结果未回报前,临床上二者鉴别诊断非常困难.患者通常合并多处浅表淋巴结肿大,反复痰涂片抗酸杆菌阳性. 痰培养药物敏感性试验提示对一线抗结核药物耐药率高,应引起临床足够重视.     

An outbreak of tuberculosis caused by multiple-drug-resistant tubercle bacilli among patients with HIV infection.

OBJECTIVE: To evaluate a nosocomial outbreak of tuberculosis caused by multiple-drug-resistant bacilli among patients with tuberculosis and HIV infection. DESIGN: A case-control study. PATIENTS: Patients with HIV infection and culture-proven tuberculosis. MEASUREMENTS: Patient characteristics, date of diagnoses of HIV infection and disease, date of diagnosis of tuberculosis, Mycobacterium tuberculosis susceptibility results, and medical center contact. RESULTS: Sixty-two patients who had tuberculosis caused by multiple-drug-resistant bacilli (cases) and 55 patients who had tuberculosis caused by susceptible or single-drug-resistant bacilli (controls) were identified. Controls were more likely to be black (odds ratio, 0.4; 95% CI, 0.2 to 0.9) or Haitian (odds ratio, 0.2; CI, 0.1 to 0.6) compared with cases, who were more likely to be homosexual men (odds ratio, 2.9; CI, 1.3 to 6.4). Forty-four cases (71%) had previous contact with an HIV clinic compared with 15 controls (27%) (P less than 0.0001). Cases were more likely to have had AIDS (odds ratio, 7.7; CI, 1.5 to 53.7), to have been hospitalized on an HIV ward (odds ratio, 8.3; CI, 2.3 to 29.7), to have been seen in an HIV clinic (odds ratio, 7.8; CI, 3.4 to 18.1), to have received intravenous therapy in an HIV clinic (odds ratio, 13.0; CI, 4.6 to 37.0), or to have received inhalation pentamidine in an HIV clinic before a diagnosis of tuberculosis was made. Multiple logistic regression analysis showed that a diagnosis of AIDS (odds ratio, 11.2; CI, 3.1 to 40.6) and HIV clinic visits (odds ratio, 13.0; CI, 2.7 to 63.7) before a diagnosis of tuberculosis were significantly associated with tuberculosis caused by multiple-drug-resistant bacilli. Using susceptibility patterns and appointment dates, we found that 22 cases had previous contact with a person who had tuberculosis caused by multiple-drug-resistant bacilli in the HIV clinic. CONCLUSIONS: Nosocomial transmission of M. tuberculosis from other HIV-infected patients with tuberculosis caused by multiple-drug-resistant bacilli can occur. These findings have serious public health implications and demand strict adherence to acid-fast bacilli isolation precautions.     

Integration of tuberculosis screening at an HIV voluntary counselling and testing centre in Haiti

OBJECTIVE: To describe the integration of tuberculosis screening into the activities of an HIV voluntary counselling and testing (VCT) centre in a country with endemic tuberculosis. SETTING: An HIV VCT centre in Port au Prince, Haiti. DESIGN: All patients presenting for HIV VCT who reported cough received same-day evaluation for active tuberculosis. Of the 1327 adults presenting to the centre for the first time between January and April 1997, 263 (20%) reported cough and of these 241 (92%) were evaluated. RESULTS: Of the 241 patients evaluated for cough, 76 (32%) were diagnosed with pulmonary tuberculosis. Of the 76 patients diagnosed with pulmonary tuberculosis, 28 (37%) had a positive smear for acid-fast bacilli (AFB), 14 (18%) had a negative AFB smear but a positive sputum culture for Mycobacterium tuberculosis, and 34 (45%) had culture-negative tuberculosis. Also, 31 out of 241 (13%) VCT clients evaluated for cough were diagnosed with bacterial pneumonia. CONCLUSION: This report confirms that in areas with a high HIV and tuberculosis prevalence, a high proportion of VCT clients have active pulmonary tuberculosis. The integration of tuberculosis screening offers several benefits, including the diagnosis and treatment of large numbers of individuals with tuberculosis, a decreased risk of nosocomial tuberculosis transmission, and the opportunity to provide tuberculosis prophylaxis to HIV-positive patients in whom tuberculosis has been excluded. Future studies are needed to determine the cost-effectiveness of integrated tuberculosis and HIV VCT services, and whether integration should be recommended in all countries with high HIV and tuberculosis rates.     

Detection of Mycobacterium tuberculosis in bronchoalveolar lavage from patients with sputum smear-negative pulmonary tuberculosis using a polymerase chain reaction assay

Abstract The objective of this study was to evaluate the utility of a polymerase chain reaction (PCR) assay in detecting Mycobacterium tuberculosis in bronchoalveolar lavage (BAL) specimens of patients suspected of having active pulmonary tuberculosis (TB) but who were sputum smear-negative. Patients undergoing investigation for suspected pulmonary TB at the University Hospital, Kuala Lumpur, and who were sputum smear-negative underwent fibreoptic bronchoscopy and BAL. One portion of each lavage specimen was submitted for smear examination for acid-fast bacilli and mycobacterial culture and the other portion assayed by PCR for the presence of a 562-base pair DNA segment belonging to the insertion sequence IS986, unique to the M. tuberculosis complex. As controls, lavage specimens from patients with other lung lesions were also similarly tested. The PCR assay gave a positivity rate of 80.9% (55 of 68) compared with 8.8% of smear examination and 7.4% of culture for detecting M. tuberculosis in BAL specimens. The assay was positive in two of 45 BAL specimens from 35 control subjects. The PCR assay was more sensitive than smear and culture in detecting M. tuberculosis in BAL specimens of patients with sputum smear-negative pulmonary TB.     

The value of contact procedures for tuberculosis in Edinburgh

We have reviewed the value of routine contact procedures (CP) in screening for tuberculosis in the Edinburgh area. Nine hundred and forty-seven index cases were notified during the 5-year period 1977-81; of these, 131 (14%) were detected by CP, 78 had previously undetected tuberculous disease and a further 53 required chemoprophylaxis (CPX). None had presented with symptoms, and disease was consequently detected at an earlier stage with fewer being sputum smear positive (10% vs 29% P less than 0.01). The 131 cases were found by CP during the screening of 4445 contacts, an overall yield of 2.9%. The highest yield was 18% for close contacts of sputum smear positive index cases, the yield for the casual contact being only 3%. The overall yield for contacts of smear negative respiratory and non-respiratory index cases was less than 2% in each group. Young contacts were particularly vulnerable and the yield in Asian children was 10.2%, twice that of the 4.9% in non-Asian children (P less than 0.001). The incidence of new cases in contacts who had previous BCG vaccination was significantly lower than that in non-vaccinated contacts (1.15% vs 3.06% P less than 0.001) suggesting a protective effect of 62%. One hundred and twenty-five (95%) of the 131 new cases were diagnosed within 3 months of first attendance, the remaining 5% at 6 months. The workload involved in screening contacts in this series could have been halved by restricting CP to all contacts of sputum smear positive index cases and only the close contacts of all other index cases. This would have resulted in missing 18% of the new cases, or three cases of tuberculosis and two cases requiring CPX per year, in a population of 608 000. Seventy-two (7.6%) of the 947 index cases were of Asian origin. Their disease occurred more in young adults, especially women, and was more frequently extrapulmonary in site (25% vs 12% in non-Asians P less than 0.01). We conclude that contact procedures remain valuable in the detection of new, asymptomatic cases of tuberculosis in Edinburgh and, by implication, in other urban areas of the United Kingdom. Particular efforts should be directed towards children, Asians and those without BCG vaccination, especially if they have been in contact with sputum smear positive index cases.     

HIV co-infection, CD4 cell counts and clinical correlates of bacillary density in pulmonary tuberculosis.

BACKGROUND: Sputum microscopy for acid-fast bacilli (AFB) is the commonest diagnostic method for pulmonary tuberculosis (PTB) in developing countries. The method is reported to be less sensitive in human immunodeficiency virus (HIV) positive compared to negative patients. We determined the bacillary density in sputum of smear-positive PTB patients and related it to the patients' HIV status, CD4 cell count, clinical and demographic characteristics. METHODS: Three sputum samples per patient were examined using microscopy before initiating therapy. The AFB density was graded according to World Health Organization recommendations. The smear with the highest density was used. High bacillary density was defined as >10 AFB/field. HIV status and CD4 cell count were determined according to the national guidelines. RESULTS: Of 844 patients, 433 (51.3%) were HIV-positive. High bacillary density was significantly less common among HIV-positive (39.0%) than -negative (75.7%) patients (prevalence ratio 0.52; 95%CI 0.45-0.59, P < 0.0001). Among HIV-positive patients, the proportion of those with high bacillary density increased progressively with CD4 cell counts (P = 0.003). CONCLUSION: HIV is associated with lower AFB concentration in sputum. The AFB density falls with falling CD4 cell count. Microscopy for AFB in sputum may be less sensitive in diagnosing PTB when HIV infection is present, especially in severely immunocompromised patients.     

23例艾滋病合并结核病患者的临床特点

目的探讨艾滋病合并结核病的临床特点、治疗及预后.方法对1997年～2004年7月间我院收治的23例艾滋病合并结核病的患者进行临床分析.结果 23例患者多为青壮年(94.3%),半年内病死11例(47.8%).人类免疫缺陷病毒(HIV)感染途径以性乱史(15例,占65.2%)为主.持续1个月以上的临床表现有发热、体重下降5～15 kg 者23例(100%),咳嗽15例(65.2%).多并发多种机会性感染.23例患者中以单纯肺结核14例(60.9%)及淋巴结结核8例(34.8%)为主;12例浸润型肺结核患者X线表现为病灶多位于双肺,多为较均匀一致的片絮状阴影,无一例出现空洞.蛋白纯化衍生物(PPD)试验弱阳性2例(8.7%),痰涂片、痰培养查抗酸杆菌仅1例阳性(4.4%).23例患者治疗前CD+4明显低于其他未合并结核病的艾滋病患者(P<0.05);而23例中,病死患者治疗前CD+4也较存活患者明显降低(P<0.05).23例患者的HIV RNA定量值明显高于未合并结核病的艾滋病患者(P<0.05).23例患者中,同时采用抗结核及抗HIV病毒药物治疗的患者,病死率较两种药物均未采用或单用抗结核药物治疗的患者明显降低(P<0.05).结论艾滋病合并结核病患者PPD试验阳性率低,肺结核X线表现不典型,淋巴结结核较多见,病死率高;治疗前CD+4明显降低,且与病死率相关;结核分枝杆菌感染可促进HIV病毒的复制;临床应尽可能同时进行抗结核与抗HIV病毒治疗.