Transmission of tuberculosis from smear negative patients: a molecular epidemiology study

BACKGROUND: While smear positive patients with tuberculosis (TB) are considered more infectious than smear negative patients, the latter can also transmit TB. METHODS: In a molecular epidemiology study of 791 patients in the Greater Vancouver regional district, the number of episodes of TB transmission from two groups of smear negative clustered patients by RFLP (assumed to be involved in recent transmission) was estimated after assessing for potential bias. Group 1 (n = 79) included patients with pulmonary TB or pulmonary + extrapulmonary disease (PTB or PTB+EPTB); group 2 (n = 129) included all patients in group 1 + extrapulmonary cases alone. RESULTS: In the total sample the mean (SD) age was 51 (21) years, 54.3% were male, and 17.0% of patients were clustered. Compared with smear negative patients, smear positive patients were more likely to be in a cluster (OR = 2.0, 95% CI 1.1 to 3.6) and to have had a history of ethanol abuse (OR = 2.7, 95% CI 1.0 to 6.7), diabetes mellitus (OR = 2.8, 95% CI 1.1 to 7.0), injection drug use (OR = 3.1, 95% CI 1.1 to 8.3), and to have had a previous hospital admission (OR = 8.5, 95% CI 5.1 to 14.0). The proportion of episodes of transmission from smear negative clustered patients ranged from 17.3% to 22.2% in group 1 and from 25% to 41% in group 2. CONCLUSION: In Greater Vancouver, smear negative cases appear responsible for at least one sixth of culture positive episodes of TB transmission.     

Current evidence on diagnostic accuracy of commercially based nucleic acid amplification tests for the diagnosis of pulmonary tuberculosis

BACKGROUND: Even though commercial nucleic acid amplification tests (NAATs) have become the most frequently used molecular tests for laboratory diagnosis of pulmonary tuberculosis (TB), published studies report variable estimates of their diagnostic accuracy. We analysed the accuracy of commercial NAATs for the diagnosis of pulmonary TB in smear positive and smear negative respiratory samples using culture as a reference standard. METHODS: English language studies reporting data sufficient for calculating sensitivity and specificity of commercial NAATs on smear positive and/or smear negative respiratory samples were included. Meta-regression was used to analyse associations with reference test quality, the prevalence of TB, sample and test type. Predictive values for different levels of pre-test probability were quantified using Bayes' approach. RESULTS: Sixty three journal articles published between 1995 and 2004 met the inclusion criteria. Pooled sensitivity and specificity were 0.96 and 0.85 among smear positive samples and 0.66 and 0.98 among smear negative samples. The number of culture media used as reference test, the inclusion of bronchial samples, and the TB prevalence were found to influence the reported accuracy. The test type had no effect on the diagnostic odds ratio but seemed to be correlated with sensitivity or specificity, probably via a threshold effect. CONCLUSIONS: Commercial NAATs can be confidently used to exclude TB in patients with smear positive samples in which environmental mycobacteria infection is suspected and to confirm TB in a proportion of smear negative cases. The methodological characteristics of primary studies have a considerable effect on the reported diagnostic accuracy.     

酶联免疫斑点法在快速诊断活动性肺结核中的应用

目的探讨酶联免疫斑点法（ELISPOT）在临床快速诊断活动性肺结核病中的应用价值。方法：采用T—SPOT．TB试剂盒对36例明确诊断为活动性肺结核的初治患者、30例健康体检者的外周血中结核分枝杆菌特异性T淋巴细胞进行检测,同时对26例活动性肺结核患者做结核菌素（PPD）试验。结果在36例活动性肺结核初治患者和30例健康对照者中,T-SPOT检测的阳性率分别为80．6％与6．7％,此技术用于诊断初治活动性肺结核患者的敏感性为80．6％,特异性为93．3％,阳性预测值为93．5％,阴性预测值为80．0％。在26例同时做PPD试验的活动性肺结核患者中,T-SPOT检测的阳性率略高于PPD试验（80．6％vs61．5％）,但差异无明显统计学意义（P〉0．05）。结论酶联免疫斑点法是一种具有较高敏感性和特异性的检测结核感染的技术,在活动性肺结核病的快速诊断中有较大应用价值。     

Pulmonary tuberculosis among political asylum seekers screened at Heathrow Airport, London, 1995-9

BACKGROUND: Over 50% of cases of tuberculosis (TB) in the UK occur in people born overseas, and new entrants to the country are screened for TB. A study was undertaken to determine the prevalence and disease characteristics of pulmonary TB in new entrants to the UK seeking political asylum. METHODS: A retrospective analysis of the results of screening 53 911 political asylum seekers arriving at Heathrow Airport between 1995 and 1999 was performed by studying Airport Health Control Unit records and hospital medical records. Outcome measures were chest radiograph abnormalities, sputum smear, culture, and drug resistance data for Mycobacterium tuberculosis. RESULTS: The overall prevalence of active TB in political asylum seekers was 241 per 100 000. There were large variations in prevalences of TB between asylum seekers from different regions, with low rates from the Middle East and high rates from the Indian subcontinent and sub-Saharan Africa. The frequency of drug resistance was high; 22.6% of culture positive cases were isoniazid resistant, 7.5% were multidrug resistant (resistant to both isoniazid and rifampicin), and 4% of cases diagnosed with active disease had multidrug resistant TB. CONCLUSIONS: The prevalence rate of TB in political asylum seekers entering the UK through Heathrow Airport is high and more M tuberculosis isolates from asylum seekers are drug resistant than in the UK population. Extrapolating these figures, it is estimated that 101 political asylum seekers with active pulmonary TB enter the UK every year, of whom about 25 would have smear positive disease.     

Mycobacterium tuberculosis infection in renal transplant recipients

Mycobacterium tuberculosis (TB) infection is more common among renal allograft recipients compared with the general population due to immunosuppression. The epidemiological risk in a country is an important determinant of transplant TB after transplantation. We retrospectively analyzed 283 renal transplant recipients who underwent renal transplantation between 1990 and 2004. We evaluated the incidence, patient and disease characteristics, prognosis, and outcome of TB infection. Tuberculosis developed in 10 (seven men and three women of mean age of 41+/-9 years) among 283 patients (3.1%). All patients were culture-positive for M tuberculosis. Although pulmonary TB was the most common presentation in the general population, 50% of patients in the study group developed extrapulmonary TB. The mean elapsed time from renal transplantation was 38 months. Three patients (1%) developed TB in the first year after transplantation. All patients were treated with a quartet of anti-TB therapy. One patient developed isoniazid-related reversible hepatotoxicity. No acute allograft rejection occurred during the anti-TB therapy. Two patients (20%) with pulmonary TB died due to dissemination of the disease. In conclusion, extrapulmonary presentations of TB are more common among renal transplant recipients with the increased risk of mortality.     

Suspected pulmonary tuberculosis in rural South Africa--sputum induction as a simple diagnostic tool?

OBJECTIVES: To assess the value of sputum induction (SI) as a diagnostic tool for patients with suspected pulmonary tuberculosis (PTB) who are unable to expectorate or who have a negative sputum smear. DESIGN: Study of an inpatient cohort undergoing SI. SETTING: Mseleni Hospital, a rural district hospital in northern KwaZulu-Natal. SUBJECTS: All adult patients with suspected TB seen at the hospital over a 4-month period. OUTCOME MEASURES: (i) Successful SI; (ii) sputum acid-fast smear result; (iii) change of admission diagnosis as a result of the induction procedure; and (iv) number of patients discharged with a diagnosis other than TB who represented within 4 months with TB. RESULTS: A total of 51 patients (31 female) underwent SI; of these 36 (71%) were able to produce a sputum sample. Fifteen (42%) of those were acid-fast smear-positive (29% of all patients included). The admission diagnosis was changed in 16 (44%) of the patients who were able to give an induced sputum sample as opposed to 4 (27%) who had been unable to expectorate despite an induction attempt (P = 0.38). Three (12.5%) of the 24 patients with a discharge diagnosis other than TB (17 pneumonia, 3 old TB, 2 carcinoma of the lung, 1 bronchiectasis) turned out to have TB within the follow-up period; 2 of those had extrapulmonary TB. CONCLUSION: SI produced a positive smear result in 29% of patients with suspected TB who had previously been smear-negative or unable to expectorate. The method proved an aid to clinical decision making.     

血液结核分枝杆菌液体培养在HIV感染者结核筛查中的应用评价

目的评价血液结核分枝杆菌液体培养对HIV感染者活动性结核病的诊断价值。方法 2006年8月至2008年7月,对广西省4个诊疗机构中HIV感染者进行包括临床、胸片、痰涂片、痰快速结核分枝杆菌培养和血液快速结核分枝杆菌培养在内的综合筛查以诊断活动性结核。分析结核分枝杆菌血培养在HIV感染者中的总体阳性率和在不同CD4水平患者中的阳性率,总结血培养阳性的结核病患者的临床特点,探讨血培养对结核的诊断价值。结果 602例HIV感染者在结核筛查时进行了血液结核分枝杆菌培养,7例检出结核分枝杆菌菌血症,血结核分枝杆菌培养在HIV感染者中的总体阳性率为1.2%。在CD4计数〈200/μl、〈100/μl和〈50/μl患者组中,血培养阳性率分别为1.4%、1.8%和2.4%,逐渐增高。共诊断活动性结核133例,其中结核分枝杆菌菌血症的阳性率为5.3%。血培养阳性的结核患者中位CD4仅为17/μl,均有明确的肺部影像学改变,2例有粟粒样表现,6例同时行痰结核分枝杆菌培养,其中5例（83%）阳性,5例患者伴有明确的肺外结核。与无结核分枝杆菌菌血症的结核/HIV合并感染者相比,有结核分枝杆菌菌血症的患者BMI和CD4计数较低,盗汗症状更常见。结论血液快速结核分枝杆菌培养在广西HIV感染者中的阳性率总体较低,但随着患者免疫缺陷的加重,阳性率逐渐增高。本研究中有结核分枝杆菌菌血症的HIV感染者均有明显肺部病变,且痰培养的阳性率高,提示结核分枝杆菌血培养对提高HIV感染者中结核的诊断率作用可能有限。     

Frequency of dual tuberculosis/human immunodeficiency virus infection in patients presenting at tertiary care centers at karachi

Objective: To determine the frequency of dual infection of Tuberculosis and Human Immunodeficiency Virus (HIV) and document the sexual practices of infected patients. Design: Cross-sectional study. Place and Duration of Study: Medical Unit-IV of Civil Hospital, Karachi, Pakistan, in collaboration with Sindh AIDS Control Program at Services Hospital, Karachi, from January 2003 to December 2004. Patients and Methods: Patients were recruited in the study at both centers and tested for both HIV and TB if any one disease was identified. Diagnosis of TB was based on positive sputum AFB smear / caseous granulomatous lesion on histopathology. Diagnosis of HIV was based on positive anti-HIV serology by LISA technique. A questionnaire was also administered to all the study participants regarding demographics, sexual practices, blood transfusion and intravenous drug abuse. Results: A total of 196 patients of HIV and TB were screened for the presence of dual infection (TB/HIV). Dual infection was present in 38 (19.39%) of patients. Out of 126 patients of HIV, evidence of TB was detected in 38 (30.16%). During the same duration, 70 patients of tuberculosis were screened for HIV and none was tested positive for HIV. History of illicit sexual relationship was found in 121 (96.03%) patients and 5 of these were homosexuals. Conclusion: Dual infection was present in patients of HIV with TB but vice versa was not documented in this study.     

Induced sputum and bronchoscopy in the diagnosis of pulmonary tuberculosis

BACKGROUND: Previous studies suggest that bronchoscopy and a single induced sputum sample are equally effective for diagnosing pulmonary tuberculosis. METHODS: In a prospective study of subjects with possibly active pulmonary tuberculosis, the diagnostic yield of three induced sputum tests was compared with that of bronchoscopy. Subjects either produced no sputum or (acid fast) smear negative sputum. Bronchoscopy was only performed if at least two induced sputum samples were smear negative. RESULTS: Of 129 subjects who completed all tests, 27 (21%) had smear negative and culture positive specimens, 14 (52%) on bronchoscopy and 26 (96%) on induced sputum (p<0.005). One patient was culture positive on bronchoscopy alone compared with 13 on induced sputum alone; 13 were culture positive on both tests. Induced sputum positivity was strikingly more prevalent when chest radiographic appearances showed any features of active tuberculosis (20/63, 32%) than when appearances suggested inactivity (1/44, 2%; p<0.005). Induced sputum costs were about one third those of bronchoscopy, and the ratio of costs of the two tests per case of tuberculosis diagnosed could be as much as 1:6. CONCLUSIONS: In subjects investigated for possibly active or inactive tuberculosis who produce no sputum or have smear negative sputum, the most cost effective strategy is to perform three induced sputum tests without bronchoscopy. Induced sputum testing carries a high risk of nosocomial tuberculosis unless performed in respiratory isolation conditions. The cost benefits shown could be lost if risk management measures are not observed.     

Drug therapy in spinal tuberculosis

Although the discovery of effective anti-tuberculosis drugs has made uncomplicated spinal tuberculosis a medical disease, the advent of multi-drug-resistant Mycobacterium tuberculosis and the co-infection of HIV with tuberculosis have led to a resurgence of the disease recently. The principles of drug treatment of spinal tuberculosis are derived from our experience in treating pulmonary tuberculosis. Spinal tuberculosis is classified to be a severe form of extrapulmonary tuberculosis and hence is included in Category I of the WHO classification. The tuberculosis bacilli isolated from patients are of four different types with different growth kinetics and metabolic characteristics. Hence multiple drugs, which act on the different groups of the mycobacteria, are included in each anti-tuberculosis drug regimen. Prolonged and uninterrupted chemotherapy (which may be ‘short course’ and ‘intermittent’ but preferably ‘directly observed’) is effective in controlling the infection. Spinal Multi-drug-resistant TB and spinal TB in HIV-positive patients present unique problems in management and have much poorer prognosis. Failure of chemotherapy and emergence of drug resistance are frequent due to the failure of compliance hence all efforts must be made to improve patient compliance to the prescribed drug regimen.

     

Analysis of DQB1 allele frequencies in pulmonary tuberculosis: preliminary report

BACKGROUND: The human leucocyte antigen (HLA) system plays an important role in the modulation of the immune response. An association between HLA and pulmonary tuberculosis (TB) has been examined in several populations but the results have been inconsistent. The aim of this study was to evaluate the correlation of DQB1 alleles with TB patients and healthy controls in the same ethnic group in Poland. METHOD: The DQB1 alleles of 38 patients with TB and 58 healthy university staff volunteers were determined by a PCR-SSP low resolution method. RESULTS: The DQB1*05 allele occurred more frequently (p adjusted for multiple comparison=0.002, OR=2.84, 95% CI 1.57 to 5.15) and the DQB1*02 allele occurred less frequently (p=0.01, OR=0.39, 95% CI 0.21 to 0.71) in patients with TB than in controls. The occurrence of DQB1*03,*04,*06 alleles was similar in the two populations. CONCLUSIONS: The occurrence of specific DQB1 alleles may be linked to susceptibility/resistance to tuberculosis.     

初治涂阳肺结核合并糖尿病标准治疗与短程治疗的临床评价

目的比较初治涂阳肺结核合并糖尿病标准治疗与短程治疗的临床疗效,为有效治疗措施提供理论依据。 方法自1997年1月至2007年1月,将1 286例初治涂阳肺结核合并糖尿病患者作为研究对象,根据自愿原则,将所有患者分为标准治疗方案组（观察组）724例和短程治疗方案组（对照组）562例。观察两组患者不同时间段血糖、痰菌转阴率以及X线病灶吸收好转情况。 结果与对照组比较,观察组患者在T1～3时间段的FPG、2 h PG均显著降低,痰菌转阴率分别为78.31%、96.54%和98.76%（χ² = 3.86、6.64、6.91,P = 0.049、0.015、0.038）以及X线病灶吸收好转率分别为23.07%、55.11%和95.17%,且差异均具有统计学意义（χ²= 12.36、13.17、14.25,P = 0.004、0.001、0.027）。 结论标准治疗可较好地改善初治涂阳肺结核合并糖尿病患者的血糖,提高痰菌转阴率,促进X线病灶吸收好转。     

结核感染T细胞斑点试验在骨与关节结核诊断中的价值

目的探讨结核感染T细胞斑点试验(T-SPOT TB)在临床诊断骨与关节结核的应用价值。方法收集154例疑似骨与关节结核患者外周抗凝血标本,依据细菌学检验、病理学结果及临床表现判定有无结核分枝杆菌感染;其中确诊骨与关节结核73例,非结核感染81例,分别进行T-SPOT TB和结核抗体(TB-Ab)检测,并分析T-SPOT TB在骨与关节结核诊断中的敏感度和特异度。结果 73例确诊骨与关节结核中,64例T-SPOT TB阳性;81例非结核中,72例T-SPOT TB阴性;T-SPOT TB检测敏感度为87.67%(64/73),TB-Ab为41.10%(30/73),T-SPOT TB诊断骨与关节结核的敏感度显著高于TB-Ab(P0.001);T-SPOT TB检测特异度为88.89%(72/81),TB-Ab为71.60%(58/81),T-SPOT TB特异度也高于TB-Ab(P=0.006)。在结核组中,涂阳与涂阴两组T-SPOT TB阳性检出率分别为95.45%(21/22)及86.49%(32/37),差异无统计学意义(P0.05)。在结核组中,病理诊断阳性率92.16%(47/51)与T-SPOT TB总阳性率87.67%(64/73)比较差异无统计学意义(P0.05)。结论 T-SPOT TB在诊断骨与关节结核中具有良好的敏感度和特异度,具有重要临床应用价值。     

Isolated spleen tuberculosis in an immunocompetent patient,a rare case report

IntroductionTuberculosis (TB), as a major public health concern, is affecting almost 10 million people globally. At present, diagnostic and screening efforts mainly focus on positive smear results. Therefore, the number of extra pulmonary and negative sputum TB is rising and hampering the diagnosis and treatment process due to the large number of false negatives. Rare cases such as solitary splenic TB are usually seen in patients with splenic abnormalities, spleen trauma, immunosuppression, sickle cell disease, pyogenic infections, etc.Presentation of caseA 40-year-old female with no comorbidity came with chief complaint of early satiety every mealtime and epigastric pain in the last 6 months prior to admission. There was no significant positive examination except for positive IGRA test and enlargement of spleen with multiple cystic lesions on abdominal CT. We performed laparotomy with splenectomy followed by a histopathology examination which showed features of primary tubercular abscess.DiscussionIn the immunocompromised patient, the visceral abdomen is usually involved and a part of miliary TB. However, this case revealed the rare possibility of a healthy person with primary isolated tubercular splenic abscess while being immunocompetent and lacking any comorbidity.ConclusionSplenic TB diagnosis is difficult in patients lacking pulmonary involvement and without specific symptoms. Thorough examinations and clinical expertise are needed to provide accurate diagnosis and treat uncommon forms of TB and cases with negative smear results in consideration of rising prevalence and difficult disease control.     

Resource implications of patients with multidrug resistant tuberculosis

BACKGROUND: Multidrug resistant tuberculosis (MDR TB) requires a complex drug regimen and lengthy multidisciplinary care. The financial cost of successful management of each case is potentially large. METHODS: The costs of managing nine HIV negative patients with pulmonary MDR TB were compared with 18 age group and ethnicity matched controls with fully sensitive disease. Calculations included: cost of outpatient visits and inpatient stays including negative pressure isolation; costs of drug provision and toxicity monitoring; costs of additional procedures and multidisciplinary referrals. RESULTS: The mean cost of managing a case of pulmonary MDR TB was in excess of 60,000 pounds sterling and for sensitive disease it was 6040 pounds sterling. CONCLUSIONS: Clinicians and healthcare commissioning authorities may both be underestimating the costs of managing MDR TB, and accordingly the consequences for units dealing with such cases may be serious. Funding of care for MDR TB in the UK requires strategic decisions at regional or governmental level.     

Evaluation of a diagnostic algorithm for smear-negative pulmonary tuberculosis in HIV-infected adults.

OBJECTIVES: To evaluate the diagnostic accuracy of and reduction in diagnostic delay attributable to a clinical algorithm used for the diagnosis of smear-negative pulmonary tuberculosis (SNPTB) in HIV-infected adults. DESIGN: An algorithm was designed to facilitate clinicoradiological diagnosis of pulmonary TB (PTB) in HIV-infected smear-negative adult patients. A folder review was performed on the first 58 cases referred for empirical TB treatment using this algorithm. SETTING: Nolungile HIV Clinic, Site C, Khayelitsha. SUBJECTS: Subjects included 58 HIV-infected adult patients with suspected PTB consecutively referred to the local TB clinic for outpatient TB treatment using this algorithm between 12 February 2004 and 30 April 2005. OUTCOME MEASURES: Outcome measures were response of C-reactive protein, haemoglobin, weight and symptoms to TB treatment, and TB culture result. Diagnostic delay (in days) was calculated. RESULTS: Thirty-two of the 58 patients (55%) had positive TB cultures (definite TB). Initiation of TB treatment occurred on average 19.5 days before the positive culture report. A further 21 patients (36%) demonstrated clinical improvement on empirical treatment (probable/possible TB). Two patients did not improve and subsequently died without a definitive diagnosis. Three patients defaulted treatment. CONCLUSIONS: SNPTB is more common in HIV-infected patients and leads to diagnostic delay. This algorithm allowed for earlier initiation of TB treatment in HIV-infected patients presenting with symptoms of PTB and negative smears or nonproductive cough in a high TB incidence setting.     

馆陶县2012至2014年初治涂阳肺结核患者分枝杆菌培养及耐药

目的调查本县初治涂阳肺结核患者分枝杆菌培养及耐药情况,为分析结核病的防治措施提供依据。 方法选择2012-2014年于本县医院诊治的初治涂阳肺结核患者,在对其进行分枝杆菌培养的基础上,将阳性菌株送至本市相关实验室进行菌种鉴定以及药物敏感性分析。 结果本研究中共收治562例初治涂阳肺结核患者,其中性别比男︰女= 2.23︰1,平均年龄（41.2±3.7）岁;菌群类别：结核分枝杆菌492株（87.54%）,非结核分枝杆菌70株（12.46%）。敏感株为448株（79.72%）,耐药菌株为114株（20.28%）,其中耐多药菌株为36株（6.41%）,单耐药患者以耐链霉素（S）为常见（5.34%）,其次为耐异烟肼（称H）（4.63%）。多耐药中以至少耐异烟肼、链霉素（HS）为常见（22/562,3.91%）,其次为耐异烟肼、利福平（耐HR）（3.73%）。多耐药中耐两药者16例（2.85%）,耐3药者17例（3.02%）,耐4药者3例（0.53%）。耐药顺序为S > H > R > E。 结论中青年男性为肺结核防治的高危人群,需要对其进行密切防控。本县结核分枝杆菌复合群菌株的耐药率虽不高,但初治涂阳患者存在耐多药,需要进一步改进结核病的防控工作。     

No association between interferon-gamma receptor-1 gene polymorphism and pulmonary tuberculosis in a Gambian population sample

BACKGROUND: Tuberculosis (TB) is a major global cause of mortality and morbidity, and host genetic factors influence disease susceptibility. Interferon-gamma mediates immunity to mycobacteria and rare mutations in the interferon-gamma receptor-1 gene (IFNGR1) result in increased susceptibility to mycobacterial infection, including TB, in affected families. The role of genetic variation in IFNGR1 in susceptibility to common mycobacterial diseases such as pulmonary TB in outbred populations has not previously been investigated. METHODS: The association between IFNGR1 and susceptibility to pulmonary TB was investigated in a Gambian adult population sample using a case-control study design. The coding and promoter regions of IFNGR1 were sequenced in 32 patients with pulmonary TB, and the frequencies of six common IFNGR1 polymorphisms were determined using PCR based methods in 320 smear positive TB cases and 320 matched controls. Haplotypes were estimated from the genotype data using the expectation-maximisation algorithm. RESULTS: There was no association between the IFNGR1 variants studied and TB in this Gambian population sample. Three common haplotypes were identified within the study population, none of which was associated with TB. CONCLUSIONS: These data represent an important negative finding and suggest that, while IFNGR1 is implicated in rare Mendelian susceptibility to mycobacterial disease, the common variants studied here do not have a major influence on susceptibility to pulmonary TB in The Gambian population.     

Use of the flexible fibreoptic bronchoscope in diagnosis of sputum-negative pulmonary tuberculosis

In four years' use of the flexible fibreoptic bronchoscope in diagnosing sputum-negative pulmonary tuberculosis, of 275 patients with tuberculosis suspected from chest radiographic appearances, 89 (32.4%) were shown to have active disease. In 60 (67.4%) of these patients the diagnosis was made from samples obtained through the fibreoptic bronchoscope (56 from bronchial brushings, four from transbronchial biopsy samples). Of the 56 positive bronchial brushings, 35 were positive on direct smear and 21 only on culture. Transbronchial biopsy exclusively accounted for only four of the 60 positive diagnoses. In the remaining 29 patients, the diagnosis was made from further sputum or biopsy specimens in 15, from the response to treatment in 12, and at necropsy in two. In six of 10 patients with military tuberculosis, bronchial brushings were positive on direct smear.     

Notification of tuberculosis: how many cases are never reported?

BACKGROUND: Notification of tuberculosis is essential for local contact tracing and for assessing the national incidence of tuberculosis. The accuracy of notification figures is uncertain. This study examined the notification rates of all patients diagnosed as having tuberculosis at two hospitals in the East End of London over five years. METHODS: In a retrospective survey of all patients aged 16 years or more presenting with tuberculosis to the London Chest Hospital or the Royal London Hospital from 1 January 1985 to 31 December 1989, cases of tuberculosis were identified from microbiology and histology records, statutory notifications, necropsy reports, coroners' records, hospital activity data, and death certificates. Clinical data were obtained from case notes and notification was determined from the local authority notification lists. RESULTS: Six hundred and nine adult patients with tuberculosis were identified. Notes were available for 580 cases (95%), of which 426 (73%) had been notified. The proportion of cases notified varied according to the specialty of the clinician in charge of the patient at diagnosis. Patients with a past history of tuberculosis and those who died within one year were less likely to have had their tuberculosis notified. Age, race, and lack of microbial or histological confirmation of diagnosis did not influence the proportion of cases notified. One hundred and eighty five patients had smear positive sputum, but 25 of these cases (14%) were not notified. Eighty five patients who had presented with pulmonary tuberculosis did not have their disease notified; 20 (24%) had smear positive sputum. CONCLUSIONS: Many cases of tuberculosis are not notified (27%). Fourteen per cent of all sputum smear positive cases of tuberculosis were not notified, and these patients are a considerable public health risk. The true incidence of tuberculosis in the area studied is at least one third higher than current notification figures suggest.