Acid-fast Bacilli Microscopy Research Articles

Description of Pediatric Tuberculosis Evaluated in a Referral Center in Istanbul Turkey

PurposeDiagnosis of tuberculosis (TB) in children is more challenging than in adults. This study aimed to describe demographical, clinical and laboratory findings of children diagnosed with tuberculosis in Turkey, including the issues of contact tracing, culture positivity and forms of the disease.Materials and MethodsClinical and laboratory data of 51 children with a mean age of 8.0±4.6 years who were diagnosed with TB were retrospectively reviewed. Main diagnostic tools included tuberculin skin test, chest X-ray, sputum/gastric aspirate culture with sensitivity testing, and direct microscopy for acid-fast bacilli on available samples. Clinical characteristics and outcomes of the patients were examined.ResultsThirty-six (70.6%) children were diagnosed with intra-thoracic and 15 (29.4%) with extra-thoracic tuberculosis. Twenty-eight of the patients had a positive Bacillus Calmette-Guérin vaccine scar (28/51, 54.9%) and 23/51 (45.1%) had a positive tuberculin skin test. An adult TB contact was identified in 27 (52.9%) of the cases. On direct microscopy, acid-fast bacilli were found in nine (17.6%) patients and positive culture for Mycobacterium tuberculosis was found in 19 (37.3%). Drug resistance to isoniazid was detected in four (7.8%). One patient with nephrotic syndrome and miliary tuberculosis died during follow-up. All other patients responded well to the treatment.ConclusionFocusing on active contact tracing among all household contacts of tuberculous cases may be helpful in early identification and controlling childhood disease, even in regions with low disease prevalence. Adopting a suspicious and proactive approach in this particular age group is warranted.

The microbiological diagnosis of tuberculosis in a resource - limited setting: is Acid-fast bacilli microscopy alone sufficient?

The objective of this study is to audit the processes for the microbiological diagnosis of tuberculosis (TB) in our resource-limited setting. A total of 694 specimens were received from 333 patients. 129 (38.7%) of these patients were positive for TB. 78 (60.5%) were positive on AFB microscopy alone, 13 (10.0%) on culture alone and 38 (29.5%) on both culture and AFB microscopy. Fifty-one (51) cases were positive on culture, 38 of these (74.5%) had growth on Lowensen-Jensen culture medium alone, 11 (19.6%) on Pyruvic Acid Enhanced Medium (PAEM) and 3 (5.9%) on both culture media. AFB microscopy showed a diagnostic specificity of 71.6% and a sensitivity of 74.5%. M. Bovis appears to be prevalent and we suggest the need for speciation. If AFB microscopy is to be routinely used alone, without confirmation by culture, then the overriding need is for quality to be fully assured in its use.

Symptom screen: diagnostic usefulness in detecting pulmonary tuberculosis in HIV-infected pregnant women in Kenya

To determine the diagnostic usefulness of tuberculosis (TB) symptom screening to detect active pulmonary TB among human immunodeficiency virus (HIV) infected pregnant women in two PMTCT (prevention of mother-to-child transmission) clinics in western Kenya that are supported by the United States Agency for International Development-Academic Model Providing Access to Healthcare partnership. Cross-sectional study. Participants were interviewed for TB symptoms with a standardized questionnaire (cough >2 weeks, fever, night sweats, weight loss or failure to gain weight). Those with cough submitted sputum specimens for smear microscopy for acid-fast bacilli and mycobacterial culture. Women at >14 weeks gestation underwent shielded chest radiography (CXR). Of 187 HIV-infected women, 38 (20%) were symptom screen-positive. Of these, 21 had a cough for >2 weeks, but all had negative sputum smears and mycobacterial cultures. CXRs were performed in 26 symptomatic women: three were suggestive of TB (1 miliary, 1 infiltrates and 1 cavitary). Of 149 women with a negative symptom screen, 100 had a CXR and seven had a CXR suggestive of TB (1 cavitary, 2 miliary and 4 infiltrates). This study did not support the utility of isolated symptom screening in identification of TB disease in our PMTCT setting. CXR was useful in identification of TB suspects in both symptomatic and asymptomatic women.

Volume of sputum to detect acid-fast bacilli as a measure of quality for the diagnosis of pulmonary tuberculosis at the Dr George Mukhari Hospital, South Africa

BackgroundOptimum sputum results for acid-fast bacilli (AFB) microscopy are linked to a sputum quantity of at least 5.0 mL. This study was aimed at establishing the effect of sputum quantity in the pick-up rate of AFB microscopy by comparing sputum samples of 5.0 mL and 2.0 mL.MethodsAn analytical cross-sectional study was carried out at the Dr George Mukhari Hospital (DGMH) in Pretoria, South Africa, from 05 January 2007 to 04 January 2008. Two sputum samples, 5.0 mL and 2.0 mL, were collected from each of the 330 adult PTB (pulmonary tuberculosis) suspects. Fluorescence microscopy was used in the sputum analysis. The yield through microscopy of the 2.0 mL specimen versus the 5.0 mL specimen was compared and analysed, using culture results as the gold standard.ResultsFrom a sample of 330 specimens, 77 tested AFB positive on microscopy. In the 5.0 mL samples, the sensitivity was 76.6% (95% CI, 66.0% – 84.7%), specificity 99.6% (95% CI 97.8% – 99.9%), positive predictive value (PV+) 98.3% (95% CI 91.1% – 99.7%), negative predictive value (PV-) 93.3% (95% CI 89.7% – 95.7%), the likelihood ratio (LR) for a positive microscopy 192 and the LR for a negative test was 0.23. In the 2.0 mL specimens, the sensitivity was 75.3% (95% CI 64.6% – 83.6%), specificity 99.2% (95% CI 97.1% – 99.8%), positive predictive value (PV+) 96.7% (95% CI 88.6% – 99.1%), negative predictive value (PV-) 93.0% (95% CI 89.3% – 95.4%), the LR for a positive microscopy was 94 and 0.25 for a negative microscopy. There was a statistically significant association (p-value < 0.001) between the microscopy and culture tests in both the 5.0 mL and the 2.0 mL specimen categories. The strength of association between the microscopy and culture, as indicated by the kappa test was 0.83 and 0.81 in the 5.0 mL and 2.0 mL categories, respectively.ConclusionCompared to the 2.0 mL specimen category, the yield for AFB microscopy in the 5.0 mL specimen category was consistently superior, as indicated by the higher sensitivity, specificity, predictive values and the likelihood ratios in the 5.0 mL specimen category. It is recommended that sputum specimen collection for AFB microscopy should aim for a minimum volume of 5.0 mL.

Granulomatous mediastinal adenopathy: can endoscopic ultrasound-guided fine-needle aspiration differentiate between tuberculosis and sarcoidosis?

Mediastinal lymphadenopathy may indicate diseases such as tuberculosis or sarcoidosis, and it is often difficult to establish a diagnosis when standard medical work-up is inconclusive. In this study we investigated the diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in the differentiation between tuberculosis and sarcoidosis. In this prospective study, 72 consecutive patients with mediastinal lymphadenopathy, negative endoscopic investigations including bronchoscopic procedures, and no radiological evidence of lung cancer or other malignancies on computed tomography were enrolled. EUS-FNA and subsequent cytology, microscopy for acid-fast bacilli, and culture were performed. At least 12 months' follow-up including further investigations was included to exclude tuberculosis. Adequate samples were obtained from 71/72 patients (36 male; mean age 50.2 years). No complications occurred. The final diagnosis included 30 cases of sarcoidosis, 28 of tuberculosis, four malignancies, one abscess, and nine benign lymphadenopathies. The size of lymph nodes on EUS varied from 0.5 cm to 4.2 cm. Tuberculosis nodes were significantly smaller than those in sarcoidosis. Unrelated nodes were significantly smaller than in either tuberculosis or sarcoidosis. The sensitivity, specificity, and positive and negative predictive values of EUS - FNA for tuberculosis were 86 %, 100 %, 100 %, and 91 %, respectively; those for sarcoidosis were 100 %, 93 %, 91 %, and 100 %, respectively. For culture of tuberculosis, they were 71 %, 100 %, 100 %, and 84 %, respectively. EUS - FNA led to a definite diagnosis in 64/72 cases (89 %) that had not been previously diagnosed by routine methods. EUS - FNA offers a high diagnostic yield for the differential diagnosis of tuberculosis and sarcoidosis that have not been diagnosed by conventional methods.

Bacteriologically Confirmed Pulmonary Tuberculosis in a Patient with Lymphangioleiomyomatosis Accompanying Tuberous Sclerosis Syndrome

Lymphangioleiomyomatosis (LAM) is a rare disease of unknown origin, that may be sporadic or develop in the course of tuberous sclerosis (TS). Patients do not present immune deficiency, but structural changes in the lung parenchyma (cysts) may encourage various infections, for example tuberculosis. Radiologic findings are often difficult to interpret, because of changes related to LAM itself. We present a young women with a history of TS and LAM, in whom protracting respiratory tract infection was finally diagnosed as tuberculosis. Initial diagnosis was based primarily on clinical signs and symptoms and treatment was started despite the negative result of the sputum microscopy for acid fast bacilli. In the course of treatment the diagnosis was supported by positive tuberculin skin test, interferon-gamma release assay and genetic test for M. tuberculosis in bronchoalveolar lavage fluid, and finally, positive sputum culture in liquid medium.

"Air - Bubble" Sign - An uncommon presentation of a common disease

Sir, A 33-year-old female presented with right-sided pleuritic chest pain and expectoration of mucopurulent, foul-smelling, and salty sputum for one year. There was a history of close contact with a pet dog for last two years. General survey and systemic examination revealed no abnormality. Absolute eosinophil count was 800/cmm. Sputum microscopy for acid fast bacilli was negative. A homogenous opacity in right lower lobe was seen in chest radiogram [Figure 1]. Contrast enhanced computed tomography (CECT) scan of thorax showed two rounded, heterogenous opacities (1 × 1 cm and 1.5 × 2 cm, respectively) with presence of air pockets within the lesions—the “air – bubble sign” [Figure 2]. Ultrasonography (USG) of thorax revealed loculated collection of fluid with echogenic organization inside. USG-guided aspiration of the lesion revealed viscid material. Cytology of the smear showed fragmented membranous structures with lamination along with aggregates of degenerated inflammatory cells in a background of proteinaceous fluid [Figure 3]. Fiberoptic bronchoscopy did not reveal any endobronchial lesion. USG of whole abdomen did not reveal cyst in intra-abdominal organs. Serum anti-echinococcal IgG level was 26.41 U/ml (normal value: <8 U/ml, ELISA method). A diagnosis of infected hydatid cyst in right lung was made and albendazole tablet, 400 mg twice daily, was started. The patient was referred to the department of cardiothoracic surgery for further management and follow up.Figure 1: Chart X-ray—PA and right lateral view showing homogenous opacity in right lower lobe with sparing of right costophrenic angleFigure 2: CECT thorax showing “Air – bubble” signFigure 3: FNAC showing fragmented membranous structures with laminationEchinococcosis, a zoonosis caused by Echinococcus granulosus is endemic in India, mostly involving liver and lungs. Most pulmonary cysts are asymptomatic and become clinically evident as a result of complications like cyst rupture and secondary infection. Pulmonary cysts are characteristically solitary and involve single lobe, mainly the lower lobe, and more common on the right.[1] Structurally, the cysts consist of pericyst, exocyst, and endocyst from outside inwards. Echinococcal cysts carry high risk of rupture with subsequent seeding to the other viscera[2] and secondary infection. The rupture may lead to anaphylactic reaction.[2] Most common respiratory symptoms of ruptured hydatid cyst are cough with fetid expectoration.[2] CECT scan of thorax is the diagnostic modality of choice for pulmonary hydatid cyst. Most of intact pulmonary cysts present as solid lesions of fluid density on CECT thorax. But ruptured cysts almost always present with a variety of radiological appearances due to different combinations of collapsed membrane, air, and fluid, making its diagnosis difficult. Sometimes, secondary bacterial infection supervenes on the ruptured cyst with subsequent increase in attenuation numbers in CECT thorax.[3] Because of solid density of the cyst, the differentiation from a pulmonary neoplasm is usually impossible. Serological test like anti-echinococcal IgG is helpful in most patients for final diagnosis, but measurable immunological response may not develop in few patients. Pulmonary hydatid cyst may rupture through pericyst only or through pericyst, exocyst, and endocyst with expulsion intracystic contents within airways. A number of radiological signs of ruptured cysts are described which include crescent sign, water lily sign, daughter cyst, double arch sign, ring within a ring sign, serpent or snake sign, and spin or whirl sign.[4] When there is dissection of air between the pericyst and parasitic membrane, due to erosion of a bronchiole by an expanding cyst, “airbubble” sign is seen. The “air bubble” sign which is a relatively newly recognized radiological sign is reported to be very sensitive and specific (85.7% sensitivity and 96.6% specificity) in establishing diagnosis of ruptured, infected hydatid cyst.[5] Air bubble sign is best seen in mediastinal window as single or multiple small, rounded radiolucent areas with sharp margins within the periphery of a solid mass lesion.

Vorsicht mit Prognosen!

A 37-years old patient of south Indian origin presented with pain in his right scapular region radiating to the right arm, numbness and muscular weakness of the fourth and fifth finger. Computed tomography (CT) revealed a mass at the right pleural dome with arrosion of the first rib (Pancoast presentation), an osteolytic process in the fourth rib and in the right hip. All three lesions had a high FDG uptake in the PET/CT suggestive for lung cancer metastases in this smoker. Surprisingly, the CT-guided fine needle biopsy revealed no malignancy, but granulomatous inflammation and epitheloid cells. Microscopy for acid-fast bacilli (AFB) was negative, but the culture was positive for AFB. The HIV-negative patient received a regular antituberculous chemotherapy. His condition as well as the radiological findings improved gradually. In the majority of cases, space occupying masses in the upper sulcus are caused by non-small cell lung cancers. Extrapulmonal tuberculosis infection presenting as a Pancoast syndrome is a curiosity. However, with respect to the patients ethnical background this diagnosis should have been considered earlier.

The Prevalence and Drug Sensitivity of Tuberculosis among Patients Dying in Hospital in KwaZulu-Natal, South Africa: A Postmortem Study

Tuberculosis is the leading cause of death in South Africa by death notification, but accurate diagnosis of tuberculosis is challenging in this setting of high HIV prevalence. We conducted limited autopsies on young adults dying in a single public hospital in the province of KwaZulu-Natal between October 2008 and August 2009 in order to estimate the magnitude of deaths attributable to tuberculosis. We studied a representative sample of 240 adult inpatients (aged 20-45 years) dying after admission to Edendale Hospital. Limited autopsies included collection of respiratory tract secretions and tissue by needle core biopsies of lung, liver, and spleen. Specimens were examined by fluorescent microscopy for acid-fast bacilli and cultured in liquid media; cultures positive for M. tuberculosis were tested for drug susceptibility to first- and second-line antibiotics. Ninety-four percent of our study cohort was HIV seropositive and 50% of decedents had culture-positive tuberculosis at the time of death. Fifty percent of the participants were on treatment for tuberculosis at the time of death and 58% of these treated individuals remained culture positive at the time of death. Of the 50% not receiving tuberculosis treatment, 42% were culture positive. Seventeen percent of all positive cultures were resistant to both isoniazid and rifampin (i.e., multidrug resistant); 16% of patients dying during the initiation phase of their first ever course of tuberculosis treatment were infected with multidrug-resistant bacilli. Our findings reveal the immense toll of tuberculosis among HIV-positive individuals in KwaZulu-Natal. The majority of decedents who remained culture positive despite receiving tuberculosis treatment were infected with pan-susceptible M. tuberculosis, suggesting that the diagnosis of tuberculosis was made too late to alter the fatal course of the infection. There is also a significant burden of undetected multidrug-resistant tuberculosis among HIV-coinfected individuals dying in this setting. New public health approaches that improve early diagnosis of tuberculosis and accelerate the initiation of treatment are urgently needed in this setting. Please see later in the article for the Editors' Summary.

Nontuberculous Mycobacteria in Solid Organ Transplant Recipients

Nontuberculous Mycobacteria in Solid Organ Transplant Recipients

EUS-FNA for the Diagnosis of Tuberculosis and Sarcoidosis

Background: Other than malignancy mediastinal lymphadenopathy may indicate benign diseases such as pulmonary tuberculosis (TB) and sarcoidosis, which are more frequently found in ethnic subgroups. Differentiation between sarcoidosis, tuberculosis and other diseases can be difficult, if standard diagnostic methods such as bronchoscopy and sputum analysis fail. Endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) of mediastinal nodes has proven to be highly sensitive and specific in the diagnosis of lung cancer. It can provide material for cytology and bacteriology but it remains unknown whether this is sufficient to differentiate between TB and sarcoidosis. Methods: Prospective study including 72 consecutive patients (Mean: 50.2 years; 36 male) with mediastinal lymphadenopathy but no suspicion of lung cancer or other malignancy on CT. All had negative investigations including bronchoscopic biopsy and bronchoalveolar lavage before EUS-FNA was carried out with at least two passes using a 22gauge needle. Cytology and microscopy for acid-fast bacilli was performed by independent physicians and material sent for TB culture. At least 9 months of clinical follow-up was undertaken to exclude TB in non-TB cases. Results: Adequate samples were obtained in 71/72 patients and no complications occurred. Cytology suggested TB in 24 cases and sarcoidosis in 33. Malignancy was found in 4 patients (n=2 lymphoma, n=2 metastatic cancer); in the remaining 10 cases, 2 abscesses and 8 non-specific inflammatory changes were found. Culture revealed TB in 20 cases. A final diagnosis of TB was made in 27 patients after at least 9 months' follow-up; of these 3 had negative cytology but positive culture. The final diagnosis of sarcoidosis was made in 30 cases; the remaining 3 with cytology suggesting sarcoidosis were proven to have TB on EUS-FNA culture. The sensitivity and specificity of EUS-FNA for TB were 0.89 and 1.0 respectively; those for sarcoidosis were 1.0 and 0.93. EUS-FNA achieved a correct diagnosis in 63/72 patients (88%). In 8 of these with non-specific inflammation no significant diagnosis was found. Lymphadenopathy was due to old TB and smoking. Conclusion: EUS-FNA cytology combined with culture offers an excellent method for the differential diagnosis of TB and sarcoidosis, which had not been diagnosed by traditional methods.

Comparison of Fluorescence Microscopy with Ziehl-Neelsen Technique in the Examination of Sputum for Acid-Fast Bacilli Using Bleach Centrifugation Method

Background: The reliability of direct smear microscopy for diagnosis of tuberculosis (TB) using Ziehl-Neelsen (ZN) technique has frequently been questioned due to low sensitivity. Fluorescent microscopy (FM) is more sensitive than ZN but its sensitivity is less than culture. Treatment of sputum with bleach has been used to increase sensitivity in many settings. However, no study has compared use FM and ZN methods for detection of acid-fast bacilli (AFB) using bleach method. Objectives: Comparison of results with fluorescence and bright-field microscopy for AFB using bleach centrifugation method. Methods: Three hundred and seventy sputum specimens were collected from new TB suspects attending Mbagathi District Hospital and processed for direct microscopy using both ZN and FM. Culture on Loweinstein Jensen egg media was used as the gold standard. FM and ZN smear negative specimens were treated with 3.5% bleach and left to stand for 30 minutes before centrifugation. Smears were prepared from each bleach treated specimen, processed and examined using either ZN or FM staining methods. Results: Of the 370 specimens, 200(54%) were culture positive. The number of smear positive by direct ZN was 138 (37.2%) which increased to 171 (46.2%) and direct FM positive was 165 (44.6%) which increased to 180 (48.6%), after treatment of direct ZN and FM smear negative specimens with 3.5% bleach, respectively. There was a significant increase in sensitivity from 66% to 81.1% (p < 0.05) using ZN technique and 75.5% to 83% (p < 0.05). Conclusion: Bleach centrifugation method significantly increases the sensitivity of smear negative specimens irrespective of the staining method used. However, FM appears to be more sensitive than ZN. 13th International Congress on Infectious Diseases Abstracts (Oral Presentations)International Journal of Infectious DiseasesVol. 12Preview Full-Text PDF Open Archive

Novel hypertonic saline–sodium hydroxide (HS–SH) method for decontamination and concentration of sputum samples for Mycobacterium tuberculosis microscopy and culture

This study evaluated a new decontamination and concentration (DC) method for sputum microscopy and culture. Sputum samples from patients with suspected pulmonary tuberculosis (TB) (n=106) were tested using the proposed hypertonic saline-sodium hydroxide (HS-SH) DC method, the recommended N-acetyl-L-cysteine-sodium citrate-sodium hydroxide (NALC-NaOH) DC method and unconcentrated direct smear (Ziehl-Neelsen) techniques for the presence of mycobacteria using Löwenstein-Jensen culture and light microscopy. Of 94 valid specimens, 21 (22.3%) were positive in culture and were further characterized as Mycobacterium tuberculosis. The sensitivity for acid-fast bacilli (AFB) smears was increased from 28.6% using the direct method to 71.4% (HS-SH) and 66.7% (NALC-NaOH) using DC methods. Both concentration techniques were highly comparable for culture (kappa=0.794) and smear (kappa=0.631) for AFB. Thus the proposed HS-SH DC method improved the sensitivity of AFB microscopy compared with a routine unconcentrated direct smear; its performance was comparable to that of the NALC-NaOH DC method for AFB smears and culture, but it was methodologically simpler and less expensive, making it a promising candidate for evaluation by national TB control programmes in developing countries.

Hoarseness due to Mycobacterium kansasii

To present a case of unilateral vocal fold paralysis due to Mycobacterium kansasii induced pressure on the left recurrent laryngeal nerve, a specific aetiology not previously reported in the world literature. A 57-year-old Caucasian man presented with a short history of productive cough, fever, hoarseness and 14-kg weight loss. He was a smoker, had an abnormal chest X-ray and was human immunodeficiency virus negative. A sputum sample was positive on direct microscopy for acid fast bacilli. Initially, the patient was treated with Rifater (rifampicin, isoniazid and pyrazinamide) and ethambutol. Mycobacterium kansasii was isolated and proved sensitive to this antimycobacterial treatment. Nasoendoscopy revealed diminished movement of the left vocal fold, and a computed tomography scan showed enlarged mediastinal lymph nodes anterior to the aortic arch. After three months of antimycobacterial treatment, the vocal folds were fully mobile at repeat nasoendoscopy, and this coincided with gradual resolution of the patient's hoarseness and weight loss. There are many causes of unilateral vocal fold paralysis. This case illustrates the importance of anatomical knowledge in reaching a diagnosis, and also presents the first reported case of Mycobacterium kansasii creating this clinical picture.

Metodologia para caracterização de proficiência em leitura de resultados baciloscópicos para o diagnóstico da tuberculose

To propose a methodology for characterizing proficiency in sputum smear microscopy for acid-fast bacilli (AFB) in the diagnosis of tuberculosis and to determine the number of microscopies necessary to establish this proficiency, as well as the quality of the transcription of results, the causes of the discrepancies in the readings (rater or microscope used), and the criterion for classification of microscopy results that poses the most difficulty in characterizing proficiency. Four hundred sputum smear microscopies for the diagnosis of tuberculosis were analyzed through double-blind readings by six professionals who usually read/supervise microscopies performed in public health care facilities. The sample was stratified to obtain, at least, a reliability of 90% in the double-blind readings, an alpha error of 5%, and a precision of 3%. The results were analyzed using observed reliability and the kappa index. Thirteen errors (0.27%) were found in the transcription of results. Reliability increased when the three distinct categories of positive results (AFB+, AFB++, and AFB+++) were grouped or when inconclusive results were excluded from the analysis. The quantification of the bacterial load was the classification criterion that posed the most difficulty in establishing proficiency. Using higher quality microscopes increased reliability. Reliability values stabilized only from the reading of 75 microscopies onward. Double-blind sputum smear microscopy readings using a panel containing 75 slides (36 negative, 4 inconclusive, and 35 positive) proved to be appropriate for characterizing proficiency in sputum smear microscopy for the diagnosis of tuberculosis when such proficiency is intended to reproduce laboratory routine.

Diagnosis of Mycobacterium ulcerans infection (Buruli ulcer) at a treatment centre in Ghana: a retrospective analysis of laboratory results of clinically diagnosed cases

Clinical diagnosis of Mycobacterium ulcerans infection is currently accepted as sufficient basis for treating the disease. Inadequate laboratory resources in the highly endemic areas of Africa often limit possibilities for in-country confirmation of clinical judgement. We analysed records of 99 Buruli ulcer (BU) patients diagnosed clinically and treated surgically at Amasaman Health Centre in Ghana, for whom post-treatment diagnostic laboratory tests were performed. Comparison of clinical diagnoses with test results obtained by an in-country laboratory on samples of excised tissue showed a high specificity of clinical judgement. Among lesions with three laboratory tests (microscopy for acid fast bacilli, culture and IS2404 polymerase chain reaction) done, 94% tested positive at least once and 83% twice. Thus correct clinical diagnosis of BU by well trained health workers is achievable, although the quality of clinical diagnosis should be monitored by intermittent testing in national reference laboratories. However, being retrospective, this study did not permit sensitivity and negative predictive value analysis.

Abdominal tuberculosis in a district general hospital: a retrospective review of 86 cases

Abdominal tuberculosis (ATB) is a great mimic and an important cause of morbidity. Its incidence is more common in certain groups. To review the cases of ATB in Blackburn from 1985 to 2004, with emphasis on presentation, investigation, diagnosis, treatment and follow-up. A retrospective cases note analysis from a prospectively compiled database. Eighty-six cases of ATB were on a prospective database of all tuberculosis (TB) cases in Blackburn for 1985-2004 inclusive. Full case papers were available for 82 and partial data for the remaining four cases. Median age was 34.8 years, with an equal sex distribution. South Asians accounted for 91% of cases. The highest proportion of patients had peritoneal TB, and a considerable number (27%) had TB at multiple sites. The diagnosis can be difficult to make because of the varied presentation, the low percentage with positive microscopy for acid-fast bacilli and the time delay of up to several weeks for a positive TB culture. The thresholds for laparoscopy and/or laparotomy for the diagnosis were therefore very low. The diagnosis could be made rapidly by these methods, and early treatment instituted. Six months short-course chemotherapy is very effective in ATB. This should be changed, if appropriate, on the basis of drug susceptibility data.

Culture-confirmed childhood tuberculosis in Cape Town, South Africa: a review of 596 cases

BackgroundThe clinical, radiological and microbiological features of culture-confirmed childhood tuberculosis diagnosed at two referral hospitals are described.MethodsCultures of Mycobacterium tuberculosis from children less than 13 years of age at Tygerberg and Red Cross Children's Hospitals, Cape Town, South Africa, were collected from March 2003 through February 2005. Folder review and chest radiography were performed and drug susceptibility tests done.ResultsOf 596 children (median age 31 months), 330 (55.4%) were males. Of all children, 281 (47.1%) were HIV-uninfected, 133 (22.3%) HIV-infected and 182 (30.5%) not tested. Contact with infectious tuberculosis adults was recorded in 295 (49.5%) children. Missed opportunities for chemoprophylaxis were present in 117/182 (64.3%) children less than 5 years of age.Extrathoracic TB was less common in HIV-infected than in HIV-uninfected children (49/133 vs. 156/281; odds ratio 0.50, 95% confidence interval 0.32–0.78). Alveolar opacification (84/126 vs. 128/274; OR 1.85, 95%CI 1.08–3.19) and cavitation (33/126 vs. 44/274; OR 2.28, 95%CI 1.44–3.63) were more common in HIV-infected than in HIV-uninfected children. Microscopy for acid-fast bacilli on gastric aspirates and sputum was positive in 29/142 (20.4%) and 40/125 (32.0%) children, respectively. Sixty-seven of 592 (11.3%) children's isolates showed resistance to isoniazid and/or rifampicin; 43 (7.3%) were isoniazid-monoresistant, 2 (0.3%) rifampicin-monoresistant and 22 (3.7%) multidrug-resistant. Death in 41 children (6.9%) was more common in HIV-infected children and very young infants.ConclusionHIV infection and missed opportunities for chemoprophylaxis were common in children with culture-confirmed TB. With cavitating disease and sputum or gastric aspirates positive for acid-fast bacilli, children may be infectious. Transmission of drug-resistant TB is high in this setting.

Manifestation of tuberculosis in patients with human immunodeficiency virus: A large Indian study

BACKGROUND:Government Hospital of Thoracic Medicine, Tambaram Sanatorium, Chennai, is the largest HIV-care center in South East Asia. As many as 29,300 HIV patients visited this center at least once in the year 2005 for care and support.OBJECTIVES:Clinical manifestations and the modes of presentation of tuberculosis were assessed among 12,750 adult and adolescent patients with human immunodeficiency virus (HIV) attending the hospital for the first time.MATERIALS AND METHODS:Database of Hospital Information System, specially evolved for managing patients afflicted with tuberculosis and HIV, was utilized. The particulars confined to patients with tuberculosis and HIV co-infection who visited the hospital for the first time from January to December 2005 were considered for the analysis. Proportion test and Chi-square test with Yates correction were done.RESULTS:As many as 12,750 adult and adolescent HIV-confirmed patients were screened for the possible presence of tuberculosis. Out of them, 4,383 (34.4%) patients had tuberculosis. Among them, 2,448 (55.9%) had pulmonary tuberculosis, and the remaining 1,935 (44.1%) had either disseminated or extra-pulmonary tuberculosis (P<0.001). Positive sputum-smear microscopy for acid fast bacilli was evident in 1,363 (31.1%) patients; however, it was significantly lower compared to positive smear rate of 44% in HIV patients (P< 0.001).CONCLUSION:Tuberculosis was found to be the predominant co-infection among the symptomatic patients infected with HIV attending the largest care center for the first time in India. Advanced tuberculosis, disseminated tuberculosis and sputum smear negative pulmonary tuberculosis were the presenting clinical manifestations in 44% of the patients, as they had moderate to advanced immunosuppression. Early detection of tuberculosis co-infection is absolutely necessary.

Comparison With The Smart Check Recombinant TB Serology Assay And Direct Sputum Microscopy For Acid Fast Bacilli Among Suspected HIV Positive Patients In Northeastern Nigeria

Currently, the Sputum smear microscopy for acid fast bacilli is the corner stone of diagnosis of HIV associated active TB in Nguru, Northeastern Nigeria. This method has low sensitivity and specificity. In this study, we set out to compare the reliability of the Smart Check Recombinant TB rapid test kit with the routine direct sputum microscopy for acid- fast bacilli (AFB). Using Ziehl-Neelsen stained sputum smear microscopy for AFB as the standard, sensitivity and specificity of the Smart Check Recombinant TB rapid test kit was 96.7 % and 82.1 % respectively. These results show that the performance of the Smart Check Recombinant TB rapid test kit was adequate in comparison with direct sputum smear microscopy by sensitivity and specificity for the diagnosis of active TB in HIV infected patients when alternative is just clinical suspicion.