sodium-hypochlorite and Tuberculosis--Pulmonary

The conventional method of processing sputum for acid fast bacilli microscopy has been a primary tool for laboratory diagnosis of pulmonary tuberculosis in Papua New Guinea. In routine preparation, untreated sputum is directly smeared on a glass slide without undergoing any stage of processing. Mounting evidence suggests that direct smearing is less sensitive and, to a certain degree, compromises infection control. A few alternatives for processing sputum have been recommended in the literature; however, their consumables are not easily accessible and are expensive for wide use in rural laboratories. The bleach concentration and processing method appears to be the most preferable choice because bleach is inexpensive, readily available, and has bactericidal properties.

Topics: Bacteriological Techniques; Humans; Mycobacterium tuberculosis; Papua New Guinea; Sensitivity and Specificity; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

Bleach digestion of sputum prior to smear preparation has been reported to increase the yield of microscopy for diagnosing pulmonary tuberculosis, even in high-HIV-prevalence settings. To determine the diagnostic accuracy of bleach microscopy, we updated a systematic review published in 2006 and applied the Grading of Recommendations Assessment, Development, and Evaluation framework to rate the overall quality of the evidence. We searched multiple databases (as of January 2009) for primary studies in all languages comparing bleach and direct microscopy. We assessed study quality using a validated tool and heterogeneity by standard methods. We used hierarchical summary receiver operating characteristic (HSROC) analysis to calculate summary estimates of diagnostic accuracy and random-effects meta-analysis to pool sensitivity and specificity differences. Of 14 studies (11 papers) included, 9 evaluated bleach centrifugation and 5 evaluated bleach sedimentation. Overall, examination of bleach-processed versus direct smears led to small increases in sensitivity (for bleach centrifugation, 6% [95% confidence interval [CI] = 3 to 10%, P = 0.001]; for bleach sedimentation, 9% [95% CI = 4 to 14%, P = 0.001]) and small decreases in specificity (for bleach centrifugation, -3% [95% CI = -4% to -1%, P = 0.004]; for bleach sedimentation, -2% [95% CI = -5% to 0%, P = 0.05]). Similarly, analysis of HSROC curves suggested little or no improvement in diagnostic accuracy. The quality of evidence was rated very low for both bleach centrifugation and bleach sedimentation. This updated systematic review suggests that the benefits of bleach processing are less than those described previously. Further research should focus on alternative approaches to optimizing smear microscopy, such as light-emitting diode fluorescence microscopy and same-day sputum collection strategies.

Topics: Bacteriological Techniques; Chi-Square Distribution; Databases, Factual; Humans; Microscopy; ROC Curve; Sensitivity and Specificity; Sodium Hypochlorite; Specimen Handling; Sputum; Tuberculosis, Pulmonary

The Revised National Tuberculosis Control Programme (RNTCP) aims to improve case detection rates of tuberculosis to facilitate prompt recognition and treatment. The low case detection rates in the programme can be directly attributed to failure to screen patients with suspected tuberculosis and the low sensitivity of the direct smear microscopy method to detect cases among the fraction of patients that are screened. Apart from low sensitivity, this method also has other disadvantages including the increased risk of infection transmission to technicians. There are several methods that can be used to improve sensitivity, but their applicability in a national programme and in resource limited settings are limited. Bleach processing of sputum smears prior to microscopy may be a cheap and effective way to improve on the sensitivity of the direct smear. Four distinctive techniques of sputum smear processing using bleach are described in the review, with the variations in each technique, along with the sensitivity. An analysis of reports published earlier on the bleach method is also presented including a discussion on when and why the bleach method works.

Topics: Bacteriological Techniques; Disinfectants; HIV Infections; Humans; Microscopy; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

It has been proposed that the sensitivity of direct sputum smear microscopy can be improved if sputum is liquefied with sodium hypochlorite (NaOCl or household bleach), and concentrated by centrifugation before acid-fast staining.. To summarise the results of the studies of the bleach method for improved sensitivity of sputum microscopy and to describe the opinions and knowledge of key persons in National Tuberculosis Control Programmes (NTPs) about this method.. We searched Medline, EMBASE and Web of Science for studies comparing the bleach method to direct sputum smear microscopy in low- or middle-income countries. Each study was assessed regarding methodology and field applicability. We also sent out questionnaires concerning the bleach method to key persons in NTPs in 85 countries.. In 15 of the 19 studies identified there was a statistically significant improvement in the proportion of positive tests or sensitivity ranging from 7-253%. The majority (73%) of the key persons had heard of the bleach method. Forty-four per cent thought it could improve case detection in their countries, while 49% did not know; 93% of them would promote the bleach method; the most common reasons for doing so would be recommendations from the WHO or the IUATLD, or favourable studies performed in their own country. The bleach method was used routinely in only three countries.. There is enough evidence to recommend the evaluation and introduction of the bleach method in most settings where mycobacterial culture is not performed routinely.

Topics: Centrifugation; Disinfectants; Humans; Microscopy; Reference Values; Sensitivity and Specificity; Sodium Hypochlorite; Specimen Handling; Sputum; Tuberculosis, Pulmonary; World Health Organization

Background: Sputum smear microscopy (SSM) is a screening test used to diagnose tuberculosis (TB); however, its performance and sensitivity are relatively low, which can lead to false negatives. We designed a cross-sectional study to estimate the performance of SSM that includes a pretreatment based on sputum digestion with bleach (sodium hypochlorite) for the diagnosis of TB. Methods: We evaluated 73 sputum samples from patients with a diagnosis of TB confirmed by the Xpert MTB/RIF test and 114 samples from patients without TB. We performed sputum digestion using a 5% sodium hypochlorite solution, centrifuged at 2000 rpm for 15 min. We prepared smears for direct and bleach-treated SSM and used Ziehl−Neelsen staining. Results: The bleach-treated SSM obtained absolute identification of the cases of TB confirmed by the Xpert test, compared to 95.9% identified by the direct smear method (without bleach treatment). We also found a significant increase (p < 0.001) in the recovery of acid-fast bacilli (AFB) obtained by the bleach-treated SSM (293.8 ± 215.1 AFB) compared to the direct SSM method (222.9 ± 195.5 AFB). The AUC of the bleach-treated SSM and direct SSM was 100% and 96.6%, respectively. Conclusion: The bleach-treated SSM performs better than the direct SSM in identifying AFB and increasing the bacillary count in the sputum samples.

Topics: Cross-Sectional Studies; Humans; Microscopy; Mycobacterium tuberculosis; Peru; Sensitivity and Specificity; Sodium Hypochlorite; Sputum; Tuberculosis; Tuberculosis, Pulmonary

The sensitivity of smear microscopy for diagnosis of tuberculosis might be improved through treatment of sputum with sodium hypochlorite and application of fluorescent microscopy. This study aimed to determine the agreement between direct Fluorescent Microscopy and Ziehl-Neelsen concentration technique by their ability of detecting acid fast bacilli in resource poor settings.. A cross sectional study was conducted at Gondar University Referral Hospital, Northwest Ethiopia. Three sputum specimens were collected from consecutive TB suspects. Direct and concentrated sputum smears were air-dried, heat-fixed and stained by auramine O and Ziehl-Neelsen staining techniques respectively. The stained slides were examined for acid fast bacilli using direct Fluorescent Microscopy and Ziehl-Neelsen concentration techniques.. Of 293 specimens, 4.4% and 2.4 % were AFB positive by direct fluorescent microscopy and Ziehl-Neelsen bleach concentrated techniques respectively. There was high percentage of tuberculosis positivity from early morning sputum samples (2.4%) compared to first spot (1.4%) and second spot (1.7%) sputum samples when using Ziehl-Neelsen sodium hypochlorite concentration technique. A moderate agreement was seen between the two methods (Kappa=0.484, P value<0.001).. Direct fluorescent microscopy has shown high positivity rate compared to Ziehl-Neelsen concentration technique. A moderate agreement was seen between the two methods. Thus, Ziehl-Neelsen bleach sedimentation technique is recommended for detection of pulmonary tuberculosis at peripheral health service level when Fluorescent Microscopy is not available.

Topics: Bacteriological Techniques; Cross-Sectional Studies; Ethiopia; Humans; Microscopy, Fluorescence; Reproducibility of Results; Sodium Hypochlorite; Sputum; Staining and Labeling; Tuberculosis, Pulmonary

The GeneXpert MTB/RIF assay (Xpert) was endorsed as the initial diagnostic tool in people suspected of human immunodeficiency virus-associated or drug-resistant tuberculosis (TB). However, information regarding the performance of Xpert for diagnosing smear-negative TB in high burden settings remains limited. We evaluated the diagnostic accuracy of Xpert and the impact of bleach concentration on the performance of Xpert using smear-negative sputum samples from human immunodeficiency virus-negative patients.. One spot and one morning smear-negative sputum samples per patient were examined using Xpert and culture at the Mycobacteriology Research Center of Jimma University, Ethiopia. The sputum culture on both Löwenstein-Jensen and/or Mycobacteria Growth Indicator Tube was the gold-standard.. Of 185 smear-negative presumptive pulmonary TB cases, 19 (10.3%) had culture-proven TB. The sensitivity of Xpert on spot and morning sputum was similar (63.2%). Testing two specimens per patient insignificantly increased the sensitivity of Xpert. Bleach concentration and pelleting improved the sensitivity of Xpert over unprocessed sputum in paired samples (73.8% vs. 63.2%) without affecting the specificity (95%). Bleach concentration and pelleting allowed an additional seven cases of TB (missed on the first and second direct Xperts) to be detected, five of which were from culture-negative cases.. Testing of a single sputum sample by Xpert can reach reasonable sensitivity and results would be available on the same day, avoiding loss of patients and treatment delay. The sensitivity of Xpert was improved after bleach concentration and pelleting, although its added value needs further study on a larger scale.

Topics: Adult; Antibiotics, Antitubercular; Bleaching Agents; Diagnostic Tests, Routine; Female; Humans; Male; Middle Aged; Mycobacterium tuberculosis; Prospective Studies; Rifampin; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary; Young Adult

The objective of the current study was to compare the efficacy of phenol ammonium sulphate (PhAS) and sodium hypochlorite (NaOCl) pretreatment methods for the direct microscopy with the Löwenstein-Jensen (LJ) culture to detect acid fast bacilli (AFB) from pulmonary tuberculosis suspected cases using sputum specimens. To evaluate PhAS and NaOCl methods, sputum specimens (n = 1145) were studied and the performance of each method was compared with LJ media. The, PhAS centrifuged smear and NaOCl centrifuged smear method demonstrated higher sensitivity (71.47% and 77%), specificity (99.61% and 98%), positive predictive value (98.8% and 94.88%) and negative predictive value (88.35% and 90.25%), respectively, when compared to LJ culture. However, the direct AFB smears and PhAS centrifugation method was ineffective to detect few Mycobacterium tuberculosis cases from sputum specimens, particularly in blood tinged specimens with scanty bacilli. Interestingly, NaOCl method could efficiently detect the Mycobacterium tuberculosis cases from blood tinged sputum specimens with scanty bacilli. The current study concluded that NaOCl method could be the most efficient and sensitive method than direct AFB smear and PhAS centrifuged smear method for the direct detection of AFB in suspected cases of pulmonary tuberculosis.

Topics: Ammonium Sulfate; Bacteriological Techniques; Centrifugation; Culture Media; Humans; Microscopy; Mycobacterium tuberculosis; Phenol; Sensitivity and Specificity; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

Direct sputum smear microscopy remains the most widespread method for the diagnosis and followup of patients with tuberculosis despite its limited sensitivity.. Our aim was to investigate whether sputum smears prepared using liquefaction with household bleach and concentration by centrifugation was more sensitive for the detection and quantification of acid-fast bacilli as compared to smears processed directly from sputum.. A cross-sectional study was conducted among patients with a clinical presentation suggestive of pulmonary tuberculosis at Gondar University Hospital, Northwest Ethiopia in April 2008. Three consecutive sputum samples were collected from the study participants and examined for acid fast bacilli using the standard direct microscopy as well as the household bleach-concentration technique.. Out of 264 samples examined, 33 (12.5 %) were smear positive by direct microscopy and 61 samples (23.2 %) were smear positive by the bleach-concentration method (OR 2.1, 95% CI 1.3-3.4, p < 0.010). There was an absolute increase in the number of acid fast bacilli per slide using the bleach-concentration technique compared to the direct method. The detection of acid fast bacilli was superior in early morning sputum followed by overnight spot samples.. The bleach-concentration method for sputum smear samples significantly increased the detection rate of smear positive patients compared to the direct method Thus, a shift from direct sputum microscopy to the bleach-concentration technique should be considered.

Topics: Adolescent; Adult; Aged; Bacteriological Techniques; Ethiopia; Female; Hospitals, University; Humans; Male; Microscopy; Middle Aged; Sodium Hypochlorite; Specimen Handling; Sputum; Tuberculosis, Pulmonary; Young Adult

Tuberculosis is a major public health problem throughout the world. Nearly one third of the world's population is infected with Mycobacterium tuberculosis (MTB) and hence at risk of developing active disease. Tuberculosis is a major cause of morbidity and mortality in Ethiopia, and the country belongs to one of the most affected high burden countries.. To determine the prevalence of smear positive pulmonary tuberculosis (PTB) and some associated risk factors among suspected patients attending Metehara sugar factory hospital, East Showa, Ethiopia.. A cross-sectional study was conducted from March 25 to May 30/2011 on 113 pulmonary tuberculosis suspected participants. Socio demographic and risk factors data were collected by using questionnaire. Sputum samples from tuberculosis suspects were collected, processed by sodium hypochlorite (bleach) centrifugation sedimentation concentration technique, stained by Ziehl-Neelsen staining and examined by Microscopy.. The overall prevalence of smear positive pulmonary tuberculosis was 14.2%. Statistical significant association was observed between age, family size, history of contact with chronic coughers (TB infected patients), smoking habit and alcoholism with pulmonary tuberculosis (P< 0.05).. The prevalence of smear positive pulmonary tuberculosis is high in Metehara sugar factory hospital. The magnitude is higher in the economically productive age group. Smoking, alcoholism and contact history with chronic coughers are highly associated with smear positive pulmonary tuberculosis Therefore, intensification of health education, early case finding & treatment are recommended to reduce the spread of the disease.

Topics: Adolescent; Adult; Age Distribution; Centrifugation; Child; Cross-Sectional Studies; Ethiopia; Female; Humans; Male; Middle Aged; Mycobacterium tuberculosis; Patients; Prevalence; Risk Factors; Sex Distribution; Socioeconomic Factors; Sodium Hypochlorite; Sputum; Surveys and Questionnaires; Tuberculosis, Pulmonary; Young Adult

Laos has a high prevalence of tuberculosis (TB) and a slowly increasing prevalence of human immunodeficiency virus/acquired immunedeficiency syndrome (HIV/AIDS). Sputum smear microscopy is the only method currently available for routine screening of pulmonary TB, although it only detects one in three cases among persons living with HIV (PLWH). Bleach treatment of sputum samples (bleach method) has been shown to significantly improve the sensitivity of the test; however, its effectiveness in PLWH remains to be determined in Laos.. To determine the performance of the bleach method as a diagnostic tool for pulmonary TB in PLWH and to assess its cost-effectiveness in Laos.. Of 174 sputum samples collected from 92 patients, 29 were culture-positive for Mycobacterium tuberculosis in 17 patients. The sensitivity of the direct method and the bleach method was respectively 59% and 93%, and specificity was 100% for both methods. The incremental cost-effectiveness ratio for screening an additional case was US$17.40.. The bleach method is simple, cheap, easy to perform and cost-effective in PLWH. Its implementation in laboratories involved in routine screening of pulmonary TB among PLWH would allow practitioners to start the treatment of this life-threatening co-infection earlier.

Topics: Adolescent; Adult; Aged; AIDS-Related Opportunistic Infections; Bacteriological Techniques; Bleaching Agents; Child; Coinfection; Cost-Benefit Analysis; Female; Health Care Costs; HIV Infections; Humans; Laos; Male; Microscopy; Middle Aged; Mycobacterium tuberculosis; Predictive Value of Tests; Prevalence; Prospective Studies; Sensitivity and Specificity; Sodium Hypochlorite; Specimen Handling; Sputum; Tuberculosis, Pulmonary; Young Adult

Bleach sedimentation is a method used to increase the diagnostic yield of sputum microscopy for countries with a high prevalence of human immunodeficiency virus (HIV) infection and limited resources.. To compare the relative cost-effectiveness of different microscopy approaches in diagnosing tuberculosis (TB) in Kenya.. An analytical decision tree model including cost and effectiveness measures of 10 combinations of direct (D) and overnight bleach (B) sedimentation microscopy was constructed. Data were drawn from the evaluation of the bleach sedimentation method on two specimens (first on the spot [1] and second morning [2]) from 644 TB suspects in a peripheral health clinic. Incremental cost per smear-positive detected case was measured. Costs included human resources and materials using a micro-costing evaluation.. All bleach-based microscopy approaches detected significantly more cases (between 23.3% for B1 and 25.9% for B1+B2) than the conventional D1+D2 approach (21.0%). Cost per tested case ranged between respectively euro 2.7 and euro 4.5 for B1 and B1+D2+B2. B1 and B1+B2 were the most cost-effective approaches. D1+B2 and D1+B1 were good alternatives to avoid using approaches exclusively based on bleach sedimentation microscopy.. Among several effective microscopy approaches used, including sodium hypochlorite sedimentation, only some resulted in a limited increase in the laboratory workload and would be most suitable for programmatic implementation.

Topics: Centrifugation; Cost-Benefit Analysis; Decision Trees; Humans; Kenya; Microscopy; Sodium Hypochlorite; Sputum; Time Factors; Tuberculosis, Pulmonary

Health centres in Awassa, southern Ethiopia.. Consecutive patients visiting health centre laboratories for the evaluation of suspected pulmonary tuberculosis (TB) between June and September 2006 were investigated. On-the-spot, morning and second on-the-spot sputum samples were pooled for each patient. Direct smears were stained with hot Ziehl-Neelsen (ZN) technique and aliquots cultured for mycobacteria on Löwenstein-Jensen media. The remaining sputum was treated with household bleach, aliquoted and processed with short-term digestion, centrifugation and sedimentation techniques, and stained with ZN.. Acid-fast bacilli were detected in respectively 126 (25%), 141 (28%), 169 (34%) and 198 (40%) of the 497 pooled sputum samples processed by the direct, short-term, sedimentation and centrifugation techniques (P < 0.001). The sensitivity of the direct, short-term, sedimentation and centrifugation techniques was respectively 51.1%, 53.2%, 57.6% and 63.6%. The difference between the direct smear and centrifugation (P < 0.001) or sedimentation (P < 0.005) methods was significant. The specificity of the direct, short-term digestion, sedimentation and centrifugation techniques was respectively 97%, 93%, 86.5% and 80.8%.. Bleach treatment of sputum and centrifugation significantly improves the sensitivity of smear microscopy for the diagnosis of TB in a health centre in a high TB burden area. It is more sensitive, but possibly less specific, than other bleach methods.

Topics: Bacteriological Techniques; Centrifugation; Humans; Mycobacterium tuberculosis; Sensitivity and Specificity; Sodium Hypochlorite; Specimen Handling; Sputum; Staining and Labeling; Tuberculosis, Pulmonary

To assess the impact of the sputum samples treatment by sodium hypochloride (NaOCl) 5% on the acid-fast bacilli (AFB) gradations in the tuberculosis diagnosis, 516 sputum samples were collected in 244 patients. The sputum smears made before and after expectorations treatment with NaOCl 5%, were stained by Ziehl-Neelsen hot method. The values obtained from the two microscopic readings were compared by using the chi2 test of McNemar. The statistical significance was set at p < 0.05. The results obtained before using NaOCl 5% showed that 357 samples were negative, while 41 were AFB scanty (gradation 1-9), 28, 40 and 50 were positive 1+, 2+ and 3+. After treatment, among 357 AFB negative expectorations, 14 (3.9%) were AFB-positive, while the AFB gradation increased for 77 (48.4%) in the 159 positive specimens. The two microscopic readings differ significantly (p = 0.001). The application of the process on a routine basis in the laboratory will require a reorganization of the tasks in order to give back the results to the patients in time. It is necessary to take into account the aspect of the samples.

Topics: Humans; Mycobacterium tuberculosis; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

Laos has a high prevalence of tuberculosis (TB) and a low prevalence of human immunodeficiency virus/acquired immune-deficiency syndrome (HIV/AIDS). Mycobacterium tuberculosis culture is not yet available. Case finding is based on the microscopic detection of acid-fast bacilli (AFB) in sputum. Liquefaction and concentration using sodium hypochlorite (bleach) could improve its yield.. To assess the gain due to the bleach method and its feasibility in Laos, and to compare the classical method sputum processing (direct microscopy) and the bleach method for AFB detection over 3 consecutive months at a central site (Vientiane) and for 1 month at a peripheral site (Attapeu).. Of 1675 sputum samples collected from 612 patients, respectively 206 (12.3%) and 275 (16.4%) were AFB-positive by the direct and bleach methods (P = 0.0007), i.e., an increase in smear positivity rate of 33.5% (95%CI 31.2-35.8). The superiority of the bleach method was confirmed, regardless of the site, the aspect of the sputum and delay before analysis. This method yielded 24 more TB patients.. The bleach method, which is very easy to use, could significantly increase the yield of sputum smear microscopy for the detection of pulmonary TB in Laos.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacteriological Techniques; Child; Child, Preschool; Colony Count, Microbial; Feasibility Studies; Female; Humans; Laos; Male; Microscopy, Fluorescence; Middle Aged; Mycobacterium tuberculosis; Predictive Value of Tests; Sodium Hypochlorite; Sputum; Staining and Labeling; Time Factors; Tuberculosis, Pulmonary; Young Adult

The purpose of the study was to evaluate the performance and feasibility of tuberculosis diagnosis by sputum microscopy after bleach sedimentation, compared with by conventional direct smear microscopy, in a setting of high prevalence of HIV.. In a community-based study in Kenya (a population in which 50% of individuals with tuberculosis are infected with HIV), individuals with suspected pulmonary tuberculosis submitted 3 sputum specimens during 2 consecutive days, which were examined by blind evaluation. Ziehl-Neelsen-stained smears were made of fresh specimens and of specimens that were processed with 3.5% household bleach followed by overnight sedimentation. Two different cutoffs for acid-fast bacilli (AFB) per 100 high-power fields (HPF) were used to define a positive smear: >10 AFB/100 HPF and 1 AFB/100 HPF. Four smear-positive case definitions, based on 1 or 2 positive smears with the 1 AFB or 10 AFB cutoff, were used.. Of 1879 specimens from 644 patients, 363 (19.3%) and 460 (24.5%) were positive by bleach sedimentation microscopy, compared with 301 (16.0%) and 374 (19.9%) by direct smear microscopy, with use of the 10 AFB/100 HPF (P < .001) and 1 AFB/100 HPF (P < .001) cutoffs, respectively. Regardless of the case definition used, bleach sedimentation microscopy detected significantly more positive cases than did direct smear microscopy: 26.7% (172 of 644) versus 21.7% (140 of 644), respectively, with the case definition of 1 positive smear and the 1 AFB/100 HPF cutoff (P < .001), and 21.4% (138 of 644) versus 18.6% (120 of 644), respectively, with the case definition of 1 positive smear and the 10 AFB/100 HPF cutoff (P < .001). Inter- and intrareader reproducibility were favorable, with kappa coefficients of 0.83 and 0.91, respectively. Bleach sedimentation was relatively inexpensive and was not time consuming.. Bleach sedimentation microscopy is an effective, simple method to improve the yield of smear microscopy in a setting of high prevalence of HIV. Further evaluation of this method, under operational conditions, is urgently needed to determine its potential as a tool for tuberculosis control.

Topics: Bacteriological Techniques; Centrifugation; HIV Infections; Humans; Microscopy; Prevalence; Sodium Hypochlorite; Specimen Handling; Sputum; Tuberculosis, Pulmonary

An experimental comparative study was conducted in order to compare the positivity pattern of sputum microscopy using the direct and overnight sedimentation Ziehl-Neelsen (ZN) smears, direct and NaOCl pretreated centrifuged ZN smears and overnight sedimentation and NaOC1 pretreated centrifuged ZN smears methods. We examined 660 sputum smeared slides for the presence of acid-fast bacillus from 220 sputum samples. Compared with the direct microscopy method, positivity increased by 91.1% after centrifugation (P < 0.001, chi(2) = 18.27) and by 71.1% after overnight sedimentation (P < 0.001, chi(2) = 11.61). No statistical significant difference was observed between the results of two different concentration techniques (P > 0.05, chi(2) = 0.789). The application of overnight sedimentation (in a laboratory without electricity) and/or the centrifugation technique could make a positive impact on the effectiveness of national tuberculosis control programmes.

Topics: Bacteriological Techniques; Centrifugation; Clinical Laboratory Techniques; Coloring Agents; Humans; Microscopy; Mycobacterium tuberculosis; Sodium Hypochlorite; Sputum; Time Factors; Tuberculosis, Pulmonary

We describe the performance of bleach-digested Zeihl-Neelsen (ZN) smears in TB suspects with/without HIV. In total, 51 (26%) and 62 (31%) out of the first 198 spot and digested smears were positive. Seven of the 30 HIV-positive patients had TB and their ZN smears were negative, scanty or 1 +. Six of seven digested smears were scanty. Forty-two of 115 HIV-negative patients had TB. Eleven (26%) of their digested smears were negative, 12 (29%) scanty and 19 (45%) positive. Despite the lower bacilli numbers of HIV-positive patients, the technique had sensitivity and specificity similar to that in HIV-negative patients.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; AIDS-Related Opportunistic Infections; Cytological Techniques; Female; HIV Infections; Humans; Male; Microscopy; Middle Aged; Mycobacterium tuberculosis; Predictive Value of Tests; Sensitivity and Specificity; Sodium Hypochlorite; Specimen Handling; Sputum; Tuberculosis, Pulmonary

The bleach digestion of sputum may improve the yield of smear microscopy but has not been validated in patients with HIV. Therefore we assessed the performance of bleach-digested smear microscopy among patients with HIV. One thousand three hundred and twenty one patients with chronic cough submitted three sputum samples for direct smear microscopy and were offered HIV tests. One sample was selected for a bleach-digested smear and another one was cultured. Patients were classified as having 'definite' (>or=2 positive smears), 'very likely' (smear-negative, culture- positive), 'less likely' (one smear-positive, culture-negative) and 'unlikely' (smear and culture negative) tuberculosis (TB). In all, 566/1045 (54%) patients were HIV positive and 731/1186 (62%) were culture positive. The digested smears were positive in 123/125 (98%) 'definite', 4/118 (3%) 'very likely' and 1/174 'unlikely' TB patients with HIV and in 125/127 (98%) 'definite', 2/74 (3%) 'very likely', 4/4 'less likely' and 2/127 'unlikely' TB without HIV. Three direct smears identified 252 (57%) and one digested smear 254 (57%) of the 444 patients with 'definite' or 'very likely' TB. One bleach-digested smear performed similarly to three direct smears. Both methods were less sensitive in HIV-positive patients. Further studies are needed to compare the performance of the two methods under operational conditions.

Topics: Cross-Sectional Studies; Disinfectants; HIV Infections; Humans; Mycobacterium tuberculosis; Prospective Studies; Sensitivity and Specificity; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

Pulmonary tuberculosis diagnosis commonly relies on the bacteriological examination of sputum. A cross-sectional hospital-based study was carried out to compare on "on the spot" sputum staining using sodium hypochlorite (bleach method) and routine Ziel-Neelsen (ZN) staining technique. Study candidates included individual patients presenting with cough <3 weeks (Group I) and > or =3 weeks (Group II). Sensitivity and specificity of the bleach method was calculated and compared at 100% using the ZN staining technique as the standard. A total of 171 patients (94 males, 77 females) with mean age 34.9 years (SD +/- 12.9) were recruited. Fifty-eight patients had coughed for <3 weeks while 113 had coughed for 23 weeks. Smear-positive TB in Group I was 13.8% (95% CI = 5-23) while in Group II was 25.7% (95% CI = 21-29). Using the bleach method, the prevalence of smear-positive TB in Group II was 28.3% (CI 95% = 20-36). This was an increase in smear-positivity rate of 15.6% as compared to the ZN technique. These results suggest that the use of bleach technique "on the spot" improve the sensitivity of tuberculosis diagnosis among patients with a history of coughing of over three weeks. However, further studies in different settings are recommended to validate the technique.

Topics: Adult; Female; Humans; Male; Microscopy; Middle Aged; Sodium Hypochlorite; Tanzania; Tuberculosis, Pulmonary

Topics: Humans; Microscopy; Sensitivity and Specificity; Sodium Hypochlorite; Specimen Handling; Sputum; Tuberculosis, Pulmonary

In an active surveillance study, the bleach concentration method to improve sputum smear microscopy for the diagnosis of pulmonary tuberculosis was applied in chest symptomatics in Mahidpur block of Ujjain district in Madhya Pradesh, India. We purposely selected twenty villages with population of approximately 20,000 individuals. 664 sputum specimens from 297 chest symptomatics were collected. Ziehl-Neelsen staining was performed on direct sputum smears, smears made after bleach method and modified Petroff's method. Out of 297 chest symptomatics, 16 cases (5.38%) were positive by direct microscopy, 27 cases (9.09%) were positive by bleach method, 22 cases (7.40%) were positive by modified Petroff's method. The bleach method is safe, cheap, easy and sensitive. It can be applied for improved detection of Mycobacterium tuberculosis in hospitals and laboratories especially in settings where mycobacterial culture facilities are not available. The implementation of bleach method clearly improves case detection and can be a useful contribution in the National Tuberculosis Control Program.

Topics: Bacteriological Techniques; Humans; India; Microscopy; Mycobacterium tuberculosis; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

The microbiological diagnosis of pulmonary tuberculosis (PTB) plays a key role in routine and Tuberculosis (TB) Control Programmes in developing countries. Concentration of acid-fast bacilli (AFB) in clinical specimens is an important step in the laboratory diagnosis of mycobacterial diseases. Microscopy of smears of sputum by direct and after mechanical sedimentation and centrifugation methods followed by treatment with 5% sodium hypochlorite (NaOCl) solution for concentration of the organisms were compared and evaluated. The rate of recovery of AFB from sputum was 8.5%, 25.5% and 38.0% for direct smear microscopy, concentration by sedimentation of NaOCl-treated sputa followed by Ziehl-Neelsen staining and concentration by centrifugation after use of NaOCl respectively. Both the concentration methods by the use of NaOCl solution increased the yield of theAFB by more than threefold compared with the direct microscopy of sputum (P < 0.05). The concentration methods by sedimentation, and centrifugation by the treatment of NaOCl, increased the sensitivity to 75% and 77.9%, respectively, and the specificity to 100% for both techniques. In conclusion, the use of NaOCl in the concentration of AFB in sputum is recommended for use in routine laboratory diagnosis of PTB in developing countries.

Topics: Adult; Bacteriological Techniques; Humans; Mycobacterium; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

In many settings, the diagnosis of pulmonary tuberculosis depends on sputum microscopy. However, this technique has low sensitivity. We studied the efficacy and safety of sputum digestion with bleach prior to Ziehl-Neelsen (ZN) staining.. Positive sputum smears were assessed for staining quality and viability of mycobacteria after varying bleaching times. Two hundred smears were then prepared from the first, second and third sputum sample of tuberculosis suspects. Equal amounts of 5% bleach were added to the remaining first sputum and ZN smears were prepared.. Optimal quality and staining was achieved with 30-45 min of bleaching. No growth was observed from positive samples after 15 min. Bleached specimens had 26% (52/200) positivity compared to 17.5% (35/ 200) of unbleached smears (P < 0.001). The bleached smears had 92.3% sensitivity, 93.4% specificity, 78.3% and 97.7% positive and negative predictive values, respectively, against a case definition. Ten patients failed to submit a second or third sputum. Six patients were positive on either the standard or bleach-digested smears, or both.. Bleach digestion is simple, cheap and kills mycobacteria. Its positivity rate is as good as three standard smears. This method has the potential to improve over-burdened services in developing countries.

Topics: Cytological Techniques; Developing Countries; Ethiopia; Humans; Safety; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

Tuberculosis has emerged as the leading cause of death due to single infectious agent. Sputum microscopy forms mainstay of diagnosis as it is most reliable, specific and objective method available especially in developing countries. However, this method is hampered by lack of sensitivity. Liquefaction and concentration of sputum before Ziehl Neelsen staining improves yield and also makes examination of smears rapid and convenient. A total of 304 sputum samples were studied by direct staining and after sodium hypochlorite treatment and centrifugation. Direct smears stained with Auramine-Phenol were also examined. Use of sodium hypochlorite method increased the number of positive samples from 52 to 96. No false positives were detected by either method. The method is simple as the only extra reagent required is sodium hypochlorite that is easily available. Additional advantage is that sodium hypochlorite, being a potent disinfectant, reduces the risk of laboratory acquired infections.

Topics: Humans; Microscopy; Mycobacterium tuberculosis; Sodium Hypochlorite; Sputum; Staining and Labeling; Tuberculosis, Pulmonary

A non-governmental organisation (NGO) supported tuberculosis control programme in Bangladesh with good smear microscopy.. To verify whether bleach sedimentation method increases the sensitivity of sputum smear microscopy for acid-fast bacilli (AFB), and if so, how.. Duplicate smears from successive routine specimens, peripheral centres examining direct smears, and blind examination of bleach sediment smears at central laboratories.. When all 3,287 sputum samples were examined in duplicate and the International Union Against Tuberculosis and Lung Disease cut-off for positivity was applied, more positives were not found by bleach sedimentation. Using the much lower American Thoracic Society (ATS) threshold, the percentage positives rose slightly from 15.5% for direct smear to 16.6% after bleach. The gain was more evident when suspect examinations only were taken into consideration, as bleach missed many positives identified by direct follow-up smear. When patients rather than individual smears were counted, more suspects were detected by bleach (10% gain on average), but with considerable variation between the centres (range 6-16%). To arrive at this gain, the ATS cut-off was used, with corrections for false results. Under routine conditions, however, this threshold is too low in view of possible transfer of AFB.. Bleach sedimentation can increase the diagnostic yield, but only to a minor extent if all other factors have been optimised already; it is not a panacea. Precautions against false negatives as well as false positives should be taken, and the additional workload is not negligible.

Topics: Bacteriological Techniques; Bangladesh; Bias; Colony Count, Microbial; False Negative Reactions; False Positive Reactions; Humans; Microscopy; Mycobacterium tuberculosis; Reproducibility of Results; Sensitivity and Specificity; Sodium Hypochlorite; Specimen Handling; Sputum; Tuberculosis, Pulmonary

Diagnosis of tuberculosis in low-income countries is hindered by the low sensitivity of direct sputum smear microscopy. We compared an improved method based on liquefaction of sputum with NaOCl followed by centrifugation with standard direct smear in a central hospital and at peripheral health centres in Honduras. Specificity was high and sensitivity significantly better with the NaOCl method. Moreover, this technique is safe, inexpensive and easy to perform. We recommend its implementation to enable rapid, sensitive laboratory diagnosis of pulmonary tuberculosis, especially in resource-poor settings where culture is not possible.

Topics: Disinfectants; Honduras; Humans; Microscopy; Sensitivity and Specificity; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

There is a great need for improved methods for the diagnosis of tuberculosis by techniques that are appropriate for control programs in low-income countries. Liquefaction of sputum with sodium hypochlorite followed by concentration of bacilli through overnight sedimentation significantly increases the sensitivity of direct microscopy, and this method could be an alternative for diagnostic centers not equipped with a centrifuge.

Topics: Bacteriological Techniques; Centrifugation; Evaluation Studies as Topic; Humans; Microscopy; Mycobacterium tuberculosis; Sensitivity and Specificity; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

To evaluate a safe sputum processing method for detection of tuberculosis in developing countries.. A sample processing method was developed in which acid fast bacilli were killed with 1% sodium hypochlorite and concentrated by flotation on a layer of xylene before staining by the Ziehl Neelsen or auramine O methods.. Best results were obtained by auramine O staining after flotation. Staining by the Ziehl Neelsen method after flotation gave better results than direct Ziehl Neelsen staining without flotation.. The flotation method with Ziehl Neelsen staining offers advantages for smear preparation in the tuberculosis control programmes of developing countries.

Topics: Bacteriological Techniques; Benzophenoneidum; Humans; Mycobacterium tuberculosis; Random Allocation; Sodium Hypochlorite; Specimen Handling; Sputum; Staining and Labeling; Tuberculosis, Pulmonary; Xylenes

Topics: Bacteriological Techniques; Centrifugation; Humans; Mycobacterium tuberculosis; Sodium Hypochlorite; Sputum; Tuberculosis, Pulmonary

Topics: Bacillus; Humans; Sodium Hypochlorite; Tuberculosis; Tuberculosis, Pulmonary