Direct Sputum Smear Microscopy Research Articles

Performance of Bleach Method Sputum Smear Microscopy for the Diagnosis of Tuberculosis in a Highly Endemic District in Lima, Peru.

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.

Concentrated specimen smear microscopy utilising a polymer membrane sandwich filtration vessel for the detection of acid-fast bacilli in health facilities in Sabah, East Malaysia

A simple, ready-to-use concentrated specimen smear microscopy method employing a nanometer silicon polyvinylidene fluoride (PVDF) polymer membrane sandwich filtration vessel to concentrate acid-fast bacilli (AFB) in samples (SFV-CSSM, Hunan-Tech New Medical System Co. Ltd. China) was compared with direct sputum smear microscopy (DSSM) to determine its performance using culture on modified Ogawa agar as reference. The results for 4114 clinical samples collected from health facilities in Sabah were interpreted with reference to culture results, sample collection-transportation conditions and clinical data including responses to anti-TB drug treatment. The SFV-CSSM showed higher sensitivity than DSSM (79.4% versus 60.5%) and less background interference. Its ability to detect low levels of AFB at an affordable cost makes it an excellent tool for the screening of pauci-bacillary samples as well as for active case finding in TB control programs.

High TB burden and low notification rates in the Philippines: The 2016 national TB prevalence survey.

SettingThe 3rd national tuberculosis (TB) survey in the Philippines in 2007 reported a significant decline in the prevalence of TB. Since then, more significant investments for TB control have been made, yet TB burden estimates from routine surveillance data remain relatively stable.ObjectiveTo estimate the prevalence of bacteriologically confirmed pulmonary TB in the Philippines amongst individuals aged ≥15 years in 2016.DesignIn March–December 2016, we conducted a population-based survey with stratified, multi-stage cluster sampling of residents in 106 clusters aged ≥15 years. Survey participants were screened for TB by symptom-based interview and digital chest X-ray. Those with cough ≥2 weeks and/or haemoptysis and/or chest X-ray suggestive of TB were requested to submit 2 sputum specimens for Xpert MTB/RIF, direct sputum smear microscopy using LED fluorescent microscopy, and mycobacterial solid culture (Ogawa method). Bacteriologically confirmed pulmonary TB was defined as MTB culture positive and/or Xpert positive.ResultsThere were 46,689 individuals interviewed, and 41,444 (88.8%) consented to a chest X-ray. There were 18,597 (39.8%) eligible for sputum examination and 16,242 (87.3%) submitted at least one specimen. Out of 16,058 sputum-eligible participants, 183 (1.1%) were smear-positive. There were 466 bacteriologically confirmed TB cases: 238 (51.1%) Xpert positive, 69 (14.8%) culture positive, and 159 (34.1%) positive by both Xpert and culture. The estimated TB prevalence per 100,000 population aged ≥15 years was 434 (95% CI: 350−518) for smear-positive TB, and 1,159 (95% CI: 1,016−1,301) for bacteriologically confirmed TB.ConclusionThis nationally representative survey found that the TB burden in the Philippines in 2016 was higher than estimated from routine TB surveillance data. There was no evidence of a decline in smear and culture positive TB from the 2007 survey despite significant investments in TB control. New strategies for case-finding and patient-centered care must be intensified and expanded.

Bleach-concentrated direct sputum smear microscopy procedure for diagnosis of pulmonary tuberculosis in poverty areas

ABSTRACT INTRODUCTION: Pulmonary tuberculosis caused by Mycobacterium tuberculosis is a serious public health problem affecting millions of people worldwide. The development of easy and low-cost diagnostic methods is crucial for disease control in rural remote and poverty areas and among vulnerable groups. OBJECTIVE: To evaluate the accuracy of laboratory methods for the diagnosis of Pulmonary tuberculosis. MATERIAL AND METHODS: Sputum samples from patients with clinical signs and symptoms were analyzed by microscopy after chemical treatment and spontaneous sedimentation and compared with methods employed routinely: direct sputum smear microscopy, culture, and GeneXpert®MTB/RIF. RESULTS: From the samples analyzed, 16% were positive by microscopy in the processed samples, 18% by both culture and Xpert®MTB/RIF, while 13% in the direct microscopy. The processed samples showed a 31% increase in positivity (57 samples) compared to conventional direct microscopy. In the analysis of the accuracy of the evaluated methods, all the results were statistically significant proving that they were not randomly positive or negative and confirming that there is a tendency for these results. CONCLUSION: Chemical treatment and spontaneous sedimentation of the sputum samples procedure represent an effective diagnostic tool in situations where more advanced technologies are not feasible. Besides the higher accuracy and greater detection of positive cases regarding the direct smear, the procedure strengthens biosafety by decreasing the risks of aerial contamination by Mycobacterium tuberculosis for laboratory professionals.

Comparative Sero-Epidemiological Prevalence of TB with Acid Fast Bacilli sputum Positive Cases in TB Suspects of Lower Dir

Background: Tuberculosis is an infection of lungs accompanied by coughing more than two weeks, fever, and night sweat, loss of appetite, weight loss and anorexia. Approximately 33% of the entire world population has infected the incidence of TB is 9 lac new cases each year with mortality rate of 1.3 million. There are 22 high risk burden countries accounting for nearly 80% entire TB of the globe. Materials and Methods: A cross sectional investigation was carried out to analyze patients by both immune chromatographic test and direct sputum smear microscopy. Patients were asked through a questionnaire mentioning the age, name, gender, location, and symptoms of TB. Thrusfield formula was used from veterinary microbiology to calculate the sample number. So, with 95% confidence interval, 5% absolute precision, I analyzed only 324 subjects of interest. Results: The entire positivity rate was 25% in which 79.5% was the rate of positivity by ICT and 20.5% by sputum smear microscopy. Higher positivity by Age range 20-40 showed 40.9% by ICT and by sputum it was found in age group 1-20 years 17.5%. Based on gender, higher positivity rate was found by both tests in females as compared to males. Females were 31.8% positive by ICT and 10% by sputum test. Males were 22.8% positive by ICT and 5% by sputum test. Marital status based higher positivity by ICT was found in married which is 29.11% while positivity in unmarried which is 12.5%. Conclusion: Tuberculosis is still a prevalent disease in lower Dir Khyber Pukhtunkhwa province of Pakistan. The more positivity rate has found in females as compared to males. It requires further sophisticated investigation to acquire a more accurate result in case of tuberculosis prevalence in lower Dir region of KP province of Pakistan. As the DOTS strategy states, Directly observed treatment and short course is a better way to early case detection and treatment otherwise the disease can become more exaggerated in short period of time because the bacteria is an airborne pathogen so it can freely transmit to the lungs.

Multidrug Resistant Mycobacterium tuberculosis Among Military and Civilian Personnel seen at a Tertiary Military Hospital, Manila, Philippines (2015-2018).

About one third of the world population is estimated to be infected with Mycobacterium tuberculosis (MTB), and this proportion is expected to be higher in countries with a high tuberculosis (TB) burden. The Philippines is both a high tuberculosis burden and a high multidrug resistant tuberculosis (MDR-TB) burden country. Though TB has been extensively described in the civilian population, there is limited data on TB in the military population. The objectives are: (1) To determine MTB/MDR-TB prevalence among military and civilian patients in the Philippines presenting with clinically suspected TB in a tertiary military hospital and (2) To determine performance of direct sputum smear microscopy (DSSM) using Ziehl-Neelsen (ZN) staining compared to Xpert MTB/RIF real-time reverse transcriptase polymerase chain reaction. Sputum samples were obtained from patients, clinically suspected with TB, and/or with TB associated signs/symptoms. Sputum specimens were tested using DSSM with ZN staining and Xpert MTB/RIF assay (Cepheid, Sunnyvale, California) and patient demographic and clinical data were collected. From March 2015 to December 2018, a total of 795 (173 military personnel [164 active duty and 9 retired]; 618 civilians; and 4 with no data on military/civilian status) patients with TB associated symptoms or clinically suspected with TB were tested. Overall, MTB prevalence was 81/795 (10%). MTB prevalence among active duty and retired military personnel were 27/164 (16%) and 4/9 (44%), respectively while MTB prevalence for civilian patients was 50/618 (8%) (p value=0.0003; OR=2.48 [95% C.I. 1.5-4]). Among active and retired military personnel who tested positive for MTB, rifampin resistance was 4/27 (15%) and 1/4 (25%), respectively, while rifampin resistance for civilian patients was 9/50 (18%) (p value=1; OR=0.88 [95% C.I. 0.26-2.90]). For active duty military personnel, average MTB prevalence (based on Xpert MTB/RIF) covering years 2015-2018 was 21% and ranged from 13% to 35%, while average rifampin resistance among MTB positive active duty military personnel was 15% and ranged from 0% to 25%. Overall sensitivity and specificity of DSSM compared to Xpert MTB/RIF were 70% and 96%, respectively. Positive and negative predictive values of DSSM to accurately categorize MTB in symptomatic cases (with Xpert MTB/RIF as "true positive" reference) were 74% and 95%, respectively. Performance of DSSM varied according to MTB load detected by Xpert MTB/RIF with increasing DSSM sensitivity observed as the MTB load detected by Xpert MTB/RIF increased (p=0.02). This report describes high MTB and MDR-TB prevalence rates among symptomatic military patients with military personnel having higher odds of MTB infection compared to the civilian patients in the study. Since DSSM (ZN) sensitivity greatly varied depending on MTB load, the Xpert MTB/RIF should be used as a first-line diagnostic tool to identify MTB and detect rifampin resistance among presumptive TB cases instead of DSSM (ZN) microscopy.

Diagnostic Performance of Xpert MTB/RIF Assay Versus Ziehl-Neelsen Method for the Diagnosis of Pulmonary Tuberculosis in Addis Ababa, Ethiopia

Background: Worldwide Tuberculosis (TB) is the ninth leading cause of death from a single infectious agent, positioning on top of Human Immuno Deficiency Virus (HIV) and it is still an eminently serious public health problem. In developing countries, Ziehl-Neelsen (ZN)-stained sputum smear microscopy is the most widely used diagnostic method in diagnosing Pulmonary Tuberculosis (PTB). This study was aimed to compare the diagnostic performances of ZN-method with Xpert MTB/RIF assay for the diagnosis of PTB in Addis Ababa, Ethiopia. Methods: Facility-based cross-sectional study design was conducted from September 2016 to June 2017 on a total of 244 sputum samples collected from presumptive TB patients. The L-J sputum culture was used as a gold standard to compare the diagnostic performances of Xpert MTB/RIF assay and ZN-methods. Kappa values were analyzed by using statistical package for Social Science (SPSS) version 20 software at 95% Confidence Interval (CI). The Sensitivity, Specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of ZN-stained sputum smear microscopy and Xpert MTB/RIF assay were calculated against the gold standard. Results: The Sensitivity, Specificity, PPV and NPV of ZN-stained sputum smear microscopy were 68.38%, 95.28%, 93.02% and 76.58% respectively, while for Xpert MTB/ RIF assay were 88.89%, 81.89%, 81.89% and 88.89% respectively. The results of the two diagnostic approaches were concordant with the gold standard with a kappa value of ZN 0.650 and 0.743 for Xpert MTB/RIF assay. Conclusion: This study concludes that the sensitivity of Xpert MTB/RIF assay was better than ZN-stained direct sputum smear microscopy for the diagnosis of pulmonary tuberculosis.

The Mono-Prep system increases the detection rate of sputum smear microscopy for diagnosing tuberculosis.

ObjectiveDirect sputum smear microscopy (DSSM) has a low detection rate. This study investigated whether an alternative method called Mono-Prep smear microscopy (MPSM) can enhance the diagnosis of tuberculosis in tuberculosis laboratories that perform direct smear microscopy in China.MethodsA total of 117 sputum samples were collected from outpatients who attended Beijing Chest Hospital. DSSM, MPSM, solid culture, and Xpert MTB/RIF were performed on the samples.ResultsThe positive rates of DSSM, MPSM, solid culture, and Xpert MTB/RIF were 27.4% (32/117), 40.2% (47/117), 35.9% (42/117), and 52.1% (61/117), respectively. MPSM could detect 15 more cases of tuberculosis compared with DSSM (47 vs 32) among 117 sputum samples. This represented a significantly higher positive rate and sensitivity of MPSM compared with DSSM. However, MPSM appeared to have a lower specificity (81.3%) compared with DSSM (90.7%) with the solid culture used as a standard.ConclusionUse of MPSM can increase the number of positive sputum samples, but it still needs improvement.

Urine Dipstick of Sputum for the Rapid Diagnosis of Community Acquired Pneumonia

IntroductionCommunity acquired pneumonia (CAP) is responsible for an important part of treatment costs across the world. Even though posterior-anterior lung radiography (PALG) and direct sputum smear microscopy are required or routine diagnoses. The purpose of this study is to determine the diagnostic value of the bedside urine strip tests in CAP. MethodsPatients who attended the emergency department (ED) between from February 2016 to September 2016 with expectoration complaints and suspicion of pneumonia. The sensitivity, specificity, and accuracy rate of the urine strip tests, direct sputum smear microscopy, and PALG were calculated and analyzed using SPSS 15.0. ResultsDuring the study period, 100 patients with pneumonia suspicion were evaluated in the ED. The sample was divided into two groups: negative and positive diagnosis of CAP. The leukocytes detecting by urine strip tests are statistical differences between the two groups (p: 0.003). The results show that the sensitivity, specificity, and accuracy rate of leukocytes detected in sputum with urine strip tests in the pneumonia diagnosis were 83.3%, 44.2% and 63% respectively. ConclusionAccording to the study, it is believed that the method of determination of leukocytes with urine strip tests in sputum combined with more detailed results. They can become part of CAP diagnosis methods.

External Quality Assessment of Laboratories Performance in AFB Microscopy in Tigray Region, North Ethiopia 2016

Background: In several countries with a high incidence of tuberculosis (TB), direct sputum smear microscopy remains the most cost effective tool for diagnosing patients with infectious tuberculosis and for monitoring their progress on treatment. The objective of the current study was to assess the quality of laboratory service in AFB microscopy of Tigray Region. Randomly selected health facilities were participated in the external quality assessment. Data was entered and analysed using SPSS version 20. Results: Between December 2015 and February 2016, a total of 80 laboratories were participated. Most (87%) of the laboratories have continuous electric supply. Only 70% of the health facilities have continuous pipe water and 56.5 % have no separate table for smear preparation, staining, microscopy and recording. From the distributed panel slides, 91% of the Health facilities were scored 100% concordant results but 9% of the health facilities were scored discordant results. The main reasons for discordant results were shortage of training, non-functional microscope, have no lens cleaning and using of unfiltered carbol fuchsin reagent. Conclusions: The performance of health facilities for smear microscopy reading and smear quality were relatively low in this study area, because smear positivity rate and annual negative slide volume of the health facilities were below the standard. Therefore Strengthening the EQA program and technical support on smear quality indicators are recommended to ensure for better quality diagnostic service of tuberculosis

Assessment of Smart Check Recombinant Test in Diagnosis of Pulmonary Tuberculosis In Al-Najaf Al-Ashraf Governorate

This cross sectional study was undertaken to evaluate the Smart Check Recombinant TB test which is a rapid membrane based screening test to detect the presence of antibodies to active M. tuberculosis (Serological test, which is used for the first time in Al - Najaf Al-Ashraf governorate) in screening for pulmonary tuberculosis as a rapid diagnostic test of pulmonary tuberculosis, in comparison with sputum smear microscopy depending on the (findings and clinical judgment). Patients involved were those who attend at Respiratory Chest Diseases Center in AL– Najaf ALAshraf Governorate. Fifty suspected patients, within the age groups 12 - 70 years old who were referred from primary health care centers, hospitals, and private clinics, between1/5/2006to31/6/2006. From 50 cases 7 (14 %) were diagnosed as pulmonary tuberculosis by Smart Check test and 43 (86%) all patients were negative, by direct sputum smear microscopy . Chi-square had been applied to test, the level of significance when alpha &lt; 0.05 and indicated there was high significant association.

External Quality Assessment of Laboratories Performance in AFB Microscopy in Tigray Region, North Ethiopia 2016

Background: In several countries with a high incidence of tuberculosis (TB), direct sputum smear microscopy remains the most cost effective tool for diagnosing patients with infectious tuberculosis and for monitoring their progress on treatment. The objective of the current study was to assess the quality of laboratory service in AFB microscopy of Tigray Region. Randomly selected health facilities were participated in the external quality assessment. Data was entered and analyzed using SPSS version 20.Results: Between December 2015 and February 2016, a total of 80 laboratories were participated. Most (87%) of the laboratories have continuous electric supply. Only 70% of the health facilities have continuous pipe water and 56.5% have no separate table for smear preparation, staining, microscopy and recording. From the distributed panel slides, 91% of the Health facilities were scored 100% concordant results but 9% of the health facilities were scored discordant results. The main reasons for discordant results were shortage of training, nonfunctional microscope, have no lens cleaning and using of unfiltered carbol fuchsin reagent.Conclusions: The performance of health facilities for smear microscopy reading and smear quality were relatively low in this study area, because smear positivity rate and annual negative slide volume of the health facilities were below the standard. Therefore Strengthening the EQA program and technical support on smear quality indicators are recommended to ensure for better quality diagnostic service of tuberculosis.

Revisiting Acid-Fast Bacilli Microscopy of Concentrated Sputum Smears as an Efficient Tool for the Diagnosis of Tuberculosis: A Study from a Tertiary Care Centre in Southern India

Background and objectives: With 2.2 million new cases every year, Tuberculosis (TB) continues to be an epidemic of large proportions in India. Conventional direct sputum smear microscopy, though limited in its sensitivity, is still the most common method of testing for TB. Newer techniques such as concentrated sputum microscopy, have shown some promise in improving this limited sensitivity. We have compared the efficacy of concentrated sputum versus the direct smear technique in 1000 sputum samples of patients suspected to be suffering from TB. Methods: A total of 1000 sputum specimens were collected for direct acid-fast bacilli (AFB) smear, concentrated AFB smear and culture from St. John’s Medical College and Hospital. 39 contaminated samples were (3.9%) omitted during the final analysis. Mycobacterial culture was used as the reference standard method for the detection of TB. Results: 184 and 198 of the 961 samples were found to AFB positive by direct smear microscopy and concentrated smear technique respectively. The measured sensitivity and specificity of direct smear microscopy were 69.86% and 95.82%, while that of concentrated smear microscopy was 76.71% and 95.96 % respectively. 33 samples found to be negative by the direct smear method turned out to be positive by the concentrated smear technique. Conclusions: Though our study suggests no significant statistical difference between the two techniques of detecting pulmonary tuberculosis, we recommend the use of the concentrated technique in centres such as ours, where facilities are already in place. In this way, the number of cases of TB that remain untreated may significantly come down.

Diagnosis of tuberculosis in a high TB-HIV environment using microscopy and culture: The example of Kakiika Prison-Kyamugorani, Mbarara, Uganda

There is growing concern about the high transmission of tuberculosis (TB) in prisons posing a risk to the outside community. There are high levels of overcrowding in the Uganda Prisons Service (UPS) with some prisons accommodating 4 times above their designed capacities. Our objective was to determine the prevalence of active pulmonary tuberculosis among prisoners. In addition we assessed the accuracy and reliability of TB smear microscopy using culture as gold standard and determined TB-HIV co-infection. Using a cross-sectional survey, we enrolled 140 male inmates in Kakiika prison-Kyamugorani, Mbarara. TB diagnosis was performed using direct sputum smear microscopy (DSSM) and culture for mycobacteria. HIV results were obtained from the clinical register with consent from the study participants. The prevalence of active pulmonary MTB was 2.9% based on culture findings. Microscopy had no smear positive results. However, there was no evidence that culture is different from microscopy in this sample (P=0.13). The overall HIV prevalence was 15.7% and TB-HIV co-infection was 25%. TB prevalence in this prison was greater than that of other prisons in Uganda at 0.7% and the general opulation at 0.4%. This is because the social and economic conditions that increase vulnerability to TB also increase vulnerability to criminal behavior and imprisonment. In addition, the high TB burden is due to the high HIV prevalence in prisons. The study recommended the use of a more sensitive technique for TB diagnosis specially in settings where the level of transmission is presumed to be high. Keywords : Culture, Microscopy, Prisons, Tuberculosis, TB/HIV co-infection

The referral pathway of presumptive drug resistant tuberculosis in the urban poor areas of Metro Manila, Philippines

Background: The National Tuberculosis Control Program (NTP) guidelines emphasize that all presumptive Drug Resistant Tuberculosis (DRTB) with history of previous tuberculosis (TB) treatment and with Multi-Drug Resistant Tuberculosis (MDRTB) contacts should be screened for MDR. Due to lack of tools to identify the referral outcome of presumptive DRTB, the RJPI developed an MDRTB Presumptive Masterlist to account referrals from health center to MDR treatment center. The study aims to understand gaps in the referral pathway experienced by Local Government Units (LGUs) and Non-Government Organizations (NGOs) from initial consultation until initiation of treatment. Methods & Materials: A retrospective descriptive study of patients’ data registered on MDRTB Presumptive Masterlist of eighteen Directly Observed Treatment Short-Course (DOTS) facilities in District 1 Tondo, Manila and Payatas, Quezon City from October 2012 to September 2013, were reviewed and analyzed using structured questionnaire. Unpaired t-test used in comparing the turnaround time between LGUs and NGOs including time between Direct Sputum Smear Microscopy (DSSM) results presented to patient and referred to MDR treatment center. A p-value < 0.05 was considered statistically significant. All analysis performed using EZR with graphical user interface for R. Results: A total of 378 Presumptive DRTB was identified and listed in the masterlist. Among them, 97% (368/378) referred and 90% (333/368) screened at MDR Treatemnt center. Among screened, 85% (283/333) completed the process of MDR screening and provided with an appropriate treatment based on NTP guidelines. 9.5% (35/368) were not screened mainly due to lost to follow up. The duration of time between sample collected and examined at laboratory of NGOs was significantly longer than LGUs (n = 283; p < 0.001). The time duration between the release of DSSM results and presentation of patient at NGOs was significantly shorter than LGUs (p = 0.009). Conclusion: Development of MDRTB Presumptive Masterlist has facilitated tracking of patients due for diagnosis and treatment. Referral system between health center and MDR treatment centers should be strengthened for proper patient endorsement and provided with an appropriate action. The NGOs should lessen diagnosis delays and LGUs should follow up patient for early start of TB treatment.

The Yield of First Spot Double Slide Smears for the Diagnosis of Pulmonary Tuberculosis

Background: Direct sputum smear microscopy is the cornerstone for the diagnosis of pulmonary tuberculosis (PTB) in resource-poor countries. However, the requirement for repeated visits to submit specimens and receive results is associated with considerable diagnostic delay, work load, patients drop-out and high expenses for patients. Although the World Health Organization (WHO) has recently changed its policy from spot morning spot (SMS) to spot morning (SM), the SM method still involves two days visits for a patient. The aim of this study was to evaluate the yield of first spot double slides smears for the diagnosis of PTB in high TB setting. Methods: A total of 362 patients who visited the out-patient department (OPD) of Dilla referral hospital and who were suspected of PTB were involved in the study. In addition SMS sputum samples were collected; double slides smears were prepared, stained by the Ziehl-Neelsen (ZN) method and 100 fields were examined under oil immersion objective for acid fast bacilli (AFB). Results: Of 362, 54 (14.92%) were smear-positives. Out of the 54 smear positive patients, 53 (98.15%) were positives by the first spot specimen. Additionally, 1 of 54 (1.85%) were positives by the morning specimen. Using the 2-day protocol (SMS) among 362 patients, 54 (14.92%) were smear positives by double slides and 53 (14.64%) by single slide smears. Whereas using the 1-day protocol (first spot); among 362 patients, 53 (14.64%) were smear positives both in double slides and single slide smears. Conclusion: The double slides smears from the first spot sputum samples appeared to be as effective as SMS strategy for the diagnosis of PTB though additional studies are required under various settings.

The Yield of First Spot Double Slide Smears for the Diagnosis of Pulmonary Tuberculosis

Background: Direct sputum smear microscopy is the cornerstone for the diagnosis of pulmonary tuberculosis (PTB) in resource-poor countries. However, the requirement for repeated visits to submit specimens and receive results is associated with considerable diagnostic delay, work load, patients drop-out and high expenses for patients. Although the World Health Organization (WHO) has recently changed its policy from spot morning spot (SMS) to spot morning (SM), the SM method still involves two days visits for a patient. Objective: This study evaluated the yield of first spot double slides smears for the diagnosis of PTB in high TB setting. Methods: A total of 362 patients who visited the out-patient department (OPD) of Dilla referral hospital and who were suspected of PTB were involved in the study. In addition SMS sputum samples were collected; double slides smears were prepared, stained by the Ziehl–Neelsen (ZN) method and 100 fields were examined under oil immersion objective for acid fast bacilli (AFB). Results: Of 362, 54(14.92%) were smear-positives. Out of the 54 smear positive subjects, 53 (98.15%) were positives by the first spot specimen. Additionally, 1 of 54 (1.85%) were positives by the morning specimen. Using the 2-day protocol (SMS) among 362 patients, 54(14.92%) were smear positives by double slides and 53(14.64%) by single slide smears. Whereas using the 1-day protocol (first spot); among 362 patients, 53(14.64%) were smear positives both in double slides and single slide smears. Conclusion: The double slides smears from the first spot sputum samples appeared to be as effective as SMS strategy for the diagnosis of PTB though additional studies are required under various settings.

Case-Detection Rate of Direct Sputum Smear Microscopy for Diagnosis of Pulmonary Tuberculosis in Abia State, Nigeria

The accuracy of sputum smear microscopy, the tuberculosis case-finding method in the Abia State TB Control Programme has never been assessed due to lack of culture facilities. To assess the accuracy of sputum smear microscopy in routine control programme conditions in Abia State, sputum samples from patients undergoing investigation for tuberculosis were analyzed using Ziehl-Neelsen staining technique for sputum smear microscopy and culture on Lowenstein-Jensen medium as reference standard. Out of 150 participants tested, 51 were smear –positive for acid fast bacilli (positivity rate, 34.0 %, 51/150) while 79 were culture positive for Mycobacterium tuberculosis complex and 12 for non-tuberculous mycobacteria (NTM). Thirty-seven of the 79 culture positive for M. tuberculosis were smear positive giving a ratio of smear to culture positivity of 46.84%. Forty-two (42.4%) of the 99 smear negative cases were culture positive for M. tuberculosis. The sensitivity of smear microscopy was 50.0% (95%CI=39.0-61.0) and specificity was 92.3% (95% CI=86.4-98.2). The prevalence of HIV/TB coinfection among the study participants was 48% (12/25). Although the case- detection rate of smear microscopy was moderate in this study, the large proportion of TB patients missed by smear microscopy is a cause for concern and requires concerted effort to improve the sensitivity of smear microscopy. Introduction of more sensitive diagnostic methods like culture also need to be considered. La precision des frottis, la methode la recherche de cas de tuberculose dans le programme de lutte contre la tuberculose dans l’Etat d'Abia n'a jamais ete evalue en raison du manque d'installations de culture. Pour evaluer la precision des frottis dans les conditions du programme de controle de routine dans cet Etat , les expectorations de patients subissant une enquete de la tuberculose ont ete analysees a l'aide de technique de coloration de Ziehl-Neelsen pour la microscopie des frottis de crachats et de la culture sur milieu de Lowenstein- Jensen en tant que norme de reference . Sur les 150 participants testes, 51 etaient a frottis positif pour les bacilles acido rapide (taux de positivite, 34,0%, 51/150), tandis que 79 etaient positifs a la culture pour complexe Mycobacterium tuberculosis et 12 pour les mycobacteries non tuberculeuses (NTM). Trente-sept de la culture 79 positive pour M.tuberculosis etaient a frottis positif donnant un ratio de frottis de positivite de la culture de 46,84 %. Quarante-deux (42,4%) des 99 cas a frottis negatifs etaient positifs a la culture pour M. tuberculosis. La sensibilite de la microscopie des frottis etait de 50,0 % (IC a 95% = 39,0 a 61,0) et la specificite etait de 92,3 % (IC a 95% = 86,4 a 98,2). La prevalence du VIH / TB coinfection parmi les participants a l'etude etait de 48% (12 /25). Bien que le taux de microscopique des frottis de depistage des cas ait ete modere dans cette etude, la forte proportion de patients atteints de tuberculose manques par examen microscopique des frottis est un sujet preoccupant et exige un effort concerte pour ameliorer la sensibilite de la microscopie des frottis. La presentation des methodes de diagnostic plus sensibles comme la culture doivent aussi etre pris en consideration.

Challenges facing lipoarabinomannan urine antigen tests for diagnosing HIV-associated tuberculosis

Challenges facing lipoarabinomannan urine antigen tests for diagnosing HIV-associated tuberculosis

Success rate of direct sputum smear microscopy (DSSM) for AFB among psychiatric patients in a Philippine government Psychiatric healthcare facility

Success rate of direct sputum smear microscopy (DSSM) for AFB among psychiatric patients in a Philippine government Psychiatric healthcare facility