Diagnosis of tuberculosis from smear-negative presumptive TB cases using Xpert MTB/Rif assay: a cross-sectional study from Nepal

2019 ◽  
Author(s):  
Priyatam Khadka ◽  
Januka Thapaliya ◽  
Ramesh Bahadur Basnet ◽  
Gokarna Raj Ghimire ◽  
Jyoti Amatya ◽  
...  

Abstract Background In most developing countries, smear-negative pulmonary TB (SNPT) often gets missed from the diagnosis of consideration, though it accounts 30-65% of total PTB cases, due to deficient or inaccessible molecular diagnostic modalities. Methods The cross-sectional study enrolled 360 patients with clinical-radiological suspicion of SNPT in Tribhuvan University Teaching Hospital (TUTH). The patient selection was done as per the algorithm of Nepal’s National Tuberculosis Programme (NTP) for Xpert MTB/RIF testing. Participants’ demographic and clinical information were collected using a pre-tested questionnaire. The specimens were collected, processed directly for Xpert MTB/RIF test according to the manufacturer’s protocol. The same samples were stained using the Ziehl-Neelsen technique then observed microscopically. Both findings were interpreted; rifampicin-resistant, if obtained, on Xpert testing was confirmed with a Line Probe Assay. Result Of 360 smear-negative sputum samples analyzed, 85(23.61%) found positive while 3(0.8%) of them were rifampicin resistance. The infection was higher in males, i.e. 60(25.3%) compared to female 25(20.3%). The age group, >45(nearly 33%) with median age 42± 21.5, were prone to the infection. During the study period, 4.6% (515/11048) sputum samples were reported as smear-positive in TUTH. Consequently, with Xpert MTB/RIF assay, the additional case 16.5% (n=85/515) from smear-negative presumptive TB cases were detected. Among the most occurring clinical presentations, cough and chest pain were positively associated with SNPT. While upper lobe infiltrates (36.4%) and pleural effusion (40.4%) were the most peculiar radiological impression noted in PTB patient. 94 multi-drug resistant(MDR) suspected cases were enrolled; of total suspects, 29(30.8%) samples were rifampicin sensitive, 1(1.06%) indeterminant, 3(3.19%) rifampicin-resistant while remaining of them were negative. 2(2.2%) MDR cases were recovered from the patient with a previous history of ATT, of total 89 previously treated cases enrolled However, a single rifampicin-resistant from the new suspects. Conclusion With an application of the assay, the additional cases, missed with smear microscopy, could be sought and exact incidence of the diseases could be revealed. Keywords: Xpert MTB/Rif assay, Mycobacterium tuberculosis, Line Probe Assay, MDR-TB, smear-negative

2019 ◽  
Author(s):  
Priyatam Khadka ◽  
Januka Thapaliya ◽  
Ramesh Bahadur Basnet ◽  
Gokarna Raj Ghimire ◽  
Jyoti Amatya ◽  
...  

Abstract Background In most developing countries, smear-negative pulmonary TB (SNPT) often gets missed from the diagnosis of consideration, though it accounts 30-65% of total PTB cases, due to deficient or inaccessible molecular diagnostic modalities. Methods The cross-sectional study enrolled 360 patients with clinical-radiological suspicion of SNPT in Tribhuvan University Teaching Hospital (TUTH). The patient selection was done as per the algorithm of Nepal’s National Tuberculosis Program (NTP) for Xpert MTB/RIF testing. Participants’ demographic and clinical information were collected using a pre-tested questionnaire. The specimens were collected, processed directly for Xpert MTB/RIF test according to the manufacturer’s protocol. The same samples were stained using the Ziehl-Neelsen technique then observed microscopically. Both findings were interpreted; rifampicin-resistant, if obtained, on Xpert testing was confirmed with a Line Probe Assay. Result Of 360 smear-negative sputum samples analyzed, 85(23.61%) found positive while 3(0.8%) of them were rifampicin resistance. The infection was higher in males, i.e. 60(25.3%) compared to female 25(20.3%). The age group, >45(nearly 33%) with median age 42± 21.5, were prone to the infection. During the study period, 4.6% (515/11048) sputum samples were reported as smear-positive in TUTH. Consequently, with Xpert MTB/RIF assay, the additional case 16.5% (n=85/515) from smear-negative presumptive TB cases were detected. Among the most occurring clinical presentations, cough and chest pain were positively associated with SNPT. While upper lobe infiltrates (36.4%) and pleural effusion (40.4%) were the most peculiar radiological impression noted in PTB patient. 94 multi-drug resistant(MDR) suspected cases were enrolled; of total suspects, 29(30.8%) samples were rifampicin sensitive, 1(1.06%) indeterminate, 3(3.19%) rifampicin-resistant while remaining of them were negative. 2(2.2%) MDR cases were recovered from the patient with a previous history of ATT, of total 89 previously treated cases enrolled However, a single rifampicin-resistant from the new suspects. Conclusion With an application of the assay, the additional cases, missed with smear microscopy, could be sought and exact incidence of the diseases could be revealed. Keywords: Xpert MTB/Rif assay, Mycobacterium tuberculosis, Line Probe Assay, MDR-TB, smear-negative


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Priyatam Khadka ◽  
Januka Thapaliya ◽  
Ramesh Bahadur Basnet ◽  
Gokarna Raj Ghimire ◽  
Jyoti Amatya ◽  
...  

Abstract Background In most developing countries, smear-negative pulmonary TB (SNPT) often gets missed from the diagnosis of consideration, though it accounts 30–65% of total PTB cases, due to deficient or inaccessible molecular diagnostic modalities. Methods The cross-sectional study enrolled 360 patients with clinical-radiological suspicion of SNPT in Tribhuvan University Teaching Hospital (TUTH). The patient selection was done as per the algorithm of Nepal’s National Tuberculosis Program (NTP) for Xpert MTB/RIF testing. Participants’ demographic and clinical information were collected using a pre-tested questionnaire. The specimens were collected, processed directly for Xpert MTB/RIF test according to the manufacturer’s protocol. The same samples were stained using the Ziehl-Neelsen technique then observed microscopically. Both findings were interpreted; rifampicin-resistant, if obtained, on Xpert testing was confirmed with a Line Probe Assay. Result Of 360 smear-negative sputum samples analyzed, 85(23.61%) found positive while 3(0.8%) of them were rifampicin resistance. The infection was higher in males, i.e. 60(25.3%) compared to female 25(20.3%). The age group, > 45(nearly 33%) with median age 42 ± 21.5, were prone to the infection. During the study period, 4.6% (515/11048) sputum samples were reported as smear-positive in TUTH. Consequently, with Xpert MTB/RIF assay, the additional case 16.5% (n = 85/515) from smear-negative presumptive TB cases were detected. Among the most occurring clinical presentations, cough and chest pain were positively associated with SNPT. While upper lobe infiltrates (36.4%) and pleural effusion (40.4%) were the most peculiar radiological impression noted in PTB patient. 94 multi-drug resistant(MDR) suspected cases were enrolled; of total suspects, 29(30.8%) samples were rifampicin sensitive, 1(1.06%) indeterminate, 3(3.19%) rifampicin-resistant while remaining of them were negative. 2(2.2%) MDR cases were recovered from the patient with a previous history of ATT, of total 89 previously treated cases enrolled However, a single rifampicin-resistant from the new suspects. Conclusion With an application of the assay, the additional cases, missed with smear microscopy, could be sought and exact incidence of the diseases could be revealed.


Author(s):  
Tade Bagbi ◽  
Ningthoukhongjam Reema ◽  
S. Bhagyabati Devi ◽  
Thangjam Gautam Singh ◽  
Mohammad Jaleel ◽  
...  

Abstract Introduction Tuberculosis (TB) in people living with human immunodeficiency virus (PLHIV) is difficult to diagnose due to fewer organisms in sputum and extrapulmonary samples. Sputum culture takes 4 to 8 weeks for growth of the mycobacteria. Delayed treatment for TB in PLHIV leads to increased mortality. This study evaluated cartridge-based nucleic acid amplification test (CBNAAT) as a diagnostic tool for diagnosis of pulmonary TB (PTB) and extrapulmonary TB (EPTB) in PLHIV in the second most HIV prevalent state in India and for comparing its efficacy between Ziehl–Neelsen (ZN) staining sputum smear–positive and sputum smear–negative TB. Methods This cross-sectional study was conducted in RIMS, Imphal, with 167 PLHIV patients, age 15 years or older, having signs and symptoms of TB. Appropriate samples for sputum microscopy and CBNAAT were sent. Conclusion The overall sensitivity of sputum smear for acid-fast bacillus (AFB) was found to be 30.71% and that of CBNAAT was 38.57%. Sensitivity of CBNAAT for sputum smear–positive and sputum smear–negative TB was 100 and 11.3%, respectively. Sensitivity of ZN smear for AFB of EPTB sample was 48.1% and that of CBNAAT was 59.25%. In both PTB and EPTB, CBNAAT showed an increase in diagnosis of microbiologically confirmed PTB cases by 7.8 and 11.1%, respectively, over and above the cases diagnosed by ZN smear microscopy. Rifampicin resistance was detected in five patients. We conclude that CBNAAT is a rapid test with better sensitivity in diagnosis of PTB and EPTB in PLHIV, compared with ZN smear microscopy. It detects rifampicin resistance for multidrug-resistant TB and helps in early treatment intervention.


2019 ◽  
Author(s):  
Priyatam Khadka ◽  
Januka Thapaliya ◽  
Ramesh Bahadur Basnet ◽  
Gokarna Raj Ghimire ◽  
Jyoti Amatya ◽  
...  

Abstract Background For improving patient care and abbreviating the disease transmission chain, speedy detection of tuberculosis and its drug-resistance with precision is crucial. Methods We analyzed, pulmonary tuberculosis (PTB) suspected, 360 smear-negative sputum from the patients attending Tribhuvan University Teaching Hospital (TUTH). The patients were selected as per the algorithm of National Tuberculosis Programme(NTP) for Xpert MTB/RIF testing. Participants’ demographic and clinical information were collected using a pre-tested questionnaire. The specimens were collected, processed directly for Xpert MTB/RIF test according to the manufacturer’s protocol. The same samples were stained using Ziehl-Neelsen technique then observed microscopically. Both findings were interpreted; rifampicin-resistant, if obtained, on Xpert testing was confirmed with Line Probe Assay. Result Of 360 smear-negative sputum samples analyzed, 85(23.61%) found positive while 3 of them were rifampicin resistance. The infection was higher in male, i.e. 60(25.3%) compared to female 25(20.3%). The age group, >45(nearly 33%) with median age 42± 21.5, were prone to the infection. During the study period, 4.6% (515/11048) sputum samples were reported as smear-positive in TUTH; consequently, with Xpert MTB/RIF assay, additional case 16.5% (n=85/515) missed on the smear microscopy, were detected—surging overall confirmed cases. Among the most occurring clinical presentations, cough and chest pain were more evident in PTB with relative-risk at 95% confident-levels i.e. 3.03(1.01-9.11) and 3.47(2.29-5.27) respectively. A higher number of new suspects (n=63) were found positive compared to previously treated suspects. The upper lobe infiltrates (36.4%) and pleural effusion (40.4%) were peculiar radiological impression noted in PTB patient. 94 MDR suspected cases were enrolled; of total suspected cases, 29 samples were found rifampicin sensitive, 1 indeterminant while 2 of them were rifampicin-resistant. However, a single rifampicin-resistant; case was detected in patient which was not MDR suspected. Conclusion Additional cases of PTB which are neglected as smear-negative on microscopy and other conventional tests can be detected with gene Xpert test. Hence, recommended to every suspect as a presumptive test could be a wise investment in diagnosis to restrict the global burden to some extent. Keywords: Xpert MTB/Rif assay, Mycobacterium tuberculosis, Line Probe Assay, MDR-TB


2020 ◽  
Vol 15 ◽  
Author(s):  
Solomon Hambisa ◽  
Rediet Feleke ◽  
Ameha Zewudie ◽  
Mohammed Yimam

Background:: Rational drug use comprises aspects of prescribing, dispensing and patient use of medicines for different health problems. This study is aimed to assess drug prescribing practice based on the world health organization prescribing indicators in Mizan-Tepi University teaching hospital. Methods:: An institutional based retrospective cross sectional study was conducted to evaluate prescribing practices in Mizan-Tepi University teaching hospital. Data were collected based on World health organization drug use indicators using prescription papers. 600 prescriptions dispensed through the general outpatient pharmacy of the hospital were collected by systematic random sampling method from prescriptions written for a 1-year time in Mizan-Tepi University teaching hospital. Results:: The present study found that the average number of drugs per prescription was 2.04 ± 0.87 in Mizan-Tepi University teaching hospital with a range between 1 and 5. Prescribing by generic name was 97.6 % and 47.8% of prescriptions contained antibiotics in the hospital. 27.7% of prescriptions contained at least one injectable medication in Mizan-Tepi University teaching hospital. From prescribed drugs, 96.7% of them were prescribed from Ethiopian essential drug list. Conclusion:: Present study indicated that the average number of drugs prescribed per encounter, the percentage of generic prescribing and prescribing from the EDL were close to optimal value. However, the percentage of encounters with antibiotics and injections prescribed were found be very high. Thus, the study highlights some improvements in prescribing habits, particularly by focusing on the inappropriate consumption of antibiotics and injections.


2020 ◽  
pp. 004947552098130
Author(s):  
Fabián R Carreño-Almánzar ◽  
Adán Coronado-Galán ◽  
Sonia A Cala-Gómez ◽  
Agustín Vega-Vera

Imported malaria has increased in Colombia since 2015 and has been attributed to migrants coming from Venezuela. We present a series of malaria cases, nested in a retrospective cross-sectional study between 2017 and 2018, aimed at calculating the prevalence of medical diseases among immigrants in a University Hospital in Colombia. Among 154 immigrants admitted for medical causes between 2017 and 2018, 8 were diagnosed with malaria, all due to Plasmodium vivax. Of these, seven had uncomplicated malaria, five had a previous history of malaria, one was critically ill, but none died. We highlight that, similar to other case series of imported malaria, Latin American migrants were young, with similar clinical profiles, having a low proportion of severe cases, and P. vivax was the most frequent cause.


BMJ Open ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. e037913
Author(s):  
Mala George ◽  
Geert-Jan Dinant ◽  
Efrem Kentiba ◽  
Teklu Teshome ◽  
Abinet Teshome ◽  
...  

ObjectivesTo evaluate the performance of the predictors in estimating the probability of pulmonary tuberculosis (PTB) when all versus only significant variables are combined into a decision model (1) among all clinical suspects and (2) among smear-negative cases based on the results of culture tests.DesignA cross-sectional study.SettingTwo public referral hospitals in Tigray, Ethiopia.ParticipantsA total of 426 consecutive adult patients admitted to the hospitals with clinical suspicion of PTB were screened by sputum smear microscopy and chest radiograph (chest X-ray (CXR)) in accordance with the Ethiopian guidelines of the National Tuberculosis and Leprosy Program. Discontinuation of antituberculosis therapy in the past 3 months, unproductive cough, HIV positivity and unwillingness to give written informed consent were the basis of exclusion from the study.Primary and secondary outcome measuresA total of 354 patients were included in the final analysis, while 72 patients were excluded because culture tests were not done.ResultsThe strongest predictive variables of culture-positive PTB among patients with clinical suspicion were a positive smear test (OR 172; 95% CI 23.23 to 1273.54) and having CXR lesions compatible with PTB (OR 10.401; 95% CI 5.862 to 18.454). The regression model had a good predictive performance for identifying culture-positive PTB among patients with clinical suspicion (area under the curve (AUC) 0.84), but it was rather poor in patients with a negative smear result (AUC 0.64). Combining all the predictors in the model compared with only the independent significant variables did not really improve its performance to identify culture-positive (AUC 0.84–0.87) and culture-negative (AUC 0.64–0.69) PTB.ConclusionsOur finding suggests that predictive models based on clinical variables will not be useful to discriminate patients with culture-negative PTB from patients with culture-positive PTB among patients with smear-negative cases.


Author(s):  
Jovilia Abong ◽  
Victoria Dalay ◽  
Ivor Langley ◽  
Ewan Tomeny ◽  
Danaida Marcelo ◽  
...  

Setting A high proportion of notified tuberculosis cases in the Philippines are clinically diagnosed (63%) as opposed to bacteriologically confirmed. Better understanding of this phenomenon is required to improve tuberculosis control. Objectives To determine the percentage of Smear Negative Presumptive Tuberculosis patients that would be diagnosed by GeneXpert; compare clinical characteristics of patients diagnosed as tuberculosis cases; and review the impact that the current single government physician and a reconstituted Tuberculosis Diagnostic committee (Expert Panel) may have on tuberculosis over-diagnosis. Design This is a cross-sectional study of 152 patients 15-85 years old with two negative Direct Sputum Smear Microscopy results, with abnormal chest X-ray who underwent GeneXpert testing and review by an Expert Panel. Results 31% (48/152) of the sample were Xpert positive. 93% (97/104) of GeneXpert negatives were clinically diagnosed by a Single Physician. Typical symptoms and X-ray findings were higher in bacteriologically confirmed tuberculosis. When compared to GeneXpert results, the Expert panel’s sensitivity for active tuberculosis was high (97.5%, 39/40) but specificity was low (40.2%, 35/87). Conclusion Using the GeneXpert would increase the level of bacteriologically confirmed tuberculosis substantially among presumptive Tuberculosis. An Expert panel will greatly reduce over-diagnosis usually seen when a decision is made by a Single Physician.


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