samuel Kudzawu | Lancaster University Management School (original) (raw)
Papers by samuel Kudzawu
West African journal of medicine
The level of drug resistance in mycobacterial isolates from previously treated cases in Ghana is ... more The level of drug resistance in mycobacterial isolates from previously treated cases in Ghana is not known although drug resistant tuberculosis threatens efforts to control the disease. To identify and determine the susceptibility of mycobacterial isolates from tuberculosis cases with clinical treatment failure. This prospective survey was undertaken at the Chest Clinic of Korle Bu Teaching Hospital in Accra, Ghana. The participants were twenty-eight cases referred to the hospital with clinical treatment failure. Two sputum specimens from each case were stained by Ziehl-Neelsen method, cultured, identified and sensitivity tests performed by the proportion method. Eighteen isolates of mycobacteria were identified from 28 failed treatment cases. Five were atypical mycobacteria. Approximately fifty percent (13/28) of cases had Mycobacterium tuberculosis, 5(18%) had atypical mycobacteria, 7(25%) had pure fungal growth and 3(11% 8) had no growth. Fifteen isolates were resistant to two or...
Ghana Medical Journal, 2011
Introduction: The burden of MDR-TB is unknown in areas that do not have drug susceptibility testi... more Introduction: The burden of MDR-TB is unknown in areas that do not have drug susceptibility testing (DST), but its frequency is expected to be higher in previously treated cases. Where DST is not available the WHO recommended standardized retreatment (Category II) regimen is given to previously treated TB patients Objective: To evaluate the frequency and pattern of drug resistance of Mycobacterium tuberculosis isolated from patients with chronic smear positive pulmonary tuberculosis. Method: We conducted a retrospective review of mycobacterial cultures and drug susceptibility testing (DST) performed on sputum samples collected, between January 2005 and September 2006, from 40 patients with pulmonary TB who had failed at least one standard retreatment regimen. Clinical data was extracted from patients' case notes. Results: M. tuberculosis was recovered from 28 (70%) of the 40 patients. Of the 28 culture positive cases, 10 (36%) had resistance to at least rifampicin and isoniazid (multi-drug resistant TB), 22 (79%) isolates had resistance to streptomycin and 13 (46%) to ethambutol. Of the patients with a positive culture, only one (3.6%) had a fully susceptible organism. Of the 10 patients with MDR TB, 7 had received two or more retreatment courses. Conclusion: The frequency of drug resistant TB was high among patients who failed at least one course of category II therapy. Effective combination regimens based on DST is necessary in patients who remain smear positive on the standardized retreatment regimen.
Transactions of the Royal Society of Tropical Medicine and Hygiene, 2011
Tuberculosis (TB) remains a major cause of mortality despite availability of effective chemothera... more Tuberculosis (TB) remains a major cause of mortality despite availability of effective chemotherapy. This study was performed to identify contributing factors for poor outcome during anti-tuberculosis treatment at a teaching hospital chest clinic. Medical records of registered patients treated for TB between 1 January and 31 December, 2009 were reviewed and abstracted for demographic, clinical and outcome data. Risk factors for mortality during therapy were assessed using bivariate and multivariate logistics approaches. Of 599 patients, 355 (58.9%) completed therapy and/or were cured, 192 (32.1%) died, and 39 (6.5%) defaulted. In multivariate analysis, independent risk factors for mortality included pulmonary cases for which sputum smear status was unknown (odds ratio [OR] 13.
Reported monthly TB cases data set for a ten-year period at the chest clinic-Korle-bu teaching ho... more Reported monthly TB cases data set for a ten-year period at the chest clinic-Korle-bu teaching hospital. (XLSX 12 kb)
S OF PLENARY PRESENTATIONS A3 ABSTRACTS OF ORAL PRESENTATIONS A5S OF ORAL PRESENTATIONS A5 ABSTRA... more S OF PLENARY PRESENTATIONS A3 ABSTRACTS OF ORAL PRESENTATIONS A5S OF ORAL PRESENTATIONS A5 ABSTRACTS OF POSTER PRESENTATIONS A16S OF POSTER PRESENTATIONS A16
Journal of Tuberculosis Research
Background: Bacteriologically-confirmed tuberculosis (TB) cases used in calculating TB prevalence... more Background: Bacteriologically-confirmed tuberculosis (TB) cases used in calculating TB prevalence in a country are obtained through laboratory examination of sputum specimens. Objective: This article describes laboratory processing of specimens, results overview, conclusions and key lessons learnt from the perspective of laboratory personnel involved in the conduct of TB disease prevalence survey in Ghana in 2013. Methods: Symptoms screening and Chest X-ray suggestive of TB were used to select participants who produced sputum to confirm TB cases using microscopy, culture and Xpert ® MTB/RIF assay (GeneXpert). Results: A total of 15,935 single and paired sputum specimens were received from eligible participants. About half of Ziehl-Nielsen (129/263) and Auramine O (122/246) stained smear positives were scanty positive. Culture positivity rate for Mycobacterium tuberculosis complex was 266/14,994 (1.7%) and 100/15,179 (0.7%) in Mycobacterial Growth Indicator Tube (MGIT) and Lowenstein-Jensen (LJ) media respectively; while non-tuberculous mycobacterium was 294/14,994 (1.96%) and 167/15,179 (1.1%). Total contamination rates in MGIT (5.4%) were higher than in LJ (1.7%). Prevalence of smear positive TB and bacteriologically confirmed TB among adult population (≥15 years) was estimated at 111 (95% CI: 76-145) and 356 (95% CI: 288-425) per 100,000 population respectively. Conclusions and Lessons Learnt: Direct supervision of specimen collection by well-trained laboratory personnel, timely transportation of specimens from field to laboratory, prompt specimen processing and use of electronic data management systems are essential for a reliable TB disease prevalence How to cite this paper:
Pan African Medical Journal
BMC Public Health
Background: The incidence of Tuberculosis (TB) differs among countries and contributes to morbidi... more Background: The incidence of Tuberculosis (TB) differs among countries and contributes to morbidity and mortality especially in the developing countries. Trends and seasonal changes in the number of patients presenting with TB have been studied worldwide including sub-Saharan Africa. However, these changes are unknown at the Korle-Bu Teaching Hospital (KBTH). The aim of this study was to obtain a time series model to estimate the incidence of TB cases at the chest clinic of the Korle-Bu Teaching hospital. Methods: A time series analysis using a Box-Jenkins approach propounded as an autoregressive moving average (ARIMA) was conducted on the monthly TB cases reported at the KBTH from 2008 to 2017. Various models were stated and compared and the best was found to be based on the Akaike Information Criterion and Bayesian Information Criterion. Results: There was no evidence of obvious increasing or decreasing trend in the TB data. The log-transformed of the data achieved stationarity with fairly stable variations around the mean of the series. ARIMA (1, 0, 1) or ARMA (1,1) was obtained as the best model. The monthly forecasted values of the best model ranged from 53 to 55 for the year 2018; however, the best model does not always produce the best results with respect to the mean absolute and mean square errors. Conclusions: Irregular fluctuations were observed in the 10-year data studied. The model equation to estimate the expected monthly TB cases at KBTH produced an AR coefficient of 0.971 plus an MA coefficient of − 0.826 with a constant value of 4.127. The result is important for developing a hypothesis to explain the dynamics of TB occurrence so as to outline prevention programmes, optimal use of resources and effective service delivery.
BMC infectious diseases, Apr 2, 2018
Mycobacterium tuberculosis drug resistance is a major challenge to the use of standardized regime... more Mycobacterium tuberculosis drug resistance is a major challenge to the use of standardized regimens for tuberculosis (TB) therapy, especially among previously treated patients. We aimed to investigate the frequency and pattern of drug resistance among previously treated patients with smear-positive pulmonary tuberculosis at the Korle-Bu Teaching Hospital Chest Clinic, Accra. This was a cross-sectional survey of mycobacterial isolates from previously treated patients referred to the Chest Clinic Laboratory between October 2010 and October 2013. The Bactec MGIT 960 system for mycobactrerial culture and drug sensitivity testing (DST) was used for sputum culture of AFB smear-positive patients with relapse, treatment failure, failure of smear conversion, or default. Descriptive statistics were used to summarize patient characteristics, and frequency and patterns of drug resistance. A total of 112 isolates were studied out of 155 from previously treated patients. Twenty contaminated (12.9...
Open Forum Infectious Diseases, 2016
Background: Previously treated tuberculosis (TB) patients have a higher risk of drug resistance d... more Background: Previously treated tuberculosis (TB) patients have a higher risk of drug resistance disease which may adversely affect treatment outcome. TB retreatment patients (RTP) include those deemed to be cured and present with recurrent TB (relapsed), or remained smear positive at the end of the fifth month of therapy (failed) or return after loss to follow up (defaulted). Based on WHO guidelines, RTP have for many years been given a standardized five-drug Category II regimen (2SHRZE/1HRZE/5HRE). However, with increasing rates of resistance reported particularly to streptomycin, this regimen may be inadequate. This is the first study to review treatment outcomes of RTP in Ghana. Methods: A retrospective review of all patients with smear/culture-positive previously-treated TB diagnosed between 1/2010 and 7/2015 at Korle-Bu Teaching Hospital Chest Clinic in Accra, Ghana. Descriptive statistics were used to summarize RTP characteristics and outcomes.
BMJ Global Health, 2017
Background Multidrug-resistant tuberculosis (MDR-TB) remains a clear threat to TB control. There ... more Background Multidrug-resistant tuberculosis (MDR-TB) remains a clear threat to TB control. There is a paucity of data A32
BMC Medicine, 2016
Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate manageme... more Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate management requires baseline drug-resistance prevalence data. In West Africa, due to a poor laboratory infrastructure and inadequate capacity, such data are scarce. Therefore, the true extent of drug-resistant TB was hitherto undetermined. In 2008, a new research network, the West African Network of Excellence for Tuberculosis, AIDS and Malaria (WANETAM), was founded, comprising nine study sites from eight West African countries
BMC Medicine, 2016
Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate manageme... more Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate management requires baseline drug-resistance prevalence data. In West Africa, due to a poor laboratory infrastructure and inadequate capacity, such data are scarce. Therefore, the true extent of drug-resistant TB was hitherto undetermined. In 2008, a new research network, the West African Network of Excellence for Tuberculosis, AIDS and Malaria (WANETAM), was founded, comprising nine study sites from eight West African countries
BMC Medicine, 2016
Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate manageme... more Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate management requires baseline drug-resistance prevalence data. In West Africa, due to a poor laboratory infrastructure and inadequate capacity, such data are scarce. Therefore, the true extent of drug-resistant TB was hitherto undetermined. In 2008, a new research network, the West African Network of Excellence for Tuberculosis, AIDS and Malaria (WANETAM), was founded, comprising nine study sites from eight West African countries
A56. EPIDEMIOLOGY OF TUBERCULOSIS, 2011
West African journal of medicine
The level of drug resistance in mycobacterial isolates from previously treated cases in Ghana is ... more The level of drug resistance in mycobacterial isolates from previously treated cases in Ghana is not known although drug resistant tuberculosis threatens efforts to control the disease. To identify and determine the susceptibility of mycobacterial isolates from tuberculosis cases with clinical treatment failure. This prospective survey was undertaken at the Chest Clinic of Korle Bu Teaching Hospital in Accra, Ghana. The participants were twenty-eight cases referred to the hospital with clinical treatment failure. Two sputum specimens from each case were stained by Ziehl-Neelsen method, cultured, identified and sensitivity tests performed by the proportion method. Eighteen isolates of mycobacteria were identified from 28 failed treatment cases. Five were atypical mycobacteria. Approximately fifty percent (13/28) of cases had Mycobacterium tuberculosis, 5(18%) had atypical mycobacteria, 7(25%) had pure fungal growth and 3(11% 8) had no growth. Fifteen isolates were resistant to two or...
Ghana Medical Journal, 2011
Introduction: The burden of MDR-TB is unknown in areas that do not have drug susceptibility testi... more Introduction: The burden of MDR-TB is unknown in areas that do not have drug susceptibility testing (DST), but its frequency is expected to be higher in previously treated cases. Where DST is not available the WHO recommended standardized retreatment (Category II) regimen is given to previously treated TB patients Objective: To evaluate the frequency and pattern of drug resistance of Mycobacterium tuberculosis isolated from patients with chronic smear positive pulmonary tuberculosis. Method: We conducted a retrospective review of mycobacterial cultures and drug susceptibility testing (DST) performed on sputum samples collected, between January 2005 and September 2006, from 40 patients with pulmonary TB who had failed at least one standard retreatment regimen. Clinical data was extracted from patients' case notes. Results: M. tuberculosis was recovered from 28 (70%) of the 40 patients. Of the 28 culture positive cases, 10 (36%) had resistance to at least rifampicin and isoniazid (multi-drug resistant TB), 22 (79%) isolates had resistance to streptomycin and 13 (46%) to ethambutol. Of the patients with a positive culture, only one (3.6%) had a fully susceptible organism. Of the 10 patients with MDR TB, 7 had received two or more retreatment courses. Conclusion: The frequency of drug resistant TB was high among patients who failed at least one course of category II therapy. Effective combination regimens based on DST is necessary in patients who remain smear positive on the standardized retreatment regimen.
Transactions of the Royal Society of Tropical Medicine and Hygiene, 2011
Tuberculosis (TB) remains a major cause of mortality despite availability of effective chemothera... more Tuberculosis (TB) remains a major cause of mortality despite availability of effective chemotherapy. This study was performed to identify contributing factors for poor outcome during anti-tuberculosis treatment at a teaching hospital chest clinic. Medical records of registered patients treated for TB between 1 January and 31 December, 2009 were reviewed and abstracted for demographic, clinical and outcome data. Risk factors for mortality during therapy were assessed using bivariate and multivariate logistics approaches. Of 599 patients, 355 (58.9%) completed therapy and/or were cured, 192 (32.1%) died, and 39 (6.5%) defaulted. In multivariate analysis, independent risk factors for mortality included pulmonary cases for which sputum smear status was unknown (odds ratio [OR] 13.
Reported monthly TB cases data set for a ten-year period at the chest clinic-Korle-bu teaching ho... more Reported monthly TB cases data set for a ten-year period at the chest clinic-Korle-bu teaching hospital. (XLSX 12 kb)
S OF PLENARY PRESENTATIONS A3 ABSTRACTS OF ORAL PRESENTATIONS A5S OF ORAL PRESENTATIONS A5 ABSTRA... more S OF PLENARY PRESENTATIONS A3 ABSTRACTS OF ORAL PRESENTATIONS A5S OF ORAL PRESENTATIONS A5 ABSTRACTS OF POSTER PRESENTATIONS A16S OF POSTER PRESENTATIONS A16
Journal of Tuberculosis Research
Background: Bacteriologically-confirmed tuberculosis (TB) cases used in calculating TB prevalence... more Background: Bacteriologically-confirmed tuberculosis (TB) cases used in calculating TB prevalence in a country are obtained through laboratory examination of sputum specimens. Objective: This article describes laboratory processing of specimens, results overview, conclusions and key lessons learnt from the perspective of laboratory personnel involved in the conduct of TB disease prevalence survey in Ghana in 2013. Methods: Symptoms screening and Chest X-ray suggestive of TB were used to select participants who produced sputum to confirm TB cases using microscopy, culture and Xpert ® MTB/RIF assay (GeneXpert). Results: A total of 15,935 single and paired sputum specimens were received from eligible participants. About half of Ziehl-Nielsen (129/263) and Auramine O (122/246) stained smear positives were scanty positive. Culture positivity rate for Mycobacterium tuberculosis complex was 266/14,994 (1.7%) and 100/15,179 (0.7%) in Mycobacterial Growth Indicator Tube (MGIT) and Lowenstein-Jensen (LJ) media respectively; while non-tuberculous mycobacterium was 294/14,994 (1.96%) and 167/15,179 (1.1%). Total contamination rates in MGIT (5.4%) were higher than in LJ (1.7%). Prevalence of smear positive TB and bacteriologically confirmed TB among adult population (≥15 years) was estimated at 111 (95% CI: 76-145) and 356 (95% CI: 288-425) per 100,000 population respectively. Conclusions and Lessons Learnt: Direct supervision of specimen collection by well-trained laboratory personnel, timely transportation of specimens from field to laboratory, prompt specimen processing and use of electronic data management systems are essential for a reliable TB disease prevalence How to cite this paper:
Pan African Medical Journal
BMC Public Health
Background: The incidence of Tuberculosis (TB) differs among countries and contributes to morbidi... more Background: The incidence of Tuberculosis (TB) differs among countries and contributes to morbidity and mortality especially in the developing countries. Trends and seasonal changes in the number of patients presenting with TB have been studied worldwide including sub-Saharan Africa. However, these changes are unknown at the Korle-Bu Teaching Hospital (KBTH). The aim of this study was to obtain a time series model to estimate the incidence of TB cases at the chest clinic of the Korle-Bu Teaching hospital. Methods: A time series analysis using a Box-Jenkins approach propounded as an autoregressive moving average (ARIMA) was conducted on the monthly TB cases reported at the KBTH from 2008 to 2017. Various models were stated and compared and the best was found to be based on the Akaike Information Criterion and Bayesian Information Criterion. Results: There was no evidence of obvious increasing or decreasing trend in the TB data. The log-transformed of the data achieved stationarity with fairly stable variations around the mean of the series. ARIMA (1, 0, 1) or ARMA (1,1) was obtained as the best model. The monthly forecasted values of the best model ranged from 53 to 55 for the year 2018; however, the best model does not always produce the best results with respect to the mean absolute and mean square errors. Conclusions: Irregular fluctuations were observed in the 10-year data studied. The model equation to estimate the expected monthly TB cases at KBTH produced an AR coefficient of 0.971 plus an MA coefficient of − 0.826 with a constant value of 4.127. The result is important for developing a hypothesis to explain the dynamics of TB occurrence so as to outline prevention programmes, optimal use of resources and effective service delivery.
BMC infectious diseases, Apr 2, 2018
Mycobacterium tuberculosis drug resistance is a major challenge to the use of standardized regime... more Mycobacterium tuberculosis drug resistance is a major challenge to the use of standardized regimens for tuberculosis (TB) therapy, especially among previously treated patients. We aimed to investigate the frequency and pattern of drug resistance among previously treated patients with smear-positive pulmonary tuberculosis at the Korle-Bu Teaching Hospital Chest Clinic, Accra. This was a cross-sectional survey of mycobacterial isolates from previously treated patients referred to the Chest Clinic Laboratory between October 2010 and October 2013. The Bactec MGIT 960 system for mycobactrerial culture and drug sensitivity testing (DST) was used for sputum culture of AFB smear-positive patients with relapse, treatment failure, failure of smear conversion, or default. Descriptive statistics were used to summarize patient characteristics, and frequency and patterns of drug resistance. A total of 112 isolates were studied out of 155 from previously treated patients. Twenty contaminated (12.9...
Open Forum Infectious Diseases, 2016
Background: Previously treated tuberculosis (TB) patients have a higher risk of drug resistance d... more Background: Previously treated tuberculosis (TB) patients have a higher risk of drug resistance disease which may adversely affect treatment outcome. TB retreatment patients (RTP) include those deemed to be cured and present with recurrent TB (relapsed), or remained smear positive at the end of the fifth month of therapy (failed) or return after loss to follow up (defaulted). Based on WHO guidelines, RTP have for many years been given a standardized five-drug Category II regimen (2SHRZE/1HRZE/5HRE). However, with increasing rates of resistance reported particularly to streptomycin, this regimen may be inadequate. This is the first study to review treatment outcomes of RTP in Ghana. Methods: A retrospective review of all patients with smear/culture-positive previously-treated TB diagnosed between 1/2010 and 7/2015 at Korle-Bu Teaching Hospital Chest Clinic in Accra, Ghana. Descriptive statistics were used to summarize RTP characteristics and outcomes.
BMJ Global Health, 2017
Background Multidrug-resistant tuberculosis (MDR-TB) remains a clear threat to TB control. There ... more Background Multidrug-resistant tuberculosis (MDR-TB) remains a clear threat to TB control. There is a paucity of data A32
BMC Medicine, 2016
Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate manageme... more Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate management requires baseline drug-resistance prevalence data. In West Africa, due to a poor laboratory infrastructure and inadequate capacity, such data are scarce. Therefore, the true extent of drug-resistant TB was hitherto undetermined. In 2008, a new research network, the West African Network of Excellence for Tuberculosis, AIDS and Malaria (WANETAM), was founded, comprising nine study sites from eight West African countries
BMC Medicine, 2016
Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate manageme... more Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate management requires baseline drug-resistance prevalence data. In West Africa, due to a poor laboratory infrastructure and inadequate capacity, such data are scarce. Therefore, the true extent of drug-resistant TB was hitherto undetermined. In 2008, a new research network, the West African Network of Excellence for Tuberculosis, AIDS and Malaria (WANETAM), was founded, comprising nine study sites from eight West African countries
BMC Medicine, 2016
Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate manageme... more Background: Drug-resistant tuberculosis (TB) is a global public health problem. Adequate management requires baseline drug-resistance prevalence data. In West Africa, due to a poor laboratory infrastructure and inadequate capacity, such data are scarce. Therefore, the true extent of drug-resistant TB was hitherto undetermined. In 2008, a new research network, the West African Network of Excellence for Tuberculosis, AIDS and Malaria (WANETAM), was founded, comprising nine study sites from eight West African countries
A56. EPIDEMIOLOGY OF TUBERCULOSIS, 2011