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Search Results: 1 - 10 of 209223 matches for " Moses L. Joloba "
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Direct susceptibility testing for multi drug resistant tuberculosis: A meta-analysis
Freddie Bwanga, Sven Hoffner, Melles Haile, Moses L Joloba
BMC Infectious Diseases , 2009, DOI: 10.1186/1471-2334-9-67
Abstract: A literature review and meta-analysis of study reports was performed. The Meta-Disc software was used to analyse the reports and tests for sensitivity, specificity, and area under the summary receiver operating characteristic (sROC) curves. Heterogeneity in accuracy estimates was tested with the Spearman correlation coefficient and Chi-square.Eighteen direct DST reports were analysed: NRA – 4, MODS- 6, Genotype MTBDR? – 3 and Genotype? MTBDRplus – 5. The pooled sensitivity and specificity for detection of resistance to rifampicin were 99% and 100% with NRA, 96% and 96% with MODS, 99% and 98% with Genotype? MTBDR, and 99% and 99% with the new Genotype? MTBDRplus, respectively. For isoniazid it was 94% and 100% for NRA, 92% and 96% for MODS, 71% and 100% for Genotype? MTBDR, and 96% and 100% with the Genotype? MTBDRplus, respectively. The area under the summary receiver operating characteristic (sROC) curves was in ranges of 0.98 to 1.00 for all the four tests. Molecular tests were completed in 1 – 2 days and also the phenotypic assays were much more rapid than conventional testing.Direct testing of rifampicin and isoniazid resistance in M. tuberculosis was found to be highly sensitive and specific, and allows prompt detection of MDR TB.Tuberculosis (TB) continues to be a leading cause of morbidity and mortality in developing countries [1]. Global efforts for TB control are being challenged by the steady increase in drug-resistant TB, particularly multidrug resistant tuberculosis (MDR TB), defined as resistance to at least rifampicin (RIF) and isoniazid (INH). The World Health Organization (WHO) estimates that 500,000 new cases of MDR TB occur globally every year and MDR TB has been reported in 2.9% and 15.3% among the new and previously treated cases, respectively [2].MDR TB requires 18–24 months of treatment with expensive second line drugs some of which are injectable agents. The cure rate is much lower than for drug susceptible TB, only around 60% [3]. Therefore,
Direct Nitrate Reductase Assay versus Microscopic Observation Drug Susceptibility Test for Rapid Detection of MDR-TB in Uganda
Freddie Bwanga,Melle Haile,Moses L. Joloba,Emmanuel Ochom,Sven Hoffner
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0019565
Abstract: The most common method for detection of drug resistant (DR) TB in resource-limited settings (RLSs) is indirect susceptibility testing on Lowenstein-Jensen medium (LJ) which is very time consuming with results available only after 2–3 months. Effective therapy of DR TB is therefore markedly delayed and patients can transmit resistant strains. Rapid and accurate tests suitable for RLSs in the diagnosis of DR TB are thus highly needed. In this study we compared two direct techniques - Nitrate Reductase Assay (NRA) and Microscopic Observation Drug Susceptibility (MODS) for rapid detection of MDR-TB in a high burden RLS. The sensitivity, specificity, and proportion of interpretable results were studied. Smear positive sputum was collected from 245 consecutive re-treatment TB patients attending a TB clinic in Kampala, Uganda. Samples were processed at the national reference laboratory and tested for susceptibility to rifampicin and isoniazid with direct NRA, direct MODS and the indirect LJ proportion method as reference. A total of 229 specimens were confirmed as M. tuberculosis, of these interpretable results were obtained in 217 (95%) with either the NRA or MODS. Sensitivity, specificity and kappa agreement for MDR-TB diagnosis was 97%, 98% and 0.93 with the NRA; and 87%, 95% and 0.78 with the MODS, respectively. The median time to results was 10, 7 and 64 days with NRA, MODS and the reference technique, respectively. The cost of laboratory supplies per sample was low, around 5 USD, for the rapid tests. The direct NRA and MODS offered rapid detection of resistance almost eight weeks earlier than with the reference method. In the study settings, the direct NRA was highly sensitive and specific. We consider it to have a strong potential for timely detection of MDR-TB in RLS.
Incremental Yield of Serial Sputum Cultures for Diagnosis of Tuberculosis among HIV Infected Smear Negative Pulmonary TB Suspects in Kampala, Uganda
Willy Ssengooba, Noah Kiwanuka, David P. Kateete, Achilles Katamba, Moses L. Joloba
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0037650
Abstract: Background Sputum culture is the gold standard for diagnosis of pulmonary tuberculosis (PTB). Although mostly used for research, culture is recommended by the World Health Organization for TB diagnosis among HIV infected smear negative PTB suspects. Even then, the number of sputum samples required remains unspecified. Here, we determined the Incremental Yield (IY) and number of samples required to diagnose an additional PTB case upon second and third serial sputum culture. Methods/Findings This was a cross sectional study done between January and March 2011. Serial sputum samples were provided by participants within two days and cultured using Lowenstein Jensen (LJ) and Mycobacteria Growth Indicator Tube (MGIT) methods. A PTB case was defined as a positive culture on either one or both methods. The IY from the second and third serial cultures was determined and the reciprocal of the product of the fractions of IY provided the number of samples required for an additional PTB case. Of the 170 smear negative PTB suspects, 62 (36.5%) met the case definition. The IY of the second sample culture was 12.7%, 23.6% and 12.6% and for the third sample culture was 6.8%, 7.5% and 7.3% with LJ, MGIT and LJ or MGIT, respectively. The number of samples required for an additional PTB case and 95% CI upon the second sample culture were 29.9 (16.6, 156.5), 11.3 (7.6, 21.9) and 20.8 (12.5, 62.7); while for the third sample culture were 55.6 (26.4, 500.4), 35.7 (19.0, 313.8) and 36.1 (19.1, 330.9) by LJ, MGIT and LJ or MGIT respectively. Conclusions/Significance Among HIV infected smear negative PTB suspects in Kampala, 93% of PTB cases are diagnosed upon the second serial sputum culture. The number of cultures needed to diagnose an additional PTB case, ranges from 11–30 and 35–56 by the second and third sputum samples, respectively.
Use of the GenoType? MTBDRplus assay to assess drug resistance of Mycobacterium tuberculosis isolates from patients in rural Uganda
Joel Bazira, Benon B Asiimwe, Moses L Joloba, Fred Bwanga, Mecky I Matee
BMC Clinical Pathology , 2010, DOI: 10.1186/1472-6890-10-5
Abstract: We enrolled, consecutively, all newly diagnosed and previously treated smear-positive TB patients aged ≥ 18 years. Isolates were tested for drug resistance against rifampicin (RIF) and isoniazid (INH) using the Genotype? MDRTBplus assay and results were compared with those obtained by the indirect proportion method on Lowenstein-Jensen media. HIV testing was performed using two rapid HIV tests.A total of 125 isolates from 167 TB suspects with a mean age 33.7 years and HIV prevalence of 67.9% (55/81) were analysed. A majority (92.8%) of the participants were newly presenting while only 7.2% were retreatment cases. Resistance mutations to either RIF or INH were detected in 6.4% of the total isolates. Multidrug resistance, INH and RIF resistance was 1.6%, 3.2% and 4.8%, respectively. The rpoβ gene mutations seen in the sample were D516V, S531L, H526Y H526 D and D516V, while one strain had a Δ1 mutation in the wild type probes. There were three strains with katG (codon 315) gene mutations while only one strain showed the inhA promoter region gene mutation.The TB resistance rate in Mbarara is relatively low. The GenoType? MTBDRplus assay can be used for rapid screening of MDR-TB in this setting.Despite the availability of drugs to treat tuberculosis (TB), it remains the world's leading cause of death from a single infectious disease. The World Health Organization (WHO) estimates current rates of multidrug resistant TB (resistance to at least isoniazid and rifampicin) in new and previously treated cases globally at 2.9% and 15.3% respectively, with 57% of multidrug resistant tuberculosis (MDR-TB) cases coming from three high burden countries (China, India, and the Russian Federation) [1].Uganda is currently ranked 16th among the highest TB burdened countries in the world [2]. The prevalence of MDR-TB in new cases in this setting has previously been reported to be low at less than 2% [3]. However, there are recent reports that 12.7% of re-treatment cases attending the Nati
Mycobacterium tuberculosis spoligotypes and drug susceptibility pattern of isolates from tuberculosis patients in peri-urban Kampala, Uganda
Benon B Asiimwe, Solomon Ghebremichael, Gunilla Kallenius, Tuija Koivula, Moses L Joloba
BMC Infectious Diseases , 2008, DOI: 10.1186/1471-2334-8-101
Abstract: This was a cross-sectional study of newly diagnosed sputum smear-positive patients aged ≥ 18 years. A total of 344 isolates were genotyped by standard spoligotyping and the strains were compared with those in the international spoligotype database (SpolDB4). HIV testing and anti-tuberculosis drug susceptibility assays for isoniazid and rifampicin were performed and association with the most predominant spoligotypes determined.A total of 33 clusters were obtained from 57 spoligotype patterns. According to the SpolDB4 database, 241 (70%) of the isolates were of the T2 family, while CAS1-Kili (3.5%), LAM9 (2.6%), CAS1-Delhi (2.6%) were the other significant spoligotypes. Furthermore, a major spoligotype pattern of 17 (4.5%) strains characterized by lack of spacers 15–17 and 19–43 was not identified in SpolDB4. A total of 92 (26.7%) of the patients were HIV sero-positive, 176 (51.2%) sero-negative, while 76 (22.1%) of the patients did not consent to HIV testing. Resistance to isoniazid was found in 8.1% of strains, while all 15 (4.4%) strains resistant to rifampicin were multi-drug resistant. Additionally, there was no association between any strain types in the sample with either drug resistance or HIV sero-status of the patients.The TB epidemic in Kampala is localized, mainly caused by the T2 family of strains. Strain types were neither associated with drug resistance nor HIV sero-status.Uganda is one of the countries with the highest burden of tuberculosis (TB) in Sub-Saharan Africa, with an estimated incidence of 559 cases per 100,000 per year and ranks 16th among the 22 high-burden countries [1]. Kampala, the capital of Uganda, has an approximate population of 2 million (Nation Census, 2002) and accounts for 30% of the TB burden in the country (National Tuberculosis and Leprosy Control Programme, 2006). To date, there are very limited data available pertaining strains circulating in Uganda and the East African region as a whole [2-5]. Poor peri-urban areas of most
Mycobacterium tuberculosis spoligotypes and drug susceptibility pattern of isolates from tuberculosis patients in South-Western Uganda
Joel Bazira, Benon B Asiimwe, Moses L Joloba, Freddie Bwanga, Mecky I Matee
BMC Infectious Diseases , 2011, DOI: 10.1186/1471-2334-11-81
Abstract: We enrolled, consecutively; all newly diagnosed and previously treated smear-positive TB patients aged ≥ 18 years. The isolates were characterized using regions of difference (RD) analysis and spoligotyping. Drug resistance against rifampicin and isoniazid were tested using the Genotype? MDRTBplus assay and the indirect proportion method on Lowenstein-Jensen media. HIV-1 testing was performed using two rapid HIV tests.A total of 125 isolates from 167 TB suspects (60% males) with a mean age 33.7 years and HIV prevalence of 67.9% (55/81) were analyzed. Majority (92.8%) were new cases while only 7.2% were retreatment cases. All the 125 isolates were identified as M. tuberculosis strict sense with the majority (92.8%) of the isolates being modern strains while seven (7.2%) isolates were ancestral strains. Spoligotyping revealed 79 spoligotype patterns, with an overall diversity of 63.2%. Sixty two (49.6%) of the isolates formed 16 clusters consisting of 2-15 isolates each. A majority (59.2%) of the isolates belong to the Uganda genotype group of strains. The major shared spoligotypes in our sample were SIT 135 (T2-Uganda) with 15 isolates and SIT 128 (T2) with 3 isolates. Sixty nine (87%) of the 79 patterns had not yet been defined in the SpolDB4.0.database. Resistance mutations to either RIF or INH were detected in 6.4% of the isolates. Multidrug resistance, INH and RIF resistance was 1.6%, 3.2% and 4.8%, respectively. The rpoβ gene mutations seen in the sample were D516V, S531L, H526Y H526D and D516V, while one strain had a Δ1 mutation in the wild type probes. There were three strains with katG (codon 315) gene mutations only while one strain showed the inhA promoter gene mutation.The present study shows that the TB epidemic in Mbarara is caused by modern M. tuberculosis strains mainly belonging to the Uganda genotype and anti-TB drug resistance rate in the region is low.Uganda ranks 16th among the world's 22 countries with the highest tuberculosis burden in the world
High prevalence of methicillin resistant Staphylococcus aureus in the surgical units of Mulago hospital in Kampala, Uganda
David P Kateete, Sylvia Namazzi, Moses Okee, Alfred Okeng, Hannington Baluku, Nathan L Musisi, Fred A Katabazi, Moses L Joloba, Robert Ssentongo, Florence C Najjuka
BMC Research Notes , 2011, DOI: 10.1186/1756-0500-4-326
Abstract: One hundred samples (from 25 patients; 36 HCW; and 39 from the environment, one sample per person/item) were cultured for the isolation of Staphylococcus aureus. Forty one S. aureus isolates were recovered from 13 patients, 13 HCW and 15 from the environment, all of which were oxacillin resistant and mecA/femA/nuc-positive. MRSA prevalence was 46% (41/89) among patients, HCW and the environment, and 100% (41/41) among the isolates. For CHROMagar, MRSA prevalence was 29% (26/89) among patients, HCW and the environment, and 63% (26/41) among the isolates. There was high prevalence of multidrug resistant isolates, which concomitantly possessed virulence and antimicrobial resistance determinants, notably biofilms, hemolysins, toxin and ica genes. One isolate positive for all determinants possessed the bhp homologue which encodes the biofilm associated protein (BAP), a rare finding in human isolates. SCCmec type I was the most common at 54% prevalence (22/41), followed by SCCmec type V (15%, 6/41) and SCCmec type IV (7%, 3/41). SCCmec types II and III were not detected and 10 isolates (24%) were non-typeable.Hyper-virulent methicillin resistant Staphylococcus aureus is prevalent in the burns unit of Mulago hospital.There is a global outbreak of Methicillin resistant Staphylococcus aureus (MRSA) infections, particularly in industrialized countries [1]. However, there is limited data on MRSA prevalence in Uganda, where ~10% of the surgical procedures become septic with S. aureus being the most frequent pathogen isolated [2-4]. Ojulong et al. 2009 determined the prevalence of MRSA in patients with post-operative surgical wound infections in the surgical wards of Mulago hospital in Kampala, Uganda [5], but the distribution of isolates among healthcare workers (HCW) and the environment was not determined. Here, we aimed to determine MRSA prevalence among patients, HCW and the environment in the burns units at Mulago hospital, and compare the performance of CHROMagar with oxac
Isolation of Mycobacterium avium subspecies paratuberculosis from Ugandan cattle and strain differentiation using optimised DNA typing techniques
Julius Okuni, Chrysostomos I Dovas, Panayiotis Loukopoulos, Ilias G Bouzalas, David Kateete, Moses L Joloba, Lonzy Ojok
BMC Veterinary Research , 2012, DOI: 10.1186/1746-6148-8-99
Abstract: Twenty one isolates of MAP were differentiated into 11 genotype profiles using seven genotyping loci consisting of Insertion Sequence 1311(IS1311), Mycobacterial interspersed repeat units (MIRU) (loci 2, 3), Variable number tandem repeats (VNTR) locus 32 and Short sequence repeats (SSR) (loci 1, 2 and 8). Three different IS1311 types and three MIRU 2 profiles (7, 9, 15 repeats) were observed. Two allelic variants were found based on MIRU 3 (1, 5 repeats), while VNTR 32 showed no polymorphism in any of the isolates from which it was successfully amplified. SSR Locus 1 revealed 6 and 7?G1 repeats among the isolates whereas SSR locus 2 revealed 10, 11 and 12?G2 repeats. SSR locus 8 was the most polymorphic locus. Phylogenetic analysis of SSR locus 8 sequences based on their single nucleotide polymorphisms separated the isolates into 8 genotypes. We found that the use of Ethylene glycol as a PCR additive improved the efficiency of the PCR reactions for MIRUs (2, 3), VNTR 32 and SSR (loci 1 and 2).There is a high strain diversity of MAP in Uganda since 21 isolates could be classified into 11 genotypes. The combination of the seven loci used in this study results into a very precise discrimination of isolates. However analysis of SNPs on locus alone 8 is very close to this combination. Most of the genotypes in this study are novel since they differed in one or more loci from other isolates of cattle origin in different studies. The large number of MAP strains within a relatively small area of the country implies that the epidemiology of paratuberculosis in Uganda may be complicated and needs further investigation. Finally, the use of Ethylene glycol as a PCR additive increases the efficiency of PCR amplification of difficult templates.Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of paratuberculosis or Johne’s disease; a chronic intractable enteritis which affects many species of animals including cattle, goats, sheep and other domestic and
Determination of circulating Mycobacterium tuberculosis strains and transmission patterns among pulmonary TB patients in Kawempe municipality, Uganda, using MIRU-VNTR
Lydia Nabyonga, David P Kateete, Fred A Katabazi, Paul R Odong, Christopher C Whalen, Katherine R Dickman, Joloba L Moses
BMC Research Notes , 2011, DOI: 10.1186/1756-0500-4-280
Abstract: MIRU-VNTR genotyping was performed by PCR-amplification of 15 MTB-MIRU loci from 113 cultured specimens from 113 PTB patients (one culture sample per patient). To determine lineages, the genotypes were entered into the MIRU-VNTRplus database [http://www.miru-vntrplus.org/ webcite] as numerical codes corresponding to the number of alleles at each locus. Ten different lineages were obtained: Uganda II (40% of specimens), Uganda I (14%), LAM (6%), Delhi/CAS (3%), Haarlem (3%), Beijing (3%), Cameroon (3%), EAI (2%), TUR (2%) and S (1%). Uganda I and Uganda II were the most predominant genotypes. Genotypes for 29 isolates (26%) did not match any strain in the database and were considered unique. There was high diversity of MIRU-VNTR genotypes, with a total of 94 distinct patterns. Thirty four isolates grouped into 15 distinct clusters each with two to four isolates. Eight households had similar MTB strains for both index and contact cases, indicating possible transmission.MIRU-VNTR genotyping revealed high MTB strain diversity with low clustering in Kawempe municipality. The technique has a high discriminatory power for genotyping MTB strains in Uganda.Tuberculosis (TB) is a leading cause of morbidity and mortality throughout sub-Saharan Africa, and Uganda ranks sixteenth among countries with the highest burden of disease [1]. Co-infection with HIV/AIDS and the emergence of multi-drug resistant (MDR) Mycobacterium tuberculosis (MTB) strains have made TB a major public health problem [2]. The incidence of TB in Uganda is estimated at 330 cases per 100,000 persons per year, and this includes both HIV infected and non-HIV infected patients [3]. TB prevalence in Uganda is believed to be higher than reported due to lack of sufficient healthcare; indeed, many people are not aware that they are infected with MTB and this has led to low levels of diagnosis and treatment [4]. Uganda also has one of the lowest TB cure rates (32%) and high drug default rate [1], which may lead to a
Aetiology of Pulmonary Symptoms in HIV-Infected Smear Negative Recurrent PTB Suspects in Kampala, Uganda: A Cross-Sectional Study
Alphonse Okwera, Freddie Bwanga, Irene Najjingo, Yusuf Mulumba, David K. Mafigiri, Christopher C. Whalen, Moses L. Joloba
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0082257
Abstract: Introduction Previously treated TB patients with pulmonary symptoms are often considered recurrent TB suspects in the resource-limited settings, where investigations are limited to microscopy and chest x-ray. Category II anti-TB drugs may be inappropriate and may expose patients to pill burden, drug toxicities and drug-drug interactions. Objective To determine the causes of pulmonary symptoms in HIV-infected smear negative recurrent pulmonary tuberculosis suspects at Mulago Hospital, Kampala. Methods Between March 2008 and December 2011, induced sputum samples of 178 consented HIV-infected smear negative recurrent TB suspects in Kampala were subjected to MGIT and LJ cultures for mycobacteria at TB Reference Laboratory, Kampala. Processed sputum samples were also tested by PCR to detect 18S rRNA gene of P.jirovecii and cultured for other bacteria. Results Bacteria, M. tuberculosis and Pneumocystis jirovecii were detected in 27%, 18% and 6.7% of patients respectively and 53.4% of the specimens had no microorganisms. S. pneumoniae, M. catarrhalis and H. influenzae were 100% susceptible to chloramphenicol and erythromycin but co-trimoxazole resistant. Conclusion At least 81.5% of participants had no microbiologically-confirmed TB. However our findings call for thorough investigation of HIV-infected smear negative recurrent TB suspects to guide cost effective treatment.
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