Belay Tessema
University of Gondar
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Belay Tessema.
BMC Public Health | 2009
Belay Tessema; Abebe Muche; Assegedech Bekele; Dieter Reissig; Frank Emmrich; Ulrich Sack
BackgroundIn Gondar University Teaching Hospital standardized tuberculosis prevention and control programme, incorporating Directly Observed Treatment, Short Course (DOTS) started in 2000. According to the proposal of World Health Organization (WHO), treatment outcome is an important indicator of tuberculosis control programs. This study investigated the outcome of tuberculosis treatment at Gondar University Teaching Hospital in Northwest Ethiopia.MethodsWe analyzed the records of 4000 tuberculosis patients registered at Gondar University Teaching Hospital from September 2003 to May 2008. Treatment outcome and tuberculosis type were categorized according to the national tuberculosis control program guideline. Multivariate analysis using logistic regression model was used to analyse the association between treatment outcome and potential predictor variables.ResultsFrom the total of 4000 patients, tuberculosis type was categorized as extrapulmonary in 1133 (28.3%), smear negative pulmonary tuberculosis in 2196 (54.9%) and smear positive pulmonary tuberculosis in 671 (16.8%) cases. Of all patients, treatment outcome was classified as successfully treated in 1181(29.5%), defaulted in 730 (18.3%), died in 403 (10.1%), treatment failed in six (0.2%) and transferred out in 1680 (42.0%) patients. Males had the trend to be more likely to experience death or default than females, and the elderly were more likely to die than younger. The proportion of default rate was increased across the years from 97(9.2%) to 228(42.9%). Being female, age group 15-24 years, smear positive pulmonary tuberculosis and being urban resident were associated with higher treatment success rate.ConclusionThe treatment success rate of tuberculosis patients was unsatisfactorily low (29.5%). A high proportion of patients died (10.1%) or defaulted (18.3%), which is a serious public health concern that needs to be addressed urgently.
BMC Infectious Diseases | 2013
Belay Tessema; Joerg Beer; Matthias Merker; Frank Emmrich; Ulrich Sack; Arne C. Rodloff; Stefan Niemann
BackgroundAlthough Ethiopia ranks seventh among the world’s 22 high-burden tuberculosis (TB) countries, little is known about strain diversity and transmission. In this study, we present the first in-depth analysis of the population structure and transmission dynamics of Mycobacterium tuberculosis strains from Northwest Ethiopia.MethodsIn the present study, 244 M. tuberculosis isolates where analysed by mycobacterial interspersed repetitive unit - variable number tandem repeat 24-loci typing and spoligotyping methods to determine phylogenetic lineages and perform cluster analysis. Clusters of strains with identical genotyping patterns were considered as an indicator for the recent transmission.ResultsOf 244 isolates, 59.0% were classified into nine previously described lineages: Dehli/CAS (38.9%), Haarlem (8.6%), Ural (3.3%), LAM (3.3%), TUR (2.0%), X-type (1.2%), S-type (0.8%), Beijing (0.4%) and Uganda II (0.4%). Interestingly, 31.6% of the strains were grouped into four new lineages and were named as Ethiopia_3 (13.1%), Ethiopia_1 (7.8%), Ethiopia_H37Rv like (7.0%) and Ethiopia_2 (3.7%) lineages. The remaining 9.4% of the isolates could not be assigned to the known or new lineages. Overall, 45.1% of the isolates were grouped in clusters, indicating a high rate of recent transmission.ConclusionsThis study confirms a highly diverse M. tuberculosis population structure, the presence of new phylogenetic lineages and a predominance of the Dehli/CAS lineage in Northwest Ethiopia. The high rate of recent transmission indicates defects of the TB control program in Northwest Ethiopia. This emphasizes the importance of strengthening laboratory diagnosis of TB, intensified case finding and treatment of TB patients to interrupt the chain of transmission.
BMC Infectious Diseases | 2012
Belay Tessema; Joerg Beer; Frank Emmrich; Ulrich Sack; Arne C. Rodloff
BackgroundThe emergence of drug resistance is one of the most important threats to tuberculosis control programs. This study was aimed to analyze the frequency of gene mutations associated with resistance to isoniazid (INH), rifampicin (RMP) and ethambutol (EMB) among Mycobacterium tuberculosis isolates from Northwest Ethiopia, and to assess the performance of the GenoType® MTBDRplus and GenoType® MTBDRsl assays as compared to the BacT/ALERT 3D system.MethodsTwo hundred sixty Mycobacterium tuberculosis isolates from smear positive tuberculosis patients diagnosed between March 2009 and July 2009 were included in this study. Drug susceptibility tests were performed in the Institute of Medical Microbiology and Epidemiology of Infectious Diseases, University Hospital of Leipzig, Germany.ResultsOf 260 isolates, mutations conferring resistance to INH, RMP, or EMB were detected in 35, 15, and 8 isolates, respectively, while multidrug resistance (MDR) was present in 13 of the isolates. Of 35 INH resistant strains, 33 had mutations in the katG gene at Ser315Thr 1 and two strains had mutation in the inhA gene at C15T. Among 15 RMP resistant isolates, 11 had rpoB gene mutation at Ser531Leu, one at His526Asp, and three strains had mutations only at the wild type probes. Of 8 EMB resistant strains, two had mutations in the embB gene at Met306Ile, one at Met306Val, and five strains had mutations only at the wild type probes. The GenoType® MTBDRplus assay had a sensitivity of 92% and specificity of 99% for INH resistance, and 100% sensitivity and specificity to detect RMP resistance and MDR. The GenoType® MTBDRsl assay had a sensitivity of 42% and specificity of 100% for EMB resistance.ConclusionThe dominance of single gene mutations associated with the resistance to INH and RMP was observed in the codon 315 of the katG gene and codon 531 of the rpoB gene, respectively. The GenoType® MTBDRplus assay is a sensitive and specific tool for diagnosis of resistance to INH, RMP and MDR. However, the GenoType® MTBDRsl assay shows limitations in detecting resistance to EMB.
Biological Trace Element Research | 2008
Afework Kassu; Tomoki Yabutani; Andargachew Mulu; Belay Tessema; Fusao Ota
Pregnant women in developing countries are vulnerable to multiple micronutrient deficiencies. Studies assessing serum levels of the micronutrients and magnitude of their deficiencies are very scarce in African subjects. This study was aimed at determining serum levels of micronutrients in 375 pregnant (42 HIV seropositive) and 76 non-pregnant women (20 HIV seropositive) who visited the University of Gondar Hospital, Gondar, Ethiopia. Serum concentrations of zinc,\ copper, selenium, calcium, and magnesium were determined using an inductively coupled plasma mass spectrometer. Irrespective of HIV serostatus, pregnant women had significantly higher serum concentrations of copper and copper/zinc ratio and significantly lower magnesium compared to those in non-pregnant women (P < 0.05). Except for selenium, which was significantly lower in HIV-seropositive pregnant women (P < 0.05), the mean serum concentrations of zinc, copper, calcium, and magnesium were not significantly different between pregnant women by HIV serostatus. The prevalence of deficiency in zinc, magnesium, selenium, and calcium in the pregnant women, irrespective of their HIV serostatus, was 66.7%, 25.6%, 21.9%, and 9.3%, respectively. The magnitude of deficiency in zinc, magnesium, and selenium was significantly higher in HIV seropositive pregnant women (76.2%, 52.4%, and 45.2%) than that in HIV-seronegative pregnant women (65.5%, 22.2%, and 18.9%) and in HIV-seronegative non-pregnant women (42.9%, 8.1%, and 30.4%; P < 0.05). Deficiency in one, two, three, or four mineral elements was observed in 44.8%, 14.4%, 9.9%, and 5.1% of the pregnant women, respectively. Only 25.9% of the pregnant women and 44.7% of the non-pregnant women were not deficient in any of the micronutrients. The high prevalence of micronutrient deficiencies in pregnant and non-pregnant women in Gondar, Ethiopia warrants the need for strategies on prevention and control of the deficiencies.
European Respiratory Journal | 2017
Paolo Miotto; Belay Tessema; Elisa Tagliani; Leonid Chindelevitch; Angela M. Starks; Claudia Emerson; Debra Hanna; Peter S. Kim; Richard Liwski; Matteo Zignol; Christopher Gilpin; Stefan Niemann; Claudia M. Denkinger; Joy Fleming; Robin M. Warren; Derrick W. Crook; James E. Posey; Sebastien Gagneux; Sven Hoffner; Camilla Rodrigues; Iñaki Comas; David M. Engelthaler; Megan Murray; David Alland; Leen Rigouts; Christoph Lange; Keertan Dheda; Rumina Hasan; Uma Devi Ranganathan; Ruth McNerney
A clear understanding of the genetic basis of antibiotic resistance in Mycobacterium tuberculosis is required to accelerate the development of rapid drug susceptibility testing methods based on genetic sequence. Raw genotype–phenotype correlation data were extracted as part of a comprehensive systematic review to develop a standardised analytical approach for interpreting resistance associated mutations for rifampicin, isoniazid, ofloxacin/levofloxacin, moxifloxacin, amikacin, kanamycin, capreomycin, streptomycin, ethionamide/prothionamide and pyrazinamide. Mutation frequencies in resistant and susceptible isolates were calculated, together with novel statistical measures to classify mutations as high, moderate, minimal or indeterminate confidence for predicting resistance. We identified 286 confidence-graded mutations associated with resistance. Compared to phenotypic methods, sensitivity (95% CI) for rifampicin was 90.3% (89.6–90.9%), while for isoniazid it was 78.2% (77.4–79.0%) and their specificities were 96.3% (95.7–96.8%) and 94.4% (93.1–95.5%), respectively. For second-line drugs, sensitivity varied from 67.4% (64.1–70.6%) for capreomycin to 88.2% (85.1–90.9%) for moxifloxacin, with specificity ranging from 90.0% (87.1–92.5%) for moxifloxacin to 99.5% (99.0–99.8%) for amikacin. This study provides a standardised and comprehensive approach for the interpretation of mutations as predictors of M. tuberculosis drug-resistant phenotypes. These data have implications for the clinical interpretation of molecular diagnostics and next-generation sequencing as well as efficient individualised therapy for patients with drug-resistant tuberculosis. A comprehensive basis for interpreting mutations to predict antibiotic resistance in tuberculosis http://ow.ly/hhwJ30g9jCY
Aids Research and Therapy | 2010
Belay Tessema; Fantahun Biadglegne; Andargachew Mulu; Assefa Getachew; Frank Emmrich; Ulrich Sack
BackgroundAdequate antiretroviral drug potency is essential for obtaining therapeutic benefit, however, the behavioral aspects of proper adherence and readiness to medication, often determine therapeutic outcome. Therefore, this study aimed to assess the level and determinants of nonadherence and nonreadiness to highly active antiretroviral therapy (HAART) among people living with HIV/AIDS (PLWHA) at Gondar University Teaching Hospital and Felege Hiwot Hospital in Northwest Ethiopia.MethodsA cross-sectional study was conducted between July and September 2008 using structured interviewer-administered questionnaire. All consecutive adult outpatients who were receiving antiretroviral treatment for at least three months, seen at both hospitals during the study period and able to give informed consent were included in the study. Multivariate logistic regression was used to determine factors associated with nonadherence and nonreadiness.ResultsA total of 504 study subjects were included in this study. The prevalence rates of nonadherence and nonreadiness to HAART were 87 (17.3%) and 70 (13.9%) respectively. Multivariate logistic regression analysis revealed that medication adverse effects, nonreadiness to HAART, contact with psychiatric care service and having no goal had statistically significant association with nonadherence. Moreover, unwillingness to disclose HIV status was significantly associated with nonreadiness to HAART.ConclusionsIn this study the level of nonadherence and nonreadiness to HAART seems to be encouraging. Several factors associated with nonadherance and nonreadiness to HAART were identified. Efforts to minimize nonadherence and nonreadiness to HAART should be integrated in to regular clinical follow up of patients.
Journal of Clinical Microbiology | 2011
Belay Tessema; Joerg Beer; Frank Emmrich; Ulrich Sack; Arne C. Rodloff
ABSTRACT Tuberculosis is a major public health problem in Ethiopia. The diagnosis and treatment of drug-resistant tuberculosis remain a challenge in the country. This study aimed to assess whether single morning sputum samples could be stored at −20°C for extended periods of time at remote settings and then transported and successfully cultured for Mycobacterium tuberculosis. Single morning sputum samples were collected from all smear-positive tuberculosis patients diagnosed at Gondar Hospital, Gondar Health Center, Metemma Hospital, Bahir Dar Hospital, and Debre Markos Hospital in Northwest Ethiopia between March and July 2009. Specimens were stored at the study sites and sent to the mycobacteriology laboratory at the University Hospital, Leipzig, Germany, where specimens were processed and inoculated into the BacT/Alert 3D system and Lowenstein-Jensen and Gottsacker media. Ice packs were added in the package of the specimens during transport. A total of 319 patients were enrolled in this study. The median specimen storage time was 132 days (range, 16 to 180 days). Of all specimens, 283 (88.7%) were culture positive by any of the three culturing systems. M. tuberculosis isolates from four contaminated specimens in all culturing systems were successfully isolated on Middlebrook 7H10 agar; thereby, the recovery rate increased to 287 (90.0%). The length of time of sputum storage had no significant effect on the rate of recovery of M. tuberculosis in all culturing systems. In conclusion, single morning sputum specimens collected at remote settings stored at −20°C for long periods of time without the addition of preservatives can yield a high recovery rate. These findings suggest a simple and cost-effective alternative method of sputum storage for epidemiological and drug resistance studies in low-resource countries.
Malaria Journal | 2013
Abebe Alemu; Hans-Peter Fuehrer; Gebeyaw Getnet; Belay Tessema; Harald Noedl
BackgroundIn Ethiopia Plasmodium falciparum and Plasmodium vivax are the dominant species accounting for roughly 60 and 40% of malaria cases, respectively. Recently a major shift from P. falciparum to P. vivax has been observed in various parts of the country but the epidemiology of the other human malaria species, Plasmodium ovale spp. and Plasmodium malariae remains poorly understood. The aim of this study was to assess P. ovale curtisi and wallikeri infection in north-west Ethiopia by using microscopy and nested PCR.MethodsA health institution-based survey using non-probability sampling techniques was conducted at Maksegnet, Enfranze and Kola Diba health centres and Metema hospital in North Gondar. Three-hundred patients with signs and symptoms consistent with malaria were included in this study and capillary blood was collected for microscopic examination and molecular analysis of Plasmodium species. Samples were collected on Whatman 903 filter papers, stored in small plastic bags with desiccant and transported to Vienna (Austria) for molecular analysis. Data from study participants were entered and analysed by SPSS 20 software.ResultsOut of 300 study participants (167 males and 133 females), 184 samples were classified positive for malaria (133 P. falciparum and 51 P. vivax) by microscopy. By species-specific PCR 233 Plasmodium spp (95% CI: 72.6-82) were detected and the majority 155 (66.5%, 95% CI: 60.2-72.3) were P. falciparum followed by P. vivax 69 (29.6%, 95% CI; 24.1-35.8) and 9 (3.9%, 95% CI: 2-7.2) samples were positive for P. ovale. Seven of P. ovale parasites were confirmed as P. ovale wallikeri and two were confirmed as P. ovale curtisi. None of the samples tested positive for P. malariae. During microscopic examination there were high (16.3%) false negative reports and all mixed infections and P. ovale cases were missed or misclassified.ConclusionThis study indicates that P. ovale malaria is under-reported in Ethiopia and provides the first known evidence of the sympatric distribution of indigenous P. ovale wallikeri and P. ovale curtisi in Ethiopia. Therefore, further studies assessing the prevalence of the rare species P. ovale and P. malariae are urgently needed to better understand the species distribution and to adapt malaria control strategies.
Malaria Research and Treatment | 2013
Getachew Ferede; Abiyu Worku; Alemtegna Getaneh; Ali Ahmed; Tarekegn Haile; Yenus Abdu; Belay Tessema; Yitayih Wondimeneh; Abebe Alemu
Background. Malaria is a major public health problem in Ethiopia where an estimated 68% of the population lives in malarious areas. Studying its prevalence is necessary to implement effective control measures. Therefore, the aim of this study was to determine seven-year slide positive rate of malaria. Methods. A retrospective study was conducted at Metema Hospital from September 2006 to August 2012. Seven-year malaria cases data had been collected from laboratory registration book. Results. A total of 55,833 patients were examined for malaria; of these, 9486 (17%) study subjects were positive for malaria. The predominant Plasmodium species detected was P. falciparum (8602) (90.7%) followed by P. vivax (852) (9%). A slide positive rate of malaria within the last seven years (2006–2012) was almost constant with slight fluctuation. The age groups of 5–14 years old were highly affected by malariainfection (1375) (20.1%), followed by 15–29 years old (3986) (18.5%). High slide positive rate of malaria occurred during spring (September–November), followed by summer (June–August). Conclusion. Slide positive rate of malaria was high in study area. Therefore, health planners and administrators should give intensive health education for the community.
Journal of global antimicrobial resistance | 2014
Feleke Moges; Mengistu Endris; Andargachew Mulu; Belay Tessema; Yeshambel Belyhun; Yitayal Shiferaw; Kahsay Huruy; Chandrashekhar Unakal; Afework Kassu
Infectious diseases of bacterial origin are a major cause of morbidity and mortality in developing countries such as Ethiopia. To minimise such burdens, proper use of antibiotics has played a vital role and saved countless lives. However, use of antimicrobials as therapeutic agents is compromised by the potential development of drug-resistant micro-organisms. Currently, antimicrobial drug resistance has become a public health concern both in developing and developed countries. Antimicrobial drug resistance is dramatically accelerated when antimicrobials are misused. This is critical, especially in developing countries where they are not only misused but are often underused due to financial constraints. Although large-scale studies on antimicrobial resistance in Ethiopia have not yet been conducted, the available reports indicate a trend towards increasing resistance rates among pathogens such as Escherichia coli, Shigella spp., Salmonella spp. and Staphylococcus aureus to commonly prescribed antibiotics, including ampicillin, amoxicillin, penicillin, tetracycline and trimethoprim/sulfamethoxazole. This review summarises the existing data on antibacterial drug resistance in this country.