84 research outputs found
Sangeda, Raphael Zozimus
No full textA scientometric analysis was conducted to map the research performance and citation impact of Tanzania scholars from 1991 to 2015. The study analyzed the growth of the Tanzanians’ scholarly literature; ascertained the year-wise distribution of publications, subject-wise distribution of publications; determined the authorship pattern and degree of collaboration; and analyzed the citation impact. Scientometric analysis is a type of quantitative methods used in evaluating research productivity of individual scientists. Data for research productivity of all Tanzania scholars were obtained using the SCOPUS database. For the Tanzanians’ scholars, a total of 12,379 articles were published from 34 academic and research institutions from 1991 to 2015. Most Tanzanians scholars had published journal articles (n= 10392, 83.9%), which was followed by review articles and conference papers. The top three universities with high cumulative number of publications were Muhimbili University of Health and Allied Sciences (MUHAS) (n=2009, 16.2 %), University of Dar es salaam (n=1880, 15.2%) and Sokoine University of Agriculture (n=1571, 12.7%). The three universities alternated the first three ranks over the period of 25 years. The top five subjects where Tanzanians scholars published were related to medicine (n=6868, 25.0%), agricultural and biological sciences (n=5260, 19.2 %), immunology and microbiology (n=2781, 10.1%), environmental sciences (n=2309, 8.4%), and biochemistry, genetics and molecular biology (n=1853, 6.8%). Forty two percent of all publications were co-authored with researchers from the United States of America and the United Kingdom each contributing almost equally. Kenya is the third collaborating country contributing to 870 publications (7.0%). The maximum number of citations received in a single publication was 1914. The study findings call for scholars to recognize the importance of publishing in visible journals in order to receive large citation counts. Institutions are urged to employ scientometrics in evaluating the research performance of their scholars since such techniques take into account a combination of several measures. These findings suggest that many factors should be considered in combination when evaluating researchers’ productivity and impact. For Tanzania to achieve its sustainable goals it and progress from a low- to a middle-income country, it needs to involve its researchers, policy-makers and providers such as the health care providers to collaborate in efforts to bridge the gaps between research, policy and practice
Dataset for a cross-sectional study on the prevalence of urinary tract infections and antibiogram of uropathogens isolated from under-five children attending Bagamoyo district hospital in Tanzania - dataset
No full textUrinary tract infection (UTI) is a common condition in children that recurs frequently. This study aimed to determine the prevalence of UTIs among under-five children attending Bagamoyo District hospital and its association with nutritional status.
This data was from a cross-sectional study that enrolled 214 under-five children attending Bagamoyo district hospital in Tanzania. Midstream urine was collected in sterile conditions and bottles. Samples were transported to the laboratory at Muhimbili University of Health and Allied Sciences for analysis, isolation and bacteria identification. Bacteria were isolated using CLED agar, followed by identification using Gram staining, single iron agar test, sulfide-indole motility test, catalase and oxidase tests. A susceptibility test was done using the disc diffusion method. Anthropometric measurements were employed to assess malnutrition status and body mass index determined using each child's weight and height.
Presented are underlining data (in Microsoft Excel format) containing the data from the questionnaire and laboratory analyses resulting from bacteria identification and antimicrobial susceptibility testing.
The second file is the questionnaire with the questions that were used in to capture the demographic information.
The data marked 'NA' implies that for these patients who were negative for urinary tract infection, the data was not available for the type of bacteria and other tests
White matter integrity in Tanzanian children with sickle cell anemia: A diffusion tensor imaging study
Get PDFBackground and Purpose- Widespread reductions in white matter integrity are associated with cognitive dysfunction in sickle cell anemia. Silent cerebral infarction (SCI), vasculopathy (VSC), and low hemoglobin concentration (Hb) are implicated; we aimed to determine independent contributions to microstructural white matter injury and whether white matter integrity differs across arterial territories. Methods- Sixty two children with sickle cell anemia aged 6 to 19 years were prospectively studied at Muhimbili National Hospital, Tanzania. SCI± and VSC± were identified on magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) scans by 2 neuroradiologists. Tract-based spatial statistics tested for voxel-wise differences in diffusion tensor imaging metrics (ie, fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity) between SCI± and VSC± groups, with correlations between diffusion tensor imaging metrics and Hb. In tract-based spatial statistics analyses, potentially mediating factors (ie, age, sex, as well as Hb, SCI, and/or vasculopathy) were covariates. Differences in mean diffusion tensor imaging metrics across regions of interest in arterial territories were explored. Results- Compared with SCI- patients (n=45), SCI+ patients (n=17) exhibited increased radial diffusivity in multiple regions; negative relationships were observed between mean diffusivity, axial diffusivity, and Hb (
P<0.005). Compared with VSC- patients (n=49), mild (n=6) or moderate (n=7) VSC+ patients exhibited reduced fractional anisotropy in widespread regions (
P<0.05) including the anterior longitudinal fasciculi, corpus callosum, internal capsule, corona radiata, and corticospinal tracts. Overall, the posterior cerebral arterial territory had higher mean mean diffusivity and mean radial diffusivity than the anterior and middle cerebral arterial territories, although no patient had vasculopathy in this area. There was an interaction between territory and vasculopathy. Conclusions- SCI, vasculopathy, and Hb are independent risk factors, and thus treatment targets, for diffuse white matter injury in patients with sickle cell anemia. Exacerbation of hemodynamic stress may play a role.
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Moeilijkheden bij het opvolgen van anti-HIV therapierespons in ontwikkelingslanden
No full textThe advent of the potent combination antiretroviral therapy (cART) in 1996, often called HAART (highly active antiretroviral therapy) changed the impact of HIV both for an individual and the population. These cocktails of three or more antiretroviral (ARV) drugs significantly improved life expectancy in patients who have access to it and thus restored hope for fighting the disease epidemic.Recently, ART is being scaled up in resource limited-settings (RLS), giving access to treatment in geographic areas where the majority of HIV infected patients reside. The main concern of scaling up ART in RLS is whether these expensive treatment programs translate to an effective reduction in morbidity and mortality among HIV and AIDS patients. Factors such as lack of potency of ARV combinations, insufficient drug adherence and transmission of drug resistant virus strains may lead to treatment failure. Therefore, HAART requires high levels of adherence, typically above 95%, in order to prevent the development of HIV drug resistance (HIVDR) mutations, which ultimately lead to poor treatment response.In developed countries, the standard of care includes virological monitoring: measuring the amount of circulating virus in the blood and determining the genotypic susceptibility of patient isolates. In this way, a rational selection and use of ARVs can bring a successful treatment response. In RLS, virological monitoring is hampered by high costs. Following reports of both acquired and transmitted resistance in sub-Saharan Africa, it is imperative to devise more robust methods for monitoring of therapy response. These reports call for cheaper and simpler viral load and resistance-testing platforms to identify virologically failing patients and measure the presence of key drug resistance mutations. Most often this is not possible and alternatives are needed for identifying therapy failure and emerging HIVDR at both population and individual levels. In RLS, ART adherence monitoring is a potential surrogate that could be incorporated into clinical care. Alternatively, a model for predicting drug resistance based on limited genotyping combined with past treatment history from large databases could be useful in RLS.Chapter one provides a general overview of the problem of HIV and AIDS epidemic, while, chapter 2 outlines the rationale and the objective of this research. In chapter 3 we studied adherence measurements in an adult cohort in Dar es Salaam, Tanzania. The first method to probe adherence was self-reports by using the visual analog scale (VAS) and the Swiss HIV cohort study-adherence questionnaire (SHCS-AQ). Additionally, pill count, appointment keeping and pharmacy prescription refill methods were used. We revealed good adherence to ART in between 50 to 86% of this population, using the different adherence measurements. Comparable adherence levels reported in other sub-Saharan Africa countries were at proportions of 96%, 82% and 78% among respondents in Ethiopia, Kenya and Cote d'Ivoire, respectively. We identified forgetfulness as a major reason for skipping medications. Older age, less alcohol consumption, being at more advanced WHO staging and having less body mass index were significant predictors of good adherence in multivariate analysis. Further, in chapter 4 we validated the different measurement outcomes of adherence against the virological outcome after one year of follow-up among for 162 patients having both baseline and follow-up viral load. The patients were followed for a period of one year median (interquartile range) 13 (11-13) months. Of these patients 34% and 10.5% had detectable viral load and immunological failure, respectively at one year after recruitment. The pharmacy refill estimate was the only adherence measurement associated to virological outcome. Further, the prediction of virological outcome was improved by combining pharmacy refill with immunological status.Information on levels of HIVDR among HIV patients on therapy is not available in Tanzania. The ultimate objective of this research was to determine genotypic HIVDR in both treatment naïve and experienced patients. Furthermore, the research intended to find cheap predictors for treatment failure and resistance development, such as adherence and treatment history. In chapter 5, genotyping was performed from virologically failing patients plasma samples in order to determine subtype diversity of HIV isolates and the mutation patterns at various stages of ART in Tanzania. The study revealed wide subtype diversity among isolates in these patients. The isolates belonged mostly to subtypes A followed by subtypes C and D; and their recombinant forms. The study did not uncover any transmitted drug resistance mutations in naïve patients initiating ART. However, a high prevalence of resistance was evident among virologically failing patients on therapy for more than four months. The major nucleoside reverse transcriptase inhibitor (NRTI) mutation M184V was found in 70% of patient failing virologically, threatening the utility of lamivudine and emtricitabine, which are the main NRTIs recommended in the Tanzanian national guidelines for management of ART. Resistance to non-nucleoside reverse transcriptase inhibitor (NNRTI) NNRTIs was found in 86% of virologically failing patients, with K103N being the most abundant mutation. All potential second line regimens were already compromised in 86% of patients. These high prevalence of HIVDR in virologically failing patients warrant appropriate interventions to prevent further transmission of multi-HIVDR in Tanzania.Chapter 6 approached our objectives from a different angle. Genetic fitness landscapes (FL) can be used to derive the genetic barrier to resistance given a baseline genotype. This in turn, can be used to predict the response to therapy. Such FLs are built in two steps, first mapping epistatic interactions among the amino acids in the targeted proteins using Bayesian Network Learning, and then scaling the FL by modelling evolution during treatment selective pressure using sequences from untreated versus treated patients. In chapter 6, we evaluated a new approach to building a FL by using longitudinal sequence pairs, instead of cross-sectional data only, using the drug indinavir as a model drug. We compared four FLs estimated from different HIV sequence populations. One was built using for both steps only cross-sectional data from drug-naïve and indinavir experienced patients. Three FLs were built by using for the first step three different cross-sectional Bayesian Networks, trained with indinavir, all protease inhibitors (PIs) and all PIs except indinavir sequence data respectively, followed by the second scaling step using longitudinal viral sequence pairs from patients failing a combination including the drug indinavir. We derived parameters of viral fitness and genetic barrier to resistance by simulating sequences over the FLs. These parameters successfully predicted the short and long term virological response at 12 and 48 weeks, respectively. The predictive power was comparable to that of standard rule based interpretation systems such as the Rega algorithm and HIVdb. Additionally, the FLs could predict a failing genotype in longitudinal sequence pairs before and after treatment with indinavir.This research investigated adherence measurements that are feasible in RLS and identified predictors of good adherence. We also found adherence in combination with immune response to be good predictors of virological response. We found no transmitted drug resistance among treatment-naïve patients, but rather high levels of HIVDR among patients failing cART in Tanzania. This signals Tanzania and other countries in sub-Saharan Africa to consider scaling resistance testing where feasible. Adherence was an independent predictor of virological failure, therefore, it can be a surrogate marker to earmark patients in need for virological and HIVDR testing. Moreover, a computational modelling approach could offer an added value by combining sparse genotypic information with other factors such as treatment history to predict therapy response.These research findings provide additional information and valuable insights for policy decisions on ART interventions that will reduce the risk of emergence of HIVDR among patients on treatment in RLS. In general, the baseline data provided by these studies collectively suggest that regular surveillance of HIVDR needs to be implemented in this setting.status: Publishe
Factors Associated with HIV Drug Resistance in Dar es Salaam, Tanzania: Analysis of a Complex Adaptive System
Get PDFHIV drug resistance (HIVDR) is a complex problem with multiple interconnected and context dependent causes. Although the factors influencing HIVDR are known and well-studied, HIVDR remains a threat to the effectiveness of antiretroviral therapy. To understand the complexity of HIVDR, a comprehensive, systems approach is needed. Therefore, a local systems map was developed integrating all reported factors influencing HIVDR in the Dar es Salaam Urban Cohort Study area in Tanzania. The map was designed based on semi-structured interviews and workshops with people living with HIV and local actors who encounter people living with HIV during their daily activities. We visualized the feedback loops driving HIVDR, compared the local map with a systems map for Sub-Saharan Africa, previously constructed from interviews with international HIVDR experts, and suggest potential interventions to prevent HIVDR. We found several interconnected balancing and reinforcing feedback loops related to poverty, stigmatization, status disclosure, self-esteem, knowledge about HIVDR and healthcare system workload, among others, and identified three potential leverage points. Insights from this local systems map were complementary to the insights from the Sub-Saharan systems map showing that both viewpoints are needed to fully understand the system. This study provides a strong baseline for quantitative modelling, and for the identification of context-dependent, complexity-informed leverage points.sponsorship: Vlaamse Interuniversitaire Raad|TZ2019SIN263status: Publishe
Cerebral infarcts and vasculopathy in Tanzanian children with sickle cell anemia
No full textBackground: Cerebral infarcts and vasculopathy in neurologically asymptomatic children with sickle cell anemia (SCA) have received little attention in African settings. This study aimed to establish the prevalence of silent cerebral infarcts (SCI) and vasculopathy and determine associations with exposure to chronic hemolysis, anemia, and hypoxia.Methods: We prospectively studied 224 children with SCA with transcranial Doppler (TCD), and magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). Regressions were undertaken with contemporaneous hemoglobin, reticulocyte count, mean prior hemoglobin, oxygen content, reticulocyte count, and indirect bilirubin.Results: Prevalence of SCI was 27% (61 of 224); cerebral blood flow velocity was abnormal (>200 cm/s) in three and conditional (>170<200 cm/s) in one. Vasculopathy grades 2 (stenosis) and 3 (occlusion) occurred in 16 (7%) and two (1%), respectively; none had grade 4 (moyamoya). SCI was associated with vasculopathy on MRA (odds ratio 2.68; 95% confidence intervals [95% CI] 1.32 to 5.46; P = 0.007) and mean prior indirect bilirubin (odds ratio 1.02, 95% CI 1.00 to 1.03, P = 0.024; n = 83) but not age, sex, non-normal TCD, or contemporaneous hemoglobin. Vasculopathy was associated with mean prior values for hemoglobin (odds ratio 0.33, 95% CI 0.16 to 0.69, P = 0.003; n = 87), oxygen content (odds ratio 0.43, 95% CI 0.25 to 0.74, P = 0.003), reticulocytes (odds ratio 1.20, 95% CI 1.01-1.42, P = 0.041; n = 77), and indirect bilirubin (odds ratio 1.02, 95% CI 1.01 to 1.04, P = 0.009).Conclusions: SCI and vasculopathy on MRA are common in neurologically asymptomatic children with SCA living in Africa, even when TCD is normal. Children with vasculopathy on MRA are at increased risk of SCI. Longitudinal exposure to anemia, hypoxia, and hemolysis appear to be risk factors for vasculopathy.</p
Pharmacists’ Knowledge, Attitude and Practice Regarding the Dispensing of Antibiotics without Prescription in Tanzania: An Explorative Cross-Sectional Study
No full textInappropriate use of antibiotics has been reported to contribute to the emergence and increase of antimicrobial resistance (AMR) in the world. The pharmacist has the responsibility to supervise the dispensing of antibiotics with prescriptions to ensure rational use. An online semi-structured questionnaire was shared with approximately 1100 licensed pharmacists in Tanzania. Study data were collected and managed using REDCap electronic data capture tools before use for analysis. Of the 226 (20.5%) received responses, 197 had given consent and provided complete surveys. Notably, 153 (77.7%) of the 197 pharmacists had excellent knowledge about the legal requirements for dispensing antibiotics and the AMR challenge. Of the 197 surveyed pharmacists, 143 (72.6%) admitted to dispensing antibiotics without a prescription in their daily practice. Notably, 84.1% (37/44) of pharmacists with masters or PhD education were more likely to dispense without a prescription compared to 69.3% (106/153) among bachelor holders (p-value = 0.04). The reasons for administering antibiotics without a prescription included the pharmacy business looking for more profit, patient failure to obtain a prescription and the lack of stringent inspection of pharmacies by the regulatory authorities. Penicillins, macrolides and fluoroquinolones were the classes of antibiotics most commonly dispensed without a prescription. Stringent inspections by the regulatory authorities should detect and reduce dispensing antibiotics without a prescription. The community should be educated on the importance of medication prescription from a qualified medical practitioner
Predictors of non adherence to antiretroviral therapy at an urban HIV care and treatment center in Tanzania
No full textRaphael Z Sangeda,1,2 Fausta Mosha,3 Said Aboud,4 Appolinary Kamuhabwa,5 Guerino Chalamilla,6,† Jurgen Vercauteren,2 Eric Van Wijngaerden,7 Eligius F Lyamuya,4 Anne-Mieke Vandamme2,8 1Department of Pharmaceutical Microbiology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania; 2Department of Microbiology and Immunology, Rega Institute for Medical Research, Clinical and Epidemiological Virology, KU Leuven – University of Leuven, Leuven, Belgium; 3Ministry of Health, Community Development, Gender, Elderly and Children, Dar es Salaam, Tanzania; 4Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania; 5Department of Clinical Pharmacy and Pharmacology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania; 6Management and Development for Health (MDH), Dar es Salaam, Tanzania; 7Department of General Internal Medicine, University Hospitals, KU Leuven – University of Leuven, Belgium; 8Center for Global Health and Tropical Medicine, Unidade de Microbiologia, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal †Dr Guerino Chalamilla passed away in November 2015 Background: Measurement of adherence to antiretroviral therapy (ART) can serve as a proxy for virologic failure in resource-limited settings. The aim of this study was to determine the factors underlying nonadherence measured by three methods. Patients and methods: This is a prospective longitudinal cohort of 220 patients on ART at Amana Hospital in Dar es Salaam, Tanzania. We measured adherence using a structured questionnaire combining a visual analog scale (VAS) and Swiss HIV Cohort Study Adherence Questionnaire (SHCS-AQ), pharmacy refill, and appointment keeping during four periods over 1 year. Overall adherence was calculated as the mean adherence for all time points over the 1 year of follow-up. At each time point, adherence was defined as achieving a validated cutoff for adherence previously defined for each method. Results: The proportion of overall adherence was 86.4% by VAS, 69% by SHCS-AQ, 79.8% by appointment keeping, and 51.8% by pharmacy refill. Forgetfulness was the major reported reason for patients to skip their medications. In multivariate analysis, significant predictors to good adherence were older age, less alcohol consumption, more advanced World Health Organization clinical staging, and having a lower body mass index with odds ratio (CI): 3.11 (1.55–6.93), 0.24 (0.09–0.62), 1.78 (1.14–2.84), and 0.93 (0.88–0.98), respectively. Conclusion: We found relatively good adherence to ART in this setting. Barriers to adherence include young age and perception of well-being. Keywords: self-report, appointment keeping, pharmacy refill, adherence barriers, resource-limited settings, AID
Research growth and citation impact of Tanzanian scholars: A 24 years scientometric study
No full textONLINE VISIBILITY OF PHARMACY RESEARCH IN TANZANIA: A SCIENTOMETRIC STUDY
No full textObjective: This scientometric analysis was carried out to map the online visibility of pharmacy research at Muhimbili University of Health and Allied Sciences (MUHAS) from 1981 to 2016.Methods: Publish or Perish software was used to collect data for 33 scientists from the School of Pharmacy at MUHAS. We retrieved data on scholars’ publications, citation counts, the number of authors per publication, average citations per paper, average citations per year, h-index, g-index, contemporary H-index (Hc index) and the HI-norm index.Results: A total of 499 publications were recorded for all scholars and the most (61; 12.2%) productive was 2013. The whole study period recorded the mean relative growth rate (RGR) and doubling time (Dt) of 1.62 and 0.46 respectively. A great majority (484; 97%) of the publications were multiple-authored with nearly one third (157; 31.5%) of these being jointly contributed by six or more authors. The maximum number of citations received in a single publication was 241. The degree of collaboration among scientists was as high as 0.97. The top ranked pharmacy researchers showed variation in various metrics.Conclusion: The study findings indicate a continuous growth of pharmacy publications at MUHAS since 1981. There is a high level of collaboration among scholars and many publications have made a great impact through citations. </jats:p
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