ghanaopendata/ghanaian-research-english huggingface dataset:
High Abundance Of Butyrate-Producing Bacteria In The Naso-Oropharynx Of SARS-Cov-2-Infected Persons In An African Population: Implications For Low Disease Severity.

The Department of Parasitology conducts research into parasitic diseases of public health importance with the overall goal of reducing their transmission and the heavy disease burden that they impose on affected populations. The Department maintains focus on parasitic diseases in general. These include major diseases such as malaria, and others listed under the Neglected Tropical Diseases (NTD) control initiative such as, lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis, trypanosomiasis and leishmaniasis.

Source: UG
High adherence level to artemisinin-based combination therapies in rural settlement 11 years after their introduction in the health system, Nanoro, Burkina Faso

Purpose: In 2005, Burkina Faso changed its first-line treatment for uncomplicated malaria from chloroquine to artemisinin-based combination therapies (ACTs). Patient adherence to ACTs regimen is a keystone to achieve the expected therapeutic outcome and prevent the emergence and spread of parasite resistance. Eleven years after the introduction of ACTs in the health system, this study aimed to measure adherence level of patients in rural settlement and investigate the determinants of nonadherence. Patients and methods: The study was carried out at public peripheral health facilities from May 2017 to August 2017 in Nanoro health district, Burkina Faso. An electronic semi-structured questionnaire was used for data collection from patients with an ACT prescription at their medical consultation exit visit and during home visit at day 5±2. Adherence level was measured through self-report and pill counts. Logistic regression was performed to identify factors for nonadherence. Results: The analysis was conducted on 199 outpatients who received ACT as prescription. About 92.5% of ACT prescriptions included artemether-lumefantrine tablets. Adherence level was measured in 97.0% of included patients at day 5±2. Of these, 86.0% were classified as “complete adherent” and 14.0% as “nonadherent”. In univariate analysis, patients/caregivers who considered that affordability of ACTs was easy seemed to be less adherent to the treatment regimen (OR: 0.26; 95% CI: 0.07–0.70). In univariate and multivariable analyses, patients/caregivers who did not receive advices from health care workers (HCWs) were more likely to be nonadherent to the prescribed ACTs (adjusted OR: 3.21; 95% CI: 1.13–9.12). Conclusion: This study demonstrates that majority of those who get an ACT prescription comply with the recommended regimen. This emphasizes that in rural settings where ACTs are provided free of charge or at a subsidized price, patient adherence to ACTs is high, thus minimizing the risk of subtherapeutic concentrations of the drug in blood which is known to increase resistance and susceptibility to new infections. Therefore, to address the problem of patient nonadherence, strategy to strengthen communication between HCWs and patients should be given greater consideration.

Source: UG
High blood pressure: the foundation for epidemic cardiovascular disease in African populations

High blood pressure is a powerful independent risk factor for death from heart disease and stroke. It is also a common clinical condition affecting more than 600 million persons worldwide and seen in nearly all populations. Although reliable, large-scale, population-based data on high blood pressure in sub-Saharan Africa (SSA) are limited, recent studies provide important and worrisome findings in both epidemiology and clinical outcomes. Although overall hypertension prevalence is between 10%-15%, prevalence rates as high as 30%-32% have been reported in middle-income urban and some rural areas. Importantly, hypertension awareness, treatment, and control rates as low as 20%, 10%, and 1%, respectively have also been found. Stroke has been by far the most common clinical sequela. In most SSA settings, hypertension control assumes a relatively low priority and little experience exists in implementing sustainable and successful programs for drug treatment. Rapid urbanization and transition from agrarian life to the wage-earning economy of city life continue to fuel increases in average blood pressure levels and prevalence of hypertension. Although the true burden of high blood pressure in sub-Saharan Africa remains largely unmeasured, compelling preliminary evidence suggests that it is the foundation for epidemic cardiovascular disease in Africa and already contributes substantively to death and disability from stroke, heart failure, and kidney failure in this region. Success in limiting this epidemic in SSA will depend heavily on the implementation of sustainable and aggressive population-based programs for high blood pressure awareness, prevention, treatment, and control. It will be critical to obtain investments in improved surveillance and program-relevant research to provide the evidence base for policy development and effective hypertension prevention and control.

Source: UG
High BMI: an important health risk factor among older adults in Ghana

Objective: We examined BMI as a health risk factor for self-reported diabetes mellitus, angina, strokes and arthritis among older Ghanaians aged 50 years and above. Design: We analysed the individual-level data from the World Health Organization Study on global AGEing and adult health Ghana Wave 2 (2014/2015). The influence of BMI on self-reported chronic conditions including diabetes, angina, stroke and arthritis was examined. Setting: Households from all the administrative regions of Ghana. Participants: Included 3350 adults aged 50 years and older. Results: The prevalence of overweight and obesity among participants was 22·8 % (95 % CI 20·6, 25·2) and 13·2 %, respectively (95 % CI 11·5, 15·1). With respect to individual chronic conditions, arthritis emerged with the highest prevalence rate of 7·3 (95 % CI 5·3, 9·9), while the prevalence rate of diabetes, angina and stroke was 2·8 % (95 % CI 2·0, 3·9), 1·7 % (95 % CI 1·1, 2·6) and 1·3 % (95 % CI 1·0, 1·8), respectively. The risk of diabetes among overweight and obesity was over three and two times, respectively, higher compared with participants with normal weights. Overweight and obesity were significantly more than two and three times likely to experience angina, respectively, compared with participants with normal weight. Obesity significantly influences arthritis with approximately two times increased odds compared with normal weight participants. Conclusion: Prevalence of obesity and overweight in Ghana is high and increasing, which poses a health risk at the individual and population levels. Inter-sectorial and multidisciplinary measures in line with the national non-communicable disease policies aimed at curbing this trend are imperative.

Source: UG
High body mass index is not associated with atopy in schoolchildren living in rural and urban areas of Ghana

The Department of Parasitology conducts research into parasitic diseases of public health importance with the overall goal of reducing their transmission and the heavy disease burden that they impose on affected populations. The Department maintains focus on parasitic diseases in general. These include major diseases such as malaria, and others listed under the Neglected Tropical Diseases (NTD) control initiative such as, lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis, trypanosomiasis and leishmaniasis.

Source: UG
High cases of submicroscopic Plasmodium falciparum infections in a suburban population of Lagos, Nigeria

Background: Asymptomatic malaria parasites are significant sources of infections for onward malaria transmission. Conventional tools for malaria diagnosis such as microscopy and rapid diagnostic test kits (RDT) have relatively low sensitivity, hence the need for alternative tools for active screening of such low-density infections. Methods: This study tested var acidic terminal sequence-based (varATS) quantitative polymerase chain reaction (qPCR) for screening asymptomatic Plasmodium falciparum infections among dwellers of a sub-urban community in Lagos, Nigeria. Clinically healthy participants were screened for malaria using microscopy, RDT and varATS qPCR techniques. Participants were stratified into three age groups: 1–5, 6–14 and > 14 years old. Results: Of the 316 participants screened for asymptomatic malaria infection, 78 (24.68%) were positive by microscopy, 99 (31.33%) were positive by RDT and 112 (35.44%) by varATS qPCR. Participants aged 6–14 years had the highest prevalence of asymptomatic malaria, with geometric means of ~ 116 parasites/μL and ~ 6689 parasites/μL as detected by microscopy and varATS, respectively. Conclusion: This study has revealed high prevalence of asymptomatic malaria in the study population, with varATS detecting additional sub-microscopic infections. The highest concentration of asymptomatic malaria was observed among school-age children between 6 and 14 years old. A large-scale screening to identify other potential hotspots of asymptomatic parasites in the country is recommended.

Source: UG
High CD4/CD45RO+ and CD8/CD45RO+ frequencies in children with vaccine-modified measles

BACKGROUND: Despite availability and wide vaccine coverage, measles infections still occur especially in developing countries. An outbreak of measles occurred among previously immunized older Ghanaian children who had milder clinical symptoms with measles-specific IgG antibodies that could have been attributed to secondary vaccine failure, suggesting that the infection was vaccine-modified measles (VMM). METHODS: Two-color immunophenotyping of the peripheral blood mononuclear cells was performed at acute, recovery and convalescence phases for 19 VMM patients (mean age 6.2 +/- 3.5 years) using flow cytometry, and compared with that of 20 healthy, sex- and age-matched controls. RESULTS: The results showed a significantly higher memory helper (CD4(+)/CD45RO(+)) cell frequency and increased suppressor cell (CD8(+)/CD45R0(+)) frequency in VMM patients compared to healthy controls. There were no complications and all the patients recovered completely. CONCLUSIONS: These findings show that the mild symptoms in patients with VMM may have correlated with the increase of memory T cells, which is in sharp contrast with previous reports on acute measles infection. This may suggest that the intact immunologic memory cells could have been crucial for the resolution of VMM.

Source: UG
High chlorpyrifos levels on vegetables in Ghana

Revelations of high levels of pesticide residues on foodstuffs has led to an outcry over the inappropriate use of pesticides on vegetables cultivated in urban and peri-urban areas of Ghana. In 2006 a survey of sixty farmers from the Volta region of Ghana revealed inappropriate pesticide application practices. Residue analysis detected the presence of chlorpyrifos, DDT, cypermethrin, and dimethoate in shallots, with levels of chlorpyrifos exceeding the Codex maximum residue level in most samples.

Source: UG
High dose cyclophosphamide in drug resistant and relapsing Burkitt's lymphoma.

Most research activities involve the use of molecular methods such as regular PCR (PCR), quantitative PCR (Q-PCR), genomic sequence and analysis using different software, genetic engineering, probe hybridization techniques, biological and molecular cloning, evaluation of immune markers for laboratory diagnosis of infections, serological assays involving the use of rapid tests, ELISA-based evaluations and immunofluorescent assay techniques.

Source: UG
High electron thermal conductivity of chiral carbon nanotubes

Solving the Boltzmann kinetic equation with energy dispersion relation obtained in the tight-binding approximation, the carrier thermal conductivity κe of a chiral carbon nanotube (CCNT) was determined. The dependence of κe on temperature T, chiral geometric angle φh and overlap integrals Δz and Δs were obtained. The results were numerically analysed. Unusually high values of κe were observed suggesting that κe is nontrivial in the calculation of the thermal conductivity κ of CCNT. More interestingly we noted also that at 104 K and for Δz and Δs values of 0.020 and 0.0150 eV, respectively the κe value is about 41,000 W/mK as reported for a 99.9% pure 12C crystal. We predict that the electron thermal conductivity of CCNT should exceed 200,000 W/mK at ∼ 80 K. © 2004 Published by Elsevier B.V.

Source: UG
High energy milling of Cu2O powders

X-ray diffraction line profile analysis based on the recently developed Whole Powder Pattern Modelling was used to investigate the microstructure changes in Cu2O powders milled in a vibrating cup mill. The reduction in the average size of coherently scattering domains - and simultaneous narrowing of the size distribution - occurs in the first minutes. An asymptotic limit of ca. 10 nm is obtained. The reduction in size is obtained at the expenses of introducing a massive quantity of dislocations in the system, reaching a limit of ca. 4×10-16 m-2. A proper nanocrystalline microstructure can be obtained for a milling of ca. 20 min.

Source: UG
High frequency amplification of acoustic phonons in fluorine-doped single-walled carbon nanotubes

Herein, we report on a strong high-frequency induced amplification of coherent acoustic phonons in a non degenerate fluorine-doped single-walled carbon nanotubes (FSWCNTs) by utilising a tractable analytical approach in the hypersound regime, ql≫1 (where q is the acoustic wavenumber and l is the carrier mean free path). The acoustoelectric gain obtained is highly nonlinear and is due to stimulated Cerenkov phonon emission by electrically driven carriers undergoing intraminiband transport and capable of performing Bloch oscillations. The transport process causes the carriers to undergo population inversion leading to intraminiband phonon assisted processes. The generation rate (phonon emission) is expansive and surpasses phonon losses. The threshold field (Eo), at which attenuation switches over to amplification (gain) depends on the FSWCNT pa rameters (Δs&Δz), carrier drift velocity (vd = μEo), sound velocity (vs) and the ratio ζs,z. This result has potential for intense sources of reasonable acoustic phonons in the sub-THz regime and is vital for the generation of SASER (sound amplification by stimulated emission of acoustic radiation). The amplified phonons also have THz fre quencies with wavelengths in the nanometer range, and depends on high spatial parameters which has potential applications for phonon filters and spectrometers.

Source: UG
High frequency electromagnetic purification of silicon

The use of electromagnetic field to remove suspended particles from metals such as aluminum by pushing to the boundary has been well studied. However, the potential of this method is yet to be exploited for the removal of inclusions from silicon. Considering the increasing amount of Top-cut SoG-Si scraps year upon year, mere is the need to harness all the potentials of technologies to recycle this materials to ensure sustainability. This study investigates, and discusses new results on the effect of processing parameters such as composition, coil current, and frequency on the removal of inclusions from silicon under high frequency AC electromagnetic field.

Source: UG
High frequency electromagnetic separation of inclusions from aluminum

Removal of inclusions from aluminum is a critical step during the production of high quality aluminum alloys. Electromagnetic purification method for the removal of inclusions has been proposed to complement the existing methods, and many researchers have devoted a lot of effort to studying the electromagnetic inclusion removal process. It has been widely published that high frequency electromagnetic field is limited in the depth of penetration into the molten metal thereby rendering the separation method ineffective. The contribution of the high circulatory fluid flow associated with such high frequencies has also been reported to be negative. The effect of wall temperature to the electromagnetic inclusion removal process has also not been clearly established. This study presents new results that show that, fluid flow contributes greatly in the presence of lower wall temperature to remove particles during high frequency (63 kHz) EM purification of aluminum, contributing to overcoming skin depth effect in small and large crucibles.

Source: UG
High frequency monitoring of swash hydro-morphodynamics on a reflective beach (Grand Popo, Benin): A new method

A new remote sensing video-based method for measuring rapid variations of the bed elevation and free-surface in the swash zone is tested on a steep reflective beach at Grand Popo. The key assumption is that the free-surface has a distinguishable optical signature with respect to the bed level. This new set up enables a high frequency description of the wave transformation, dissipation and reflection in the swash zone as well as the variations of the bed evolution at the wave-by-wave scale. At a more integrated scale, a good correlation is found between the offshore reflected energy measured by an ADCP, the incident offshore wave characteristics and the swash local morphology, suggesting the importance of the swash dynamics on the energy reflection mechanism.

Source: UG
High frequency of circulating γδ T cells with dominance of the V(δ)1 subset in a healthy population.

The Epidemiology Department contributes to the mission of the institute through basic and applied epidemiological research on, but not limited to, malaria and other diseases of public health importance. It is also home to the Social Science Unit of the Institute, including the Health Support Centre for HIV/AIDS and other communicable and noncommunicable health problems.

Source: UG
High Frequency of First-Line Anti-Tuberculosis Drug Resistance among Persons with Chronic Pulmonary Tuberculosis at a Teaching Hospital Chest Clinic

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.

Source: UG
High frequency of the Duffy‑negative genotype and absence of Plasmodium vivax infections in Ghana

Background: Recent studies from different malaria-endemic regions including western Africa have now shown that Plasmodium vivax can infect red blood cells (RBCs) and cause clinical disease in Duffy-negative people, though the Duffy-negative phenotype was thought to confer complete refractoriness against blood invasion with P. vivax. The actual prevalence of P. vivax in local populations in Ghana is unknown and little information is available about the distribution of Duffy genotypes. The aim of this study was to assess the prevalence of P. vivax in both asymptomatic and symptomatic outpatients and the distribution of Duffy genotypes in Ghana. Methods: DNA was extracted from dried blood spots (DBS) collected from 952 subjects (845 malaria patients and 107 asymptomatic persons) from nine locations in Ghana. Plasmodium species identification was carried out by nested polymerase chain reaction (PCR) amplification of the small-subunit (SSU) rRNA genes. For P. vivax detection, a second PCR of the central region of the Pvcsp gene was carried out. Duffy blood group genotyping was performed by allele-specific PCR to detect the presence of the FYES allele. Results: No cases of P. vivax were detected in any of the samples by both PCR methods used. Majority of infections (542, 94.8%) in the malaria patient samples were due to P. falciparum with only 1 infection (0.0017%) due to Plasmodium malariae, and 2 infections (0.0034%) due to Plasmodium ovale. No case of mixed infection was identified. Of the samples tested for the FYES allele from all the sites, 90.5% (862/952) had the FYES allele. All positive samples were genotyped as FY*B-33/FY*B-33 (Duffy-negative homozygous) and therefore classified as Fy(a−b−). Conclusions: No cases of P. vivax were detected by both PCRs and majority of the subjects tested carried the FYES allele. The lack of P. vivax infections observed can be attributed to the high frequency of the FYES allele that silences erythroid expression of the Duffy. These results provide insights on the host susceptibility for P. vivax infections that had not been investigated in Ghana before.

Source: UG
High frequency of the Dufy-negative genotype and absence of Plasmodium vivax infections in Ghana

Background: Recent studies from diferent malaria-endemic regions including western Africa have now shown that Plasmodium vivax can infect red blood cells (RBCs) and cause clinical disease in Dufy-negative people, though the Dufy-negative phenotype was thought to confer complete refractoriness against blood invasion with P. vivax. The actual prevalence of P. vivax in local populations in Ghana is unknown and little information is available about the distribution of Dufy genotypes. The aim of this study was to assess the prevalence of P. vivax in both asymptomatic and symptomatic outpatients and the distribution of Dufy genotypes in Ghana. Methods: DNA was extracted from dried blood spots (DBS) collected from 952 subjects (845 malaria patients and 107 asymptomatic persons) from nine locations in Ghana. Plasmodium species identifcation was carried out by nested polymerase chain reaction (PCR) amplifcation of the small-subunit (SSU) rRNA genes. For P. vivax detection, a second PCR of the central region of the Pvcsp gene was carried out. Dufy blood group genotyping was performed by allele-specifc PCR to detect the presence of the FYES allele. Results: No cases of P. vivax were detected in any of the samples by both PCR methods used. Majority of infections (542, 94.8%) in the malaria patient samples were due to P. falciparum with only 1 infection (0.0017%) due to Plasmo dium malariae, and 2 infections (0.0034%) due to Plasmodium ovale. No case of mixed infection was identifed. Of the samples tested for the FYES allele from all the sites, 90.5% (862/952) had the FYES allele. All positive samples were genotyped as FY*B-33/FY*B-33 (Dufy-negative homozygous) and therefore classifed as Fy(a−b−). Conclusions: No cases of P. vivax were detected by both PCRs and majority of the subjects tested carried the FYES allele. The lack of P. vivax infections observed can be attributed to the high frequency of the FYES allele that silences erythroid expression of the Dufy. These results provide insights on the host susceptibility for P. vivax infections that had not been investigated in Ghana before.

Source: UG