Browsing by Author "Asiedu, K."
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Item Buruli Ulcer: a Review of the Current Knowledge(Current Tropical Medicine Reports, 2018-12) Yotsu, R.R.; Suzuki, K.; Simmonds, R.E.; Bedimo, R.; Ablordey, A.; Yeboah-Manu, D.; Phillips, R.; Asiedu, K.Purpose of the Review Buruli ulcer (BU) is a necrotizing and disabling cutaneous disease caused by Mycobacterium ulcerans, one of the skin-related neglected tropical diseases (skin NTDs). This article aims to review the current knowledge of this disease and challenges ahead. Recent Findings Around 60,000 cases of BU have been reported from over 33 countries between 2002 and 2017. Encouraging findings for development of point-of-care tests for BU are being made, and its treatment is currently in the transition period from rifampicin plus streptomycin (injection) to all-oral regimen. A major recent advance in our understanding of its pathogenesis has been agreement on the mechanism of action of the major virulence toxin mycolactone in host cells, targeting the Sec61 translocon during a major step in protein biogenesis. Summary BU is distributed mainly in West Africa, but cases are also found in other parts of the world. We may be underestimating its true disease burden, due to the limited awareness of this disease. More awareness and more understanding of BU will surely contribute in enhancing our fight against this skin NTD.Item Comparative efficacy of low-dose versus standard-dose azithromycin for patients with yaws: a randomised non-inferiority trial in Ghana and Papua New Guinea(The Lancet Global Health, 2018-04) Marks, M.; Mitjà, O.; Bottomley, C.; Kwakye, C.; Houinei, W.; Bauri, M.; Adwere, P.; Abdulai, A.A.; Dua, F.; Boateng, L.; Wangi, J.; Ohene, S.A.; Wangnapi, R.; Simpson, S.V.; Miag, H.; Addo, K.K.; Basing, L.A.; Danavall, D.; Chi, K.H.; Pillay, A.; Ballard, R.; Solomon, A.W.; Chen, C.Y.; Bieb, S.V.; Adu-Sarkodie, Y.; Mabey, D.C.W.; Asiedu, K.; Study teamBackground: A dose of 30 mg/kg of azithromycin is recommended for treatment of yaws, a disease targeted for global eradication. Treatment with 20 mg/kg of azithromycin is recommended for the elimination of trachoma as a public health problem. In some settings, these diseases are co-endemic. We aimed to determine the efficacy of 20 mg/kg of azithromycin compared with 30 mg/kg azithromycin for the treatment of active and latent yaws. Methods: We did a non-inferiority, open-label, randomised controlled trial in children aged 6–15 years who were recruited from schools in Ghana and schools and the community in Papua New Guinea. Participants were enrolled based on the presence of a clinical lesion that was consistent with infectious primary or secondary yaws and a positive rapid diagnostic test for treponemal and non-treponemal antibodies. Participants were randomly assigned (1:1) to receive either standard-dose (30 mg/kg) or low-dose (20 mg/kg) azithromycin by a computer-generated random number sequence. Health-care workers assessing clinical outcomes in the field were not blinded to the patient's treatment, but investigators involved in statistical or laboratory analyses and the participants were blinded to treatment group. We followed up participants at 4 weeks and 6 months. The primary outcome was cure at 6 months, defined as lesion healing at 4 weeks in patients with active yaws and at least a four-fold decrease in rapid plasma reagin titre from baseline to 6 months in patients with active and latent yaws. Active yaws was defined as a skin lesion that was positive for Treponema pallidum ssp pertenue in PCR testing. We used a non-inferiority margin of 10%. This trial was registered with ClinicalTrials.gov, number NCT02344628. Findings: Between June 12, 2015, and July 2, 2016, 583 (65·1%) of 895 children screened were enrolled; 292 patients were assigned a low dose of azithromycin and 291 patients were assigned a standard dose of azithromycin. 191 participants had active yaws and 392 had presumed latent yaws. Complete follow-up to 6 months was available for 157 (82·2%) of 191 patients with active yaws. In cases of active yaws, cure was achieved in 61 (80·3%) of 76 patients in the low-dose group and in 68 (84·0%) of 81 patients in the standard-dose group (difference 3·7%; 95% CI −8·4 to 15·7%; this result did not meet the non-inferiority criterion). There were no serious adverse events reported in response to treatment in either group. The most commonly reported adverse event at 4 weeks was gastrointestinal upset, with eight (2·7%) participants in each group reporting this symptom. Interpretation: In this study, low-dose azithromycin did not meet the prespecified non-inferiority margin compared with standard-dose azithromycin in achieving clinical and serological cure in PCR-confirmed active yaws. Only a single participant (with presumed latent yaws) had definitive serological failure. This work suggests that 20 mg/kg of azithromycin is probably effective against yaws, but further data are needed. Funding: Coalition for Operational Research on Neglected Tropical Diseases. © 2018 World Health OrganizationItem Complete genome sequences of 11 Haemophilus ducreyi isolates from children with cutaneous lesions in Vanuatu and Ghana(American Society for Microbiology, 2016) Pillay, A.; Katz, S.S.; Abrams, A.J.; Ballard, R.C.; Simpson, S.V.; Taleo, F.; Lahra, M.M.; Batra, D.; Rowe, L.; Trees, D.L.; Asiedu, K.; Chen, C.-Y.Haemophilus ducreyi causes chancroid and has recently been shown to be a significant cause of cutaneous lesions in tropical or subtropical regions where yaws is endemic. Here, we report the draft genome assemblies for 11 cutaneous strains of Haemophilus ducreyi, isolated from children in Vanuatu and Ghana. � 2016 Pillay et al.Item Environmental Education and Training - A Study of the Abokobi Afforestation Programme(University of Ghana, 1998-12) Essuman, S. O.; Asiedu, K.; Parry, I. W.; Badu-Nyarko, S.; University of Ghana, College of Education, School of Education and Leadership, Department of Educational Studies and LeadershipThis is a study on environmental education and training carried out at Abokobi village fo r an afforestation programme on the hillsides of the Betebete hills. This study specifically set out to find out; 1. The methods of teaching and training that were used in imparting Knowledge, creating awareness and giving skills to the participants. 2. The extent of impact of the programme on the lifestyle (i.e. attitudinal change) of the people. 3. How the change has helped in managing the environment. A sample size of fifty-two respondents was selected through purposive sampling technique from members of the Abokobi - "Friends of the Earth" branch who participated in the programme. They were put in five groups. A focused group interview schedule method was used in collecting data from them. In addition a questionnaire and an interview were, used to collect data from the s ta f f at “FOE" office, the organisation that delivered the education and training. The major finding of the study was that group discussions, workshops and field demonstration methods were some of the techniques adopted in education respondents. These methods were very appropriate and well embraced since they portrayed a participatory and interactive manner of teaching and learning 1+ was also discovered that the get - involved practical approach of training respondents to acquire skill has empowered them with problem - solving capacity and a self-reliant attitude towards the project. These human capacity development skills have brought a change in their attitudes towards the environment and it is believed that it would go a long way in sustaining the project. Another major finding too was that knowledge transfer through pictures, posters, visual aids and the like have positive e ffe c t in educating people with low educational background reinforcing effect of attitude change. The study concludes by recommending that similar educational techniques be adopted fo r most of our rural dwellers who are experiencing deforestation problems. With trees and forest products as the main source of energy for most rural dwellers, afforestation programmes of this sort should be intensified throughout the country to address the desertification issue approaching the northern sector and the savannah zones.Item Evaluation of the fluorescent-thin layer chromatography (f-TLC) for the diagnosis of Buruli ulcer disease in Ghana(PLOS ONE, 2022) Amewu, R.K.; Akolgo, G.A.; Asare, M.E.; Abdula, Z.; Ablordey, A.S.; Asiedu, K.Buruli ulcer is a tissue necrosis infection caused by an environmental mycobacterium called Mycobacterium ulcerans (MU). The disease is most prevalent in rural areas with the highest rates in West and Central African countries. The bacterium produces a toxin called mycolactone which can lead to the destruction of the skin, resulting in incapacitating deformities with an enormous economic and social burden on patients and their caregivers. Even though there is an effective antibiotic treatment for BU, the control and management rely on early case detection and rapid diagnosis to avert morbidities. The diagnosis of Mycobacterium ulcerans relies on smear microscopy, culture histopathology, and PCR. Unfortunately, all the current laboratory diagnostics have various limitations and are not available in endemic communities. Consequently, there is a need for a rapid diagnostic tool for use at the community health centre level to enable diagnosis and confirmation of suspected cases for early treatment. The present study corroborated the diagnostic performance and utility of fluorescent-thin layer chromatography (f-TLC) for the diagnosis of Buruli ulcer.Item Functional Characterization of Plasmodium falciparum Surface Related Antigen (PfSRA) as a Potential Blood-Stage Vaccine Target(Journal of Infectious Diseases, 2018-04) Amlabu, E.; Mensah-Brown, H.; Nyarko, P.B.; Akuh, O.A.; Opoku, G.; Ilani, P.; Oyagbenro, R.; Asiedu, K.; Aniweh, Y.; Awandare, G.A.Plasmodium falciparum erythrocyte invasion is a multistep process that involves a spectrum of interactions that are not well characterized. We have characterized a 113-kDa immunogenic protein, PF3D7_1431400 (PF14_0293), that possesses coiled-coil structures. The protein is localized on the surfaces of both merozoites and gametocytes, hence the name Plasmodium falciparum surface-related antigen (PfSRA). The processed 32-kDa fragment of PfSRA binds normal human erythrocytes with different sensitivities to enzyme treatments. Temporal imaging from initial attachment to internalization of viable merozoites revealed that a fragment of PfSRA, along with PfMSP119, is internalized after invasion. Moreover, parasite growth inhibition assays showed that PfSRA P1 antibodies potently inhibited erythrocyte invasion of both sialic acid–dependent and –independent parasite strains. Also, immunoepidemiological studies show that malaria-infected populations have naturally acquired antibodies against PfSRA. Overall, the results demonstrate that PfSRA has the structural and functional characteristics of a very promising target for vaccine development.Item Immunological Characterization Of A Novel Merozoite Surface Protein (PFMSP11)(University Of Ghana, 2020-12) Asiedu, K.Background: Plasmodium falciparum merozoite surface protein 11 (PfMSP11) is a novel surface protein that plays a critical role during the parasite’s blood stage development. This project aimed at immunologically characterizing the Plasmodium falciparum Merozoite Surface protein (PfMSP11). Method: Antibody (IgG) responses from 283 child clinical malaria samples Accra, Kintampo and Navrongo which represents different transmission intensities, were measured against the 20 synthetic peptides of PfMSP1 using ELISA. Overall 27 synthetic peptides were tested against PBMCs from 10 apparently healthy subjects to measure IFN-γ responses using ELISpot. Results: Peptides at the C-terminus of PfMSP11 gave higher antibody responses than peptides at the N-terminus. Peptide 2 to Peptide 12, and Peptide 17 recorded low antibody responses across all sites. Peptide 16 recorded the highest antibody responses across all sites. One subject (M14) showed a highest response across all pools in measuring IFN-γ responses . Subject M9 tested positive for pools 1 and 3 while subject M10 and M12 tested positive for pool 2Peptide 7 in pool 2 against subject M10 was the only peptide that tested positive. In conclusion, this study has shown that there are more antibody epitopes at the C-terminus than the N-terminus and more immunogenic T cell epitopes at the N-terminus.Item In the case of transmission of Mycobacterium ulcerans in buruli ulcer disease Acanthamoeba species stand accused(Ghana medical journal, 2011-03) Wilson, M.D.; Boakye, D.A.; Mosi, L.; Asiedu, K.Buruli ulcer disease caused by Mycobacterium ulcerans results in extensive destruction of skin and soft tissue and long-term functional disabilities that ultimately require surgery and rehabilitation. The disease is associated with aquatic and swampy environments with the mycobacterium occurring in biofilms, soil, aquatic insects, fish and wildlife however, the mode of transmission to humans remains an enigma. Current transmission ideas including bites from predatory water bugs and mosquitoes, do not explain satisfactorily the spasmodic disease distribution in human populations. Here we argue that Acanthamoeba species are the natural hosts of M. ulcerans and are mainly responsible for disease transmission because; (i) Acanthamoebae are known natural hosts of several microbial pathogens including M. marinum, M. avium and Legionella pneumophila, (ii) culture of slow-to-grow microbial pathogens hosted in nature by Acanthamoeba spp is enhanced when the media is seeded with the protozoa, (iii) acanthamoebae and M. ulcerans share similar bio-ecological and epidemiological settings, (iv) documented evidence that prior growth of L. pneumophila and M. avium in acanthamoebae influences entry mechanisms, intracellular growth and virulence in human monocytes, (v) Acanthamoeba spp also infect humans and cause diseases via routes of openings including broken skin and sites of trauma similar to M. ulcerans and (vi) M. ulcerans is rather a fastidious intracellular organism as recent analysis of the genome indicate. We argue further that temperature plays a significant role in transmission determining the fate of either the intracellular microbe or the host cells. Also, Acanthamoeba-pathogen association has a long evolutionary history because the same set of bacterial genes and gene products e.g. in L. pneumophila are required for survival in both mammalian and protozoan host cells. We suggest that the involvement of Acanthamoeba in the transmission of M. ulcerans to humans better explains the disease's epidemiology.Item Knowledge, attitudes and practices towards yaws and yaws-like skin disease in Ghana(PLoS Neglected Tropical Diseases, 2017-08) Marks, M.; Kwakye-Maclean, C.; Doherty, R.; Adwere, P.; Aziz Abdulai, A.; Duah, F.; Ohene, S.-A.; Mitja, O.; Oguti, B.; Solomon, A.W.; Mabey, D.C.W.; Adu-Sarkodie, Y.; Asiedu, K.; Ackumey, M.M.Introduction: Yaws is endemic in Ghana. The World Health Organization (WHO) has launched a new global eradication campaign based on total community mass treatment with azithromycin. Achieving high coverage of mass treatment will be fundamental to the success of this new strategy; coverage is dependent, in part, on appropriate community mobilisation. An understanding of community knowledge, attitudes and practices related to yaws in Ghana and other endemic countries will be vital in designing effective community engagement strategies. Methods: A verbally administered questionnaire was administered to residents in 3 districts in the Eastern region of Ghana where a randomised trial on the treatment of yaws was being conducted. The questionnaire combined both quantitative and qualitative questions covering perceptions of the cause and mechanisms of transmission of yaws-like lesions, the providers from which individuals would seek healthcare for yaws-like lesions, and what factors were important in reaching decisions on where to seek care. Chi-square tests and logistic regression were used to assess relationships between reported knowledge, attitudes and practices, and demographic variables. Thematic analysis of qualitative data was used to identify common themes. Results: A total of 1,162 individuals participated. The majority of individuals (n = 895, 77%) reported that “germs” were the cause of yaws lesions. Overall 13% (n = 161) of respondents believed that the disease was caused by supernatural forces. Participants frequently mentioned lack of personal hygiene, irregular and inefficient bathing, and washing with dirty water as fundamental to both the cause and the prevention of yaws. A majority of individuals reported that they would want to take an antibiotic to prevent the development of yaws if they were asymptomatic (n = 689, 61.2%), but a substantial minority reported they would not want to do so. A majority of individuals (n = 839, 72.7%) reported that if they had a yaws-like skin lesion they would seek care from a doctor or nurse. Both direct and indirect costs of treatment were reported as key factors affecting where participants reported they would seek care. Discussion: This is the first study that has explored community knowledge, attitudes and practices in relation to yaws in any endemic population. The belief that ‘germs’ are in some way related to disease through a variety of transmission routes including both contact and dirty water are similar to those reported for other skin diseases in Ghana. The prominent role of private healthcare providers is an important finding of this study and suggests engagement with this sector will be important in yaws eradication efforts. Strategies to address the substantial minority of individuals who reported they would not take treatment for yaws if they were currently asymptomatic will be needed to ensure the success of yaws eradication efforts. The data collected will be of value to the Ghana Health Service and also to WHO and other partners, who are currently developing community mobilisation tools to support yaws eradication efforts worldwide. © 2017 Marks et al.Item Simple, Rapid Mycobacterium ulcerans Disease Diagnosis from Clinical Samples by Fluorescence of Mycolactone on Thin Layer Chromatography(Public Library of Science, 2015) Wadagni, A.; Frimpong, M.; Phanzu, D.M.; Ablordey, A.; Kacou, E.; Gbedevi, M.; Marion, E.; Xing, Y.; Babu, V.S.; Phillips, R.O.; Wansbrough-Jones, M.; Kishi, Y.; Asiedu, K.Introduction: Mycobacterium ulcerans infection, known as Buruli ulcer, is a disease of the skin and subcutaneous tissues which is an important but neglected tropical disease with its major impact in rural parts of West and Central Africa where facilities for diagnosis and management are poorly developed. We evaluated fluorescent thin layer chromatography (f-TLC) for detection of mycolactone in the laboratory using samples from patients with Buruli ulcer and patients with similar lesions that gave a negative result on PCR for the IS2404 repeat sequence of M. ulcerans Methodology/Principal findings: Mycolactone and DNA extracts from fine needle aspiration (FNA), swabs and biopsy specimen were used to determine the sensitivity and specificity of f-TLC when compared with PCR for the IS2404. For 71 IS2404 PCR positive and 28 PCR negative samples the sensitivity was 73.2% and specificity of 85.7% for f-TLC. The sensitivity was similar for swabs (73%), FNAs (75%) and biopsies (70%). Conclusions: We have shown that mycolactone can be detected from M. ulcerans infected skin tissue by f-TLC technique. The technique is simple, easy to perform and read with minimal costs. In this study it was undertaken by a member of the group from each endemic country. It is a potentially implementable tool at the district level after evaluation in larger field studies. © 2015, Public Library of Science. All rights reserved.Item A Single Dose Oral Azithromycin versus Intramuscular Benzathine Penicillin for the Treatment of Yaws-A Randomized Non Inferiority Trial in Ghana(Public Library of Science, 2017) Kwakye-Maclean, C.; Agana, N.; Gyapong, J.; Nortey, P.; Adu-Sarkodie, Y.; Aryee, E.; Asiedu, K.; Ballard, R.; Binka, F.Background: Yaws is a treponemal infection that was almost eradicated fifty years ago; however, the disease has re-emerged in a number of countries including Ghana. A single-dose of intramuscular benzathine penicillin has been the mainstay of treatment for yaws. However, intramuscular injections are painful and pose safety and logistical constraints in the poor areas where yaws occurs. A single center randomized control trial (RCT) carried out in Papua New Guinea in 2012 demonstrated the efficacy of a single-dose of oral azithromycin for the treatment of yaws. In this study, we also compared the efficacy of a single oral dose of azithromycin as an alternative to intramuscular benzathine penicillin for the treatment of the disease in another geographic setting. Methodology: We conducted an open-label, randomized non-inferiority trial in three neighboring yaws-endemic districts in Southern Ghana. Children aged 1–15 years with yaws lesions were assigned to receive either 30mg/kg of oral azithromycin or 50,000 units/kg of intramuscular benzathine penicillin. The primary end point was clinical cure rate, defined as a complete or partial resolution of lesions 3 weeks after treatment. The secondary endpoint was serological cure, defined as at least a 4-fold decline in baseline RPR titre 6 months after treatment. Non- inferiority of azithromycin treatment was determined if the upper bound limit of a 2 sided 95% CI was less than 10%. Findings: The mean age of participants was 9.5 years (S.D.3.1, range: 1–15 years), 247(70%) were males. The clinical cure rates were 98.2% (95% CI: 96.2–100) in the azithromycin group and 96.9% (95% CI: 94.1–99.6) in the benzathine penicillin group. The serological cure rates at 6 months were 57.4% (95% CI: 49.9–64.9) in the azithromycin group and 49.1% (95% CI: 41.2–56.9) in the benzathine penicillin group, thus achieving the specified criteria for non-inferiority. Conclusions: A single oral dose of azithromycin, at a dosage of 30mg/kg, was non-inferior to a single dose of intramuscular benzathine penicillin for the treatment of early yaws among Ghanaian patients, and provides additional support for the WHO policy for use of oral azithromycin for the eradication of yaws in resource-poor settings. Trial Registration: Pan African Clinical Trials Registry PACTR2013030005181 http://www.pactr.org/ © 2017 Public Library of Science. All Rights Reserved.