Research Articles
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A research article reports the results of original research, assesses its contribution to the body of knowledge in a given area, and is published in a peer-reviewed scholarly journal. The faculty publications through published and on-going articles/researches are captured in this community
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Item From research to health policy: The Noguchi story in the past, present and next 25 years(Frontiers in Tropical Diseases, 2023) Yeboah-Manu, D.; Odoom, J.K.; Osei-Wusu, S.; et al.The Noguchi Memorial Institute for Medical Research (NMIMR) is a semi-autonomous institute of the College of Health Sciences, University of Ghana. Legon. Founded in 1979, the Institute was built with grant aid from the Government of Japan as a gift to the people of Ghana in memory of the renowned Japanese medical scientist, Dr. Hideyo Noguchi, who died from Yellow fever infection while conducting research on the disease in Ghana. The The institute has a three-pronged mandate to conduct health-related research, build human capacity and provide specialized diagnostic and disease monitoring services in support of the Ghana Health Service. Over the past 40 years, the Institute has grown to be a leading biomedical research institute in the African region. It has strong and long-standing collaborations with scientists and institutions in Africa, Japan, Europe, Australia and North America on several projects on diseases of public health importance. The Institute also hosts several regional and national centers, such as the Regional Influenza Laboratory. The The institute's research activities are relevant to the control and prevention of infectious diseases in Ghana, particularly HIV/AIDS, Tuberculosis, Buruli ulcer, Polio, malaria, and emerging infectious diseases. The Institute also plays a technical/advisory role to government through collaborations with disease control programmes and has since inception provided the country with needed critical evidence in support of health policy as well as laboratory diagnostic services, among others. Going forward, the Institute seeks to expand and consolidate its activities in areas of antimicrobial resistance (AMR), clinical trials, genomic surveillance and academic programs, and in the next 25 years, NMIMR hopes to approach every research area using one health approach.Item Prevalence of non-tuberculous mycobacteria among previously treated TB patients in the Gulf of Guinea, Africa(IJID Regions, 2022) Pokam, B.D.T.; Yeboah-Manu, D.; Ofori, S.; et alObjective: Differentiation between non-tuberculous mycobacteria ( NTM) and Mycobacterium tuberculosis com- plex (MTBC) is crucial for case management with the appropriate antimycobacterials. This study was undertaken in three West and Central African countries to understand NTM associated with pulmonary tuberculosis in the sub-region. Methods: A collection of 503 isolates (158 from Cameroon, 202 from Nigeria and 143 from Ghana) obtained from solid and liquid cultures were analysed. The isolates were tested for drug susceptibility, and MTBC were confirmed using IS 6110 . All IS 6110 -negative isolates were identified by 65-kilodalton heat shock protein ( hsp65 ) gene amplification, DNA sequencing and BLAST analysis. Results: Overall, the prevalence of NTM was 16/503 (3.2%), distributed as 2/202 (1%) in Nigeria, 2/158 (1.3%) in Cameroon and 12/143 (8.4%) in Ghana. The main NTM isolates included 5/16 (31.3%) M. fortuitum , 2/16 (12.5%) M. intracellulare and 2/16 (12.5%) M. engbaekii. Eight (57.1%) of the 14 previously treated patients harboured NTM (odds ratio 0.21, 95% confidence interval 0.06–0.77; P = 0.021). Three multi-drug-resistant strains were identified: M. engbaekii, M. fortuitum and M. intracellulare. Conclusion: NTM were mainly found among individuals with unsuccessful treatment. This highlights the need for mycobacterial species differentiation using rapid molecular tools for appropriate case management, as most are resistant to routine first-line antimycobacterials.Item Emergence of New SARS-Cov-2 Variant of Concern Omicron (B.1.1.529) - Highlights Africa’s Research Capabilities, but Exposes Major Knowledge Gaps, Inequities of Vaccine Distribution, Inadequacies in Global COVID-19 Response and Control Efforts(Elsevier Ltd, 2022) Petersen, E.; Ntoumi, F.; Yeboah-Manu, D.; et al.Item Control of Streptococcal Infections: Is a Common Vaccine Target Achievable Against Streptococcus agalactiae and Streptococcus pneumoniae(Frontiers, 2021) Bedeley, E.; Gori, A.; Yeboah-Manu, D.; Diallo, K.Both Streptococcus agalactiae [group B streptococcus (GBS)] and Streptococcus pneumoniae (pneumococcus) remain significant pathogens as they cause life threatening infections mostly in children and the elderly. The control of diseases caused by these pathogens is dependent on antibiotics use and appropriate vaccination. The introduction of the pneumococcal conjugate vaccines (PCVs) against some serotypes has led to reduction in pneumococcal infections, however, the subsequent serotype switching, and replacement has been a serious challenge. On the other hand, no vaccine is yet licensed for use in the control of GBS diseases. In this review, we provide an overview of the history and global disease burden, disease pathophysiology and management, vaccines update, and the biology of both pathogens. Furthermore, we address recent findings regarding structural similarities that could be explored for vaccine targets across both mucosal pathogens. Finally, we conclude by proposing future genomic sequence comparison using the wealth of available sequences from both species and the possibility of identifying more related structural components that could be exploited for pan-pathogen vaccine development.Item TB-Diabetes Co-Morbidity in Ghana: The Importance of Mycobacterium Africanum Infection(PLOS, 2019) Asante-Poku, A.; Asare, P.; Yeboah-Manu, D.; et al.Background Diabetes Mellitus (DM) is a known risk factor for tuberculosis (TB) but little is known on TBDiabetes Mellitus (TBDM) co-morbidity in Sub-Saharan Africa. Methods Consecutive TB cases registered at a tertiary facility in Ghana were recruited from September 2012 to April 2016 and screened for DM using random blood glucose and glycated hemoglobin (HbA1c) level. TB patients were tested for other clinical parameters including HIV co-infection and TB lesion location. Mycobacterial isolates obtained from collected sputum samples were characterized by standard methods. Associations between TBDM patients’ epidemiological as well as microbiological variables were assessed. Results The prevalence of DM at time of diagnosis among 2990 enrolled TB cases was 9.4% (282/ 2990). TBDM cases were significantly associated with weight loss, poor appetite, night sweat and fatigue (p<0.001) and were more likely (p<0.001) to have lower lung cavitation 85.8% (242/282) compared to TB Non-Diabetic (TBNDM) patients 3.3% (90/2708). We observed 22.3% (63/282) treatment failures among TBDM patients compared to 3.8% (102/ 2708) among TBNDM patients (p<0.001). We found no significant difference in the TBDM burden attributed by M. tuberculosis sensu stricto (Mtbss) and Mycobacterium africanum (Maf) and (Mtbss; 176/1836, 9.6% and Maf; 53/468, 11.3%, p = 0.2612). We found that diabetic individuals were suggestively likely to present with TB caused byM. africanum Lineage 6 as opposed to Mtbss (odds ratio (OR) = 1.52; 95% confidence interval (CI): 0.92–2.42, p = 0.072). Conclusion Our findings confirms the importance of screening for diabetes during TB diagnosis and highlights the association between genetic diversity and diabetes in Ghana.Item COVID-19—Zoonosis or Emerging Infectious Disease?(Frontiers, 2020) Haider, N.; Rothman-Ostrow, P.; Yeboah-Manu, D.; et al.The World Health Organization defines a zoonosis as any infection naturally transmissible from vertebrate animals to humans. The pandemic of Coronavirus disease (COVID-19) caused by SARS-CoV-2 has been classified as a zoonotic disease, however, no animal reservoir has yet been found, so this classification is premature. We propose that COVID-19 should instead be classified an “emerging infectious disease (EID) of probable animal origin.” To explore if COVID-19 infection fits our proposed re-categorization vs. the contemporary definitions of zoonoses, we reviewed current evidence of infection origin and transmission routes of SARS-CoV-2 virus and described this in the context of known zoonoses, EIDs and “spill-over” events. Although the initial one hundred COVID-19 patients were presumably exposed to the virus at a seafood Market in China, and despite the fact that 33 of 585 swab samples collected from surfaces and cages in the market tested positive for SARS-CoV-2, no virus was isolated directly from animals and no animal reservoir was detected. Elsewhere, SARS-CoV-2 has been detected in animals including domesticated cats, dogs, and ferrets, as well as captive-managed mink, lions, tigers, deer, and mice confirming zooanthroponosis. Other than circumstantial evidence of zoonotic cases in mink farms in the Netherlands, no cases of natural transmission from wild or domesticated animals have been confirmed. More than 40 million human COVID-19 infections reported appear to be exclusively through human-human transmission. SARS-CoV-2 virus and COVID-19 do not meet the WHO definition of zoonoses. We suggest SARS-CoV-2 should be re-classified as an EID of probable animal origin.Item Lockdown Measures in Response to COVID-19 in Nine Sub-Saharan African Countries(BMJ, 2020) Haider, N.; Yeboah-Manu, D.; et al.Lockdown measures have been introduced worldwide to contain the transmission of COVID-19. However, the term ‘lockdown’ is not well-defined. Indeed, WHO’s reference to ‘so-called lockdown measures’ indicates the absence of a clear and universally accepted definition of the term ‘lockdown’. We propose a definition of ‘lockdown’ based on a two-by- two matrix that categorises different communicable disease measures based on whether they are compulsory or voluntary; and whether they are targeted at identifiable individuals or facilities, or whether they are applied indiscriminately to a general population or area. Using this definition, we describe the design, timing and implementation of lockdown measures in nine countries in sub-Saharan Africa: Ghana, Nigeria, South Africa, Sierra Leone, Sudan, Tanzania, Uganda, Zambia and Zimbabwe. While there were some commonalities in the implementation of lockdown across these countries, a more notable finding was the variation in the design, timing and implementation of lockdown measures. We also found that the number of reported cases is heavily dependent on the number of tests carried out, and that testing rates ranged from 2031 to 63 928 per million population up until 7 September 2020. The reported number of COVID-19 deaths per million population also varies (0.4 to 250 up until 7 September 2020), but is generally low when compared with countries in Europe and North America. While lockdown measures may have helped inhibit community transmission, the pattern and nature of the epidemic remains unclear. However, there are signs of lockdown harming health by affecting the functioning of the health system and causing social and economic disruption.Item A Molecular and Epidemiological Study of Vibrio Cholerae Isolates from Cholera Outbreaks in Southern Ghana(PLOS, 2020) Danso, E.K.; Asare, P.; Yeboah-Manu, D.; et al.Cholera remains a major global public health threat and continuous emergence of new Vibrio cholerae strains is of major concern. We conducted a molecular epidemiological study to detect virulence markers and antimicrobial resistance patterns of V. cholerae isolates obtained from the 2012–2015 cholera outbreaks in Ghana. Archived clinical isolates obtained from the 2012, 2014 and 2015 cholera outbreaks in Ghana were revived by culture and subjected to microscopy, biochemical identification, serotyping, antibiotic susceptibility testing, molecular detection of distinct virulence factors and Multi-Locus Variable-Number of Tandem-Repeat Analysis (MLVA). Of 277 isolates analysed, 168 (60.6%) were confirmed to be V. cholerae and 109 (39.4%) isolates constituted other bacteria (Escherichia coli, Aeromonas sobria, Pseudomonas aeruginosa, Enterobacter cloacae and Enterococci faecalis). Serotyping the V. cholerae isolates identified 151 (89.9%) as Ogawa, 3 (1.8%) as Inaba and 14 (8.3%) as non-O1/O139 serogroup. The O1 serogroup isolates (154/168, 91.7%) carried the cholera toxin ctxB gene as detected by PCR. Additional virulence genes detected include zot, tcpA, ace, rtxC, toxR, rtxA, tcpP, hlyA and tagA. The most common and rare virulence factors detected among the isolates were rtxC (165 isolates) and tcpP (50 isolates) respectively. All isolates from 2014 and 2015 were multidrug resistant against the selected antibiotics. MLVA differentiated the isolates into 2 large unique clones A and B, with each predominating in a particular year. Spatial analysis showed clustering of most isolates at Ablekuma sub-district. Identification of several virulence genes among the two different genotypes of V. cholerae isolates and resistance to first- and second-line antibiotics, calls for scaleup of preventive strategies to reduce transmission, and strengthening of public health laboratories for rapid antimicrobial susceptibility testing to guide accurate treatment. Our findings support the current WHO licensed cholera vaccines which include both O1 Inaba and Ogawa serotypesItem Zoonotic Tuberculosis – The Changing Landscape(Elsevier Ltd, 2021) Kock, R.; Yeboah-Manu, D.; Michel, A.L.; et al.Despite slow reductions in the annual burden of active human tuberculosis (TB) cases, zoonotic TB (zTB) remains a poorly monitored and an important unaddressed global problem. There is a higher incidence in some regions and countries, especially where close association exists between growing numbers of cattle (the major source of Mycobacterium bovis) and people, many suffering from poverty, and where dairy products are consumed unpasteurised. More attention needs to be focused on possible increased zTB incidence resulting from growth in dairy production globally and increased demand in low income countries in particular. Evidence of new zoonotic mycobacterial strains in South Asia and Africa (e.g. M. orygis), warrants urgent assessment of prevalence, potential drivers and risk in order to develop appropriate interventions. Control of M. bovis infection in cattle through detect and cull policies remain the mainstay of reducing zTB risk, whilst in certain circumstances animal vaccination is proving beneficial. New point of care diagnostics will help to detect animal infections and human cases. Given the high burden of human tuberculosis (caused by M. tuberculosis) in endemic areas, animals are affected by reverse zoonosis, including multi-drug resistant strains. This, may create drug resistant reservoirs of infection in animals. Like COVID-19, zTB is evolving in an ever-changing global landscape.Item Commemorating World TB Day 2020: “IT’S TIME” — It’s time to End the Global TB Epidemic(Elsevier Ltd, 2020) Tiberi, S.; Yeboah-Manu, D.; et al.