Rie Yotsu

Dr. Rie Yotsu


Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 September 2018 in Current Tropical Medicine Reports
Verified
Journal Article
Open access
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RYRie Yotsu
Rie Yotsu
KSKoichi Suzuki
Koichi Suzuki
RSRachel E. Simmonds
Rachel E. Simmonds
RBRoger Bedimo
Roger Bedimo
AAAnthony Ablordey
Anthony Ablordey
KAKingsley Asiedu
Kingsley Asiedu
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.

17 May 2018 in PLOS Neglected Tropical Diseases
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Journal Article
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RYRie Yotsu
Rie Yotsu
KKKouamé Kouadio
Kouamé Kouadio
BVBamba Vagamon
Bamba Vagamon
KNKonan N'Guessan
Konan N'Guessan
AAAmari Jules Akpa
Amari Jules Akpa
KAKingsley Asiedu
Kingsley Asiedu
Early detection of several skin-related neglected tropical diseases (skin NTDs)–including leprosy, Buruli ulcer, yaws, and scabies- may be achieved through school surveys, but such an approach has seldom been tested systematically on a large scale in endemic countries. Additionally, a better understanding of the spectrum of skin diseases and the at-risk populations to be encountered during such surveys is necessary to facilitate the process. We performed a school skin survey for selected NTDs and the spectrum of skin diseases, among primary schoolchildren aged 5 to 15 in Côte d’Ivoire, West Africa. This 2-phase survey took place in 49 schools from 16 villages in the Adzopé health district from November 2015 to January 2016. The first phase involved a rapid visual examination of the skin by local community healthcare workers (village nurses) to identify any skin abnormality. In a second phase, a specialized medical team including dermatologists performed a total skin examination of all screened students with any skin lesion and provided treatment where necessary. Of a total of 13,019 children, 3,504 screened positive for skin lesions and were listed for the next stage examination. The medical team examined 1,138 of these children. The overall prevalence of skin diseases was 25.6% (95% CI: 24.3–26.9%). The predominant diagnoses were fungal infections (n = 858, prevalence: 22.3%), followed by inflammatory skin diseases (n = 265, prevalence: 6.9%). Skin diseases were more common in boys and in children living along the main road with heavy traffic. One case of multi-bacillary type leprosy was detected early, along with 36 cases of scabies. Our survey was met with very good community acceptance. We carried out the first large-scale integrated, two-phase pediatric multi-skin NTD survey in rural Côte d’Ivoire, effectively reaching a large population. We found a high prevalence of skin diseases in children, but only limited number of skin NTDs. With the lessons learned, we plan to expand the project to a wider area to further explore its potential to better integrate skin NTD screening in the public health agenda. Integration of neglected tropical diseases (NTDs) into the public health agenda has been a priority in global health for the last decade. A common feature shared by several NTDs is skin involvement. Conditions within this group of NTDs have now been classified as skin NTDs to promote wider NTD integration. Several skin NTDs including leprosy, Buruli ulcer, yaws, and scabies are co-endemic in Côte d’Ivoire, West Africa. As children are vulnerable to these diseases, we carried out the first large-scale integrated, multi-skin NTD school survey in a rural district of this country. Our strategy of involving community healthcare workers and dermatologists effectively reached a large population. However, the detection of skin NTDs may have been limited because of the low schooling and attendance rate. We found a high prevalence of skin diseases among schoolchildren (26%), possibly due to poor socio-economic status and air pollution, which requires more attention. This high prevalence of skin diseases posed a challenge for our project as the need for medications and those with dermatological skills exceeded our capacity to reach our initial target population. Our study provides important lessons that will aid the framing of future school skin surveys in sub-Saharan Africa.

1 July 2014 in Journal of Diabetes and its Complications
Verified
Journal Article
Closed access
RYRie Yotsu
Rie Yotsu
NPNgoc Minh Pham
Ngoc Minh Pham
MOMakoto Oe
Makoto Oe
TNTakeshi Nagase
Takeshi Nagase
HSHiromi Sanada
Hiromi Sanada
TTTakeshi Tamaki
Takeshi Tamaki

1 September 2015 in The Journal of Dermatology
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Journal Article
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RYRie Yotsu
Rie Yotsu
CMChiaki Murase
Chiaki Murase
MSMariko Sugawara
Mariko Sugawara
KSKoichi Suzuki
Koichi Suzuki
KNKazue Nakanaga
Kazue Nakanaga
KAKingsley Asiedu
Kingsley Asiedu
Buruli ulcer (BU), or Mycobacterium ulcerans infection, is a new emerging infectious disease which has been reported in over 33 countries worldwide. It has been noted not only in tropical areas, such as West Africa where it is most endemic, but also in moderate non‐tropical climate areas, including Australia and Japan. Clinical presentation starts with a papule, nodule, plaque or edematous form which eventually leads to extensive skin ulceration. It can affect all age groups, but especially children aged between 5 and 15 years in West Africa. Multiple‐antibiotic treatment has proven effective, and with surgical intervention at times of severity, it is curable. However, if diagnosis and treatment is delayed, those affected may be left with life‐long disabilities. The disease is not yet fully understood, including its route of transmission and pathogenesis. However, due to recent research, several important features of the disease are now being elucidated. Notably, there may be undiagnosed cases in other parts of the world where BU has not yet been reported. Japan exemplifies the finding that awareness among dermatologists plays a key role in BU case detection. So, what about in other countries where a case of BU has never been diagnosed and there is no awareness of the disease among the population or, more importantly, among health professionals? This article will revisit BU, reviewing clinical features as well as the most recent epidemiological and scientific findings of the disease, to raise awareness of BU among dermatologists worldwide.

Verified
Journal Article
Open access
PDF file
RYRie Yotsu
Rie Yotsu
Integration of neglected tropical diseases (NTDs) into the public health agenda has been a priority in global health for the last decade. Because a number of these diseases share not only the geographical distribution, but also a common feature which is skin involvement, bringing together a sub-group of ‘skin NTDs’ is one way forward to promote further integration among NTDs. With these diseases, which include leprosy, Buruli ulcer, yaws, mycetoma, lymphatic filariasis, and leishmaniasis, patients may be left with life-long deformities and disabilities when diagnosis and treatment are delayed. Stigma is another serious consequence of skin NTDs as it places a large barrier on the economic activities and social life of a patient. As a result, this creates a vicious cycle and obstructs a key goal of society, the elimination of poverty. Enhancement in surveillance systems as well as the further development of diagnostic methods, improvement in treatment and management, and identification of preventative measures for skin NTDs are therefore urgently needed. This article summarizes the existing practices and field research on skin NTDs and identifies potential synergies that could be achieved by adopting this integrated approach.

14 August 2023 in PLOS Neglected Tropical Diseases
Verified
Journal Article
Open access
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RYRie Yotsu
Rie Yotsu
ZDZhengming Ding
Zhengming Ding
JHJihun Hamm
Jihun Hamm
RBRonald E. Blanton
Ronald E. Blanton
Background: Deep learning, which is a part of a broader concept of artificial intelligence (AI) and/or machine learning has achieved remarkable success in vision tasks. While there is growing interest in the use of this technology in diagnostic support for skin-related neglected tropical diseases (skin NTDs), there have been limited studies in this area and fewer focused on dark skin. In this study, we aimed to develop deep learning based AI models with clinical images we collected for five skin NTDs, namely, Buruli ulcer, leprosy, mycetoma, scabies, and yaws, to understand how diagnostic accuracy can or cannot be improved using different models and training patterns.Methodology: This study used photographs collected prospectively in Côte d’Ivoire and Ghana through our ongoing studies with use of digital health tools for clinical data documentation and for teledermatology. Our dataset included a total of 1,709 images from 506 patients. Two convolutional neural networks, ResNet-50 and VGG-16 models were adopted to examine the performance of different deep learning architectures and validate their feasibility in diagnosis of the targeted skin NTDs.Principal findings: The two models were able to correctly predict over 70% of the diagnoses, and there was a consistent performance improvement with more training samples. The ResNet-50 model performed better than the VGG-16 model. A model trained with PCR confirmed cases of Buruli ulcer yielded 1–3% increase in prediction accuracy across all diseases, except, for mycetoma, over a model which training sets included unconfirmed cases.Conclusions: Our approach was to have the deep learning model distinguish between multiple pathologies simultaneously–which is close to real-world practice. The more images used for training, the more accurate the diagnosis became. The percentages of correct diagnosis increased with PCR-positive cases of Buruli ulcer. This demonstrated that it may be better to input images from the more accurately diagnosed cases in the training models also for achieving better accuracy in the generated AI models. However, the increase was marginal which may be an indication that the accuracy of clinical diagnosis alone is reliable to an extent for Buruli ulcer. Diagnostic tests also have their flaws, and they are not always reliable. One hope for AI is that it will objectively resolve this gap between diagnostic tests and clinical diagnoses with the addition of another tool. While there are still challenges to be overcome, there is a potential for AI to address the unmet needs where access to medical care is limited, like for those affected by skin NTDs.