Frontiers in tropical diseases最新文献

{"title":"Molecular approaches to deploy singlet oxygen in a Leishmania model as an unassailable biocide for disease mitigation and vector control","authors":"Kwang Poo Chang, Joseph Reynolds, Dennis K. P. Ng, Yun-Hung Tu, Chia-Kwung Fan, Shin-Hong Shiao","doi":"10.3389/fitd.2024.1306429","DOIUrl":"https://doi.org/10.3389/fitd.2024.1306429","url":null,"abstract":"Singlet oxygen (1O2) is a potent biocide potentially deployable for integrated control of tropical diseases and their insect vectors. This very short-lived free radical is highly destructive of cellular molecules when generated intracellularly. Most organisms, including parasites and vectors, are defenseless against 1O2 except for plants, which produce it abundantly during photosynthesis, hence, the acquisition of specific mechanisms for its detoxification. In the presence of O2 under physiological conditions, certain dyes or photosensitizers (PS), e.g., porphyrins and phthalocyanines (PC), are excitable by light to produce biocidal 1O2. Its half-life is in the order of microseconds, necessitating its intracellular generation in order to harness its biocidal activity most effectively. This is achievable by loading cells with PS for excitation with light to produce 1O2in situ. One example to achieve this is the genetic engineering of Leishmania to complement its inherent defects in porphyrin biosynthesis, resulting in cytosolic accumulation of abundant PS in the form of uroporphyrin 1 (URO). Another example is the chemical engineering of PC for hydrophilicity, thereby facilitating the endocytosis of such PS by cells. Leishmania loaded with cytosolic URO and endosomal PC are inactivated by the 1O2 produced via light-activation of these PS in the two different cell compartments. The inactivated Leishmania are nonviable, but have their natural vaccines and adjuvants well-preserved for prophylactic vaccination against experimental leishmaniasis. 1O2-inactivated Leishmania is potentially useful to serve as a platform for the safe and effective delivery of transgenically add-on vaccines against malignant and viral diseases in experimental models. Hydrophilic and cationic PC were also shown experimentally to act as a new type of dim light-activable insecticides, i.e., their mosquito larvicidal activities with <µM LD50 values. Similar results are expected by studying PC in additional laboratory insect models. A significant advantage has long been attributed to this type of insecticide, i.e., their aversion to a selection of genetic variants for resistance. An additional advantage of PC is their excitability to produce insecticidal 1O2 with deep-penetrating red or infrared light invisible to most insects, thereby potentially increasing the range and scope of targetable insect vectors.","PeriodicalId":73112,"journal":{"name":"Frontiers in tropical diseases","volume":"95 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141004206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial: Public health surveillance systems and outbreak response: evidence from the field","authors":"E. Kenu, D. Bandoh, B. B. Kaburi, Joyce Berkumwin Der","doi":"10.3389/fitd.2024.1386668","DOIUrl":"https://doi.org/10.3389/fitd.2024.1386668","url":null,"abstract":"","PeriodicalId":73112,"journal":{"name":"Frontiers in tropical diseases","volume":"37 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141022619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Host skin immunity to arthropod vector bites: from mice to humans","authors":"Joshua R. Lacsina, Ryan Kissinger, Johannes S. P. Doehl, Maria Disotuar, George Petrellis, Mara Short, Elliot Lowe, James Oristian, Daniel Sonenshine, Thiago DeSouza-Vieira","doi":"10.3389/fitd.2024.1308585","DOIUrl":"https://doi.org/10.3389/fitd.2024.1308585","url":null,"abstract":"Infections caused by vector-borne pathogens impose a significant burden of morbidity and mortality in a global scale. In their quest for blood, hematophagous arthropods penetrate the host skin and may transmit pathogens by the bite. These pathogens are deposited along with saliva and a complex mixture of vector derived factors. Hematophagous arthopod vectors have evolved a complex array of adaptations to modulate the host immune response at the bite site with the primary goal to improve blood feeding, which have been exploited throughout evolution by these pathogens to enhance infection establishment in the host. While this paradigm has been firmly established in mouse models, comparable data from human studies are scarce. Here we review how the host skin immune response to vector bites in animal models is hijacked by microbes to promote their pathogenesis. We mainly explored four distinct vector-pathogen pairs of global health importance: sand flies and Leishmania parasites, Ixodes scapularis ticks and Borrelia burgdorferi, Aedes aegypti mosquitoes and arboviruses, and Anopheles gambiae mosquitos and Plasmodium parasites. Finally, we outline how critical it is for the field of vector biology to shift from rodent models to clinical studies focused on the interface of vector-pathogen-host immune system to push further the frontiers of knowledge of the field.","PeriodicalId":73112,"journal":{"name":"Frontiers in tropical diseases","volume":"84 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141050581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in filarial hydrocelectomy reporting in Uganda and Nigeria","authors":"Susan F. D’Souza, J. P. Awio, Jehoshaphat Albarka, W. R. Bougma, Sarah Bartlett, Christian Nwosu, Babacar Ngom, Anthony Wani, Anita Gwom, Moses Okello, Abraham Aba, Sarah Irema, Martins Imhansoloeva, Dauda Nurudeen, Charles Wamboga, M. T. Debam, Haruna Zainab, Attahiru Aleiro, Malam H. Salah, Philip Downs","doi":"10.3389/fitd.2024.1379902","DOIUrl":"https://doi.org/10.3389/fitd.2024.1379902","url":null,"abstract":"Surgery for hydrocele is part of the WHO recommended essential package of care for people affected by Lymphatic filariasis (LF). In Uganda and Nigeria, LF programme support for hydrocele surgery began in 2017. In 2021 the two programmes adopted a newly developed smartphone-based application to monitor hydrocele surgery and outcome. The application, referred to as the Hydrocele Tracker, gathers information on surgical registration, preoperative information, intraoperative information, postoperative information and follow-up evaluations. It was developed to improve supervision, understand surgical outcomes and reasons for complications, improve reporting and improve data quality for Ministries of Health with active LF programmes.Hydrocele patient information was collected between October 2021 and May 2023 in Uganda (Lango sub-region, 9 districts) and March 2021 - September 2022 in Nigeria (Benue, Kaduna, Kebbi, Sokoto and Kogi States). Additionally patient feedback surveys were undertaken to elicit patient experience and satisfaction with the hydrocele surgery.Patient data from 2,911 records in the Hydrocele Tracker are presented.The discussion highlights the implications of the data for LF programming, the value of digitisation and approaches to address data quality.","PeriodicalId":73112,"journal":{"name":"Frontiers in tropical diseases","volume":"13 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140666970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Representations of Chagas disease among Bolivian immigrants in the city of São Paulo","authors":"C. Silveira, Colin Forsyth, Nivaldo Carneiro Júnior, Alejandro Goldberg, Lia Maria Britto da Silva, Rubens Antonio da Silva, M. Shikanai-Yasuda","doi":"10.3389/fitd.2024.1331026","DOIUrl":"https://doi.org/10.3389/fitd.2024.1331026","url":null,"abstract":"Transnational immigrants are particularly impacted by neglected diseases, which take a heavy biological, social, and emotional toll in these marginalized communities. Chagas disease has transformed from an exclusively rural to an increasingly urban phenomenon encompassing non-endemic areas in Latin America.Through semi-structured interviews, we investigated representations of Chagas disease in Bolivian immigrants in São Paulo, Brazil. Between August and September 2015, 27 adult migrants were interviewed, 11 of them with Chagas disease. We explored problems of access to health services and essential knowledge about the disease, as well as related conceptions and health practices.Participants constructed social representations of Chagas through interactions with family and social networks, drawing on earlier experiences in Bolivia. Diagnosis often provoked fear, and participants faced barriers to care based on language differences and uncertainties about the disease and treatment options. Healthcare personnel played an important role in alleviating concerns and facilitating access to information.The complex intersection of migration and neglected diseases creates challenges for local and national health programs, requiring innovative responses incorporating the perspectives and needs of the often vulnerable affected communities.","PeriodicalId":73112,"journal":{"name":"Frontiers in tropical diseases","volume":"58 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140675845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Households neighboring wildlife protected areas may be at a higher risk of rabies than those located further away: a community-based cross-sectional cohort study at Pian Upe game reserve, Bukedea district, Eastern Uganda","authors":"Collins G. K. Atuheire, James Okwee-Acai, Martha Taremwa, Paul Ssajjakambwe, Musso Munyeme, C. Kankya, Odoch Terence, S. N. Ssali, F. Mwiine, Kayla J. Buhler, Morten Tryland","doi":"10.3389/fitd.2024.1272141","DOIUrl":"https://doi.org/10.3389/fitd.2024.1272141","url":null,"abstract":"This study examines rabies incidence and associated risk factors at the interface between wildlife and human communities near Pian-Upe game reserve in Eastern Uganda. We hypothesized that human settlements in closer proximity to the reserve would exhibit higher rabies risk compared to those located further away.Using a standard questionnaire, households within <4, 4-14, and >14 km from the Pian Upe game reserve in Bukedea District were interviewed. Data on socio-demographic characteristics, recent rabid animal bites, and suspected human and livestock rabies cases for the past year (2023) were collected after seeking informed consent. Descriptive statistics were used to analyze socio-demographic information and incidence data, while separate binomial generalized linear models with log-link function were used to identify predictors of rabies incidence and mortality.Between January and March 2023, 302 participants were interviewed. Respondents had an average age of 44 years with 34% (n=103) being female. All households owned at least one dog, though only 47% (n=142) had vaccinated their dogs against rabies in the past year. Additionally, 39% (n=118) of respondents used dogs for hunting. Rabies annual incidence increased with decreasing distance to the game reserve (7.5 to 15.7% for humans, for the dogs, and 5.0 to 9.8% for livestock, including cows, goats and sheep). Significant factors associated with rabies in humans included primary education level (aRR=3.8, 95%CI 1.0-23.7) and grazing livestock in the reserve (aRR=5.30, 95%CI 1.0-40.3). Mortality was associated with fetching firewood from the game reserve (aRR=4.7, 95%CI 1.3-17.5).This study reveals that there is an increased risk of rabies for domesticated animals and people located within proximity to the game reserve. Further efforts to prevent the spread of rabies could include increasing education and awareness for communities along with targeted dog vaccination in settlements surrounding wildlife protected areas.","PeriodicalId":73112,"journal":{"name":"Frontiers in tropical diseases","volume":"15 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140673653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leaving no one behind: hernia, a neglected surgical condition identified during hydrocele surgery camps in Tanzania","authors":"Kelly Zongo, Faraja Lyamuya, Kimberly Kamara, Martha Mberu, N. Kivuyo, Larry Akoko","doi":"10.3389/fitd.2024.1357802","DOIUrl":"https://doi.org/10.3389/fitd.2024.1357802","url":null,"abstract":"Programs focused on elimination of lymphatic filariasis include the provision of surgery to address hydrocele, a complication of infection. Corrective surgical interventions are fully funded so that affected men in Tanzania can live normal and productive lives. Active case finding is used to identify candidates for hydrocele surgery. Oftentimes this results in men being identified as needing a hydrocelectomy when they actually have inguinal hernias. Given different funding streams, men with hernias do not have access to funded surgeries and are turned away during hydrocele surgical camps despite a clear need for surgical intervention; this poses an ethical dilemma. Also, hernias can occur in conjunction with hydroceles or be misdiagnosed as hydrocele. When misdiagnosis is identified during surgery, and there are no prior preparations to address both, complications can occur. Support from the private sector to complement NTD programs as a viable solution to providing hernia surgeries during hydrocelectomy camps has been used on a small scale in Tanzania and could be replicated on a larger scale.","PeriodicalId":73112,"journal":{"name":"Frontiers in tropical diseases","volume":" 23","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140688081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial: Challenges for diagnosis, treatment, and elimination of malaria","authors":"Manuela Berto Pucca, T. N. de Sousa, Gisely Cardoso de Melo, Giselle Maria Rachid Viana","doi":"10.3389/fitd.2024.1394693","DOIUrl":"https://doi.org/10.3389/fitd.2024.1394693","url":null,"abstract":"","PeriodicalId":73112,"journal":{"name":"Frontiers in tropical diseases","volume":" 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140689606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative development of human filariae Loa loa, Onchocerca volvulus and Mansonella perstans in immunocompromised mouse strains","authors":"V. C. Chunda, Fanny F. Fombad, Chi A Kien, Rene Ebai, Frederick Esofi, Anna Ning Ntuh, Emmanuel Ouam, N. V. Gandjui, Relindis Ekanya, Franck Nietcho, Lucy Cho Nchang, Chefor Magha, A. Njouendou, P. Enyong, Achim Hoerauf, S. Wanji, M. Ritter","doi":"10.3389/fitd.2024.1293632","DOIUrl":"https://doi.org/10.3389/fitd.2024.1293632","url":null,"abstract":"Introduction Mouse models of human filarial infections are not only urgently needed to investigate the biology of the nematodes and their modulation of the host’s immunity, but will also provide a platform to screen and test novel anti-filarial drugs. Recently, murine Loa loa infection models have been stablished using immunocompromised mouse strains, whereas murine Mansonella perstans infections have not been implemented until now. Methods Therefore, we aim to establish experimental M. perstans infections using the immunocompromised mouse strains RAG2IL-2Rγ−/− (lack B, T and natural killer cells), IL-4Rα/IL-5−/− (impaired IL-4/5 signalling and eosinophil activation) and NOD.Cg-PrkdcscidIl2rgtm1Wj l/SzJ (NOD scid gamma, NSG) BALB/c mice (lack mature lymphocytes) through subcutaneous (s.c.) or intraperitoneal (i.p.) inoculation of infective stage 3 larvae (L3) isolated from engorged vectors. Results In total, 145 immunocompromised mice have been inoculated with 3,250 M. perstans, 3,337 O. volvulus, and 2,720 Loa loa L3 to comparatively analyse which immunocompromised mouse strain is susceptible to human filarial infections. Whereas, no M. perstans and O. volvulus L3 could be recovered upon 2-63 days post-inoculation, a 62-66% Loa loa L3 recovery rate could be achieved in the different mouse strains. Gender of mice, type of inoculation (s.c. or i.p.) or time point of analysis (2-63 days post inoculation) did not interfere with the success of L3 recovery. In addition, administration of the immune suppressants hydrocortisone, prednisolone and cyclophosphamide did not restore M. perstans L3 recovery rates. Discussion These findings show that RAG2IL-2Rg−/−BALB/c and C57BL/6, IL-4Rα/IL-5−/− BALB/c and NSG mice were not susceptible to M. perstans and O. volvulus L3 inoculation using the applied methods, whereas Loa loa infection could be maintained. Further studies should investigate if humanized immunocompromised mice might be susceptible to M. perstans. and O. volvulus.","PeriodicalId":73112,"journal":{"name":"Frontiers in tropical diseases","volume":"45 40","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140701927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnosis of female genital schistosomiasis and other genital infections in young South African women: challenges in the syndromic approach","authors":"Solrun Søfteland, Motshedisi Sebitloane, H. Galappaththi-Arachchige, E. Kleppa, S. Holmen, P. Pillay, Patrica Doris Ndhlovu, Myra Taylor, B. Vennervald, S. Naidoo, Anne C. Staff, Manala Makua, S. G. Gundersen, Eyrun Floerecke Kjetland","doi":"10.3389/fitd.2024.1379526","DOIUrl":"https://doi.org/10.3389/fitd.2024.1379526","url":null,"abstract":"Female genital schistosomiasis is a common but neglected disease, which results in symptoms similar to sexually transmitted infections in Schistosoma haematobium-endemic areas of Africa and Middle East. In primary healthcare of low-income countries, healthcare professionals use syndromic management protocols for guidance when treating symptoms of genital infection, due to lack of laboratory resources. These protocols do not include treatment for female genital schistosomiasis, despite the overlap of symptoms. Women are at risk of not receiving the appropriate treatment. The aim of this study was to investigate challenges and missed opportunities when using syndromic management protocols for sexually transmitted infections in female genital schistosomiasis-endemic areas.This is a secondary analysis of data from a large cross-sectional prevalence study conducted in 2011 in KwaZulu-Natal, South Africa. Young women in schistosomiasis-endemic areas were asked about genital symptoms and underwent laboratory testing and gynecological examinations to look for common genital infections including female genital schistosomiasis. We used the current South African syndromic management protocols as the basis and analyzed the associations between the reported genital symptoms and the differential diagnoses with logistic regression.By use of the syndromic approach the conditions gonorrhea, trichomoniasis and herpes could be identified. The symptom “lower abdominal pain” was significantly associated with documented female genital schistosomiasis. However, the same association was not found with gonorrhea or chlamydia. We found no significant association between reported vaginal discharge syndrome and female genital schistosomiasis or between genital ulcer syndrome and female genital schistosomiasis.Female genital schistosomiasis frequently co-exists with, and mimics other genital infections in rural areas of Sub-Saharan Africa. The management protocols in schistosomiasis endemic countries should include advice on how to diagnose and manage this chronic, waterborne genital condition. There is an urgent need to upscale laboratory and diagnostic resources in low-and middle-income countries and specifically schistosomiasis-endemic areas, to diagnose these common genital infections more accurately and to treat affected women accordingly.","PeriodicalId":73112,"journal":{"name":"Frontiers in tropical diseases","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140724012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}