Kashmira Date, Christopher LeBoa, Seth A Hoffman, Pradeep Haldar, Pauline Harvey, Qian An, Chenhua Zhang, Vijay N Yewale, Savita Daruwalla, Dhanya Dharmapalan, Jeetendra Gavhane, Shrikrishna Joshi, Rajesh Rai, Varsha Rathod, Keertana Shetty, Divyalatha S Warrier, Shalini Yadav, Rahul Shimpi, Niniya Jayaprasad, Lily Horng, Kirsten Fagerli, Priyanka Borhade, Debjit Chakraborty, Arun Katkar, Abhishek Kunwar, Jason R Andrews, Sunil Bahl, Pankaj Bhatnagar, Shanta Dutta, Stephen P Luby
Typbar-TCV®, a typhoid conjugate vaccine (TCV), was prequalified by the World Health Organization in 2017. We evaluated its effectiveness in a mass vaccination program targeting children 9 months to 14 years in Navi Mumbai, India, from September 2018 to July 2020. We compared laboratory-confirmed typhoid cases from six clinical sites with age-matched community controls. Of 38 cases, three (8.6%) received TCV through the campaign, compared with 53 (37%) of 140 controls. The adjusted odds ratio of typhoid fever among vaccinated children was 0.16 (95% CI: 0.05-0.55), equivalent to a vaccine effectiveness of 83.7% (95% CI: 45.0-95.3). Vaccine effectiveness of Typbar-TCV in this large public sector vaccine introduction was similar to prior randomized controlled trials, providing reassurance to policymakers that TCV effectiveness is robust in a large-scale implementation.
{"title":"Field Effectiveness of a Typhoid Conjugate Vaccine: The 2018 Navi Mumbai Pediatric TCV Campaign.","authors":"Kashmira Date, Christopher LeBoa, Seth A Hoffman, Pradeep Haldar, Pauline Harvey, Qian An, Chenhua Zhang, Vijay N Yewale, Savita Daruwalla, Dhanya Dharmapalan, Jeetendra Gavhane, Shrikrishna Joshi, Rajesh Rai, Varsha Rathod, Keertana Shetty, Divyalatha S Warrier, Shalini Yadav, Rahul Shimpi, Niniya Jayaprasad, Lily Horng, Kirsten Fagerli, Priyanka Borhade, Debjit Chakraborty, Arun Katkar, Abhishek Kunwar, Jason R Andrews, Sunil Bahl, Pankaj Bhatnagar, Shanta Dutta, Stephen P Luby","doi":"10.4269/ajtmh.24-0181","DOIUrl":"10.4269/ajtmh.24-0181","url":null,"abstract":"<p><p>Typbar-TCV®, a typhoid conjugate vaccine (TCV), was prequalified by the World Health Organization in 2017. We evaluated its effectiveness in a mass vaccination program targeting children 9 months to 14 years in Navi Mumbai, India, from September 2018 to July 2020. We compared laboratory-confirmed typhoid cases from six clinical sites with age-matched community controls. Of 38 cases, three (8.6%) received TCV through the campaign, compared with 53 (37%) of 140 controls. The adjusted odds ratio of typhoid fever among vaccinated children was 0.16 (95% CI: 0.05-0.55), equivalent to a vaccine effectiveness of 83.7% (95% CI: 45.0-95.3). Vaccine effectiveness of Typbar-TCV in this large public sector vaccine introduction was similar to prior randomized controlled trials, providing reassurance to policymakers that TCV effectiveness is robust in a large-scale implementation.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luz M Toribio, Alessandra Vásquez, Yesenia Castillo, S Mathof Salas, Erika Perez, Javier A Bustos, Seth E O'Neal, Hector H Garcia
Neurocysticercosis is a parasitic disease of major public health importance. Definitive diagnosis requires neuroimaging, which is typically unavailable in rural impoverished regions of endemicity. Screening immunoassays can support diagnosis in this setting by identifying individuals most likely to have severe forms of disease for referral to imaging. Urine sampling is convenient, painless, and generally well accepted. We developed a rapid point-of-care (POC) assay to detect urinary antigens and assessed concordance with a standard antigen ELISA (Ag-ELISA), both using monoclonal antibodies TsW8/TsW5. From 28,145 stored community samples with Ag-ELISA results, we selected 843 for comparison, 281 each from nonreactive (ratio <1), reactive-below-cutoff (ratio 1:3), and positive (ratio ≥3) samples. Overall agreement was 73.6%, with strong agreement observed in the nonreactive (280/281, 99.6%) and positive (255/281, 90.8%) groups. This affordable noninvasive POC test can be applied to identify individuals in the community most at risk of developing severe disease.
{"title":"Concordance between a New Rapid Point-Of-Care Assay and Standard ELISA in the Detection of Cysticercosis Antigens in Urine.","authors":"Luz M Toribio, Alessandra Vásquez, Yesenia Castillo, S Mathof Salas, Erika Perez, Javier A Bustos, Seth E O'Neal, Hector H Garcia","doi":"10.4269/ajtmh.24-0171","DOIUrl":"10.4269/ajtmh.24-0171","url":null,"abstract":"<p><p>Neurocysticercosis is a parasitic disease of major public health importance. Definitive diagnosis requires neuroimaging, which is typically unavailable in rural impoverished regions of endemicity. Screening immunoassays can support diagnosis in this setting by identifying individuals most likely to have severe forms of disease for referral to imaging. Urine sampling is convenient, painless, and generally well accepted. We developed a rapid point-of-care (POC) assay to detect urinary antigens and assessed concordance with a standard antigen ELISA (Ag-ELISA), both using monoclonal antibodies TsW8/TsW5. From 28,145 stored community samples with Ag-ELISA results, we selected 843 for comparison, 281 each from nonreactive (ratio <1), reactive-below-cutoff (ratio 1:3), and positive (ratio ≥3) samples. Overall agreement was 73.6%, with strong agreement observed in the nonreactive (280/281, 99.6%) and positive (255/281, 90.8%) groups. This affordable noninvasive POC test can be applied to identify individuals in the community most at risk of developing severe disease.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leishmaniasis poses significant public health challenges in endemic regions. Understanding the prevalence of asymptomatic Leishmania infection and identifying risk factors among blood donors is crucial. This study addressed a knowledge gap by evaluating the prevalence of asymptomatic Leishmania infection and pinpointing associated risk factors among blood donors in an endemic area in Thailand and aimed to enhance blood donation safety protocols and reduce the risk of transfusion-transmitted Leishmania infection. A cross-sectional study and a longitudinal follow-up were conducted among 500 blood donors in Trang Province, southern Thailand. A serological test was performed using the direct agglutination test (DAT), and DNA detection was performed using nested polymerase chain reaction (nPCR) to screen for Leishmania infection. Potential risk factors associated with the infection were also assessed. The study identified a 19.0% prevalence of asymptomatic Leishmania infection among blood donors, with nPCR proving more effective in detecting infections (13.0%) than DAT (6.4%). Notably, Leishmania martiniquensis was the predominant species identified, highlighting the local epidemiological profile of Leishmania infection. Furthermore, using multivariate analysis, living in stilt houses was independently associated with Leishmania infection (adjusted odds ratio = 1.85; 95% CI = 1.04-3.28; P = 0.035). A high prevalence of asymptomatic Leishmania infection among blood donors underscores the need for integrating comprehensive Leishmania screening protocols into blood donation processes, particularly in endemic regions. It advocates for using molecular diagnostics to enhance detection accuracy. Furthermore, living in stilt houses as a risk factor emphasizes the importance of environmental management in leishmaniasis control efforts.
利什曼病给流行地区的公共卫生带来了重大挑战。了解无症状利什曼原虫感染的流行情况并确定献血者中的风险因素至关重要。本研究通过评估无症状利什曼原虫感染的流行率,并找出泰国流行地区献血者中的相关风险因素,填补了知识空白,旨在加强献血安全规程,降低输血传播利什曼原虫感染的风险。研究人员对泰国南部 Trang 省的 500 名献血者进行了横断面研究和纵向随访。使用直接凝集试验(DAT)进行血清学检测,并使用巢式聚合酶链反应(nPCR)进行 DNA 检测,以筛查利什曼原虫感染。此外,还评估了与感染相关的潜在风险因素。研究发现,献血者中无症状利什曼原虫感染率为 19.0%,nPCR 在检测感染(13.0%)方面比 DAT(6.4%)更有效。值得注意的是,马氏利什曼原虫(Leishmania martiniquensis)是主要的鉴定物种,这突出了当地利什曼原虫感染的流行病学特征。此外,通过多变量分析,居住在棚屋中与利什曼原虫感染有独立关联(调整后的几率比 = 1.85;95% CI = 1.04-3.28;P = 0.035)。无症状利什曼原虫感染在献血者中的高流行率凸显了将全面利什曼原虫筛查方案纳入献血流程的必要性,尤其是在利什曼原虫流行地区。它提倡使用分子诊断技术来提高检测的准确性。此外,居住在棚屋中也是一个风险因素,这强调了环境管理在利什曼病控制工作中的重要性。
{"title":"Asymptomatic Leishmania Infection among Blood Donors in a Southern Province of Thailand.","authors":"Phunlerd Piyaraj, Lertwut Bualert, Areerat Kalrat, Saovanee Leelayoova, Toon Ruang-Areerate, Nisaichol Theprin, Tawee Naaglor, Mathirut Mungthin","doi":"10.4269/ajtmh.24-0218","DOIUrl":"https://doi.org/10.4269/ajtmh.24-0218","url":null,"abstract":"<p><p>Leishmaniasis poses significant public health challenges in endemic regions. Understanding the prevalence of asymptomatic Leishmania infection and identifying risk factors among blood donors is crucial. This study addressed a knowledge gap by evaluating the prevalence of asymptomatic Leishmania infection and pinpointing associated risk factors among blood donors in an endemic area in Thailand and aimed to enhance blood donation safety protocols and reduce the risk of transfusion-transmitted Leishmania infection. A cross-sectional study and a longitudinal follow-up were conducted among 500 blood donors in Trang Province, southern Thailand. A serological test was performed using the direct agglutination test (DAT), and DNA detection was performed using nested polymerase chain reaction (nPCR) to screen for Leishmania infection. Potential risk factors associated with the infection were also assessed. The study identified a 19.0% prevalence of asymptomatic Leishmania infection among blood donors, with nPCR proving more effective in detecting infections (13.0%) than DAT (6.4%). Notably, Leishmania martiniquensis was the predominant species identified, highlighting the local epidemiological profile of Leishmania infection. Furthermore, using multivariate analysis, living in stilt houses was independently associated with Leishmania infection (adjusted odds ratio = 1.85; 95% CI = 1.04-3.28; P = 0.035). A high prevalence of asymptomatic Leishmania infection among blood donors underscores the need for integrating comprehensive Leishmania screening protocols into blood donation processes, particularly in endemic regions. It advocates for using molecular diagnostics to enhance detection accuracy. Furthermore, living in stilt houses as a risk factor emphasizes the importance of environmental management in leishmaniasis control efforts.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nouh Saad Mohamed, Yousif Ali, Emmanuel Edwar Siddig, Ayman Ahmed
Assessing the COVID-19 surveillance system is vital. It identifies cases swiftly and is crucial in curbing COVID-19 spread, especially among vulnerable groups. Public health surveillance collects, analyzes, and shares data systematically, informing actions to lessen disease impact. Here we used a mixed-approach method to assess the COVID-19 surveillance system in Sudan by reviewing the secondary data (line list) from January 28, 2020 to November 2, 2022. The system's effectiveness was rated weak based on the poor quality and incompleteness of the collected data, as well as the reporting process to policymakers and responders. Moreover, the system's acceptability score was low, mainly because of the incompleteness and delays in data reported from the private sector. This assessment recommends that the Federal Ministry of Health invest in improving the surveillance system by building the technical capacity of the staff, infrastructure, and utilization of the District Health Information Software-2 for data collection, analysis, and dissemination.
{"title":"Assessment of the COVID-19 Surveillance System in Sudan: Performance, Limitations, and Recommendations.","authors":"Nouh Saad Mohamed, Yousif Ali, Emmanuel Edwar Siddig, Ayman Ahmed","doi":"10.4269/ajtmh.23-0624","DOIUrl":"https://doi.org/10.4269/ajtmh.23-0624","url":null,"abstract":"<p><p>Assessing the COVID-19 surveillance system is vital. It identifies cases swiftly and is crucial in curbing COVID-19 spread, especially among vulnerable groups. Public health surveillance collects, analyzes, and shares data systematically, informing actions to lessen disease impact. Here we used a mixed-approach method to assess the COVID-19 surveillance system in Sudan by reviewing the secondary data (line list) from January 28, 2020 to November 2, 2022. The system's effectiveness was rated weak based on the poor quality and incompleteness of the collected data, as well as the reporting process to policymakers and responders. Moreover, the system's acceptability score was low, mainly because of the incompleteness and delays in data reported from the private sector. This assessment recommends that the Federal Ministry of Health invest in improving the surveillance system by building the technical capacity of the staff, infrastructure, and utilization of the District Health Information Software-2 for data collection, analysis, and dissemination.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mid-Borderline Leprosy with Type I Reaction.","authors":"Jorge C F Nakazaki, Malika Madhava, Cesar Ramos","doi":"10.4269/ajtmh.24-0217","DOIUrl":"https://doi.org/10.4269/ajtmh.24-0217","url":null,"abstract":"","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elizabeth Córdoba-Lanús, María Reyes-Batlle, Angélica Domínguez-de-Barros, Patricia Pérez-Pérez, Rubén L Rodríguez-Expósito, Alma García-Ramos, Inés Sifaoui, Omar García-Pérez, Germán Aneiros-Giraldez, José E Piñero, Jacob Lorenzo-Morales
Free-living amoebae (FLA) are widely distributed in the environment. Among these, Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris, and Vermamoeba vermiformis have been reported as human pathogens with health effects ranging from lethal encephalitis to different epithelial disorders. Despite this, FLA still present many diagnostic challenges. The aim of this study was to develop a rapid and efficient multiplex real-time quantitative polymerase chain reaction (qPCR) to simultaneously detect Acanthamoeba spp., N. fowleri, B. mandrillaris, and V. vermiformis in different water sources. For the validation of the qPCR assay, 38 samples (19 tap water and 19 stagnant water sources) were analyzed. The qPCR assay accurately identified the four types of FLA with no cross-reactivity. Considering water samples with results subsequently confirmed by conventional PCR, the multiplex qPCR assay detected 18/38 (47.4%) positive samples (Acanthamoeba spp. in 44.7% and V. vermiformis in 31.6%) and growth in nonnutritive agar (NNA) cultures identified 7/38 (18.4%) positive samples. Of the tap water samples analyzed, 26.3% of samples positive for FLA were detected by growth in NNA culture whereas 31.6% were identified by qPCR. In addition, FLA were detected in 2/19 stagnant water samples (10.5%) by growth in NNA culture and in 12/19 stagnant water samples (63.2%) by qPCR. Neither N. fowleri nor B. mandrillaris was detected in the water samples analyzed. In conclusion, the qPCR developed showed its potential as a rapid tool for detection of Acanthamoeba spp., N. fowleri, B. mandrillaris, and V. vermiformis. Moreover, FLA species were detected in half of the water sources evaluated, suggesting the importance of the surveillance of these potential infectious agents.
自由生活阿米巴原虫(FLA)广泛分布于环境中。其中,阿卡阿米巴属、奈格勒阿福勒氏虫、山魈巴拉穆氏虫和疣状蛭属阿米巴虫已被报道为人类病原体,对健康的影响从致命性脑炎到不同的上皮疾病不等。尽管如此,FLA 仍给诊断带来许多挑战。本研究旨在开发一种快速高效的多重实时定量聚合酶链反应(qPCR),以同时检测不同水源中的棘阿米巴属、N. fowleri、B. mandrillaris 和 V. vermiformis。为了验证 qPCR 分析法,共分析了 38 个样本(19 个自来水样本和 19 个死水源样本)。qPCR 分析法准确鉴定了四种 FLA,且无交叉反应。对于随后通过传统 PCR 法确认结果的水样,多重 qPCR 法检测出了 18/38 个(47.4%)阳性样本(44.7% 为阿卡他米巴属,31.6% 为疣状葡萄球菌),在非营养琼脂(NNA)培养物中生长的阳性样本为 7/38 个(18.4%)。在分析的自来水样本中,26.3%的 FLA 阳性样本是通过 NNA 培养物的生长检测到的,而 31.6% 是通过 qPCR 检测到的。此外,在 2/19 个积水样本(10.5%)中,通过 NNA 培养生长检测到了 FLA;在 12/19 个积水样本(63.2%)中,通过 qPCR 检测到了 FLA。在分析的水样中均未检测到 N. fowleri 或 B. mandrillaris。总之,所开发的 qPCR 显示了其作为快速检测棘阿米巴属、N. fowleri、B. mandrillaris 和 V. vermiformis 的工具的潜力。此外,在一半的评估水源中都检测到了 FLA 物种,这表明对这些潜在传染源进行监测的重要性。
{"title":"Multiplex Real-Time Polymerase Chain Reaction Assay To Detect Acanthamoeba spp., Vermamoeba vermiformis, Naegleria fowleri, and Balamuthia mandrillaris in Different Water Sources.","authors":"Elizabeth Córdoba-Lanús, María Reyes-Batlle, Angélica Domínguez-de-Barros, Patricia Pérez-Pérez, Rubén L Rodríguez-Expósito, Alma García-Ramos, Inés Sifaoui, Omar García-Pérez, Germán Aneiros-Giraldez, José E Piñero, Jacob Lorenzo-Morales","doi":"10.4269/ajtmh.24-0028","DOIUrl":"10.4269/ajtmh.24-0028","url":null,"abstract":"<p><p>Free-living amoebae (FLA) are widely distributed in the environment. Among these, Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris, and Vermamoeba vermiformis have been reported as human pathogens with health effects ranging from lethal encephalitis to different epithelial disorders. Despite this, FLA still present many diagnostic challenges. The aim of this study was to develop a rapid and efficient multiplex real-time quantitative polymerase chain reaction (qPCR) to simultaneously detect Acanthamoeba spp., N. fowleri, B. mandrillaris, and V. vermiformis in different water sources. For the validation of the qPCR assay, 38 samples (19 tap water and 19 stagnant water sources) were analyzed. The qPCR assay accurately identified the four types of FLA with no cross-reactivity. Considering water samples with results subsequently confirmed by conventional PCR, the multiplex qPCR assay detected 18/38 (47.4%) positive samples (Acanthamoeba spp. in 44.7% and V. vermiformis in 31.6%) and growth in nonnutritive agar (NNA) cultures identified 7/38 (18.4%) positive samples. Of the tap water samples analyzed, 26.3% of samples positive for FLA were detected by growth in NNA culture whereas 31.6% were identified by qPCR. In addition, FLA were detected in 2/19 stagnant water samples (10.5%) by growth in NNA culture and in 12/19 stagnant water samples (63.2%) by qPCR. Neither N. fowleri nor B. mandrillaris was detected in the water samples analyzed. In conclusion, the qPCR developed showed its potential as a rapid tool for detection of Acanthamoeba spp., N. fowleri, B. mandrillaris, and V. vermiformis. Moreover, FLA species were detected in half of the water sources evaluated, suggesting the importance of the surveillance of these potential infectious agents.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141896523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shubhada Hooli, Tim Colbourn, Manish I Shah, Kristy Murray, Anna Mandalakas, Eric D McCollum
Acute lower respiratory infections (ALRI) are the leading post-neonatal cause of death in children under 5 years old. There is a high prevalence of pediatric ALRI-related hypoxemia in low- and middle-income countries. The WHO defines clinically meaningful hypoxemia in children as a SpO2 (peripheral oxygen saturation) <90%. Multiple studies put this convention into question and found SpO2 of 90% to 92% to be associated with child ALRI mortality. An evolving body of evidence suggests that pulse oximeters systematically overestimate oxygen saturation in individuals with dark skin tones. We conducted a narrative review of pediatric studies evaluating pulse oximeter accuracy in children without COVID-19. Four studies, one prospective, examined pulse oximeter accuracy in children of varying ages with dark skin tones. All studies had limitations that affect their generalizability. There is evidence that certain pulse oximeters may overestimate oxygen saturation in children with dark skin tones. Further prospective research is urgently needed to identify affected populations and clinical implications. Despite recognized challenges, we strongly urge continued and expanded use of pulse oximetry as its use will save lives.
{"title":"Pulse Oximetry Accuracy in Children with Dark Skin Tones: Relevance to Acute Lower Respiratory Infection Care in Low- and Middle-Income Countries.","authors":"Shubhada Hooli, Tim Colbourn, Manish I Shah, Kristy Murray, Anna Mandalakas, Eric D McCollum","doi":"10.4269/ajtmh.23-0656","DOIUrl":"10.4269/ajtmh.23-0656","url":null,"abstract":"<p><p>Acute lower respiratory infections (ALRI) are the leading post-neonatal cause of death in children under 5 years old. There is a high prevalence of pediatric ALRI-related hypoxemia in low- and middle-income countries. The WHO defines clinically meaningful hypoxemia in children as a SpO2 (peripheral oxygen saturation) <90%. Multiple studies put this convention into question and found SpO2 of 90% to 92% to be associated with child ALRI mortality. An evolving body of evidence suggests that pulse oximeters systematically overestimate oxygen saturation in individuals with dark skin tones. We conducted a narrative review of pediatric studies evaluating pulse oximeter accuracy in children without COVID-19. Four studies, one prospective, examined pulse oximeter accuracy in children of varying ages with dark skin tones. All studies had limitations that affect their generalizability. There is evidence that certain pulse oximeters may overestimate oxygen saturation in children with dark skin tones. Further prospective research is urgently needed to identify affected populations and clinical implications. Despite recognized challenges, we strongly urge continued and expanded use of pulse oximetry as its use will save lives.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141896524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Atypical presentations of filariasis have posed diagnostic challenges due to the complexity of identifying the causative species and the difficulties in both diagnosis and treatment. In this study, we present the integrative histological and molecular analysis of seven atypical filariasis cases observed in regions of nonendemicity of Thailand. All filariasis cases were initially diagnosed based on histological findings. To confirm the causative species, molecular characterization based on both filarial mitochondrial (mt 12S rRNA and COI genes) and nuclear ITS1 markers was performed, together with the identification of associated Wolbachia bacterial endosymbionts. Among the cases studied, Brugia pahangi (N = 3), Brugia malayi (N = 1), Dirofilaria sp. "hongkongensis" (N = 2), and a suspected novel filarial species genetically related to Pelecitus copsychi (N = 1) were identified. By targeting the 16S rRNA gene, Wolbachia was also molecularly amplified in two cases of infection with Dirofilaria sp. "hongkongensis." Phylogenetic analysis further revealed that the detected Wolbachia could be classified into supergroups C and F, indicating the high genetic diversity of this endosymbiont in Dirofilaria sp. "hongkongensis." Furthermore, this study demonstrates the consistency between histological findings and species identification based on mitochondrial loci rather than on the nuclear ITS1. This suggests the utility of mitochondrial markers, particularly COI, as a highly sensitive and reliable diagnostic tool for the detection and differentiation of filarial species in clinical specimens. Precise identification of the causative species will facilitate accurate diagnosis and treatment and is also essential for the development of epidemiological and preventive strategies for filariasis.
{"title":"Integrated Histological and Molecular Analysis of Filarial Species and Associated Wolbachia Endosymbionts in Human Filariasis Cases Presenting Atypically in Thailand.","authors":"Patsharaporn T Sarasombath, Panitta Sitthinamsuwan, Sirirat Wijit, Kedsara Panyasu, Kosol Roongruanchai, Sukhum Silpa-Archa, Matya Suwansirikul, Peerasak Chortrakarnkij, Pichet Ruenchit, Kanok Preativatanyou, Sirichit Wongkamchai","doi":"10.4269/ajtmh.24-0147","DOIUrl":"10.4269/ajtmh.24-0147","url":null,"abstract":"<p><p>Atypical presentations of filariasis have posed diagnostic challenges due to the complexity of identifying the causative species and the difficulties in both diagnosis and treatment. In this study, we present the integrative histological and molecular analysis of seven atypical filariasis cases observed in regions of nonendemicity of Thailand. All filariasis cases were initially diagnosed based on histological findings. To confirm the causative species, molecular characterization based on both filarial mitochondrial (mt 12S rRNA and COI genes) and nuclear ITS1 markers was performed, together with the identification of associated Wolbachia bacterial endosymbionts. Among the cases studied, Brugia pahangi (N = 3), Brugia malayi (N = 1), Dirofilaria sp. \"hongkongensis\" (N = 2), and a suspected novel filarial species genetically related to Pelecitus copsychi (N = 1) were identified. By targeting the 16S rRNA gene, Wolbachia was also molecularly amplified in two cases of infection with Dirofilaria sp. \"hongkongensis.\" Phylogenetic analysis further revealed that the detected Wolbachia could be classified into supergroups C and F, indicating the high genetic diversity of this endosymbiont in Dirofilaria sp. \"hongkongensis.\" Furthermore, this study demonstrates the consistency between histological findings and species identification based on mitochondrial loci rather than on the nuclear ITS1. This suggests the utility of mitochondrial markers, particularly COI, as a highly sensitive and reliable diagnostic tool for the detection and differentiation of filarial species in clinical specimens. Precise identification of the causative species will facilitate accurate diagnosis and treatment and is also essential for the development of epidemiological and preventive strategies for filariasis.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141896501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Meng Yee Lai, Ainaa Nadrah Sohairi, Lee Phone Youth Zen, Mohd Lutfi Abdullah, Yee Ling Lau
Zoonotic malaria, caused by Plasmodium knowlesi, Plasmodium cynomolgi, Plasmodium coatneyi, and Plasmodium inui, is a significant global health concern. The gold standard microscopy, while widely used for malaria diagnosis, faces limitations in differentiating between malaria species. Polymerase chain reaction (PCR), despite its accuracy, is characterized by high costs and time-consuming procedures. This study aims to develop and validate a rapid and accurate diagnostic test for detecting four simian Plasmodium species by using loop-mediated isothermal amplification (LAMP). Loop-mediated isothermal amplification is a cost-effective and faster molecular testing alternative for malaria diagnosis. The project involved designing specific primers, testing sensitivity and specificity against various parasites (including human Plasmodium species, protozoa, and helminths), and evaluating the LAMP assay using 60 macaque samples infected with simian Plasmodium. The LAMP assay exhibited a sensitivity profile enabling the detection of P. knowlesi, P. coatneyi, and P. cynomolgi across a concentration gradient from 5 × 108 down to 5 × 105 parasites/µL. Notably, P. inui was detectable at 5 × 108 parasites/µL. Furthermore, the specificity of the primer tailored for the four simian Plasmodium species was proven, as it produced a positive amplification exclusively for the respective target species and generated negative results for nontarget species. The results indicated that the LAMP assay is capable of detecting simian Plasmodium within a short span of 60 minutes, without any false positives from other samples. This new test has the potential to revolutionize malaria diagnosis, surveillance, and control, thereby mitigating the impact of zoonotic malaria in regions of endemicity.
{"title":"Loop-Mediated Isothermal Amplification for Diagnosis of Zoonotic Malaria.","authors":"Meng Yee Lai, Ainaa Nadrah Sohairi, Lee Phone Youth Zen, Mohd Lutfi Abdullah, Yee Ling Lau","doi":"10.4269/ajtmh.23-0879","DOIUrl":"10.4269/ajtmh.23-0879","url":null,"abstract":"<p><p>Zoonotic malaria, caused by Plasmodium knowlesi, Plasmodium cynomolgi, Plasmodium coatneyi, and Plasmodium inui, is a significant global health concern. The gold standard microscopy, while widely used for malaria diagnosis, faces limitations in differentiating between malaria species. Polymerase chain reaction (PCR), despite its accuracy, is characterized by high costs and time-consuming procedures. This study aims to develop and validate a rapid and accurate diagnostic test for detecting four simian Plasmodium species by using loop-mediated isothermal amplification (LAMP). Loop-mediated isothermal amplification is a cost-effective and faster molecular testing alternative for malaria diagnosis. The project involved designing specific primers, testing sensitivity and specificity against various parasites (including human Plasmodium species, protozoa, and helminths), and evaluating the LAMP assay using 60 macaque samples infected with simian Plasmodium. The LAMP assay exhibited a sensitivity profile enabling the detection of P. knowlesi, P. coatneyi, and P. cynomolgi across a concentration gradient from 5 × 108 down to 5 × 105 parasites/µL. Notably, P. inui was detectable at 5 × 108 parasites/µL. Furthermore, the specificity of the primer tailored for the four simian Plasmodium species was proven, as it produced a positive amplification exclusively for the respective target species and generated negative results for nontarget species. The results indicated that the LAMP assay is capable of detecting simian Plasmodium within a short span of 60 minutes, without any false positives from other samples. This new test has the potential to revolutionize malaria diagnosis, surveillance, and control, thereby mitigating the impact of zoonotic malaria in regions of endemicity.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141896502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eliana L Parra-Barrera, Solmara Bello-Piruccini, Karina Rodríguez, Carolina Duarte-Valderrama, Marisa Torres, Eduardo A Undurraga
Leptospirosis, a bacterial infection transmitted through contact with infected animals or contaminated water sources, imposes a substantial health burden in Colombia. Since 2007, the National Institute of Health (INS) has mandated the notification and confirmation of all suspected leptospirosis cases. This passive surveillance program employs the microscopic agglutination test (MAT) on serum samples to ascertain confirmed cases of leptospirosis infection. However, the absence of a robust surveillance system has hindered our comprehensive understanding of the morbidity, mortality, geographical distribution, species/serovars, and strains responsible for severe disease. Our study aimed to provide an epidemiological overview of MAT-confirmed human leptospirosis cases reported over 6 years (2015-2020) in Colombia. In addition, we offer insights into the status of leptospirosis in the country, focusing on risk factors and proposing potential improvements for diagnosis and disease management. During the 6-year surveillance period, the laboratory at the INS received 3,535 serum samples from suspected human leptospirosis cases, with 880 (25%) confirmed through MAT. The incidence of leptospirosis was calculated at 1.9 cases per 100,000 people, with a higher prevalence among men (82.1%). Furthermore, 54 (6.1%) deaths were confirmed as leptospirosis, and cases were documented across nearly all regions of Colombia. Our findings emphasize the urgent need to strengthen leptospirosis laboratory surveillance, implement effective prevention measures, and enhance diagnostic capabilities in Colombia. The analysis conducted in this study provides the groundwork for estimating the impact of leptospirosis and raises awareness of its significance in public health.
{"title":"Serologically Confirmed Human Leptospirosis in Colombia, 2015-2020.","authors":"Eliana L Parra-Barrera, Solmara Bello-Piruccini, Karina Rodríguez, Carolina Duarte-Valderrama, Marisa Torres, Eduardo A Undurraga","doi":"10.4269/ajtmh.23-0654","DOIUrl":"10.4269/ajtmh.23-0654","url":null,"abstract":"<p><p>Leptospirosis, a bacterial infection transmitted through contact with infected animals or contaminated water sources, imposes a substantial health burden in Colombia. Since 2007, the National Institute of Health (INS) has mandated the notification and confirmation of all suspected leptospirosis cases. This passive surveillance program employs the microscopic agglutination test (MAT) on serum samples to ascertain confirmed cases of leptospirosis infection. However, the absence of a robust surveillance system has hindered our comprehensive understanding of the morbidity, mortality, geographical distribution, species/serovars, and strains responsible for severe disease. Our study aimed to provide an epidemiological overview of MAT-confirmed human leptospirosis cases reported over 6 years (2015-2020) in Colombia. In addition, we offer insights into the status of leptospirosis in the country, focusing on risk factors and proposing potential improvements for diagnosis and disease management. During the 6-year surveillance period, the laboratory at the INS received 3,535 serum samples from suspected human leptospirosis cases, with 880 (25%) confirmed through MAT. The incidence of leptospirosis was calculated at 1.9 cases per 100,000 people, with a higher prevalence among men (82.1%). Furthermore, 54 (6.1%) deaths were confirmed as leptospirosis, and cases were documented across nearly all regions of Colombia. Our findings emphasize the urgent need to strengthen leptospirosis laboratory surveillance, implement effective prevention measures, and enhance diagnostic capabilities in Colombia. The analysis conducted in this study provides the groundwork for estimating the impact of leptospirosis and raises awareness of its significance in public health.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141896525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}