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Ameen E, Nin Zhu S, Morales Guzman C, Taub E, Siles C, Meza Sanchez G, Vilcarromero S, Ramal C, Tangoa N, Marcos LA. Feasibility of Training Community Health Workers to Use Smartphone-Attached Microscopy for Point-of-Care Visualization of Soil-Transmitted Helminths in the Peruvian Amazon. Am J Trop Med Hyg 2023; 108:1175-1182. [PMID: 37068753 PMCID: PMC10540104 DOI: 10.4269/ajtmh.22-0210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 11/21/2022] [Indexed: 04/19/2023] Open
Abstract
The prevalence of soil-transmitted helminths (STH) is high in communities within the Peruvian Amazon despite repeated mass-drug administration, demanding alternative strategies of control. Smartphone-attached microscopy (SAM) permits visualization of STH from a small portable microscope through a smartphone screen, potentially providing an inexpensive and rapid method of STH visualization in communities where diagnostic laboratories with microscopes are inaccessible. In this study, a total of 45 community health workers who work within the health systems of Loreto, Peru, attended a 1-day training session with lectures and practicums on STH and SAM. Participants received a pre- and post-intervention questionnaire. Post-intervention, participants were significantly more confident using SAM and identifying parasite images, symptoms, transmission, and treatment (P ≤ 0.0045). Post-intervention, participants correctly labeled a median of five of seven SAM apparatus components and five of eight steps of Kato-Katz technique, were less likely to choose taking medicine to prevent parasite infection (P = 0.0075), and were more likely to select Kato-Katz technique as a type of diagnostic test (P < 0.0001). Most participants felt ready to use SAM in their communities and stated that it could help rural communities far from health centers or laboratories (24%); provide faster identification, results, diagnosis (19%); permit at-home or on-the-spot visualization (14%); and save money (14%). Results show that community health workers show a high level of willingness and competency to learn about both STH and SAM and may be a yet-unexplored practical method of augmenting STH visualization, bringing healthcare to communities in Loreto with poor access to diagnostic laboratories and clinics.
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Affiliation(s)
- Eve Ameen
- Renaissance School of Medicine, Stony Brook University, Stony Brook, New York
| | - Simon Nin Zhu
- Renaissance School of Medicine, Stony Brook University, Stony Brook, New York
| | | | - Erin Taub
- Global Health Institute, Stony Brook University Hospital, Stony Brook, New York
| | | | | | | | - Cesar Ramal
- Universidad Nacional de la Amazonía Peruana, Iquitos, Peru
| | - Nolberto Tangoa
- Centro de Salud San Juan, Ministerio de Salud Peruana, Iquitos, Peru
| | - Luis A. Marcos
- Global Health Institute, Stony Brook University Hospital, Stony Brook, New York
- Infectious Diseases Division, Department of Medicine, Stony Brook University, Stony Brook, New York
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Peñataro Yori P, Paredes Olórtegui M, Schiaffino F, Colston JM, Pinedo Vasquez T, Garcia Bardales PF, Shapiama Lopez V, Zegarra Paredes LF, Perez K, Curico G, Flynn T, Zhang J, Ramal Asayag C, Meza Sanchez G, Silva Delgado H, Casapia Morales M, Casanova W, Jiu B, Oberhelman R, Munayco Escate C, Silver R, Henao O, Cooper KK, Liu J, Houpt ER, Kosek MN. Etiology of acute febrile illness in the peruvian amazon as determined by modular formatted quantitative PCR: a protocol for RIVERA, a health facility-based case-control study. BMC Public Health 2023; 23:674. [PMID: 37041550 PMCID: PMC10088183 DOI: 10.1186/s12889-023-15619-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/06/2023] [Indexed: 04/13/2023] Open
Abstract
BACKGROUND The study of the etiology of acute febrile illness (AFI) has historically been designed as a prevalence of pathogens detected from a case series. This strategy has an inherent unrealistic assumption that all pathogen detection allows for causal attribution, despite known asymptomatic carriage of the principal causes of acute febrile illness in most low- and middle-income countries (LMICs). We designed a semi-quantitative PCR in a modular format to detect bloodborne agents of acute febrile illness that encompassed common etiologies of AFI in the region, etiologies of recent epidemics, etiologies that require an immediate public health response and additional pathogens of unknown endemicity. We then designed a study that would delineate background levels of transmission in the community in the absence of symptoms to provide corrected estimates of attribution for the principal determinants of AFI. METHODS A case-control study of acute febrile illness in patients ten years or older seeking health care in Iquitos, Loreto, Peru, was planned. Upon enrollment, we will obtain blood, saliva, and mid-turbinate nasal swabs at enrollment with a follow-up visit on day 21-28 following enrollment to attain vital status and convalescent saliva and blood samples, as well as a questionnaire including clinical, socio-demographic, occupational, travel, and animal contact information for each participant. Whole blood samples are to be simultaneously tested for 32 pathogens using TaqMan array cards. Mid-turbinate samples will be tested for SARS-CoV-2, Influenza A and Influenza B. Conditional logistic regression models will be fitted treating case/control status as the outcome and with pathogen-specific sample positivity as predictors to attain estimates of attributable pathogen fractions for AFI. DISCUSSION The modular PCR platforms will allow for reporting of all primary results of respiratory samples within 72 h and blood samples within one week, allowing for results to influence local medical practice and enable timely public health responses. The inclusion of controls will allow for a more accurate estimate of the importance of specific prevalent pathogens as a cause of acute illness. STUDY REGISTRATION Project 1791, Registro de Proyectos de Investigación en Salud Pública (PRISA), Instituto Nacional de Salud, Perú.
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Affiliation(s)
- Pablo Peñataro Yori
- Division of Infectious Disease and International Health, School of Medicine, University of Virginia, Charlottesville, VA, USA
- Asociación Benefica PRISMA, Iquitos, Loreto, Peru
| | | | - Francesca Schiaffino
- Division of Infectious Disease and International Health, School of Medicine, University of Virginia, Charlottesville, VA, USA
- Faculty of Veterinary Medicine, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Josh M Colston
- Division of Infectious Disease and International Health, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | | | | | | | | | - Karin Perez
- Asociación Benefica PRISMA, Iquitos, Loreto, Peru
| | | | - Thomas Flynn
- Division of Infectious Disease and International Health, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Jixian Zhang
- Division of Infectious Disease and International Health, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Cesar Ramal Asayag
- Universidad Nacional de La Amazonia Peruana, Loreto, Peru
- Hospital Regional de Loreto, Iquitos, Loreto, Peru
| | - Graciela Meza Sanchez
- Universidad Nacional de La Amazonia Peruana, Loreto, Peru
- Direccion Regional de Salud, Loreto, Peru
| | | | - Martin Casapia Morales
- Universidad Nacional de La Amazonia Peruana, Loreto, Peru
- Hospital Regional de Loreto, Iquitos, Loreto, Peru
| | - Wilma Casanova
- Universidad Nacional de La Amazonia Peruana, Loreto, Peru
| | - Bruce Jiu
- Laboratorio de Referencia en Salud Publica de la Direccion Regional de Salud- Diresa, Loreto, Peru
| | - Richard Oberhelman
- Tulane School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | - Cesar Munayco Escate
- Centro Nacional de Epidemiologia, Prevencion, y Control de Enfermedades, Ministerio de Salud de Peru, Jesus Maria, Peru
| | - Rachel Silver
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Olga Henao
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Kerry K Cooper
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - Jie Liu
- School of Public Health, Qingdao University, Qingdao, China
| | - Eric R Houpt
- Division of Infectious Disease and International Health, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Margaret N Kosek
- Division of Infectious Disease and International Health, School of Medicine, University of Virginia, Charlottesville, VA, USA.
- Asociación Benefica PRISMA, Iquitos, Loreto, Peru.
- Division of Infectious Diseases and International Health, Public Health Sciences, 345 Crispell Dr, Rm 2525, Charlottesville, USA.
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Peñataro Yori P, Paredes Olórtegui M, Schiaffino F, Perez K, Curico Huansi G, Flynn T, Zhang J, Ramal Asayag C, Meza Sanchez G, Silva Delgado H, Casapia Morales M, Casanova W, Jiu B, Munayco Escate C, Silver R, Henao O, Cooper KK, Liu J, Houpt E, Kosek MN, Colston JM, Oberhelman R, Pinedo Vasquez T, Garcia Bardales PF, Shapiama Lopez WV, Zegarra Paredes LF. Etiology of Acute Febrile Illness in the Peruvian Amazon as determined by modular formatted quantitative PCR: A Protocol for RIVERA, a Health Facility-Based Case-Control Study. Res Sq 2023:rs.3.rs-2635774. [PMID: 37034707 PMCID: PMC10081374 DOI: 10.21203/rs.3.rs-2635774/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Background The study of the etiology of acute febrile illness (AFI) has historically been designed as a prevalence of pathogens detected from a case series. This strategy has an inherent unrealistic assumption that all pathogen detection allows for causal attribution, despite known asymptomatic carriage of the principal causes of acute febrile illness in most low- and middle-income countries (LMICs). We designed a semi-quantitative PCR in a modular format to detect bloodborne agents of acute febrile illness that encompassed common etiologies of AFI in the region, etiologies of recent epidemics, etiologies that require an immediate public health response and additional pathogens of unknown endemicity. We then designed a study that would delineate background levels of transmission in the community in the absence of symptoms to provide corrected estimates of attribution for the principal determinants of AFI. Methods A case-control study of acute febrile illness in patients ten years or older seeking health care in Iquitos, Loreto, Peru, was planned. Upon enrollment, we will obtain blood, saliva, and mid-turbinate nasal swabs at enrollment with a follow-up visit on day 21-28 following enrollment to attain vital status and convalescent saliva and blood samples, as well as a questionnaire including clinical, socio-demographic, occupational, travel, and animal contact information for each participant. Whole blood samples are to be simultaneously tested for 32 pathogens using TaqMan array cards. Mid-turbinate samples will be tested for SARS-CoV-2, Influenza A and Influenza B. Conditional logistic regression models will be fitted treating case/control status as the outcome and with pathogen-specific sample positivity as predictors to attain estimates of attributable pathogen fractions for AFI. Discussion The modular PCR platforms will allow for reporting of all primary results of respiratory samples within 72 hours and blood samples within one week, allowing for results to influence local medical practice and enable timely public health responses. The inclusion of controls will allow for a more accurate estimate of the importance of specific, prevalent pathogens as a cause of acute illness. Study Registration Project 1791, Registro de Proyectos de Investigación en Salud Pública (PRISA), Instituto Nacional de Salud, Perú.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | - Cesar Munayco Escate
- Centro de Epidemiologia, Prevencion, y Control de Enfermedades, Ministerio de Salud
| | | | - Olga Henao
- Centers for Disease Control and Prevention
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François R, Yori PP, Rouhani S, Siguas Salas M, Paredes Olortegui M, Rengifo Trigoso D, Pisanic N, Burga R, Meza R, Meza Sanchez G, Gregory MJ, Houpt ER, Platts-Mills JA, Kosek MN. The other Campylobacters: Not innocent bystanders in endemic diarrhea and dysentery in children in low-income settings. PLoS Negl Trop Dis 2018; 12:e0006200. [PMID: 29415075 PMCID: PMC5819825 DOI: 10.1371/journal.pntd.0006200] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 02/20/2018] [Accepted: 12/31/2017] [Indexed: 12/13/2022] Open
Abstract
Background Campylobacter is one of the main causes of gastroenteritis worldwide. Most of the current knowledge about the epidemiology of this food-borne infection concerns two species, C. coli and C. jejuni. Recent studies conducted in developing countries and using novel diagnostic techniques have generated evidence of the increasing burden and importance of other Campylobacter species, i.e. non-C. coli/jejuni. We performed a nested case-control study to compare the prevalence of C. coli/jejuni and other Campylobacter in children with clinical dysentery and severe diarrhea as well as without diarrhea to better understand the clinical importance of infections with Campylobacter species other than C. coli/jejuni. Methodology/Principal findings Our nested case-control study of 439 stool samples included dysenteric stools, stools collected during severe diarrhea episodes, and asymptomatic stools which were systematically selected to be representative of clinical phenotypes from 9,160 stools collected during a birth cohort study of 201 children followed until two years of age. Other Campylobacter accounted for 76.4% of the 216 Campylobacter detections by qPCR and were more prevalent than C. coli/jejuni across all clinical groups. Other Campylobacter were also more prevalent than C. coli/jejuni across all age groups, with older children bearing a higher burden of other Campylobacter. Biomarkers of intestinal inflammation and injury (methylene blue, fecal occult test, myeloperoxidase or MPO) showed a strong association with dysentery, but mixed results with infection. MPO levels were generally higher among children infected with C. coli/jejuni, but Shigella-infected children suffering from dysentery recorded the highest levels (26,224 ng/mL); the lowest levels (10,625 ng/mL) were among asymptomatic children infected with other Campylobacter. Adjusting for age, sex, and Shigella infection, dysentery was significantly associated with C. coli/jejuni but not with other Campylobacter, whereas severe diarrhea was significantly associated with both C. coli/jejuni and other Campylobacter. Compared to asymptomatic children, children suffering from dysentery had a 14.6 odds of C. coli/jejuni infection (p-value < 0.001, 95% CI 5.5–38.7) but were equally likely to have other Campylobacter infections–odds ratio of 1.3 (0.434, 0.7–2.4). Children suffering from severe diarrhea were more likely than asymptomatic children to test positive for both C. coli/jejuni and other Campylobacter–OR of 2.8 (0.034, 1.1–7.1) and 1.9 (0.018, 1.1–3.1), respectively. Compared to the Campylobacter-free group, the odds of all diarrhea given C. coli/jejuni infection and other Campylobacter infection were 8.8 (<0.001, 3.0–25.7) and 2.4 (0.002, 1.4–4.2), respectively. Eliminating other Campylobacter in this population would eliminate 24.9% of the diarrhea cases, which is almost twice the population attributable fraction of 15.1% due to C. coli/jejuni. Conclusions/Significance Eighty-seven percent of the dysentery and 59.5% of the severe diarrhea samples were positive for Campylobacter, Shigella, or both, emphasizing the importance of targeting these pathogens to limit the impact of dysentery and severe diarrhea in children. Notably, the higher prevalence of other Campylobacter compared to C. coli/jejuni, their increasing burden during early childhood, and their association with severe diarrhea highlight the importance of these non-C. coli/jejuni Campylobacter species and suggest a need to clarify their importance in the etiology of clinical disease across different epidemiological contexts. Campylobacter is a major public health concern in developed and developing countries. C. coli and C. jejuni have long been considered to be the major disease-causing species, and clinical microbiologic approaches target these two species. However, less selective diagnostic approaches have shown the increasing importance of other Campylobacter species (i.e. non-C. coli/jejuni). Our case-control study investigated the association between diarrhea, C. coli/jejuni, and other Campylobacter among 439 stool samples from 201 children in peri-urban communities in Loreto, Peru. Three quarters of the 216 Campylobacter detections were associated with other Campylobacter, whose prevalence increased with age and was greater than that of C. coli/jejuni in all age and clinical groups (dysentery, severe diarrhea, and asymptomatic). Despite their lower prevalence, C. coli/jejuni were more strongly associated with higher levels of myeloperoxidase, clinical dysentery, and the presence of leukocytes and blood in the stool compared to other Campylobacter. Other Campylobacter were equally likely as C. coli/jejuni to be detected in severe diarrhea cases–odds ratio of 1.9 (p-value = 0.018, 95% CI 1.1–3.1) and 2.8 (0.034, 1.1–7.1), respectively. Removing C. coli/jejuni in this population would eliminate 15.1% of diarrhea compared to 24.9% if other Campylobacter were eliminated.
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Affiliation(s)
- Ruthly François
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States of America
| | - Pablo Peñataro Yori
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States of America
- Biomedical Research, Asociación Benéfica PRISMA, Iquitos, Peru
| | - Saba Rouhani
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States of America
| | | | | | | | - Nora Pisanic
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States of America
| | - Rosa Burga
- Bacteriology Department, Naval Medical Research Unit-6 (NAMRU-6), Lima, Peru
| | - Rina Meza
- Bacteriology Department, Naval Medical Research Unit-6 (NAMRU-6), Lima, Peru
| | - Graciela Meza Sanchez
- Facultad de Medicina Humana, Universidad Nacional de la Amazonía Peruana, Iquitos, Peru
| | - Michael J. Gregory
- Bacteriology Department, Naval Medical Research Unit-6 (NAMRU-6), Lima, Peru
| | - Eric R. Houpt
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, United States of America
| | - James A. Platts-Mills
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, United States of America
| | - Margaret N. Kosek
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States of America
- Biomedical Research, Asociación Benéfica PRISMA, Iquitos, Peru
- Division of Infectious Diseases, Johns Hopkins School of Medicine, Baltimore, United States of America
- * E-mail:
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Frank AL, Beales ER, de Wildt G, Meza Sanchez G, Jones LL. "We need people to collaborate together against this disease": A qualitative exploration of perceptions of dengue fever control in caregivers' of children under 5 years, in the Peruvian Amazon. PLoS Negl Trop Dis 2017; 11:e0005755. [PMID: 28873408 PMCID: PMC5600389 DOI: 10.1371/journal.pntd.0005755] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 09/15/2017] [Accepted: 06/28/2017] [Indexed: 11/30/2022] Open
Abstract
Background Dengue Fever presents a significant and growing burden of disease to endemic countries, where children are at particular risk. Worldwide, no effective anti-viral treatment has been identified, thus vector control is key for disease prevention, particularly in Peru where no vaccine is currently available. This qualitative study aimed to explore the perceptions of dengue control in caregivers’ of children under 5 years in Peru, to help direct future mosquito control programmes and strategy. Methods Eighteen semi-structured interviews were conducted in one health centre in Iquitos, Peru. Interviews were audio-recorded, transcribed and translated by an independent translator. Data were analysed using an inductive thematic approach. Findings Three core analytic themes were interpreted: (1) awareness of dengue and its control, (2) perceived susceptibility of children, rural riverside communities and city inhabitants, and (3) perceived responsibility of vector control. Participants were aware of dengue symptoms, transmission and larvae eradication strategies. Misconceptions about the day-time biting behaviour of the Aedes aegypti mosquito and confusion with other mosquito-borne diseases influenced preventative practice. Community-wide lack of cooperation was recognised as a key barrier. This was strengthened by attitudes that the government or health centre were responsible for dengue control and a belief that the disease cannot be prevented through individual actions. Participants felt powerless to prevent dengue due to assumed inevitability of infection and lack of faith in preventative practices. However, children and rural communities were believed to be most vulnerable. Conclusions Perceptions of dengue control amongst caregivers to under 5’s were important in shaping their likelihood to participate in preventative practices. There is a need to address the perceived lack of community cooperation through strategies creating a sense of ownership of community control and enhancing social responsibility. The belief that dengue cannot be prevented by individual actions in a community also warrants attention. Specific misconceptions about dengue should be addressed through the community health worker system and further research directed to identify the needs of certain vulnerable groups. Dengue fever is the most rapidly spreading mosquito-borne viral disease in the world and is a significant international health problem. It is endemic in the Peruvian Amazon and since there is no available vaccine or effective treatment, mosquito control is key. This novel study used qualitative interviews to explore the perceptions and experiences of dengue control in caregivers’ to children under 5 years, to help inform future Peruvian mosquito control programmes. Findings suggested that caregivers had basic knowledge about dengue, but that misconceptions around the mosquito itself and confusion with other diseases (like malaria) influenced people’s protective practice. Furthermore, participants felt powerless to prevent dengue since the invisible mosquito, perceived ineffective prevention methods, and rural riverside environment made the disease seem inevitable. Despite this, children and rural riverside communities were identified as most vulnerable groups. Key findings suggested a lack of community cooperation in mosquito prevention due to an attitude that the government and health centre were responsible for disease control, and the belief that dengue cannot be prevented through individual actions alone. These were important barriers to community mosquito prevention efforts. The findings from this study provide novel insights into how perceptions of dengue control can impact prevention in an endemic country.
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Affiliation(s)
- Amy L Frank
- University of Birmingham Medical School, University of Birmingham, Birmingham, United Kingdom
| | - Emily R Beales
- University of Birmingham Medical School, University of Birmingham, Birmingham, United Kingdom
| | - Gilles de Wildt
- University of Birmingham Medical School, University of Birmingham, Birmingham, United Kingdom
| | | | - Laura L Jones
- Institute of Applied Health Research, University of Birmingham, Birmingham, United Kingdom
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Kosek MN, Mduma E, Kosek PS, Lee GO, Svensen E, Pan WKY, Olortegui MP, Bream JH, Patil C, Asayag CR, Sanchez GM, Caulfield LE, Gratz J, Yori PP. Plasma Tryptophan and the Kynurenine-Tryptophan Ratio are Associated with the Acquisition of Statural Growth Deficits and Oral Vaccine Underperformance in Populations with Environmental Enteropathy. Am J Trop Med Hyg 2016; 95:928-937. [PMID: 27503512 PMCID: PMC5062803 DOI: 10.4269/ajtmh.16-0037] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 06/14/2016] [Indexed: 01/22/2023] Open
Abstract
Early childhood enteric infections have adverse impacts on child growth and can inhibit normal mucosal responses to oral vaccines, two critical components of environmental enteropathy. To evaluate the role of indoleamine 2,3-dioxygenase 1 (IDO1) activity and its relationship with these outcomes, we measured tryptophan and the kynurenine–tryptophan ratio (KTR) in two longitudinal birth cohorts with a high prevalence of stunting. Children in rural Peru and Tanzania (N = 494) contributed 1,251 plasma samples at 3, 7, 15, and 24 months of age and monthly anthropometrics from 0 to 36 months of age. Tryptophan concentrations were directly associated with linear growth from 1 to 8 months after biomarker assessment. A 1-SD increase in tryptophan concentration was associated with a gain in length-for-age Z-score (LAZ) of 0.17 over the next 6 months in Peru (95% confidence interval [CI] = 0.11–0.23, P < 0.001) and a gain in LAZ of 0.13 Z-scores in Tanzania (95% CI = 0.03–0.22, P = 0.009). Vaccine responsiveness data were available for Peru only. An increase in kynurenine by 1 μM was associated with a 1.63 (95% CI = 1.13–2.34) increase in the odds of failure to poliovirus type 1, but there was no association with tetanus vaccine response. A KTR of 52 was 76% sensitive and 50% specific in predicting failure of response to serotype 1 of the oral polio vaccine. KTR was associated with systemic markers of inflammation, but also interleukin-10, supporting the association between IDO1 activity and immunotolerance. These results strongly suggest that the activity of IDO1 is implicated in the pathophysiology of environmental enteropathy, and demonstrates the utility of tryptophan and kynurenine as biomarkers for this syndrome, particularly in identifying those at risk for hyporesponsivity to oral vaccines.
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Affiliation(s)
- Margaret N Kosek
- Department of International Health, Johns Hopkins School of Public Health, Baltimore, Maryland
| | - Estomih Mduma
- Global Health Research Center, Haydom Lutheran Hospital, Manyara, Tanzania
| | | | - Gwenyth O Lee
- Department of Global Community Health and Behavioral Sciences, Tulane University, New Orleans, Louisiana
| | | | - William K Y Pan
- Duke Global Health Institute, Nicholas School of Environment, Duke University, Durham, North Carolina
| | - Maribel Paredes Olortegui
- Asociacion Benefica Proyectos de Informática, Salud, Medicina, y Agricultura (PRISMA), Iquitos, Peru
| | - Jay H Bream
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Crystal Patil
- Department of Women, Children, and Family Health Science, University of Illinois at Chicago College of Nursing, Chicago, Illinois
| | | | | | - Laura E Caulfield
- Department of International Health, Johns Hopkins School of Public Health, Baltimore, Maryland
| | - Jean Gratz
- Center for Global Health, University of Virginia, Charlottesville, Virginia
| | - Pablo Peñataro Yori
- Department of International Health, Johns Hopkins School of Public Health, Baltimore, Maryland
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Kosek M, Yori PP, Gilman RH, Vela H, Olortegui MP, Chavez CB, Calderon M, Bao JP, Hall E, Maves R, Burga R, Sanchez GM. Facilitated molecular typing of Shigella isolates using ERIC-PCR. Am J Trop Med Hyg 2012; 86:1018-25. [PMID: 22665611 DOI: 10.4269/ajtmh.2012.11-0671] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
To evaluate the performance of enterobacterial repetitive intergenic sequence-based polymerase chain reaction (ERIC-PCR) typing versus the current standard for the typing of Shigella pulsed gel electrophoresis (PFGE), we typed 116 Shigella isolates from a village in an endemic setting over a 20-month period using both methods. PFGE identified 37 pulse types and had a discrimination index of 0.925 (95% confidence interval = 0.830-1.00), whereas ERIC-PCR identified 42 types and had a discrimination index of 0.961 (95% confidence interval = 0.886-1.00). PFGE and ERIC-PCR showed a 90.4% correlation in the designation of isolates as clonal or non-clonal in pairwise comparisons. Both systems were highly reproducible and provided highly similar and supplementary data compared with serotyping regarding the transmission dynamics of shigellosis in this community. ERIC-PCR is considerably more rapid and inexpensive than PFGE and may have a complementary role to PFGE for initial investigations of hypothesized outbreaks in resource-limited settings.
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Affiliation(s)
- Margaret Kosek
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
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Asayag CR, Garay CR, Sanchez GM, Angeles CC, Baca CJ, Evans C, Yori PP, Kosek M. Eight year old with fever, hepatomegaly, and positive thick smear. Am J Trop Med Hyg 2008; 79:473. [PMID: 18840731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
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Asayag CR, Baca CJ, Sanchez GM, Yori PP, Garay CR, Evans C, Angeles CC, Kosek M. Eight Year Old with Fever, Hepatomegaly, and Positive Thick Smear. Am J Trop Med Hyg 2008. [DOI: 10.4269/ajtmh.2008.79.473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kosek M, Yori PP, Pan WK, Olortegui MP, Gilman RH, Perez J, Chavez CB, Sanchez GM, Burga R, Hall E. Epidemiology of highly endemic multiply antibiotic-resistant shigellosis in children in the Peruvian Amazon. Pediatrics 2008; 122:e541-9. [PMID: 18710884 PMCID: PMC6204332 DOI: 10.1542/peds.2008-0458] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVE Our goal was to estimate the impact of a Shigella vaccine in an area where shigellosis is endemic by characterizing the disease burden and antibiotic-resistance profiles of isolates and by determining the prevalence of Shigella flexneri serotypes. PATIENTS AND METHODS We conducted a 43-month-long prospective, community-based diarrheal disease surveillance in 442 children <72 months of age in the Peruvian Amazon between October 1, 2002, and April 15, 2006. RESULTS The incidence of diarrheal disease was 4.38 episodes per child-year. The incidence rate for shigellosis was 0.34 episodes per child-year in children <72 months of age and peaked in children between 12 and 23 months at 0.43 episodes per child-year. Maternal education at or beyond the primary grade level, piped water supply, weight-for-age z score, and improved water-storage practices were the most significant determinants of disease in this community with living conditions comparable to many rural areas in the developing world. CONCLUSIONS Children living in this region had a 20-fold higher rate of disease incidence detected by active surveillance as those recently estimated by passive detection. Most symptomatic disease was caused by S flexneri, although the diversity of serotypes will require a multivalent vaccine to have a significant impact on the burden of disease caused by shigellosis. Several other public health disease-control interventions targeted at water source and improved storage, nutritional interventions, and improved maternal education seem to have a greater impact than a univalent S flexneri 2a vaccine.
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Affiliation(s)
- Margaret Kosek
- Johns Hopkins School of Public Health, Department of International Health, 615 N Wolfe St, W 5515, Baltimore, MD 21205, USA.
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Yori PP, Kosek M, Gilman RH, Cordova J, Bern C, Chavez CB, Olortegui MP, Montalvan C, Sanchez GM, Worthen B, Worthen J, Leung F, Oré CV. Seroepidemiology of strongyloidiasis in the Peruvian Amazon. Am J Trop Med Hyg 2006; 74:97-102. [PMID: 16407351 PMCID: PMC1483914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023] Open
Abstract
A stool and serosurvey for Strongyloides stercoralis was conducted in a community in the Peruvian Amazon region. Strongyloidiasis stercoralis was identified in the stool of 69 (8.7%) of 792 participants. Six hundred nine sera were tested using by an enzyme-linked immunosorbent assay (ELISA), which had a sensitivity of 92% and a specificity of 94%; 442 (72%) were positive. In multivariable logistic regression models, having S. stercoralis in stool was associated with hookworm in the same specimen (odds ratio [OR] = 4.44, 95% confidence interval [CI] = 2.02-9.79), occasionally or never wearing shoes (OR = 1.89, 95% CI = 1.10-3.27), and increasing age (OR = 1.012 for each one-year increase, 95% CI = 1.00-1.03). Similarly, occasionally or never wearing shoes (OR = 1.54, 95% CI = 1.01-2.37) and increasing age (OR = 1.04 for each one-year increase, 95% CI = 1.02-1.06) were associated with an increased risk of a positive S. stercoralis ELISA result. The ELISA had a negative predictive value of 98% and is an excellent screening test for strongyloidiasis.
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Sanchez GM. For the sake of knowing... S D J Med 1999; 52:191-3. [PMID: 10419406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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