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Mengistu B, Liyew EF, Chernet M, Tasew G, Gomez SR, Maddren R, Collyer B, Anjulo U, Tamiru A, Forbes K, Mehari Z, Deribe K, Yadeta T, Salasibew M, Tollera G, Anderson R. Correction: Progress in controlling the transmission of schistosome parasites in Southern Ethiopia: the Geshiyaro Project in the Wolaita Zone. Parasit Vectors 2024; 17:158. [PMID: 38549079 PMCID: PMC10979624 DOI: 10.1186/s13071-024-06251-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/01/2024] Open
Affiliation(s)
- Birhan Mengistu
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK.
| | - Ewnetu Firdawek Liyew
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Melkie Chernet
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Geremew Tasew
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Santiago Rayment Gomez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK
| | - Rosie Maddren
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK
| | - Benjamin Collyer
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK
| | - Ufaysa Anjulo
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Addis Ababa, Ethiopia
| | - Adugna Tamiru
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Addis Ababa, Ethiopia
| | - Kathryn Forbes
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK
| | | | | | | | | | - Getachew Tollera
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Roy Anderson
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK
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Mengsitu B, Liyew EF, Chernet M, Tasew G, Gomez SR, Maddren R, Collyer B, Anjulo U, Tamiru A, Forbes K, Mehari Z, Deribe K, Yadeta T, Salasibew M, Tollera G, Anderson R. Progress in controlling the transmission of schistosome parasites in Southern Ethiopia: the Geshiyaro Project in the Wolaita Zone. Parasit Vectors 2024; 17:113. [PMID: 38448997 PMCID: PMC10919034 DOI: 10.1186/s13071-024-06156-1] [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: 09/04/2023] [Accepted: 01/22/2024] [Indexed: 03/08/2024] Open
Abstract
BACKGROUND This paper describes changes in the prevalence and intensity of schistosome parasite infections in a project integrating mass drug administration (MDA), water, sanitation, and hygiene (WaSH), and behavioral change interventions. METHODS The Geshiyaro Project comprises three intervention arms. Arm 1 is subdivided into "Arm 1 pilot" (one district) and Arm 1 (four other districts), both receiving integrated community-wide MDA with intensive WaSH interventions. Arm 2 involves 17 districts with community-wide MDA interventions, while Arm 3 serves as a control with school-based MDA interventions in three districts. A total of 150 individuals, stratified by age group, were randomly selected from each of the 45 sentinel sites. Arm sizes were 584 (Arm 1 pilot), 1636 (Arm 1), 2203 (Arm 2), and 2238 (Arm 3). Statistical tests were employed to compare infection prevalence and intensity across the different arms. RESULTS The prevalence of schistosome parasite infection ranged from 0% to 2.6% and from 1.7% to 25.7% across districts, employing the Kato-Katz (KK) and point-of-care circulating cathodic antigen (POC-CCA) diagnostics, respectively. The mean infection intensity level showed no marked difference between baseline and follow-up surveys when measured by KK, except in Arm 2 (t = 6.89, P < 0.0001). Infection prevalence decreased significantly in Arm 1 (t = 8.62, P < 0.0001), Arm 2 (t = 6.94, P < 0.0001), and Arm 3 (t = 8.83, P < 0.0001), but not in Arm 1 pilot (t = 1.69, P = 0.09) by POC-CCA, when trace was considered positive. The decrease was significant only in Arm 1 (t = 3.28, P = 0.0001) and Arm 2 (t = 7.62, P < 0.0001) when the trace was considered negative in POC-CCA. Arm 2 demonstrated a significant difference in difference (DID) compared to the control group, Arm 3, regardless of whether trace in POC-CCA was considered positive (DID = 3.9%, df = 8780, P = 0.025) or negative (DID = -5.2, df = 8780, P = 0.0004). CONCLUSIONS The prevalence of schistosomiasis was low when employing the KK diagnostic but moderate in some locations by the POC-CCA diagnostic. The infection level had decreased across all arms of the Geshiyaro study at mid-term of the 7-year project, but further efforts are needed to reduce the rate of parasite transmission based on the POC-CCA diagnostic scores.
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Affiliation(s)
- Birhan Mengsitu
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK.
| | - Ewnetu Firdawek Liyew
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Melkie Chernet
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Geremew Tasew
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Santiago Rayment Gomez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK
| | - Rosie Maddren
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK
| | - Benjamin Collyer
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK
| | - Ufaysa Anjulo
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Addis Ababa, Ethiopia
| | - Adugna Tamiru
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Addis Ababa, Ethiopia
| | - Kathryn Forbes
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK
| | | | | | | | | | - Getachew Tollera
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Roy Anderson
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, UK
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Rayment Gomez S, Maddren R, Liyew EF, Chernet M, Anjulo U, Tamiru A, Tollera G, Tasew G, Mengistu B, Collyer B, Forbes K, Anderson R. Spatial heterogeneity in mass drug administration from a longitudinal epidemiological study assessing transmission interruption of soil transmitted helminths in the Wolaita zone of southern Ethiopia (Geshiyaro Project). PLoS Negl Trop Dis 2024; 18:e0011947. [PMID: 38330143 PMCID: PMC10880954 DOI: 10.1371/journal.pntd.0011947] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 02/21/2024] [Accepted: 01/28/2024] [Indexed: 02/10/2024] Open
Abstract
OBJECTIVES Deworming programmes of soil-transmitted helminths are generally monitored and evaluated by aggregating drug coverage and infection levels at a district level. However, heterogeneity in drug coverage at finer spatial scales means indicators may remain above thresholds for elimination as a public health problem or of transmission in some areas. This paper aims to highlight the misleading information that aggregating data at larger spatial scales can have for programme decision making. METHODS Drug coverage data from the Geshiyaro project were compared at two spatial scales with reference to the World Health Organisation's targets. District (woreda) and village (kebele) level were compared. The association between infection levels and drug coverage was analysed by fitting a weighted least-squares function to the mean intensity of infection (eggs per gram of faeces) against drug coverage. RESULTS The data show clearly that when the evaluation of coverage is aggregated to the district level, information on heterogeneity at a finer spatial scale is lost. Infection intensity decreases significantly (p = 0.0023) with increasing drug coverage. CONCLUSION Aggregating data at large spatial scales can result in prematurely ceasing deworming, prompting rapid infection bounce-back. There is a strong need to define context-specific spatial scales for monitoring and evaluating intervention programmes.
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Affiliation(s)
- Santiago Rayment Gomez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Rosie Maddren
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Ewnetu Firdawek Liyew
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Melkie Chernet
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Ufaysa Anjulo
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Wolaita, Ethiopia
| | - Adugna Tamiru
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Wolaita, Ethiopia
| | - Getachew Tollera
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Geremew Tasew
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Birhan Mengistu
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Benjamin Collyer
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Kathryn Forbes
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Roy Anderson
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
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Roberts T, Keddie SH, Rattanavong S, Gomez SR, Bradley J, Keogh RH, Bärenbold O, Falconer J, Mens PF, Hopkins H, Ashley EA. Accuracy of the direct agglutination test for diagnosis of visceral leishmaniasis: a systematic review and meta-analysis. BMC Infect Dis 2023; 23:782. [PMID: 37946107 PMCID: PMC10636880 DOI: 10.1186/s12879-023-08772-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 06/29/2023] [Accepted: 10/30/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Parasitological investigation of bone marrow, splenic or lymph node aspirations is the gold standard for the diagnosis of visceral leishmaniasis (VL). However, this invasive test requires skilled clinical and laboratory staff and adequate facilities, and sensitivity varies depending on the tissue used. The direct agglutination test (DAT) is a serological test that does not need specialised staff, with just minimal training required. While previous meta-analysis has shown DAT to have high sensitivity and specificity when using parasitology as the reference test for diagnosis, meta-analysis of DAT compared to other diagnostic techniques, such as PCR and ELISA, that are increasingly used in clinical and research settings, has not been done. METHODS We conducted a systematic review to determine the diagnostic performance of DAT compared to all available tests for the laboratory diagnosis of human VL. We searched electronic databases including Medline, Embase, Global Health, Scopus, WoS Science Citation Index, Wiley Cochrane Central Register of Controlled Trials, Africa-Wide Information, LILACS and WHO Global Index. Three independent reviewers screened reports and extracted data from eligible studies. A meta-analysis estimated the diagnostic sensitivity and specificity of DAT. RESULTS Of 987 titles screened, 358 were selected for full data extraction and 78 were included in the analysis, reporting on 32,822 participants from 19 countries. Studies included were conducted between 1987-2020. Meta-analysis of studies using serum and DAT compared to any other test showed pooled sensitivity of 95% (95%CrI 90-98%) and pooled specificity of 95% (95%CrI 88-98%). Results were similar for freeze-dried DAT and liquid DAT when analysed separately. Sensitivity was lower for HIV-positive patients (90%, CrI 59-98%) and specificity was lower for symptomatic patients (70%, CrI 43-89%). When comparing different geographical regions, the lowest median sensitivity (89%, CrI 67-97%) was in Western Asia (five studies). CONCLUSIONS This systematic review and meta-analysis demonstrates high estimated pooled sensitivity and specificity of DAT for diagnosis of VL, although sensitivity and specificity were lower for different patient groups and geographical locations. This review highlights the lack of standardisation of DAT methods and preparations, and the lack of data from some important geographical locations. Future well-reported studies could provide better evidence to inform test implementation for different patient populations and use cases. PROSPERO REGISTRATION CRD42021240830.
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Affiliation(s)
- Tamalee Roberts
- Lao- Oxford-Mahosot Hospital- Wellcome Trust Research Unit, Mahosot Hospital, Mahosot Road, Vientiane, Lao People's Democratic Republic.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | | | - Sayaphet Rattanavong
- Lao- Oxford-Mahosot Hospital- Wellcome Trust Research Unit, Mahosot Hospital, Mahosot Road, Vientiane, Lao People's Democratic Republic
| | - Santiago Rayment Gomez
- Department of Infectious Disease Epidemiology, Faculty of Medicine, London Centre for Neglected Tropical Disease Research, St Marys Campus, Imperial College London, London, UK
| | - John Bradley
- London School of Hygiene & Tropical Medicine, London, UK
| | - Ruth H Keogh
- London School of Hygiene & Tropical Medicine, London, UK
| | | | - Jane Falconer
- London School of Hygiene & Tropical Medicine, London, UK
| | - Petra F Mens
- Department of Medical Microbiology, Experimental Parasitology Unit, Amsterdam University Medical Centers, Academic Medical Center at the University of Amsterdam, Amsterdam, The Netherlands
| | - Heidi Hopkins
- London School of Hygiene & Tropical Medicine, London, UK
| | - Elizabeth A Ashley
- Lao- Oxford-Mahosot Hospital- Wellcome Trust Research Unit, Mahosot Hospital, Mahosot Road, Vientiane, Lao People's Democratic Republic
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Maddren R, Phillips A, Rayment Gomez S, Forbes K, Collyer BS, Kura K, Anderson R. Individual longitudinal compliance to neglected tropical disease mass drug administration programmes, a systematic review. PLoS Negl Trop Dis 2023; 17:e0010853. [PMID: 37459369 PMCID: PMC10374057 DOI: 10.1371/journal.pntd.0010853] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 07/27/2023] [Accepted: 06/05/2023] [Indexed: 07/28/2023] Open
Abstract
Repeated distribution of preventative chemotherapy (PC) by mass drug administration forms the mainstay of transmission control for five of the 20 recognised neglected tropical diseases (NTDs); soil-transmitted helminths, schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. The efficiency of such programmes is reliant upon participants swallowing the offered treatment consistently at each round. This is measured by compliance, defined as the proportion of eligible participants swallowing treatment. Individually linked longitudinal compliance data is important for assessing the potential impact of MDA-based control programmes, yet this accurate monitoring is rarely implemented in those for NTDs. Longitudinal compliance data reported by control programmes globally for the five (PC)-NTDs since 2016 is examined, focusing on key associations of compliance with age and gender. PubMed and Web of Science was searched in January 2022 for articles written in English and Spanish, and the subsequent extraction adhered to PRISMA guidelines. Study title screening was aided by Rayyan, a machine learning software package. Studies were considered for inclusion if primary compliance data was recorded for more than one time point, in a population larger than 100 participants. All data analysis was conducted in R. A total of 89 studies were identified containing compliance data, 57 were longitudinal studies, of which 25 reported individually linked data reported by varying methods. The association of increasing age with the degree of systematic treatment was commonly reported. The review is limited by the paucity of data published on this topic. The varying and overlapping terminologies used to describe coverage (receiving treatment) and compliance (swallowing treatment) is reviewed. Consequently, it is recommended that WHO considers clearly defining the terms for coverage, compliance, and longitudinal compliance which are currently contradictory across their NTD treatment guidelines. This review is registered with PROSPERO (number: CRD42022301991).
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Affiliation(s)
- Rosie Maddren
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Anna Phillips
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
- FHI 360, Durham, North Carolina, United States of America
| | - Santiago Rayment Gomez
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Kathryn Forbes
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Benjamin S Collyer
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Klodeta Kura
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Roy Anderson
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
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Cross JH, Jarjou O, Mohammed NI, Gomez SR, Touray BJB, Kessler NJ, Prentice AM, Cerami C. Iron homeostasis in full-term, normal birthweight Gambian neonates over the first week of life. Sci Rep 2023; 13:10349. [PMID: 37365154 PMCID: PMC10293170 DOI: 10.1038/s41598-023-34592-z] [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: 12/30/2022] [Accepted: 05/04/2023] [Indexed: 06/28/2023] Open
Abstract
Human neonates elicit a profound hypoferremia which may protect against bacterial sepsis. We examined the transience of this hypoferremia by measuring iron and its chaperone proteins, inflammatory and haematological parameters over the first post-partum week. We prospectively studied term, normal weight Gambian newborns. Umbilical cord vein and artery, and serial venous blood samples up to day 7 were collected. Hepcidin, serum iron, transferrin, transferrin saturation, haptoglobin, c-reactive protein, α1-acid-glycoprotein, soluble transferrin receptor, ferritin, unbound iron-binding capacity and full blood count were assayed. In 278 neonates we confirmed the profound early postnatal decrease in serum iron (22.7 ± 7.0 µmol/L at birth to 7.3 ± 4.6 µmol/L during the first 6-24 h after birth) and transferrin saturation (50.2 ± 16.7% to 14.4 ± 6.1%). Both variables increased steadily to reach 16.5 ± 3.9 µmol/L and 36.6 ± 9.2% at day 7. Hepcidin increased rapidly during the first 24 h of life (19.4 ± 14.4 ng/ml to 38.9 ± 23.9 ng/ml) and then dipped (32.7 ± 18.4 ng/ml) before rising again at one week after birth (45.2 ± 19.1 ng/ml). Inflammatory markers increased during the first week of life. The acute postnatal hypoferremia in human neonates on the first day of life is highly reproducible but transient. The rise in serum iron during the first week of life occurs despite very high hepcidin levels indicating partial hepcidin resistance.Trial Registration: clinicaltrials.gov (NCT03353051). Registration date: November 27, 2017.
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Affiliation(s)
- James H Cross
- Medical Research Council Unit The Gambia at the London, School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia
| | - Ousman Jarjou
- Medical Research Council Unit The Gambia at the London, School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia
| | - Nuredin Ibrahim Mohammed
- Medical Research Council Unit The Gambia at the London, School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia
| | | | - Bubacarr J B Touray
- Medical Research Council Unit The Gambia at the London, School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia
| | - Noah J Kessler
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
| | - Andrew M Prentice
- Medical Research Council Unit The Gambia at the London, School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia
| | - Carla Cerami
- Medical Research Council Unit The Gambia at the London, School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia.
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Rayment Gomez S, Maddren R, Liyew EF, Chernet M, Anjulo U, Tamiru A, Mengitsu B, Forbes K, Collyer B, Salasibew M, Anderson R. Predisposition to soil-transmitted helminth reinfection after four rounds of mass drug administration: results from a longitudinal cohort in the Geshiyaro project, a transmission elimination feasibility study in the Wolaita zone of southern Ethiopia. Trans R Soc Trop Med Hyg 2023:7080902. [PMID: 36939014 DOI: 10.1093/trstmh/trad007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 02/01/2023] [Accepted: 02/23/2023] [Indexed: 03/21/2023] Open
Abstract
BACKGROUND Current WHO strategies for reaching soil-transmitted helminths (STH) elimination as a public health problem excludes treating certain adult populations in endemic areas, creating infection reservoirs that drive 'bounce back' of STH infection to pretreatment levels post-mass drug administration (MDA). Predisposition is a widespread, but poorly understood phenomena among helminth infections where individuals are predisposed to reinfection after repeated treatments. METHODS This analysis uses Geshiyaro project data, an STH control programme exploring transmission interruption by community-wide MDA and enhanced water, sanitation and hygiene during 2019-2023. Parasitological survey data from longitudinal cohorts are analysed using Kendall's Tau-b rank correlation to assess the evidence for predisposition to light or heavy infection between four consecutive rounds of MDA. RESULTS Correlation analyses revealed the strongest evidence for predisposition to heavy or light Ascaris lumbricoides infection was between survey 1 and 2 (Tau-b 0.29; p<0.001). Overall patterns were not observed for Trichuris trichiura or hookworm infections, however, some significant and notable correlations were recorded for some stratifications and time points. CONCLUSIONS Evidence for predisposition in endemic settings in southern Ethiopia with low STH prevalence suggests that more targeted approaches to MDA in those predisposed to infection may be a sensible control strategy if cheap, point of care diagnostics are available.
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Affiliation(s)
- Santiago Rayment Gomez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London W2 1NY, UK
| | - Rosie Maddren
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London W2 1NY, UK
| | - Ewnetu Firdawek Liyew
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ayat Zone 8, Ethiopia
| | - Melkie Chernet
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ayat Zone 8, Ethiopia
| | - Ufaysa Anjulo
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Wolaita, Ethiopia
| | - Adugna Tamiru
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Wolaita, Ethiopia
| | - Birhan Mengitsu
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London W2 1NY, UK
| | - Kathryn Forbes
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London W2 1NY, UK
| | - Benjamin Collyer
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London W2 1NY, UK
| | | | - Roy Anderson
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London W2 1NY, UK
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Landeryou T, Maddren R, Rayment Gomez S, Kalahasti S, Liyew EF, Chernet M, Mohammed H, Wuletaw Y, Truscott J, Phillips AE, Ower A, Forbes K, Anjulo U, Mengistu B, Tasew G, Salasibew M, Anderson R. Longitudinal monitoring of prevalence and intensity of soil-transmitted helminth infections as part of community-wide mass drug administration within the Geshiyaro project in the Bolosso Sore district, Wolaita, Ethiopia. PLoS Negl Trop Dis 2022; 16:e0010408. [PMID: 36121895 PMCID: PMC9521932 DOI: 10.1371/journal.pntd.0010408] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 04/12/2022] [Revised: 09/29/2022] [Accepted: 08/19/2022] [Indexed: 11/18/2022] Open
Abstract
Mass drug administration (MDA), targeted at school-aged children (SAC) is recommended by the World Health Organization for the control of morbidity induced by soil-transmitted helminth (STH) infection in endemic countries. However, MDA does not prevent reinfection between treatment rounds, and research suggests that only treating SAC will not be sufficient to interrupt transmission of STH. In countries with endemic infection, such as Ethiopia, the coverage, community-groups targeted, and rates of reinfection will determine how effective MDA is in suppressing transmission in the long-term. In this paper, individually-linked longitudinal data from three epidemiological STH surveys conducted between November 2018 and November 2020 in the Wolaita region of Ethiopia are analysed to determine how STH prevalence and intensity changes according to individual level treatment data collected over two rounds of MDA. This study demonstrates that while community-wide MDA successfully reduces overall infection intensity across the villages treated, the observed levels of non-compliance to treatment by individuals acts to maintain levels of parasite abundance whereby transmission interruption is not possible at to, despite reasonable levels of MDA coverage in the communities studied (ranging from 65% to 84% of the village populations). This quantifies with substantial data the often-postulated difference between coverage (accepting treatment) and compliance (swallowing of treatment), the latter impacting the former to a previously unquantified level. The paper highlights the need to focus treatment to partially treated, or never treated groups of individuals within existing community wide MDA control activities to interrupt the transmission of STH, and to reduce the basic reproductive number, R0, of the parasites to less than unity in value.
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Affiliation(s)
- Toby Landeryou
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
- * E-mail:
| | - Rosie Maddren
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Santiago Rayment Gomez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Suprabhath Kalahasti
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Ewnetu Firdawek Liyew
- Bacterial, Parasitic and Zoonotic Diseases Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Melkie Chernet
- Bacterial, Parasitic and Zoonotic Diseases Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Hussein Mohammed
- Bacterial, Parasitic and Zoonotic Diseases Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Yonas Wuletaw
- Bacterial, Parasitic and Zoonotic Diseases Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - James Truscott
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Anna E. Phillips
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Alison Ower
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Kathryn Forbes
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Ufaysa Anjulo
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Wolaita, Ethiopia
| | - Birhan Mengistu
- Children’s Investment fund Foundation, London, United Kingdom
| | - Geremew Tasew
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Wolaita, Ethiopia
| | | | - Roy Anderson
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
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9
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Cross J, Jarjou O, Mohammed N, Gomez SR, Touray BJB, Prentice A, Cerami C. Iron Homeostasis over the First Week of Life: A Prospective Cohort Study in Hospital-Delivered Gambian Neonates. Curr Dev Nutr 2020. [DOI: 10.1093/cdn/nzaa054_035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Objectives
Full-term newborns elicit an immediate postnatal hypoferremia at birth. We examined whether preterm and low birthweight babies are capable of a similar response. The transience of this innate defence in full-term babies was assessed by measuring iron, inflammatory and haematological parameters over the first postpartum week.
Methods
We conducted an observational study of 152 babies who were either preterm (>32 to <37weeks gestational age) and/or low birthweight (<2500 g) (PTB/LBW) and 278 term, normal-weight babies (FTB/NBW). Blood was sampled from the umbilical cord and matched venous blood samples were taken from all neonates between 6–24 hours after delivery. Term, normal-weight babies were then randomised to a second blood draw at 25–80 h (V2), 81–136 h (V3) or 137–192 h (V4). We measured haematological, iron and inflammatory markers in all samples.
Results
PTB/LBW and FTB/NBW babies decreased serum iron 3-fold within 12 h of postpartum life compared to cord blood (7.5 ± 4.5 vs 23.3 ± 7.1 ng/ml, P < 0.001, n = 425). Transferrin saturation showed a similar decline. C-reactive protein levels increased over 10-fold (P < 0.001) and hepcidin levels doubled (P < 0.001). No difference was observed in these responses between study groups. FTB/NBW newborns then steadily increased serum iron (16.5 ± 3.9 µmol/L) and TSAT (36.7 ± 9.2%) by V4 (P for trend <0.0001 for each). Hepcidin (45.2 ± 19.1 ng/ml) increased during this period (P for trend <0.0001), showing only a weak influence on serum iron and TSAT. Inflammatory markers increased from V1 to V4.
Conclusions
Premature and low birthweight babies mount a rapid postnatal hypoferremia equal to that in term babies. Data suggest that this hepcidin-mediated response is triggered by acute inflammation at birth. This evolved method of protection against septicaemia is transient, with a later increase in serum iron despite very high hepcidin. This indicates hepcidin resistance possibly caused by macrophage iron saturation. Pharmacological prolongation of hypoferremia might offer an ancillary tool in the arsenal against infection, however, it would need to overcome the hepcidin resistance we now report.
Funding Sources
Bill & Melinda Gates Foundation.
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Affiliation(s)
- James Cross
- Medical Research Council Unit The Gambia (MRCG) at LSHTM
| | - Ousman Jarjou
- Medical Research Council Unit The Gambia (MRCG) at LSHTM
| | | | | | | | | | - Carla Cerami
- Medical Research Council Unit The Gambia (MRCG) at LSHTM
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10
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Cross JH, Jarjou O, Mohammed NI, Rayment Gomez S, Touray BJB, Prentice AM, Cerami C. Early postnatal hypoferremia in low birthweight and preterm babies: A prospective cohort study in hospital-delivered Gambian neonates. EBioMedicine 2020; 52:102613. [PMID: 31981986 PMCID: PMC6992934 DOI: 10.1016/j.ebiom.2019.102613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 11/29/2019] [Accepted: 12/17/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Neonates, particularly those born preterm (PTB) and with low birthweight (LBW), are especially susceptible to bacterial and fungal infections that cause an estimated 225,000 deaths annually. Iron is a vital nutrient for the most common organisms causing septicaemia. Full-term babies elicit an immediate postnatal hypoferremia assumed to have evolved as an innate defence. We tested whether PTB and LBW babies are capable of the same response. METHODS We conducted an observational study of 152 babies who were either PTB (born ≥32 to <37 weeks gestational age) and/or LBW (<2500 g) (PTB/LBW) and 278 term, normal-weight babies (FTB/NBW). Blood was sampled from the umbilical cord vein and artery, and matched venous blood samples were taken from all neonates between 6-24 h after delivery. We measured haematological, iron and inflammatory markers. FINDINGS In both PTB/LBW and FTB/NBW babies, serum iron decreased 3-fold within 12 h of delivery compared to umbilical blood (7·5 ± 4·5 vs 23·3 ± 7·1 ng/ml, P < 0·001, n = 425). Transferrin saturation showed a similar decline with a consequent increase in unsaturated iron-binding capacity. C-reactive protein levels increased over 10-fold (P < 0·001) and hepcidin levels doubled (P < 0·001). There was no difference in any of these responses between PTB/LBW and FTB/NBW babies. INTERPRETATION Premature or low birthweight babies are able to mount a very rapid hypoferremia that is indistinguishable from that in normal term babies. The data suggest that this is a hepcidin-mediated response triggered by acute inflammation at birth, and likely to have evolved as an innate immune response against bacterial and fungal septicaemia. TRIAL REGISTRATION clinicaltrials.gov (NCT03353051). Registration date: November 27, 2017. FUNDING Bill & Melinda Gates Foundation (OPP1152353).
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Affiliation(s)
- James H Cross
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia
| | - Ousman Jarjou
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia
| | - Nuredin Ibrahim Mohammed
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia
| | | | - Bubacarr J B Touray
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia
| | - Andrew M Prentice
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia
| | - Carla Cerami
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Atlantic Boulevard, Fajara, P.O. Box 273, Banjul, The Gambia.
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11
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Gomez SR, Yuen CT, Asokanathan C, Douglas-Bardsley A, Corbel MJ, Coote JG, Parton R, Xing DKL. ADP-ribosylation activity in pertussis vaccines and its relationship to the in vivo histamine-sensitisation test. Vaccine 2007; 25:3311-8. [PMID: 17287049 DOI: 10.1016/j.vaccine.2007.01.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [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: 11/06/2006] [Revised: 12/20/2006] [Accepted: 01/03/2007] [Indexed: 10/23/2022]
Abstract
Pertussis toxin (PTx) is a major virulence factor produced by Bordetella pertussis. In its detoxified form (PTd), it is an important component of acellular pertussis vaccines although some residual PTx activity may likely be present because of the limitations of the detoxification processes used. Furthermore, different detoxification procedures have been shown to result in different amino acid side-chain modifications for the resulting PTd. The histamine-sensitisation test (HIST) in mice is currently used for the safety testing of these vaccines. However, an alternative test is needed because of large assay variability and ethical concerns. The ADP-ribosylation enzyme activity of PTx is thought to be the major factor responsible for the histamine-sensitising activity detected in vivo. In the present study, the ADP-ribosylation activity in different acellular pertussis-based combination vaccine formulations was measured and compared with reactivity in the HIST. The results indicated that different products showed differences in ADP-ribosylation activity and a level which would be significant in relation to the reactivity seen in the HIST could not be defined, except for vaccines that contain genetically detoxified PTx, which do not have enzymatic activity nor in vivo toxicity. Different detoxification procedures as well as formulation factors could contribute to this variation. Relying solely on the residual enzyme activity of PTx in vaccines containing chemically detoxified PTd may not fully reflect the in vivo reactivity observed by the HIST. Refinement of the in vitro test to include a step which monitors the B-subunit activity of PTx may provide a better correlation with the in vivo HIST.
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Affiliation(s)
- S R Gomez
- Division of Bacteriology, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, EN6 3QG, UK
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12
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Alvarado AA, Moreno-Gonzalez E, Gomez SR, Musella M, Loinaz SC, Gonzalez-Pinto AI, Garcia GI, Jimenez RC, Castellon PC, Rodriguez S. [Biliary stenosis in patients treated with liver transplantation. Diagnostic approach]. Ann Ital Chir 1995; 66:711-8. [PMID: 8948809] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Between April 1986 and August 1994, 393 orthotopic liver transplantation (OLT) have been performed at "12 de Octubre" Hospital. Among these ones we consider 274 OLT made in 223 adults and in 47 children (4 intraoperative deaths). The reconstruction of the biliary tract was performed with a choledocho-choledochostomy with T tube (CD-CD T) in 131 patients, a choledocho-choledochostomy without T tube or stent (CD-CD) in 75, a Roux-en-y-hepatico-jejunostomy (H-J) in 248, a hepatico-jejunostomy with stent (H-J St) in 13 and a choledocho-cholecisto-jejunostomy (CD-CC-J) in 3 patients. Thirthy six (13.3%) patients developed biliary complications (30 adults and 6 childrens). Fourteen (18.6%) occurred in CD-CD reconstruction and 13 (11.4%) in CD-CD T. The most common complications were leakage and stricture. Thirteen ERCP were performed in 12 patients (1 failed), all adults (CD-CD T: 3; CD-CD: 10). The main indication for ERCP was cholestasis and inability of non invasive methods ultrasound, scintigraphy and computerized tomography in determining the underlying etiology. ERCP was successful in all 12 patients: detecting strictures in 8, strictures + lithiasis in 1, stricture+lekage in 1 and leakage in 2. No complications were encountered after ERCP in our patients. ERCP is the method of choice in diagnosis of biliary complications in CD-CD biliary reconstruction.
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Affiliation(s)
- A A Alvarado
- Servicio de Cirugia General Digestiva y Trasplante de Organos Abdominales Jefe, Hospital Universitario 12 de Octubre, Madrid, España
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13
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Moreno GE, Garcia GI, González Pinto I, Gomez SR, Loinaz SC, Riaño CD, Maffettone V, Bercedo MJ, Perez-Cerdá F, Ibañez AJ. Results of orthotopic liver transplantation: a personal experience. Hepatogastroenterology 1992; 39:405-12. [PMID: 1459519] [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] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The authors report on their experience of 158 liver transplants performed on 135 patients. Nineteen underwent re-transplantation and four of these required a second re-transplantation; total number of re-transplantations: 23 (14.6%). Hepatic cirrhosis was the most common indication (50.6%), of which alcoholic cirrhosis was the most common type (32.5%). The authors briefly report on their operative techniques and the results of their procedures. The operative mortality (30 days) was 13.3% (18 out of 135 patients). Complications included nine cases of hepatic artery thrombosis (5.7%), four of arterial stenosis (2.5%), one case of portal venous stenosis (0.63%), four cases of post-operative portal venous thrombosis (2.5%), seven of biliary fistula (4.4%; five following choledochocholedochostomy and two following choledochojejunostomy), and two cases of common bile duct stenosis (1.3%). The actuarial survival rate at 48 months is 80%.
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Affiliation(s)
- G E Moreno
- Hospital Universitario 12 De Octubre, General and Digestive Surgery Service C, Madrid, Spain
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14
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Gomez SR, Parker RA, Dosman JA, McDuffie HH. Respiratory health effects of alkali dust in residents near desiccated Old Wives Lake. Arch Environ Health 1992; 47:364-9. [PMID: 1444599 DOI: 10.1080/00039896.1992.9938376] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Several years of drought have contributed to the desiccation of Old Wives Lake, a shallow, alkaline lake in southern Saskatchewan. The prevailing northwest wind, which blows across the 177-km2 dry lake bed, has generated airborne sodium sulfate, silt, and clay. Residents have reported nasal, eye, and respiratory irritation. A cross-sectional design that included 300 controls and 300 exposed subjects elucidated the potential adverse respiratory health effects of exposure to blowing alkali salt and dust. An increased prevalence of current cough, current wheeze, chronic cough, chronic wheeze, chronic eye irritation, and chronic nasal irritation was identified in the exposed population. Smoking-adjusted odds ratios were consistent with the prevalence ratios. Lung function did not differ between the exposed and the control populations. Rainfall during the study period reduced airborne dust levels and may have precluded demonstration of previously reported adverse effects.
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Affiliation(s)
- S R Gomez
- Centre for Agricultural Medicine, University of Saskatchewan, Saskatoon, Canada
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Abstract
The idea that increases in airways responsiveness--either as a result of exposure to cigarette smoke and/or pre-existing increases in bronchial responsiveness, possibly genetically mediated--might be causal in the pathogenesis of the development of COPD in cigarette smokers presents an attractive hypothesis. The fact that a relatively small proportion of cigarette smokers develop COPD begs for specific susceptibilities as an explanation of selective pathogenesis. In our view, the evidence for modest increases in airways responsiveness in cigarette smokers who do not have asthma or allergies is convincing. Such increases in bronchial responsiveness are modest when compared to patients with asthma and may have a different mechanism. However, the demonstration by Verma et al that two types of patients with cigarette smoke-induced COPD, "bronchitis" patients and "emphysematous" patients, have virtually identical alterations in bronchial responsiveness, and that these alterations appear to be a function of airways caliber, has led us to believe that the changes in airways tone in patients with COPD may be reflective more of changes in airways geometry imposed by the development of disease rather than a measurement of a risk factor in the development of COPD. Of the epidemiologic studies that have emerged throughout the 1980s, problems of possible inclusion of asthmatic subjects in the study groups and of baseline airflow rates as a function of bronchial responsiveness have limited the ability of data to implicate increases in airways responsiveness as a risk factor in the development of COPD.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J A Dosman
- Department of Medicine, University of Saskatchewan, Saskatoon, Canada
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