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Moon J, Yoo H. Misdiagnosis in occupational and environmental medicine: a scoping review. J Occup Med Toxicol 2021; 16:33. [PMID: 34429147 PMCID: PMC8383455 DOI: 10.1186/s12995-021-00325-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 08/11/2021] [Indexed: 11/21/2022] Open
Abstract
Introduction There has been no comprehensive review for misdiagnosis in Occupational and Environmental Medicine (OEM). The possible ramifications of an occupational disease (OD) or an environmental disease (ED) misdiagnosis are not just confined to the individual case but may extend to others exposed to the occupational or environmental hazard. Therefore, a comprehensive scoping review of published literature is imperative for understanding the nature of misdiagnoses in OEM. Methods A medical librarian searched MEDLINE (PubMed), EMBASE, and the Cochrane Library (on 06 November 2020). All collected OEM misdiagnoses were classified based on 2 conceptual frameworks, the typical framework, and the causation model. The distribution of misdiagnosis across each medical specialty, each diagnostic step of the typical framework and the causation model, and false-negative and false-positive were summarized. Results A total of 79 articles were included in the scoping review. For clinical specialty, pulmonology (30 articles) and dermatology or allergy (13 articles) was most frequent and second-most frequent, respectively. For each disease, occupational and environmental interstitial lung diseases, misdiagnosed as sarcoidosis (8 articles), and other lung diseases (8 articles) were most frequent. For the typical framework, the most vulnerable step was the first step, evidence of a disease (38 articles). For the causation model, the first step, knowledge base, was the most vulnerable step (42 articles). For reported articles, the frequency of false-negative (55 articles) outnumbered the frequency of false-positive (15 articles). Discussion In OEM, compared to general medicine, causal misdiagnosis associated with the probability of causation is also important. For making a diagnosis in OEM, a knowledge base about possible ODs and EDs is essential. Because of this reason, the education and training of treating physicians for common ODs and EDs are important. For ODs and EDs, various intentional behaviors of stakeholders should be considered. This scoping review might contribute to the improvement of understanding for misdiagnosis in OEM. Supplementary Information The online version contains Supplementary theoretical review and Supplementary materials available at 10.1186/s12995-021-00325-z.
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Affiliation(s)
- Jinyoung Moon
- Department of Environmental Health Science, Graduate School of Public Health, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08826, South Korea. .,Department of Occupational and Environmental Medicine, Seoul Saint Mary's Hospital, Banpo-daero 222, Seocho-gu, Seoul, 06591, South Korea.
| | - HyeKyoung Yoo
- Department of Environmental Health Science, Graduate School of Public Health, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08826, South Korea
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Knight D, Ehrlich R, Cois A, Fielding K, Grant AD, Churchyard G. Predictors of silicosis and variation in prevalence across mines among employed gold miners in South Africa. BMC Public Health 2020; 20:829. [PMID: 32487111 PMCID: PMC7268682 DOI: 10.1186/s12889-020-08876-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 05/07/2020] [Indexed: 01/15/2023] Open
Abstract
Background The stated intention to eliminate silicosis from the South African goldmining industry as well as current programmes to find and compensate ex-miners with silicosis require an understanding of variation in silicosis prevalence across the industry. We aimed to identify the predictors of radiological silicosis in a large sample of working miners across gold mines in South Africa. Methods Routine surveillance chest radiographs were collected from 15 goldmine “clusters” in a baseline survey undertaken in preparation for a separate tuberculosis isoniazid prophylaxis trial. All images were read for silicosis by a health professional experienced in using the International Labour Organisation (ILO) classification. Profusion thresholds of > 1/0 and > 1/1 were used. Demographic and occupational information was obtained by questionnaire. Predictors of silicosis were examined in a multivariable logistic regression model, including age, gender, racial ascription, country of origin, years since starting mine employment, mine shaft, skill category, underground work status and tuberculosis. Results The crude silicosis prevalence at ILO > 1/1 was 3.8% [95% confidence interval (CI) 3.5–4.1%]. The range across mine shafts was 0.8–6.9%. After adjustment for covariates, the interquartile range across shafts was reduced from 2.4 to 1.2%. Black miners [adjusted odds ratio (aOR) 2.8; 95% CI 1.1–7.2] and miners in full-time underground work (aOR 2.1; 95% CI 1.3–3.4) had substantially elevated odds of silicosis, while workers from Mozambique had lower odds (aOR 0.54; 95% CI 0.38–0.77). Silicosis odds rose sharply with both age and years since starting in the industry (p for linear trend < 0.005), with 95.5% of affected miners having > 15 years since first exposure and 2.2% < 10 years. Conclusions In surveillance of silicosis in working gold miners time since first exposure remains a powerful predictor. Age appears to be an independent predictor, while the detection of radiological silicosis in short-service miners requires attention. Public risk reporting by mines should include factors bearing on silicosis prevalence, specifically dust concentrations, with independent verification. Studies of silicosis and tuberculosis in ex-miners are needed, supported by an accessible electronic database of the relevant medical and dust exposure records of all gold miners.
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Affiliation(s)
- Dave Knight
- International SOS, Singapore, Singapore. .,Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, PO Box 43915, Scarborough, Cape Town, 7975, South Africa.
| | - Rodney Ehrlich
- Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, PO Box 43915, Scarborough, Cape Town, 7975, South Africa
| | - Annibale Cois
- Burden of Disease Research Unit, South African Medical Research Council, Parow Valley, South Africa.,Division of Epidemiology and Biostatistics, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
| | - Katherine Fielding
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.,London School of Hygiene and Tropical Medicine, London, UK
| | - Alison D Grant
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.,London School of Hygiene and Tropical Medicine, London, UK.,Africa Health Research Institute, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| | - Gavin Churchyard
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.,London School of Hygiene and Tropical Medicine, London, UK.,The Aurum Institute, Johannesburg, South Africa
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Abstract
The purpose of this commentary is to bring the neglected phenomenon of subradiological silicosis and its implications to the attention of readers. We define subradiological silicosis as silicosis detectable on pathological examination of lung tissue but not visible radiologically. For extent of the phenomenon, we draw on a study using a large South African autopsy database of deceased miners and chest radiographs taken in life. At an International Labour Organization threshold of >1/0 only 43% of all pathologically detected cases were detected on chest radiograph, and only 62% of those classified on pathology as "moderate or marked" silicosis. Subradiological silicosis has a number of implications for research and practice: for dose-response studies of silicosis; for studies of the relationship between silica and conditions such as tuberculosis, lung cancer, and autoimmune disease, including the mechanistic role of fibrogenesis; for prognostication in silica exposed workers; and for workers' compensation criteria.
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Affiliation(s)
- Rodney Ehrlich
- Centre for Occupational and Environmental Health Research; School of Public Health and Family Medicine; University of Cape Town; Cape Town South Africa
| | - Jill Murray
- School of Public Health; University of the Witwatersrand; Johannesburg South Africa
| | - David Rees
- National Institute for Occupational Health; and School of Public Health; University of the Witwatersrand; Johannesburg South Africa
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Mandrioli D, Schlünssen V, Ádám B, Cohen RA, Colosio C, Chen W, Fischer A, Godderis L, Göen T, Ivanov ID, Leppink N, Mandic-Rajcevic S, Masci F, Nemery B, Pega F, Prüss-Üstün A, Sgargi D, Ujita Y, van der Mierden S, Zungu M, Scheepers PTJ. WHO/ILO work-related burden of disease and injury: Protocol for systematic reviews of occupational exposure to dusts and/or fibres and of the effect of occupational exposure to dusts and/or fibres on pneumoconiosis. ENVIRONMENT INTERNATIONAL 2018; 119:174-185. [PMID: 29958118 DOI: 10.1016/j.envint.2018.06.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 05/20/2018] [Accepted: 06/06/2018] [Indexed: 05/18/2023]
Abstract
BACKGROUND The World Health Organization (WHO) and the International Labour Organization (ILO) are developing a joint methodology for estimating the national and global work-related burden of disease and injury (WHO/ILO joint methodology), with contributions from a large network of experts. In this paper, we present the protocol for two systematic reviews of parameters for estimating the number of deaths and disability-adjusted life years attributable to pneumoconiosis from occupational exposure to dusts and/or fibres, to inform the development of the WHO/ILO joint methodology. OBJECTIVES We aim to systematically review studies on occupational exposure to dusts and/or fibres (Systematic Review 1) and systematically review and meta-analyse estimates of the effect of occupational exposure to dusts and/or fibres on pneumoconiosis (Systematic Review 2), applying the Navigation Guide systematic review methodology as an organizing framework. DATA SOURCES Separately for Systematic Reviews 1 and 2, we will search electronic academic databases for potentially relevant records from published and unpublished studies, including Medline, EMBASE, Web of Science and CISDOC. We will also search electronic grey literature databases, Internet search engines and organizational websites; hand-search reference list of previous systematic reviews and included study records; and consult additional experts. STUDY ELIGIBILITY AND CRITERIA We will include working-age (≥15 years) study participants in the formal and informal economy in any WHO and/or ILO Member State but exclude children (<15 years) and unpaid domestic workers. Eligible risk factors will be dusts and/or fibres from: (i) asbestos; (ii) silica; and/or (iii) coal (defined as pure coal dust and/or dust from coal mining). Included outcomes will be (i) asbestosis; (ii) silicosis; (iii) coal worker pneumoconiosis; and (iv) unspecified pneumoconiosis. For Systematic Review 1, we will include quantitative prevalence studies of occupational exposure to dusts and/or fibres (i.e. no versus any exposure) stratified by country, sex, age and industrial sector or occupation. For Systematic Review 2, we will include randomized controlled trials, cohort studies, case-control studies and other non-randomized intervention studies with an estimate of any occupational exposure to dusts and/or fibres on the prevalence of, incidence of or mortality due to pneumoconiosis, compared with the theoretical minimum risk exposure level of no exposure. STUDY APPRAISAL AND SYNTHESIS METHODS At least two review authors will independently screen titles and abstracts against the eligibility criteria at a first stage and full texts of potentially eligible records at a second stage, followed by extraction of data from qualifying studies. At least two review authors will assess risk of bias and the quality of evidence, using the most suited tools currently available. For Systematic Review 2, if feasible, we will combine relative risks using meta-analysis. We will report results using the guidelines for accurate and transparent health estimates reporting (GATHER) for Systematic Review 1 and the preferred reporting items for systematic reviews and meta-analyses guidelines (PRISMA) for Systematic Review 2. PROSPERO REGISTRATION NUMBER CRD42018084131.
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Affiliation(s)
- Daniele Mandrioli
- Cesare Maltoni Cancer Research Center, Ramazzini Institute, Bologna, Italy.
| | - Vivi Schlünssen
- Aarhus University, Aarhus, Denmark; National Research Center for the Working Environment, Copenhagen, Denmark.
| | | | - Robert A Cohen
- Feinberg School of Medicine, Northwestern University, Chicago, IL, United States.
| | - Claudio Colosio
- Department of Health Sciences, University of Milano, Milano, Italy; International Centre for Rural Health, San Paolo Hospital, Milano, Italy.
| | - Weihong Chen
- Department of Occupational & Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | | | | | - Thomas Göen
- University of Erlangen-Nuremberg, Erlangen, Germany.
| | - Ivan D Ivanov
- Department of Public Health, Environmental and Social Determinants of Health, World Health Organization, Geneva, Switzerland.
| | - Nancy Leppink
- Labour Administration, Labour Inspection and Occupational Safety and Health Branch, International Labour Organization, Geneva, Switzerland.
| | | | - Federica Masci
- Department of Health Sciences, University of Milano, Milano, Italy.
| | | | - Frank Pega
- Department of Public Health, Environmental and Social Determinants of Health, World Health Organization, Geneva, Switzerland.
| | - Annette Prüss-Üstün
- Department of Public Health, Environmental and Social Determinants of Health, World Health Organization, Geneva, Switzerland.
| | | | - Yuka Ujita
- Labour Administration, Labour Inspection and Occupational Safety and Health Branch, International Labour Organization, Geneva, Switzerland.
| | | | - Muzimkhulu Zungu
- National Institute for Occupational Health, South Africa, Johannesburg, Gauteng Province, South Africa.
| | - Paul T J Scheepers
- Radboud Institute for Health Sciences, Radboudumc, Nijmegen, the Netherlands.
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Knight D, Ehrlich R, Fielding K, Jeffery H, Grant A, Churchyard G. Trends in silicosis prevalence and the healthy worker effect among gold miners in South Africa: a prevalence study with follow up of employment status. BMC Public Health 2015; 15:1258. [PMID: 26686997 PMCID: PMC4684919 DOI: 10.1186/s12889-015-2566-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 12/03/2015] [Indexed: 11/28/2022] Open
Abstract
Background Given the intimate association between silicosis and tuberculosis, understanding the epidemiology of the South African gold mining industry silicosis epidemic is essential to current initiatives to control both silicosis and tuberculosis in this population, one of the most heavily affected globally. The study’s objectives were to compare the prevalence of silicosis among working black gold miners in South Africa during 2004–2009 to that of previous studies, including autopsy series, and to analyse the influence of silicosis and/or tuberculosis on exiting employment. Methods Routine chest radiographs from a cohort of gold miners were read for silicosis by an experienced reader (I), and a subset re-read by a B-trained reader (II). Two methods of presenting the readings were used. Additionally, with baseline status of silicosis and previous or active tuberculosis as predictors, survival analysis examined the probability of exiting the workforce for any reason during 2006–2011. Results Reader I read 11 557 chest radiographs and reader II re-read 841. Overall, silicosis prevalence (ILO ≥1/0: 5.7 and 6.2 % depending on reader method) was similar to the age adjusted prevalence found in a large study in 1984 (5.0 %). When comparison was restricted to a single mine shaft previously studied in 2000, a decline in prevalence (ILO ≥1/1) was suggested for one of the reading methods (duration adjusted 20.5 % vs. 13.0 % in the current study). These findings are discordant with a long-term rising autopsy prevalence of silicosis over this period. Overall, relative to miners with neither disease, the adjusted hazard ratio for exiting employment during the follow-up period was 1.54 for baseline silicosis [95 % confidence interval (CI) 1.17, 2.04], 1.71 for tuberculosis (95 % CI 1.51, 1.94) and 1.53 for combined disease (95 % CI 1.20, 1.96). Conclusions This study found, a) there was no significant decline in overall silicosis prevalence among working black miners in the South African gold mining industry between 1984 and 2004–2009, and b) a possible decline at one mine shaft more recently. In the absence of evidence of declining respirable silica concentrations between the 1980s and 2000s, the trends found are plausibly due to a healthy worker survivor effect, which may be accelerating. Electronic supplementary material The online version of this article (doi:10.1186/s12889-015-2566-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- David Knight
- Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa. .,International SOS, Singapore, Singapore.
| | - Rodney Ehrlich
- Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa.
| | | | - Hannah Jeffery
- London School of Hygiene and Tropical Medicine, London, United Kingdom.
| | - Alison Grant
- London School of Hygiene and Tropical Medicine, London, United Kingdom.
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Vynnycky E, Sumner T, Fielding KL, Lewis JJ, Cox AP, Hayes RJ, Corbett EL, Churchyard GJ, Grant AD, White RG. Tuberculosis control in South African gold mines: mathematical modeling of a trial of community-wide isoniazid preventive therapy. Am J Epidemiol 2015; 181:619-32. [PMID: 25792607 PMCID: PMC4388015 DOI: 10.1093/aje/kwu320] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 10/16/2014] [Indexed: 01/22/2023] Open
Abstract
A recent major cluster randomized trial of screening, active disease treatment, and mass isoniazid preventive therapy for 9 months during 2006-2011 among South African gold miners showed reduced individual-level tuberculosis incidence but no detectable population-level impact. We fitted a dynamic mathematical model to trial data and explored 1) factors contributing to the lack of population-level impact, 2) the best-achievable impact if all implementation characteristics were increased to the highest level achieved during the trial ("optimized intervention"), and 3) how tuberculosis might be better controlled with additional interventions (improving diagnostics, reducing treatment delay, providing isoniazid preventive therapy continuously to human immunodeficiency virus-positive people, or scaling up antiretroviral treatment coverage) individually and in combination. We found the following: 1) The model suggests that a small proportion of latent infections among human immunodeficiency virus-positive people were cured, which could have been a key factor explaining the lack of detectable population-level impact. 2) The optimized implementation increased impact by only 10%. 3) Implementing additional interventions individually and in combination led to up to 30% and 75% reductions, respectively, in tuberculosis incidence after 10 years. Tuberculosis control requires a combination prevention approach, including health systems strengthening to minimize treatment delay, improving diagnostics, increased antiretroviral treatment coverage, and effective preventive treatment regimens.
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Affiliation(s)
- Emilia Vynnycky
- Correspondence to Dr. Emilia Vynnycky, Statistics, Modelling and Economics Department, Public Health England, 61 Colindale Avenue, London NW9 5EQ, United Kingdom (e-mail: or )
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Abstract
The year 2011 marked the centenary of compensation legislation for miners' lung disease in South Africa. This commentary aims to demonstrate that the current compensation system does not serve its intended beneficiaries, particularly the large population of former gold miners affected by high rates of silicosis and tuberculosis. The system has a complex legislative history, reflecting contending political, and economic forces, and characterized by racial discrimination. The financial basis of the system is currently in crisis owing to historical underfunding and failure to take into account the mounting burden of disease among black former miners. The real value of compensation awards fell sharply between 1973 and 1993, only partly recovering in recent years. Barriers to claiming benefits, particularly by black former miners who know little about the process, have been extensively documented. Integration of miners' compensation into general workers' compensation has been mooted since the 1980s but has stalled, owing to the high cost of closing the gap between the mostly inferior financial benefits under the mining legislation and those available under workers' compensation legislation. A recent constitutional court decision has opened the way for unprecedented civil litigation against the gold mining industry for silicosis, adding to the pressure for reform. A number of changes are called for: harmonization of financial benefits with retention of certain of the special arrangements for miner claims, a regional cross-border system of medical examination points for former miners, education of miners about the system, and some degree of privatization of claims processing.
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Affiliation(s)
- Rodney Ehrlich
- Centre for Occupational and Environmental Health Research, School of Public Health and Family Medicine, University of Cape Town, South Africa.
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Change of exposure response over time and long-term risk of silicosis among a cohort of Chinese pottery workers. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2011; 8:2923-36. [PMID: 21845166 PMCID: PMC3155337 DOI: 10.3390/ijerph8072923] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 07/06/2011] [Accepted: 07/06/2011] [Indexed: 01/09/2023]
Abstract
An analysis was conducted on a cohort of Chinese pottery workers to estimate the exposure-response relationship between respirable crystalline silica dust exposure and the incidence of radiographically diagnosed silicosis, and to estimate the long-term risk of developing silicosis until the age of 65. The cohort comprised 3,250 employees with a median follow-up duration of around 37 years. Incident cases of silicosis were identified via silicosis registries (Chinese X-ray stage I, similar to International Labor Organisation classification scheme profusion category 1/1). Individual exposure to respirable crystalline silica dust was estimated based on over 100,000 historical dust measurements. The association between dust exposure, incidence and long-time risk of silicosis was quantified by Poisson regression analysis adjusted for age and smoking. The risk of silicosis depended not only on the cumulative respirable crystalline silica dust exposures, but also on the time-dependent respirable crystalline silica dust exposure pattern (long-term average concentration, highest annual concentration ever experienced and time since first exposure). A long-term "excess" risk of silicosis of approximately 1.5/1,000 was estimated among workers with all annual respirable crystalline silica dust concentration estimates less than 0.1 mg/m(3), using the German measurement strategy. This study indicates the importance of proper consideration of exposure information in risk quantification in epidemiological studies.
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Nelson G, Girdler-Brown B, Ndlovu N, Murray J. Three decades of silicosis: disease trends at autopsy in South African gold miners. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:421-426. [PMID: 20194070 PMCID: PMC2854773 DOI: 10.1289/ehp.0900918] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Accepted: 11/23/2009] [Indexed: 05/28/2023]
Abstract
BACKGROUND Eliminating silicosis is a priority of the International Labour Organization and the World Health Organization. Prevalence is particularly high in developing countries. OBJECTIVES We describe trends in silicosis among South African gold miners who had had an autopsy between 1975 and 2007 and quantify the contributions of age at autopsy and employment duration to these trends. METHODS South African miners and ex-miners are eligible for autopsy examination for occupational lung disease, regardless of the clinical cause of death, and the families of deceased mine workers may receive compensation from the government of South Africa. Miners who died from external causes and who had been employed in the gold mines for > 1 year were stratified by population group because of differences in exposure, patterns of employment, and autopsy referral patterns. We extracted data from PATHAUT (Pathology Automation System) and used Stata 10 to estimate trends in relative proportions of silicosis that were standardized for age and employment duration. RESULTS The crude proportion of silicosis for white miners was six times that of black miners in 1975. By 2007, it was 1.5 times higher for black miners. The proportion of miners with silicosis increased from 0.03 to 0.32 for black miners and from 0.18 to 0.22 for white miners. The increase can be explained by increasing age and employment duration for white miners. For black miners, it can be only partly explained by these two factors. CONCLUSION As miners continue to age and work for longer periods, the burden of silicosis will continue to rise. South Africa is committed to global efforts to eliminate silicosis by 2030. The autopsy database allows for disease surveillance, which is necessary to monitor the success of this initiative.
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Affiliation(s)
- Gill Nelson
- National Institute for Occupational Health, National Health Laboratory Service, Johannesburg, South Africa.
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10
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Vennervald BJ, Kenty L, Butterworth AE, Kariuki CH, Kadzo H, Ireri E, Amaganga C, Kimani G, Mwatha J, Otedo A, Booth M, Ouma JH, Dunne DW. Detailed clinical and ultrasound examination of children and adolescents in a Schistosoma mansoni endemic area in Kenya: hepatosplenic disease in the absence of portal fibrosis. Trop Med Int Health 2004; 9:461-70. [PMID: 15078264 DOI: 10.1111/j.1365-3156.2004.01215.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hepatosplenic schistosomiasis involving organomegaly, portal fibrosis and portal hypertension has been observed in autopsy studies. Here, we have tested the hypothesis that hepatosplenic disease including organomegaly and markers of increased portal pressure can occur in school aged children in the absence of fibrosis. A case-only study of 96 children aged 7-20 years defined by ultrasound detectable hepatomegaly was undertaken in Makueni district, Kenya. A novel method of clinical examination that involved a consensus scoring by three or four examiners was used to classify children as presenting with severe or moderate hepatosplenic disease after palpation of livers and spleens. Ultrasound examination of livers and spleens was based on the Niamey protocol. Clinical measurements included spleen enlargement along the mid-clavicular and mid-axillary lines, liver enlargement along the mid-sternal (MSL) and mid-clavicular lines, as well as organ consistency. The clinical examination indicated that 9% and 60% of the children had severe or moderate hepatosplenomegaly, respectively. Amongst egg-positive children, all clinical measurements, except MSL liver enlargement, correlated with egg count, as did portal vein diameter, spleen length and liver length measured by ultrasound. Peri-portal fibrosis was not observed in any child, whereas 28% of the children were classified as having increased portal pressure according to World Health Organization criteria. There was no effect of malaria parasitaemia or hepatitis seropositvity on any of the observed parameters. These results indicate that hepatosplenic disease in school-aged children attributable to S. mansoni infection, involving hepatosplenomegaly and increased portal vein diameter, can occur in the absence of peri-portal fibrosis.
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Corbett EL, Mozzato-Chamay N, Butterworth AE, De Cock KM, Williams BG, Churchyard GJ, Conway DJ. Polymorphisms in the tumor necrosis factor-alpha gene promoter may predispose to severe silicosis in black South African miners. Am J Respir Crit Care Med 2002; 165:690-3. [PMID: 11874815 DOI: 10.1164/ajrccm.165.5.2010050] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Susceptibility to silicosis is in part genetically determined. Polymorphisms in the promoter region of tumor necrosis factor (TNF)-alpha, a cytokine with a central role in the pathophysiology of silicosis, have been associated with predisposition to several infectious and inflammatory diseases. Polymorphisms at positions -308, -238, and -376 in the TNF-alpha promoter region were compared in nine patients with severe silicosis with International Labour Office (ILO) grade 3 nodularity, 112 patients with less severe silicosis (ILO grades 1/1 to 2/2), and 120 black South African gold miners without silicosis (ILO grades 0/0) in an age-frequency-matched case- control study. There were no significant differences between miners with less severe silicosis and controls at any loci in the TNF-alpha promoter region, but miners with severe silicosis were significantly more likely than controls to have -238A (33% versus 6%, Fisher's exact p value = 0.022) and -376A (33% versus 5%, Fisher's exact p value = 0.016). These alleles were in linkage disequilibrium (p < 0.001), and so were not independent. The association remained significant (Fisher's exact p values = 0.011 and 0.011, respectively) when analysis was limited to the majority tribe (Basotho), which included all subjects with severe silicosis. Subjects with severe silicosis were also significantly more likely to have the -308A allele (Fisher's exact p value = 0.034), but this result was confounded by ethnicity and was not significant within Basotho tribe members (Fisher's exact p value = 0.15). TNF-alpha promoter polymorphisms are associated with severe, but not less severe, silicosis in this population. A predominant effect on disease severity, rather than on disease frequency, appears to be a general feature of promoter polymorphism in diseases in which TNF-alpha has a critical role.
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Affiliation(s)
- Elizabeth L Corbett
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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Pneumoconiosis in Coal Workers: Cellular Concepts of Dust-Induced Lung Injury, Radiographic Diagnosis, and Pulmonary Infections With Mycobacteria. ACTA ACUST UNITED AC 2001. [DOI: 10.1097/00045413-200101000-00003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Corbett EL, Churchyard GJ, Clayton TC, Williams BG, Mulder D, Hayes RJ, De Cock KM. HIV infection and silicosis: the impact of two potent risk factors on the incidence of mycobacterial disease in South African miners. AIDS 2000; 14:2759-68. [PMID: 11125895 DOI: 10.1097/00002030-200012010-00016] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the combined effects of HIV infection and silicosis on mycobacterial disease. DESIGN AND SETTING A retrospective cohort of 1374 HIV-positive and 2648 HIV-negative miners who attended a South African gold mining hospital and primary health clinics. PARTICIPANTS Miners who had been tested for HIV, with consent, at primary health clinics during 1991-1996, predominantly because of a symptomatic sexually transmitted disease. RESULTS Tuberculosis (TB) incidence was 4.9 and 1.1 per 100 person-years in HIV-positive and HIV-negative miners respectively. The incidence of Mycobacterium kansasii disease was also high (0.32 and 0.10 per 100 person-years, respectively). Silicosis was highly prevalent, implying inadequate dust control, and was a significant TB risk factor among both HIV-positive and HIV-negative men (adjusted incidence rate ratios 1.4-2.5 according to radiological severity). The data were consistent with the risks of silicosis and HIV combining multiplicatively, but did not fit an additive model. The incidence of HIV-associated TB increased significantly during the study, with no corresponding change in HIV-negative rates, to reach 16.1 per 100 person-years among HIV-positive silicotics. CONCLUSIONS The risks of silicosis and HIV infection combine multiplicatively, so that TB remains as much a silica-related occupational disease in HIV-positive as in HIV-negative miners, and HIV-positive silicotics have considerably higher TB incidence rates than those reported from other HIV-positive Africans. The increasing impact of HIV over time may indicate epidemic TB transmission with rapid disease development in HIV-infected miners. Similar but currently unrecognized interactions may be contributing to TB control problems in other industrializing countries affected by the HIV epidemic.
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Affiliation(s)
- E L Corbett
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, UK.
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