Silicosis in Zambian ex-copper miners: A cross-sectional study

BackgroundThe 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.MethodsRoutine 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.ResultsThe 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.ConclusionsIn 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.

The International Labour Organization (ILO) Classification of Radiographs of Pneumoconioses is used as the primary tool to determine compensation for pneumoconiosis in Turkey. We aimed to evaluate how the ILO classification applied, but obtaining chest radiographs in the workplace for screening until the completion of compensation claim files by the referral centres, based on the ILO reading. The study included 320 digital chest radiographs previously taken for screening from eight different ceramic factories and having finalised claim files by referral centres. We used an expert reference panel consisting of five ILO readers to re-evaluate all the radiographs independently using ILO standard films and reached a conclusion based on the agreement among at least three readers. The evaluation primarily included technical quality and silicosis diagnosis with an ILO 1/0 or above small profusion. The results were compared with previous findings. Sixty-three (20%) chest radiographs were unacceptable for classification purposes according to the ILO technical quality grades. Among the remaining 257 chest radiographs, we diagnosed 103 with silicosis (40%), while the referral centres diagnosed 182 (71%). A discrepancy was found between our results and previous evaluations. We diagnosed silicosis in 50% and 17% of the previous silicosis and normal evaluations, respectively. Our findings suggest that the use of the ILO classification for compensation claims may be problematic due to the way of its implementation in Turkey in addition to its subjectivity.

BackgroundGiven 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.MethodsRoutine 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.ResultsReader 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).ConclusionsThis 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 materialThe online version of this article (doi:10.1186/s12889-015-2566-8) contains supplementary material, which is available to authorized users.

Cigarette smoking-induced airway disease commonly results in an overall increase of non-specific lung markings on chest radiography. This has been described as "dirty chest". As the morphological substrate of this condition is similar to the anthracosilicosis of coal workers, we hypothesised that it is possible to quantify the radiological changes using the International Labour Organization (ILO) classification of pneumoconiosis. The aims of this study were to evaluate whether there is a correlation between the extent of cigarette smoking and increased lung markings on chest radiography and to correlate the chest radiographic scores with findings on CT studies. In a prospective analysis a cohort of 85 smokers was examined. The cigarette consumption was evaluated in pack years (defined as 20 cigarettes per day over 1 year). Film reading was performed by two board-certified radiologists. Chest radiographs were evaluated for the presence of thickening of bronchial walls, the presence of linear or nodular opacities, and emphysema. To correlate the smoking habits with the increase of overall lung markings in chest radiography, the ILO profusion score was converted to numbers ranging from zero to nine. Chest radiographs were rated according to the complete set of standard films of the revised ILO classification. 63/85 (74%) of the smokers showed an increase in overall lung markings on chest radiography; 32 (37%) had an ILO profusion score of <1/1, 29 (34%) had an ILO profusion score of <2/2 and 2 (2%) had an ILO score of ≥ 2/2. There was a significant positive linear correlation between the increase of overall lung markings on chest radiography and the cigarette consumption quantified as pack years (r=0.68). The majority of the heavy smokers (>40 pack years) showed emphysema; there was no significant difference between the prevalence of emphysema as diagnosed by CT (62%) or chest radiography (71%) (p<0.05).The most common findings in CT were thickening of bronchial walls (64%) and the presence of emphysema (62%) and of intralobular opacities (61%). Ground-glass opacities were seen in only 7% of our patients. Bronchial wall thickening and intralobular opacities as seen in CT showed a positive linear correlation with the increase of overall lung markings on chest radiography.

Aims: To measure the prevalence of silicosis among black migrant contract workers on a South African goldmine and to investigate exposure-response relations with silica dust. Methods: In a cross sectional...

Denim sandblasting-induced silicosis is a recently identified occupational disease. In this study, we aimed to evaluate pulmonary and radiological changes in the long-term follow-up of former denim sandblasters. Ninety former denim sandblasters were followed from 2007 to 2018. Chest X-rays were evaluated according to the International Labour Organization (ILO) classification. Baseline and final data were compared. Silicosis prevalence, radiological progression and pulmonary dysfunction were evaluated. All of the sandblasters were men. Their mean age was 34 ± 5 years, mean follow-up time was 9 ± 2 years (mean time since initial exposure: 17 ± 2 years) and mean duration of exposure was 34 ± 25 months. Rates of radiological progression and decline in pulmonary during follow-up were 63% and 39%, respectively. During follow-up, all patients were diagnosed with silicosis. All workers who were ILO category 0 at baseline (n = 26, 29%) progressed to higher categories. The number of patients in Category 2 doubled and the number of patients in Category 3 increased by 2.5-fold. Eleven patients developed new large opacities and the number of patients with category C opacity increased from 4 to 13. Exposure time was an independent determinant of radiological progression (OR: 1.0, P = 0.036) and decline in pulmonary function (OR: 1.3, P = 0.019). The prevalence of silicosis in denim sandblasters increases steadily even after exposure is discontinued. Radiological progression was observed in a higher proportion of workers than a decline in lung function. Duration of exposure was the major determinant of disease progression in our study.

In Thailand, epidemiological data on silicosis in the ceramic sector is lacking and the underdiagnosis of silicosis remains an extensive concern. Therefore, this study aimed to determine the prevalence of silicosis and the extent of underdiagnosis among Thai ceramic workers by reinterpreting chest radiographs previously taken by a health check-up unit. This retrospective cross-sectional study was conducted on ceramic workers undergoing health surveillance using chest radiographs in one ceramic factory in September 2018. All chest radiographs were done retrospectively, then were reinterpreted by professional readers specially trained in using the ILO International Classification of Radiograph of Pneumoconioses (ILO/ICRP). Chest radiographs with a profusion of 1/1 or greater were suggestive of silicosis. Out of the 244 participants undergoing chest radiography, the prevalence of silicosis was 2.9%. Overall, the mean age of the participants was 41 years, and 72.1% were female. Among individuals with silicosis, the median age was 43 years; 71.4% were male; the average employment duration was 26.9 years; while the male sex was the significant variable associated with silicosis with an odds ratio of 7.01 (95% confidence interval 1.31 to 37.4). Regarding the underdiagnosis, the health check-up unit failed to recognize all individuals with silicosis, and could not detect any radiographic chest abnormalities in 57.1% of those with silicosis. Despite the low prevalence of silicosis among Thai ceramic workers, this finding indicates ongoing exposure to silica in the ceramic industry. In addition, a significant proportion of the silicosis cases were underrecognized. Future efforts to prevent underdiagnosis and improve an occupational health surveillance service in Thailand are needed.

Background and aims: Diabetes mellitus (DM) is a risk factor for pulmonary tuberculosis (TB), increasing the risk of progression of latent tuberculosis infection (LTBI) to active TB threefold, threatening the TB control, especially in developing countries. The aim of this study was to assess active and latent TB infection frequency in patients with DM. Material and methods: There were enrolled in this study 503 adult DM patients. Active TB screening was performed through anamnestic data, clinical examination and chest X-ray and latent TB infection screening was evaluated using the tuberculin skin tests (TST). Results: A number of 63 (12.5%) patients had type 1 DM and 440 (87.5%) had type 2 DM. Personal history of TB was present in 21 (4.2%) subjects, 5 (8.1%) with type 1 DM and 16 (3.6%) with type 2 DM. The TST was positive in 258 (51.5%) patients and 54 (10.7%) presented cough for more than two weeks at the time of examination. The chest X-ray revealed suggestive lesions for active TB in 4 (1%) subjects and lesions of inactive TB in 90 (22.4%) subjects. Conclusions: TB screening must receive proper attention in patients with DM, being essential for diagnosis in those with nonspecific symptoms.

Objective To explore the risk factors of pulmonary tuberculosis complicated with pulmonary infection and to analyze the pathogens characteristics. Methods 158 patients diagnosed with tuberculosis were chosen. patient medical records with clinicians report were collected, risk factors of pulmonary tuberculosis in patients with pulmonary infection were analyzed by statistical review of specialized personnel to fill in the unified form. With the characteristics of fresh sputum, pathogen isolation and identification of bacteria were analyzed. Results Secondary pulmonary tuberculosis, pulmonary tuberculosis retreatment, acid fast sputum smear staining was negative, long- term use of glucocorticoid, long- term use of broad- spectrum antibiotics, with basic diseases as the variables were associated with risk factors of pulmonary infection, there were statistically significant(P< 0.05). Etiological analysis showed that gram positive bacteria, gram negative bacteria, fungi accounted for pathogens,70.25%,3.86%,25.95%.Among them,Klebsiella pneumoniae, Pseudomonas aeruginosa and Streptococcus pneumoniae accounted for the highest proportion. Drug sensitive test showed cefepime(Ma Siping)the highest sensitivity(87.80%), compound sulfamethoxazole were the most resistance(72.00%). Conclusion Pulmonary tuberculosis complicated with pulmonary infection risk factors were: Pulmonary tuberculosis, pulmonary tuberculosis retreatment, acid fast sputum smear staining was negative, long- term use of glucocorticoid,long- term use of broad- spectrum antibiotics, with basic diseases. Patients of routine application of penicillin and cephalosporin effect of pulmonary tuberculosis complicated with pulmonary infection is not necessarily ideal. It should be given to drug use three generation cephalosporins, quinolones and aminoglycosides, such as high sensitivity in drug sensitivity results back to front. Key words: Pulmonary tuberculosis; Pulmonary infection; Pathogen

Background: Estimated 1.1 million children developed tuberculosis (TB) globally in 2020. Household air pollution has been associated with increased respiratory tract infections among children. Nonetheless, there are scarce data regarding the association of indoor environment with pediatric TB. Objectives: To determine the association of indoor urban environment and conventional risk factors for pulmonary TB among children 1-12 years and to discern the differences of these factors among younger (1-5 years) and older children (6-12 years). Materials and Methods: We conducted an age-matched case-control study among children in 2 hospitals (tertiary and secondary care) in megacity, Karachi, Pakistan. A total of 143 pulmonary TB cases, diagnosed on Pakistan Paediatric Association Scoring Chart for Diagnosis of Tuberculosis (PPASCT), were compared with 286 age-matched controls (ratio 1:2). Indoor urban environment and other conventional risk factors were ascertained through a questionnaire and analyzed by conditional logistic regression. Results: Overall, being a female child [matched odds ratio (mOR): 2.03, 95% confidence interval (CI): 1.16-3.53], having household TB contact (mOR: 8.64, 95% CI: 4.82-15.49), open kitchen for cooking in household (mOR: 1.99, 95% CI: 1.59-5.66), and poorly ventilated house (mOR: 2.37, 95% CI: 1.09-3.65) increased the risk of TB among children (1-12 years). Open kitchen was a risk factor for younger children (1-5 years), whereas poorly ventilated house and being female child was a risk factor for older children (6-12 years), respectively. Conclusions: This study strengthens the evidence that a poor indoor environment increases the risk for childhood TB. Concerted efforts are needed to improve the indoor air environment in urban areas for prevention of TB in addition to addressing the conventional risk factors.

There is a high burden of both diabetes (DM) and tuberculosis (TB) in China, and as DM increases the risk of TB and adversely affects TB treatment outcomes, there is a need for bidirectional screening of the two diseases. How this is best performed is not well determined. In this pilot project in China, we aimed to assess the feasibility and results of screening DM patients for TB within the routine healthcare setting of five DM clinics. Agreement on how to screen, monitor and record was reached in May 2011 at a national stakeholders meeting, and training was carried out for staff in the five clinics in July 2011. Implementation started in September 2011, and we report on 7 months of activities up to 31 March 2012. DM patients were screened for TB at each clinic attendance using a symptom-based enquiry, and those positive to any symptom were referred for TB investigations. In the three quarters, 72% of 3174 patients, 79% of 7196 patients and 68% of 4972 patients were recorded as having been screened for TB, resulting in 7 patients found who were already known to have TB, 92 with a positive TB symptom screen and 48 of these newly diagnosed with TB as a result of referral and investigation. All patients except one were started on anti-TB treatment. TB case notification rates in screened DM patients were several times higher than those of the general population, were highest for the five sites combined in the final quarter (774/100 000) and were highest in one of the five clinics in the final quarter (804/100 000) where there was intensive in-house training, special assignment of staff for screening and colocation of services. This pilot project shows that it is feasible to carry out screening of DM patients for TB resulting in high detection rates of TB. This has major public health and patient-related implications.

Background:High prevalence of Tuberculosis (TB) among prisoners is reported as an alarming public health problem in the world, especially in the developing countries.Objectives:Since there is almost no information from TB in this population in Khuzestan province, the current study aimed to assess the prevalence and identify risk factors of TB among the prisoners of this region.Patients and Methods:In a retrospective study, medical files of patients with Tuberculosis in Khuzestan Health Center (KHC), from 2005 to 2010, were studied. Patients with Pulmonary TB were placed in two groups as the Inmate Prison (IP) and Non-Inmate Prison (NIP) groups. Data extracted from the patients' records in the two groups were compared by SPSS software system using Chi square and Fisher exact tests. P-value was considered less than 0.05.Results:From the reported 4562 patients with Tuberculosis, 363 (7.9%) were prison inmates at the time of TB diagnosis. Prevalence of TB cases among the prison inmates was 403.3 per 100'000.The annual TB case rate in the general population during this period was 16.4 per 100,000. Among the TB risk factors close contact [odds ratio (OR), 95% confidence interval (CI), 19.4, 8.9-41.8, P < 001] especially in the recent 2 years, injection drug use (IDU) [OR, 95% CI, 4.61, 1.7-12.4, P = 006], and Human Immunodeficiency Virus (HIV) infection [OR, 95% CI, 2.4, 1.1-5.0, P = 025] were more frequent in the prisoners than in the general population with TB.Conclusions:In the region under study the prevalence of TB among the prisoners was higher than the general population. The main risk factors for Pulmonary TB in this population were close contact, IDU and HIV infection.

Primary Mycobacterium tuberculosis complex cutaneous infection: report of two cases and literature review

Our aim was to determine the prevalence of tuberculosis (TB), the number needed to screen (NNS), and the diagnostic accuracy of chest X-ray (CXR) screening to detect active pulmonary TB during the 2015 European refugee crisis. We evaluated data of all refugees who underwent CXR screeningin a single-centre of one German metropolitan area in 2015. We determined the prevalence of TB, NNS, and accuracy of CXR to detect active pulmonary TB. Reference method for active TB was the database of all definite TB cases registered at the Department of Public Health. A total of 17,487 immigrants underwent single-centre CXR screening in 2015; prevalence of definite pulmonary TB was 0.103%. The NNS for detecting one case of active pulmonary TB was 1749. CXR had a sensitivity of 55.6% [95% confidence interval (CI) 30.8-78.5%) and a specificity 98.3% (CI 98.1-98.5%) to reveal one case of active TB. Our single-centre study indicates that chest X-ray screening for TB during the 2015 European refugee crisis was of low yield due the low prevalence of TB and high number needed to screen, thus implicating the need for improved screening algorithms adapted to the overwhelming number of refugees. • Prevalence of pulmonary tuberculosis (TB) among refugees in 2015 was low (0.103%). • The number needed to screen to detect one case of active pulmonary TB was 1749. • Tuberculosis X-ray screening resulted in a low sensitivity and high specificity. • Tuberculosis X-ray screening during the European refugee crisis is of low yield. • Improved screening algorithms are needed due to the overwhelming the number of refugees.

Introduction Secondhand smoke (SHS) exposure and biomass cooking fuel utilization represent persistent and growing health threats in regions where tuberculosis (TB) poses major public health risks. This comprehensive study conducted in Nuh district, Haryana, India, investigated the association between environmental exposures, includingSHSand biomass cooking fuel use, with pulmonary TB development. Methodology This matched case-control study included 218 newly diagnosed pulmonary TB cases matched with 218 non-TB controls recruited from the same healthcare facility. Cases comprised nonsmoking adult men and women presenting as incident pulmonary TB patients diagnosed at the Tuberculosis Detection Center (TDC) through standard guidelines.Data were collected as a structured questionnaire. Bivariate logistic regression assessed associations between dependent and independent variables.Adjusted odds ratios were calculated for significant associations. Results Kitchen facilities analysis showed 192/436 (44%) homes without separate cooking areas and 215/436 (49.3%) lacking exhaust ventilation. Cooking fuel analysis revealed 73/218 (33.5%) cases used biomass fuels compared to 42/218 (19.3%) controls. Results demonstrated significant associations between TB and environmental risk factors: SHS exposure (adjusted odds ratio (OR) 2.83, 95% confidence interval (CI): 1.39-5.75), biomass fuel use (adjusted OR 1.85, 95% CI: 1.13-3.03), overcrowding (adjusted OR 2.85, 95% CI: 1.69-4.78), and inadequate ventilation (adjusted OR 1.65, 95% CI: 1.08-2.52). Conclusions The findings provide compelling evidence for the role of indoor air pollution and environmental tobacco smoke exposure in TB pathogenesis among vulnerable populations in resource-limited settings. SHS exposure and biomass cooking fuel use emerged as independent risk factors with substantial effect sizes, supporting biological mechanisms linking indoor air pollution to TB susceptibility.Additional environmental factors, including overcrowding, dampness, and inadequate ventilation, demonstrated strong associations with disease occurrence.