Concurrent silicosis and pulmonary mycosis at death

Our plain-English summary of Concurrent silicosis and pulmonary mycosis at death, by Y. Iossifova, R. Bailey, J. Wood, et al (Emerging Infectious Diseases, 2010).

The study

• Authors: Y. Iossifova, R. Bailey, J. Wood, K. Kreiss
• Journal: Emerging Infectious Diseases
• Published: 2010;16(2):318-20
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

To examine risk for mycosis among persons with silicosis, we examined US mortality data for 1979-2004. Persons with silicosis were more likely to die with pulmonary mycosis than were those without pneumoconiosis or those with more common pneumoconioses. Health professionals should consider enhanced risk for mycosis for silica-exposed patients.

In plain English

The authors used US death certificate data from 1979 to 2004 for people older than 45 at death. They compared how often a fungal lung infection (pulmonary mycosis) was listed among deaths whose certificates mentioned silicosis (6,723 deaths), asbestosis (23,899) or coal worker pneumoconiosis (46,088), and among 51,677,216 other deaths. Pulmonary mycosis was listed for 0.55% of silicosis deaths, 0.19% of asbestosis deaths and 0.06% of other deaths. Compared with deaths without these diseases, the prevalence rate ratio for pulmonary mycosis was 9.5 (95% confidence interval 6.9 to 13.1) with silicosis, 3.3 (2.5 to 4.4) with asbestosis and 1.4 (1.0 to 2.0) with coal worker pneumoconiosis. Aspergillosis was the most common type among people with pneumoconiosis. The authors concluded that people who die with silicosis are more likely to die with pulmonary mycosis than people without pneumoconiosis or with the more common pneumoconioses. They noted three limits. Death certificates often leave out silicosis. Coding of fungal infections can vary. They could not study risk among silica-exposed people without silicosis.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Analysis of US national mortality (death certificate) data, comparing the share of deaths with pulmonary mycosis listed between groups using prevalence rate ratios
• Who was studied: US residents older than 45 at death, 1979 to 2004. There were 6,723 deaths with silicosis mentioned, 23,899 with asbestosis, 46,088 with coal worker pneumoconiosis (CWP), and 51,677,216 other deaths. Deaths with more than one of these pneumoconioses were excluded.
• Exposure: Any mention on the death certificate of silicosis, asbestosis, or coal worker pneumoconiosis, compared with no mention. Dust or fiber exposure was not measured, and no asbestos fiber types were named.
• Main results:
  • Pulmonary mycosis was listed for 37 of 6,723 silicosis deaths (0.55%), compared with 29,914 of 51,677,216 deaths without these pneumoconioses (0.06%).
  • Compared with people without pneumoconiosis, people with silicosis were 4.5 times (95% CI 3.4 to 6.0) more likely to have any mycosis at death.
  • Compared with people without pneumoconiosis, people with silicosis were 9.5 times (95% CI 6.9 to 13.1) more likely to have pulmonary mycosis at death.
  • People with silicosis were 2.9 times (95% CI 1.9 to 4.4) more likely than people with asbestosis to have pulmonary mycosis at death.
  • People with silicosis were 6.7 times (95% CI 4.3 to 10.5) more likely than people with CWP to have pulmonary mycosis at death.
  • Among asbestosis deaths, 46 of 23,899 (0.19%) had pulmonary mycosis listed. Compared with deaths without pneumoconiosis, the prevalence rate ratio was 3.3 (95% CI 2.5 to 4.4); for any mycosis it was 1.5 (1.2 to 2.0).
  • For CWP deaths, the prevalence rate ratio for pulmonary mycosis compared with deaths without pneumoconiosis was 1.4 (95% CI 1.0 to 2.0).
  • Aspergillosis was the most common pulmonary mycosis among people who died with pneumoconiosis.
  • Compared with deaths without pneumoconiosis, the prevalence rate ratio for aspergillosis was 13.9 (95% CI 9.2 to 21.1) for silicosis deaths (22 of 6,723).
  • For asbestosis deaths (31 of 23,899), the prevalence rate ratio for aspergillosis was 5.5 (95% CI 3.9 to 7.8).
  • In southwestern states, people with silicosis were 27.9 times (95% CI 12.6 to 62.0) more likely than people without pneumoconioses to have coccidioidomycosis at death.
  • In southwestern states, people with asbestosis were 4.5 times (95% CI 1.9 to 10.8) more likely than people without pneumoconioses to have coccidioidomycosis at death.
  • In states bordering the Ohio, Missouri and Mississippi River valleys, the ratio for histoplasmosis was 4.8 (95% CI 0.7 to 34.0) for people with silicosis. For people with asbestosis it was 3.9 (95% CI 1.3 to 12.2).
• The authors' conclusion: The authors concluded that persons who die with silicosis are more likely to die with pulmonary mycosis than those who die without pneumoconiosis or with the more common pneumoconioses.
• Limitations the authors state:
  • The study relied on death certificate data. Only about 1 in 6 people who had silicosis had it recorded as a cause of death.
  • The authors could not address whether silica-exposed people without a silicosis diagnosis have increased risk, and the analysis may underrepresent concurrent silicosis and mycosis.
  • The sensitivity of ICD coding for fungal infections can vary between institutions and over time, especially if fungal infections are underdiagnosed.
  • ICD-9 codes for many mycoses do not separate pulmonary from other types of mycosis.

Topics

Medical terms in this study, explained in our Lexicon: Silicosis, Pneumoconiosis.

Related studies

• TruCutR needle biopsy in asbestosis and silicosis: correlation of histological changes with radiographic changes and pulmonary function in 41 patients — P. Tukiainen, E. Taskinen, et al. (1978)
• Mixed pneumoconiosis: silicosis, asbestosis, talcosis, and berylliosis — G.J. Mark, C.B. Monroe, et al. (1979)
• Silicosis, asbestosis, and cancer of the lung — W.C. Hueper (1955)
• Silicosis and asbestosis: diagnosis, prevention and treatment — O.A. Sander (1955)
• Benign asbestos pleural effusion associated with pulmonary aspergilloma — J. Hiyama, M. Marukawa, et al. (1998)
• Silicosis among foundry workers. Implication for the need to revise the OSHA standard — K.D. Rosenman, M.J. Reilly, et al. (1996)

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