Immunological Risk Factors for Community-Acquired Pneumonia in Chrysotile Asbestos Workers

Abstract

Introduction: The paper presents the results of a retrospective analysis of the incidence rates of community-acquired pneumonia in chrysotile miners and millers in comparison with the adult population of a municipality. It also demonstrates findings of the study of some immune response parameters in Streptococcus pneumoniae carriers among chrysotile asbestos workers. The objective of the research was to study specifics of the development of community-acquired pneumonia and to determine immune indices in healthy workers (Streptococcus pneumoniae carriers) occupationally exposed to chrysotile asbestos. Materials and methods: First, we analyzed community-acquired pneumonia incidence rates in chrysotile asbestos workers. For the retrospective analysis, we extracted comprehensive emergency notifications about cases of infectious disease, food poisoning, acute occupational poisoning, community-acquired pneumonia, and vaccine adverse reactions (Form 058/u) from the Epidemiologic Surveillance Information System maintained by the Sverdlovsk Regional Center for Hygiene and Epidemiology and Federal Statistics Form No. 2 “Information about Infectious and Parasitic Diseases” in the Sverdlovsk Region. We defined jobs and formed three groups of workers with high incidence rates of community-acquired pneumonia: group 1 included workers involved in extraction and transportation of chrysotile asbestos, group 2 consisted of workers of the ore-dressing factory while group 3 included workers of auxiliary subdivisions (logistics, security, administration, central automated control station). In 2011, 2012, 2013, and 2019, the incidence rate of community-acquired pneumonia in workers was significantly higher. The annual increase had been observed since 2016 and reached its maximum of 1,032.97±158.88 in 2019 exceeding the long-term average rate in the industry and the town by 12.77 % and 15 %, respectively. We assessed the immune status and performed a comparative analysis of immunological indices in 143 workers of selected jobs, both carriers and noncarriers of Streptococcus pneumoniae. The carriers demonstrated a significant increase in the production immunoglobulin E indicating general sensitization and immunoglobulin G, a significantly lower relative count of mature T cells, and a higher lymphocyte count in the populations of natural killer cells.