Silicotuberculosis and silicosis as occupational diseases: report of two cases.

BACKGROUND

Silicosis, the most prevalent of the pneumoconioses, is caused by inhalation of crystalline silica particles. Silica-exposed workers are at increased risk for tuberculosis and other mycobacterium-related diseases. The risk of a patient with silicosis developing tuberculosis is higher (2.8 to 39 fold higher, depending on the severity of silicosis) than that found in healthy controls.

METHODS

The first patient was a 52-year-old male who was admitted in 2002 for the second time with dyspnoea, wheezing and fatigue over the last 11 years. He had worked in an iron smelting factory and was exposed to silica dust for 20 years. First hospitalization chest radiography showed bilateral pleural adhesions, diffuse lung fibrosis with signs of a specific lung process. Second hospitalization chest radiography showed bilateral massive irregular, non-homogenous calcified changes in the upper and middle parts of lungs. The patient died due to respiratory failure and chronic pulmonary heart in 2007. The main causes of his death were silicotuberculosis and chronic obstructive pulmonary disease. The second patient was a 50-year-old male who was admitted in 2005 for the second time with chest tightness, dyspnoea, wheezing and fatigue over the last 10 years. He had worked in an iron smelting factory and was exposed to silica dust for 30 years. First hospitalization chest radiography showed diffuse lung fibrosis and small nodular opacities. The patient was diagnosed with silicosis, small opacities sized level p/q, and profusion level 2/3. Second hospitalization chest radiography and CT showed diffuse lung fibrosis and small nodular opacities predominantly in the upper lobes. The patient was recognized as having an occupational disease, and received early retirement due to disability.

CONCLUSIONS

In low-income countries, new cases of silicosis and associated lung cancer, chronic obstructive pulmonary disease and tuberculosis are likely to be seen for decades because necessary reduction of silica use will take time to be achieved.