LETTER TO EDITOR
|Year : 2022 | Volume
| Issue : 2 | Page : 133-134
Are silicosis patients at risk of developing COVID-19?
Department of Medical, ICMR-NIIRNCD (Formerly Called as Desert Medicine Research Centre), New Pali Road, Jodhpur, Rajasthan, India
|Date of Submission||26-Apr-2021|
|Date of Decision||10-Aug-2021|
|Date of Acceptance||06-Dec-2021|
|Date of Web Publication||4-Jul-2022|
Dr. Vikas Dhikav
Scientist-D (Medical), ICMR-NIIRNCD (Formerly Called as Desert Medicine Research Centre), New Pali Road, Jodhpur (Rajasthan)
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Dhikav V. Are silicosis patients at risk of developing COVID-19?. Indian J Occup Environ Med 2022;26:133-4
Silicosis is a respiratory disease that presents with cough, exertional dyspnea, chest pain, loss of appetite, weight loss, etc. The disease is common among mine, quarry and construction workers, and is the most common occupational lung disease.,,, Jodhpur is the major sandstone belt of Rajasthan where there are more than 12,000 mines and quarries (DMRC' 2002).
Ever since the coronavirus pandemic started, it was cautioned that patients with overt or covert pre-existing lung diseases are more likely to develop COVID-19 infection, probably due to a compromised immune system and state of their health. The purpose of this study was to test this hypothesis among the residents living in five silicosis-prone villages and sub-urban areas of Jodhpur among mine and quarry workers working in the sandstone belt of Rajasthan.
Data of a total of 2,000 subjects who underwent COVID-19 testing in the sandstone belt of Jodhpur (Rajasthan) were obtained. The current study used a mixed method approach: Telephonic survey of those tested positive for COVID-19 (n = 167) among the residents living in the silicosis prone area. A cross section of the sandstone mine and quarry workers were used as comparison controls (n=110 workers). The study was done between June 2020 to December 2020 and the study was approved by Institute Ethics Committee.
Residents who underwent COVID-19 testing were interviewed regarding their COVID-19 positive status and diagnosis of silicosis (if anyone had). A total of 167 subjects (36.08 ± 16.75 years; M: F = 120:47, 154 adults) were found to be COVID-19 positive out of a population of 2000 mentioned above (8.35%). None of the 167 subjects, who tested positive out of the 2000 studied carried a diagnosis of silicosis.
To test the hypothesis that patients with diagnosis of silicosis are more likely to have COVID-19, a survey of mine workers was done on the ground, among a different subset of mine workers (n = 110; all adult males) regarding their COVID-19 status in which a total of 3 (2.72%) were found to be COVID-19 positive, based on laboratory reports. As per the data available in public domain, as of 11 January 2021, India's percent positivity was at 5.86%, that of Rajasthan was at 5.7%, and Jodhpur district and Fidusar area were at 5% and 4.1% respectively. No patient carrying COVID-19 positive status and a confirmed diagnosis of silicosis was identified in the current study.
None of the COVID-19 positive patients had a diagnosis of silicosis in the present study. Several factors could have accounted for lack of any patient with diagnosis of silicosis and COVID-19 positive status in the present findings. Social distancing is a proven intervention to check COVID-19 spread. High incidence of malaria in this area could have conferred protection against the development of COVID-19 (as per one of the stated hypotheses that malaria protects against COVID-19). Apart from this, a potentially inherent lack of susceptibility of silicosis patients to COVID-19 cannot be ruled out. In recent times, from 23 November to 29 November 2020, more than 3000 cases were reported from Jodhpur area with a percent positivity of around 20%. Even till December 2020, Jodhpur's positivity hovered around 12%. Chi-squares analysis of the results ((165/2000 = 8.5%) and (3/110 = 2.5%)) showed a statistically significant difference with P < 0.05. This suggested that both groups were different, implying that in mines and quarries, social distancing could have been responsible for a lower frequency.
Though not definitive and though this is an initial report, the study results indicate that subjects in silicosis-prone area may not be at a higher risk for developing COVID-19, as proposed otherwise. However, it goes without saying that all residents should follow guidelines for prevention of COVID-19 infection.
Biological mechanisms protecting silicosis patients or those constantly exposed to dust from COVID-19 are unknown but could potentially be extensive pulmonary fibrosis found in these patients where inflammation with activated macrophages/lymphocytes is already present.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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