NRS 617.366: Employment-related aggravation of preexisting condition which is not employment related; aggravation of employment-related occupational disease by incident which is not employment related.

1. The resulting condition of an employee who:

(a) Has a preexisting condition from a cause or origin that did not arise out of and in the course of the employee’s current or past employment; and

(b) Subsequently contracts an occupational disease which aggravates, precipitates or accelerates the preexisting condition,

Ê shall be deemed to be an occupational disease that is compensable pursuant to the provisions of chapters 616A to 617, inclusive, of NRS, unless the insurer can prove by a preponderance of the evidence that the occupational disease is not a substantial contributing cause of the resulting condition.

2. The resulting condition of an employee who:

(a) Contracts an occupational disease; and

(b) Subsequently aggravates, precipitates or accelerates the occupational disease in a manner that does not arise out of and in the course of his or her employment,

Ê shall be deemed to be an occupational disease that is compensable pursuant to the provisions of chapters 616A to 617, inclusive, of NRS, unless the insurer can prove by a preponderance of the evidence that the occupational disease is not a substantial contributing cause of the resulting condition.