If you mean what I think you mean, that's entirely up to your employer. You are not in one of the two states that ever requires expenses to be reimbursed; in one of the two states that does, only mileage is guarantee reimbursable by law. Even in the final state, I doubt sincerely that the law would require the employer to reimburse you, since you really can't prove that you wouldn't have gotten sick if you hadn't traveled.
Bottom line; no law is going to force your employer to reimburse you - no law is going to prohibit your employer from reimbursing you.
But I really, really, really wouldn't hold my breath expecting it.

