Can I get out of lease due to bed bug infestation?

In every lease there is an implied warranty of habitability which requires the landlord to maintain the premises in a habitable condition by complying with local and state housing codes.  When there is  a breach of the implied warranty of habitability, the tenant notifies the landlord and the landlord has to respond within a reasonable time by making the necessary repairs.  When the landlord fails to make the necessary repairs, the tenant has the following options:  the tenant can make the repairs and deduct the cost from the rent (this would be impractical in your situation since spraying has not been effective) or the tenant can move out and terminate the obligation to pay rent for the balance of the term of the lease or if the tenant stays on the premises, the tenant can withhold rent and defend against eviction.  Another alternative is to sue the landlord for breach of the implied warranty of habitability.  Your argument is that the bedbug infestation constitutes a breach of the implied warranty of habitability because it is a health issue.  It would be advisable to report the bedbug infestation to your local housing code inspector.