Suffolk County Executive Steve Bellone and the New York Blood Center have declared a blood emergency.

The emergency means there is less than a two-day supply for the universal blood type O-negative.

 Officials say in order to maintain a safe blood supply, a seven-day inventory of all types must be continually replenished.  

Companies, organizations and community groups are encouraged to step up to host a blood drive in July or August to help rebuild the blood supply.