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Health officials are reminding people that condoms are not reusable.

The Centers for Disease Control and Prevention tweeted on its sexually transmitted disease site that condoms are for single use. Officials say they needed to tweet the message because people are washing or reusing condoms instead of throwing them away.

The agency also says condoms have expiration dates.

The CDC says correctly using condoms can reduce, but not eliminate, the risk of . They also can protect against other diseases that may be transmitted through sex, such as the Zika virus.