Sexually Transmitted Infections


About 1 in every 4 Americans has a sexually transmitted infection or sexually transmitted disease (STI or STD). These are most commonly spread through anal, oral, or vaginal sex. Some, like hepatitis B and HIV, can also be transmitted through blood-to-blood contact by sharing needles or equipment to inject drugs. Pregnant women with an STI may pass their infections to their babies during pregnancy, delivery or through breastfeeding.

For people who are sexually active, consistent and correct use of latex condoms by male partners can reduce (though not eliminate) the risk of infection, including HIV infection.

Some sexually transmitted infections or diseases are curable with antibiotics, others are treatable, and all are preventable. See disease fact sheets for more information, including signs, symptoms and treatment information.

Getting Tested 

If you are sexually active, have a new sexual partner or if you have more than one sex partner, it is important to get tested. You may get or give an infection to your sex partner(s) without ever having symptoms. If you are having symptoms, it is especially important to get tested.

The only way to know if you have an STI or STD is to get tested. If you have a doctor, ask about testing and treatment options. If not, contact the Snohomish County Health Department for low-cost  testing options.

If You Think You Have a sexually transmitted infection

  • Call your doctor to schedule an appointment to be tested or contact the Snohomish County Health Department 
  • Stop having sex until you and your partner(s) get tested
  • Tell your partner(s)

Treatment for Your Sex Partner

Expedited Partner Therapy (EPT) is another way in which Snohomish County Health Department or your doctor can treat the sex partners of people infected with chlamydia or gonorrhea without requiring partners to be tested or even seen by health care providers. EPT is available at no cost. Please call 425-339-5261 if you or a partner have tested positive for chlamydia and/or gonorrhea and would like EPT.

Reporting sexually transmitted infections in Snohomish County

The Snohomish County Health Department’s goal is to prevent future illness for you and the spread to others. Doctors, hospitals and labs are required by law to report certain diseases, including certain sexually transmitted diseases. When we learn of someone diagnosed with chlamydia, gonorrhea and/or syphilis, our disease intervention specialists may contact you (while being careful to respect your privacy) to ensure you and your sex partner(s) receive appropriate testing and treatment.

In Washington State, health care providers, health care facilities and laboratories are legally required to notify their local public health agency about a positive STI or HIV test. You can find the STI/HIV Reporting Form here. If you have questions about reporting to the Snohomish County Health Department, please call 425-339-5261.