Communicable Disease
Washington County, Oregon

The Sexually Transmitted Infections (STIs) Team are nurses and community health workers who follow up with people who have an STI (specifically gonorrhea, syphilis and human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS). These are infections reported by law by health care providers and laboratories to Washington County Public Health. The STIs Team educates patients and their partners about their infection(s), ensures they are receiving appropriate treatment, and helps facilitate linkage to follow-up services through our high risk clinic, private providers or safety net clinics. Individuals with HIV/AIDS are connected with case managers, to make sure they have access to care and continuous support managing their disease. This is part of Washington County’s commitment to end HIV in our communities.

Despite these efforts, Washington County, like other counties, continues to see rising rates of chlamydia, gonorrhea and syphilis. We also see disparities in this data, meaning some communities are experiencing higher rates than others. Due to harmful stereotypes and societal stigma about sexuality, it may be easy to look at the rates below and attribute them to individual behavior. Culturally responsive sexuality education in schools, communication about sexual health with patients, and access to prevention tools and treatment are just a few ways we can shift these disparities.


Chlamydia is the highest reported sexually transmitted infection or communicable disease in Washington County, reflecting state and national trends. 

In 2016, 2,260 new infections were reported to the county. Chlamydia is an infection disproportionately seen in younger adults, with the highest number of reported infections seen in those 15 to 24 years of age. Non-Hispanic (NH) Black or African American and Hispanic people have higher rates of chlamydia, compared to the total chlamydia rate for Washington County.


Over the last ten years, the number of reported gonorrhea infections rose over 260%.

From 2007 to 2016 in Washington County, the number of reported gonorrhea infections increased dramatically, rising from 125 to 457 cases. Gonorrhea heavily impacts sexually active adults, and communities of color consistently have higher rates of infection than the total population.

Early Syphilis

In 2016, Washington County investigated 116 cases of syphilis in the early stage (primary, secondary and early latent). In 2007, only one case of early syphilis infection was reported in Washington County.

Men, and more specifically men who have sex with men (MSM), make up the majority of reported syphilis infections. Non-Hispanic Black or African American and Hispanic have higher rates of early syphilis, compare to the total rate for Washington County.

In addition to MSM being disproportionately affected by syphilis, we are also seeing an increase in infections among women. Identification of infections, especially among women of childbearing age, is crucial for the prevention of congenital syphilis, which is transmission to the baby in utero or during delivery. As the number of women infected with syphilis increases, so has the number of congenital syphilis cases, highlighting the importance of our disease investigator specialists’ work to identify, treat and prevent syphilis infections in our community. 

Congenital syphilis can cause miscarriages, stillbirths and complications in infants such as blindness and deafness. Untreated early syphilis in women can lead to infection of the fetus in up to 80% of cases, and in up to 40% of cases, stillbirth or death may result. Treatment of pregnant women who deliver after 20 weeks of pregnancy is 98% effective at preventing infection in the baby. 

To reduce congenital syphilis cases, the timely investigation of syphilis cases and their sex partners is essential to identifying potentially exposed women of childbearing age. It is also important to screen for syphilis infection during multiple prenatal visits.

People living with HIV/AIDS

As of September 2018, 922 people were living with HIV/AIDS in Washington County, mostly adult men.

Similar to other sexually transmitted infections, communities of color (in particular Black or African American) are disproportionally affected. Men who report ever having sex with men make up the majority of people living with HIV/AIDS in our county. Less than five percent of persons living with HIV/AIDS report injection drug use.

Vaccine Preventable Infections

Vaccine preventable infections have been seeing a resurgence in recent years.

In 2017, the Washington County Communicable Disease Team investigated over 1,000 diseases reported by providers, laboratories and the public. In comparison to 2016, we saw a rise in the vaccine-preventable disease whooping cough (pertussis), and investigated cases involved in five school outbreaks. We also had more reports of mumps infections in 2017 compared to the average from the previous five years. Pertussis and mumps are included as part of recommended and routine childhood immunizations and are required as part of the Oregon Immunization School Law. For more information, visit the Oregon Health Authority's page on immunization.

Data Source

All data for this report is from the STI Team and the Communicable Disease Team at Washington County.

Additional Resources

CDC STI Resources and Education

National Prevention Information Network