RATES OF MOST SEXUALLY TRANSMITTED INFECTIONS BEGINNING TO DECLINE
Sexually transmitted infections (STIs) are passed from one person to another through sexual activity. STIs are typically treatable, but there may not be any symptoms or only mild symptoms resulting from an infection. Thus, prevention and screening for infection are important public health interventions. According to the National Centers for Disease Control and Prevention, roughly half of STIs occur among young people ages 15-24 years old. These infections can lead to long-term health consequences, such as infertility and an increased likelihood of acquiring HIV (human immunodeficiency virus). Beyond the impact on an individual’s health, STIs are also an economic drain on the U.S. healthcare system, costing billions annually.[1] This indicator tracks the prevalence of three common STIs: chlamydia, gonorrhea, and syphilis (including congenital syphilis).[2]
TREND
Chlamydia has increased 10% over the past 10 years, from 512.2 cases per 100,000 residents in 2014 to 562.1 cases per 100,000 residents in 2023. The one-year trend is slightly up from 557.5 chlamydia cases per 100,000 residents in 2022.
While gonorrhea incidence in San Bernardino County increased 33% over the past 10 years, from 124.2 reported cases per 100,000 people in 2014 to 164.6 per 100,000 people in 2023, the rate is steadily decreasing from a high of 253.0 reported cases per 100,000 people in 2021.
Syphilis occurs at a much lower rate and appears to be decreasing among San Bernardino County residents. While the rate of primary and secondary stage syphilis (the most infectious stages of the disease) almost tripled in the past 10 years, from 4.8 cases per 100,000 residents in 2014 to 14.3 cases per 100,000 residents in 2023, there has been a 32% decline from 2022 when there were 21.1 cases reported per 100,000 residents.
Common STIs and Complications, if Untreated
Chlamydia, a bacterial infection, is the most commonly reported STI in the United States. Untreated chlamydia infection in women can result in pelvic inflammatory disease, which is a major cause of infertility, ectopic pregnancy, and chronic pelvic pain. Untreated chlamydia in men can cause urethral infection or swollen testicles.
Gonorrhea is the second most common STI in the U.S. and is also a bacterial infection. As with chlamydia, it can cause pelvic inflammatory disease. It can also be passed from a pregnant mother to her child and can lead to blindness and pneumonia in the child.
Syphilis is a genital ulcerative disease (also a bacterial infection). If left untreated, syphilis can cause mental illness, blindness, and death. Congenital syphilis is when the infection is passed from a pregnant mother to the unborn baby, and can lead to a low birth weight, premature birth, or stillbirth. Infants infected with congenital syphilis may develop serious health problems such as cataracts, deafness, and seizures, and can die.
According to the Centers for Disease Control and Prevention, individuals who are infected with STIs are two- to five-times more likely than uninfected individuals to acquire HIV infection if they are exposed to the virus through sexual contact. Each of these STIs, if left untreated, can facilitate the transmission of HIV infection. Almost half of all new STI cases each year are in people between the ages of 15 and 24 years.
CASE RATE OF CHLAMYDIA APPEARS TO HAVE STABILIZED
Incidence of Chlamydia per 100,000 Residents in San Bernardino County, California, and the United States, 2014-2023
CASE RATE OF GONORRHEA TRENDING DOWN
Incidence of Gonorrhea per 100,000 Residents in San Bernardino County, California, and the United States, 2014-2023
CASE RATE OF SYPHILIS DECLINING IN RECENT YEARS
Incidence of Syphilis per 100,000 Residents in San Bernardino County, California, and the United States, 2014-2023
GEOGRAPHIC COMPARISON
San Bernardino County’s STI rates are higher than the state and nation for chlamydia and lower than the state and nation for gonorrhea and syphilis. Specifically, the San Bernardino County chlamydia rate of 562.1 per 100,000 is higher than both the California and United States chlamydia rates of 491.1 and 492.2 cases per 100,000 residents, respectively. In comparison, San Bernardino County’s gonorrhea rate of 164.6 per 100,000 is lower than both the California rate of 190.2 per 100,000 and the U.S. rate of 179.5 per 100,000. San Bernardino County’s rate of primary and secondary syphilis (14.3 per 100,000 people) was lower than California’s (16.3 per 100,000 people) and the U.S. rate (15.8 per 100,000 people).
[1] Centers for Disease Control and Prevention, multiple sources: www.cdc.gov/sti/?CDC_AAref_Val=https://www.cdc.gov/std/stats/; www.cdc.gov/sti-statistics/media/pdfs/2024/11/2022-STI-Surveillance-Report-PDF.pdf; www.cdc.gov/sti/media/images/SPICE-overview.png (accessed April 6, 2025)
[2] Syphilis is divided into stages including primary, secondary, latent, and tertiary. This indicator tracks the incidence of primary and secondary syphilis – which are the most infectious stages of the disease – as well as congenital syphilis, which is syphilis in an infant that has been passed from mother to child. Latent and tertiary syphilis are not tracked in this indicator.