Table of ContentsView AllTable of ContentsPreexisting InfectionsTreatment FailureIncomplete STI ScreeningFalse-Negative TestsAsymptomatic InfectionsAccidental CureWays STIs Are Not TransmittedNon-Sexual STI Transmission
Table of ContentsView All
View All
Table of Contents
Preexisting Infections
Treatment Failure
Incomplete STI Screening
False-Negative Tests
Asymptomatic Infections
Accidental Cure
Ways STIs Are Not Transmitted
Non-Sexual STI Transmission
Despite what you may think, it is possible to get a sexually transmitted infection (STI) like chlamydia, gonorrhea, or herpes without your partner cheating on you. This could be due to a long-standing infection that was never diagnosed or one that is asymptomatic (symptom-free). It is also possible for an STI treatment to fail, erasing the symptoms but not the underlying infection.
When dealing with an STI, the first and most important thing to do is get treated. If possible, it is also important to know the source of the infection so that the person who spread the infection can get treated, too.
One possible reason for an unexplainedSTIwithout your partner cheating is that they got an STI before the two of you entered into a relationship and didn’t know.
For example, chlamydia often has no symptoms. When symptoms do occur, they may not occur until weeks after the infection.
So, if you test positive for chlamydia and your partner indicates they don’t have the infection, it is possible that you caught the infection previously and were not aware. It is also feasible that your partner has chlamydia and passed it to you, but they weren’t aware of their infection.
Many STIs do not exhibit symptoms right away. First, there is anincubation period, meaning the time between exposure to the STI and the appearance of symptoms.
Additionally, if and when symptoms do occur, some STIs, like genital herpes,human papillomavirus(HPV), and HIV, can take months or years for symptoms to appear. Both chlamydia and gonorrhea infections are often subclinical (meaning that they don’t produce notable symptoms) or produce generalized, non-specific symptoms that are easily mistaken for other conditions like aurinary tract infection.
This is why it is essential to receive STI testing as part of your annual exam or based on your healthcare provider’s recommendations.
If your partner gives you an STI, it may be because an old infection wasn’t fully cleared when it was first treated. One example is syphilis, a common STI that occurs in four distinct stages: primary, secondary, latent, and tertiary syphilis.
If treatment fails at any of the stages, the disease can progress invisibly and may only become apparent weeks, months, or years later when severe symptoms develop or a sexual partner is infected.
With syphilis, the failure often occurs in one of two ways:
Treatment can also fail because ofantibiotic resistance.This is common with bacterial STIs like chlamydia. If you do not take the entire course of antibiotics as prescribed (or stop early), you can become resistant, making the infection harder to treat.
If you are screened for STIs, your healthcare provider will likely test for more common STIs like chlamydia, gonorrhea, syphilis, and HIV. Other less common STI tests may only be ordered if you belong to certain high-risk groups.
At the same time, the healthcare provider may only perform a swab test on your genitals — such as for gonorrhea, chlamydia, herpes, and HPV. They may not test the mouth, throat, or anus.
While less common, it is possible to have anoral infectionand transmit this to someone’s genitals during oral sex.In such cases, an STI may go undiagnosed until the infection is passed to someone else.
False-negative resultshappen when a test says you don’t have an STI, and you do. Rarely, this can happen because of a faulty test. More likely, this happens because you were tested for an infection too soon.
Most tests rely on detecting immune proteins, calledantibodies, produced in response to the infection. During the incubation period, the body can take time to produce enough antibodies to reach detectable levels in blood tests.
If you test during the incubation, or “window period,” you may get a false-negative result and pass the infection to your partner.
This is why your healthcare provider and STI clinics will routinely ask when you think you were exposed. If you are concerned about STI exposure, the provider may ask you to return later for an additional STI test.
People infected with chlamydia, gonorrhea, herpes, HIV, and HPV are often asymptomatic but still can infect others without even realizing they have an STI.
This is especially true with herpes, an incurable infection in which the vast majority of people are asymptomatic and will never have symptoms. While the virus that causes herpes can’t be cured, there areantiviral medicationsyou can take to help prevent flares.
The herpes virus is often latent (dormant) but can activate during episodic flare-ups. This is true whether a person has symptoms or not. During flares, a person can shed viruses through the skin and infect others without knowing it. Sometimes, a flare simply looks like an ingrown hair.
Similarly, up to 75% of females with chlamydia are asymptomatic.
If you or your partner needed antibiotics at any point after contracting an STI, the antibiotics for the known infection could also treat the unrecognized STI. Many antibiotics used to treat common infections such as strep throat or anear infectioncan also treat bacterial STIs such as chlamydia and gonorrhea.
So, it is possible to test positive for chlamydia or other STIs and your partner test negative if they were treated for other infection(s) that you were not treated for.
But there are exceptions.
Passing an STI viafomite transmission (objects or materials)is theoretically possible. Fomite transmission can occur when body fluids from someone with an STI get on surfaces and objects. If you come into contact with these fluids, you can get infected due to hand-to-mouth or hand-to-genital contact.
However, this is incredibly rare. The more likely scenario is a hand-to-eye transmission of gonorrhea.Or a shared sex toy could potentially spread an infection.
Most STIs are passed through sexual contact via genital or anal sex. Occasionally, oral sex can transmit STIs.
Some STIs, such as chlamydia, gonorrhea, and syphilis, caninfect the eyes. While rare, hand-to-eye transmission of these infections can occur.
Summary
It is possible for two faithful partners to get chlamydia. If you’re in a monogamous relationship and either you or your partner develops an STI, both you and your partner(s) should be tested and treated appropriately. Regular STI screening for both partners can help build a timeline of infection.
Additionally, even if someone has chlamydia, they don’t necessarily spread the infection every time they have sex. In one study, the male-to-female transmission rate was 32.1% and 34.9%, and the female-to-male transmission rate was 21.4% and 4.6%.
So, depending on how careful you and your partner are with condoms and how frequently you have sex, one person may have an asymptomatic or subclinical infection and avoid spreading it to their partner for some time. Seek testing and treatment from a healthcare provider if you are concerned you have an STI.
A Word From VerywellA positive STI test doesn’t necessarily mean your partner has been unfaithful, but it can be hard to tell when you were exposed and from whom. It’s a good idea to get regular STI testing if you are sexually active, which can help narrow down the timeline of exposure. Testing is recommended before every new monogamous relationship or every few months if active with more than one partner.—CORDELIA NWANKWO, MD, MEDICAL EXPERT BOARD
A Word From Verywell
A positive STI test doesn’t necessarily mean your partner has been unfaithful, but it can be hard to tell when you were exposed and from whom. It’s a good idea to get regular STI testing if you are sexually active, which can help narrow down the timeline of exposure. Testing is recommended before every new monogamous relationship or every few months if active with more than one partner.—CORDELIA NWANKWO, MD, MEDICAL EXPERT BOARD
A positive STI test doesn’t necessarily mean your partner has been unfaithful, but it can be hard to tell when you were exposed and from whom. It’s a good idea to get regular STI testing if you are sexually active, which can help narrow down the timeline of exposure. Testing is recommended before every new monogamous relationship or every few months if active with more than one partner.
—CORDELIA NWANKWO, MD, MEDICAL EXPERT BOARD
15 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.About chlamydia.Shim BS.Current concepts in bacterial sexually transmitted diseases.Korean J Urol. 2011;52(9):589-597. doi:10.4111/kju.2011.52.9.589National Health Service (UK).Sexually transmitted infections (STIs).University of Michigan Health.Stages of syphilis.Luo Z, Zhu L, Ding Y, et al.Factors associated with syphilis treatment failure and reinfection: a longitudinal cohort study in Shenzhen, China.BMC Infect Dis. 2017;17(1):620. doi:10.1186/s12879-017-2715-zCenters for Disease Control and Prevention.Drug-resistant gonorrhea.MedlinePlus.Sexually transmitted infections.MedlinePlus.Sexually transmitted infection (STI) tests.MedlinePlus.Chlamydia infections.Centers for Disease Control and Prevention.About genital herpes.Patel CG, Trivedi S, Tao G.The proportion of young women tested for chlamydia who had urogenital symptoms in physician offices.Sex Transm Dis. 2018 Sep;45(9):e72-e74. doi:10.1097/OLQ.0000000000000858Kraay A, Hayashi M, Hernandez-Ceron N et al.Fomite-mediated transmission as a sufficient pathway: a comparative analysis across three viral pathogens.BMC Infect Dis. 2018;18(1). doi:10.1186/s12879-018-3425-xChitneni P, Owembabazi M, Kanini E, et al.Sexually transmitted infection (Sti) knowledge and perceptions among people in HIV-sero-different partnerships in rural southwestern Uganda.PLOS Glob Public Health. 2024;4(1):e0002817.Godoy-Mancilla J, Oyarzun-Barrientos C, Marín-Cornuy M, Carrasco-Sanhueza E, Águila-Torres P.Bacterial eye infections associated with sexual transmission infections: A review.Arch Soc Esp Oftalmol (Engl Ed). 2022;97(1):17-27.Lewis J, White PJ, Price MJ.Per-partnership transmission probabilities for Chlamydia trachomatis infection: evidence synthesis of population-based survey data.Int J Epidemiol. 2021;50(2):510-517.
15 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.About chlamydia.Shim BS.Current concepts in bacterial sexually transmitted diseases.Korean J Urol. 2011;52(9):589-597. doi:10.4111/kju.2011.52.9.589National Health Service (UK).Sexually transmitted infections (STIs).University of Michigan Health.Stages of syphilis.Luo Z, Zhu L, Ding Y, et al.Factors associated with syphilis treatment failure and reinfection: a longitudinal cohort study in Shenzhen, China.BMC Infect Dis. 2017;17(1):620. doi:10.1186/s12879-017-2715-zCenters for Disease Control and Prevention.Drug-resistant gonorrhea.MedlinePlus.Sexually transmitted infections.MedlinePlus.Sexually transmitted infection (STI) tests.MedlinePlus.Chlamydia infections.Centers for Disease Control and Prevention.About genital herpes.Patel CG, Trivedi S, Tao G.The proportion of young women tested for chlamydia who had urogenital symptoms in physician offices.Sex Transm Dis. 2018 Sep;45(9):e72-e74. doi:10.1097/OLQ.0000000000000858Kraay A, Hayashi M, Hernandez-Ceron N et al.Fomite-mediated transmission as a sufficient pathway: a comparative analysis across three viral pathogens.BMC Infect Dis. 2018;18(1). doi:10.1186/s12879-018-3425-xChitneni P, Owembabazi M, Kanini E, et al.Sexually transmitted infection (Sti) knowledge and perceptions among people in HIV-sero-different partnerships in rural southwestern Uganda.PLOS Glob Public Health. 2024;4(1):e0002817.Godoy-Mancilla J, Oyarzun-Barrientos C, Marín-Cornuy M, Carrasco-Sanhueza E, Águila-Torres P.Bacterial eye infections associated with sexual transmission infections: A review.Arch Soc Esp Oftalmol (Engl Ed). 2022;97(1):17-27.Lewis J, White PJ, Price MJ.Per-partnership transmission probabilities for Chlamydia trachomatis infection: evidence synthesis of population-based survey data.Int J Epidemiol. 2021;50(2):510-517.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Centers for Disease Control and Prevention.About chlamydia.Shim BS.Current concepts in bacterial sexually transmitted diseases.Korean J Urol. 2011;52(9):589-597. doi:10.4111/kju.2011.52.9.589National Health Service (UK).Sexually transmitted infections (STIs).University of Michigan Health.Stages of syphilis.Luo Z, Zhu L, Ding Y, et al.Factors associated with syphilis treatment failure and reinfection: a longitudinal cohort study in Shenzhen, China.BMC Infect Dis. 2017;17(1):620. doi:10.1186/s12879-017-2715-zCenters for Disease Control and Prevention.Drug-resistant gonorrhea.MedlinePlus.Sexually transmitted infections.MedlinePlus.Sexually transmitted infection (STI) tests.MedlinePlus.Chlamydia infections.Centers for Disease Control and Prevention.About genital herpes.Patel CG, Trivedi S, Tao G.The proportion of young women tested for chlamydia who had urogenital symptoms in physician offices.Sex Transm Dis. 2018 Sep;45(9):e72-e74. doi:10.1097/OLQ.0000000000000858Kraay A, Hayashi M, Hernandez-Ceron N et al.Fomite-mediated transmission as a sufficient pathway: a comparative analysis across three viral pathogens.BMC Infect Dis. 2018;18(1). doi:10.1186/s12879-018-3425-xChitneni P, Owembabazi M, Kanini E, et al.Sexually transmitted infection (Sti) knowledge and perceptions among people in HIV-sero-different partnerships in rural southwestern Uganda.PLOS Glob Public Health. 2024;4(1):e0002817.Godoy-Mancilla J, Oyarzun-Barrientos C, Marín-Cornuy M, Carrasco-Sanhueza E, Águila-Torres P.Bacterial eye infections associated with sexual transmission infections: A review.Arch Soc Esp Oftalmol (Engl Ed). 2022;97(1):17-27.Lewis J, White PJ, Price MJ.Per-partnership transmission probabilities for Chlamydia trachomatis infection: evidence synthesis of population-based survey data.Int J Epidemiol. 2021;50(2):510-517.
Centers for Disease Control and Prevention.About chlamydia.
Shim BS.Current concepts in bacterial sexually transmitted diseases.Korean J Urol. 2011;52(9):589-597. doi:10.4111/kju.2011.52.9.589
National Health Service (UK).Sexually transmitted infections (STIs).
University of Michigan Health.Stages of syphilis.
Luo Z, Zhu L, Ding Y, et al.Factors associated with syphilis treatment failure and reinfection: a longitudinal cohort study in Shenzhen, China.BMC Infect Dis. 2017;17(1):620. doi:10.1186/s12879-017-2715-z
Centers for Disease Control and Prevention.Drug-resistant gonorrhea.
MedlinePlus.Sexually transmitted infections.
MedlinePlus.Sexually transmitted infection (STI) tests.
MedlinePlus.Chlamydia infections.
Centers for Disease Control and Prevention.About genital herpes.
Patel CG, Trivedi S, Tao G.The proportion of young women tested for chlamydia who had urogenital symptoms in physician offices.Sex Transm Dis. 2018 Sep;45(9):e72-e74. doi:10.1097/OLQ.0000000000000858
Kraay A, Hayashi M, Hernandez-Ceron N et al.Fomite-mediated transmission as a sufficient pathway: a comparative analysis across three viral pathogens.BMC Infect Dis. 2018;18(1). doi:10.1186/s12879-018-3425-x
Chitneni P, Owembabazi M, Kanini E, et al.Sexually transmitted infection (Sti) knowledge and perceptions among people in HIV-sero-different partnerships in rural southwestern Uganda.PLOS Glob Public Health. 2024;4(1):e0002817.
Godoy-Mancilla J, Oyarzun-Barrientos C, Marín-Cornuy M, Carrasco-Sanhueza E, Águila-Torres P.Bacterial eye infections associated with sexual transmission infections: A review.Arch Soc Esp Oftalmol (Engl Ed). 2022;97(1):17-27.
Lewis J, White PJ, Price MJ.Per-partnership transmission probabilities for Chlamydia trachomatis infection: evidence synthesis of population-based survey data.Int J Epidemiol. 2021;50(2):510-517.
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