Is It Possible For STDs to Spread?

While each sexually transmitted disease (STD) has a different level of transmission risk and manner of transmission, all STDs are contagious. STDs can be transmitted at any time after infection; many STIs have periods of viral shedding during which the virus replicates and can then be exposed outside the body. Open sores can further enhance the risk of transmission through bodily fluids. Naturally, discussing the possibility of STD infection can make anyone nervous, but understanding STDs, how they are transmitted, and when they are most contagious can safeguard not only your sexual health but also the health of others! By being aware and obtaining STD test on a regular basis, as advised by the Centers for Disease Control (CDC) for sexually active individuals aged 13 to 64, you will be taking all essential precautions to avoid these contagious sexually transmitted infections. 1

How Contagious Are STDs?

Many sexually transmitted diseases (STDs) are contagious and can be transferred through sexual encounters such as oral, anal, or vaginal sex. Yet, each viral or bacterial infection has unique characteristics that can influence risk. Factors such as viral load, number of partners, contact with open sores, and needle sharing can all increase the chance of developing an STD.

Contagious STD risk factors include viral load, number of partners, contact with open sores, and the sharing of needs.

Is Chlamydia Spreadable?

Chlamydia is one of the most prevalent sexually transmitted infections and is extremely contagious, thanks in part to a lack of symptoms. Chlamydia symptoms typically manifest as discharge or painful urination, both of which can be readily misdiagnosed as a UTI. Unfortunately, this STI is commonly missed and might worsen without being detected. This bacterial STI, according to the CDC, can be transmitted during anal, vaginal, or oral sex and can be caught again after treatment if exposed. 2 Chlamydia, on the other hand, is not spread by casual contact such as shaking hands or embracing.

Is Gonorrhea Spreadable?

Gonorrhea is another very prevalent and contagious STD. This bacteria, like Chlamydia, does not usually show indications of infection. Symptoms of gonorrhea include irregular discharge, pain during sex, and spotting between periods, however this infection is often asymptomatic, which can lead to unintended transmission. Because this infection normally goes undetected, the bacteria can spread easily during unprotected anal, vaginal, or oral intercourse, according to the CDC. 3 This virus, on the other hand, is not contagious in the sense that it cannot be spread through everyday activities or encounters.

Is Hepatitis B Infectious?

Hepatitis B, on the other hand, is a contagious infection that can be transmitted by sexual contact, blood, or other bodily fluids. Because this virus is a blood-borne disease, it can be transmitted through vaginal, anal, or oral sex, as well as by sharing or using contaminated needles or syringes, according to the CDC. 4 It can also be communicable outside the body for around 7 days, and most people have no hepatitis B symptoms. Yet, while this STD is fairly contagious, it is not shared through normal interactions such as sharing utensils, a drink, or kissing. Therefore, unlike the aforementioned bacterial illnesses, you cannot get hepatitis B again4.

Is Hepatitis C Infectious?

Hepatitis C is similar to Hepatitis B in that both induce liver inflammation and are highly contagious. This STD, like its B version, is contagious and can be transmitted via sex, blood, sperm, and other bodily fluids, but not via kissing, holding hands, hugging, or other casual encounters. Because there are numerous genotypes of the hepatitis C virus, the CDC warns that reinfection with another strain is possible. 5 While hepatitis C symptoms are uncommon in the acute or chronic stages of the disease, they might appear weeks to months later. 5

Is HIV infectious?

Another contagious STD is HIV. According to the CDC, HIV is typically transmitted through vaginal or anal intercourse, needle sharing, and/or mother-to-child transmission. 6 The risk of transmission rises in direct proportion to the viral load of the infection (how prevalent the virus is throughout the body) 7. While it is extremely unlikely, this STD can be transmitted by other mechanisms such as bites, open-mouth kissing, and tattoo needles. 6 But, contrary to popular assumption, HIV cannot be transmitted through everyday interactions such as closed-mouthed kissing or dish sharing. 6.

Is Trichomoniasis Spreadable?

Trichomoniasis is a unique STD because, instead of being caused by bacteria or viruses, it is caused by a protozoan parasite. Those with trichomoniasis, like those with other STDs, rarely suffer symptoms and are more likely to be asymptomatic. Even though the CDC claimed millions of illnesses in their 2018 report, trichomoniasis remains one of the most frequent treatable STDs. 8 Yet, this STD is fairly easy to spread, and women have a higher rate of infection than men. 8 This STI can be passed from person to person, however it is typically seen solely in the vaginal region (rarely in other areas of the body such as the anus or mouth). 8 While the infection’s restrictions are relieving, trichomoniasis is nonetheless highly contagious and should not be treated lightly.

STD cases hit record high for fifth year running, as prevention efforts hit by budget cuts - ABC News

Is Syphilis Spreadable?

Syphilis, like other bacterial STIs, is contagious. According to the CDC, syphilis is transferred by contact with a sore caused by the STD. 9 These contagious syphilis symptoms are typically elevated and painless sores that appear during the primary and secondary phases of the infection but subside during the latent (asymptomatic) period. 9 During pregnancy, it can also be transferred from mother to child9. Because of the latent stage of this STD, syphilis can easily progress to problems before being detected or diagnosed.

Is Herpes A Contagious Disease?

Herpes is a highly contagious STD due to the herpes symptoms it is capable of creating. An STD is caused by a virus that does not generally manifest as symptoms. Nonetheless, the CDC notes that this virus might manifest as contagious herpes lesions. 10 Physical contact with these lesions or contaminated bodily fluids (oral or vaginal) further increases the chance of transmission. 10 Herpes is also known for its viral shedding, which can cause the skin around the diseased location to get infected with the STD. 10


Many STDs, both viral and bacterial, are highly contagious and spread quickly. While all STDs can be transmitted through unprotected intercourse, various characteristics of each infection can raise or decrease its chance of transmission. Yet, of course, no one should take a chance with their sexual health. Protective measures like as male and female condoms, as well as dental dams, can all help you or your partner(s) avoid developing a STI.