How are STDs Spread?

The spread of sexually transmitted diseases, or STDs, is a scary thought for many. And it should be. In theory, the readily available precautions should be enough to fully prevent the transmission of any diseases. In reality, however, not everyone is fully aware of the different ways that STDs can spread. This makes complete prevention a difficult task to accomplish. To help inform the public about steps they can take to prevent STD transmission, we at Stony Brook Women’s Health have outlined the various causes.

 

What is an STD?

Before detailing the most common ways that STDs are spread, it’s important to understand the basics about STDs and STIs. An STD (also commonly referred to as an STI) is any disease that is spread primarily through sexual contact, skin-to-skin contact, or blood. This can also take place through shared needles, which is most common for drug users. In their strongest form, there may be a multitude of symptoms. In their weakest, however, there may be no symptoms at all.

 

Some of the Ways STDs are Spread

1. Vaginal Sex

While this is obvious, the importance of this cannot be overstated. STDs are most frequently transmitted through sexual intercourse. Even if your partner genuinely believes that they are free of any diseases, there may be an asymptomatic condition present. For this reason, you should always use condoms.

 

2. Anal Sex

Some believe that anal sex is less likely to result in STD transmission. However, the truth is quite the opposite.

According to the CDC, anal sex is the sexual behavior most likely to result in STD transmission, particularly for HIV. This is primarily due to the fact that the rectum lining is easily torn, and can cause blood, semen or other bodily fluids to spread. Transmission is possible for both partners.

While not a fully preventative measure, condoms are recommended for any who engage in anal sex.

 

3. Oral Sex

Though it is the least likely of the three to cause STD transmission, oral sex can sometimes still spread diseases. Dental dams, pieces of rubber that line the mouth of the receptive partner, are the best way to prevent transmission.

 

4. Kissing

It’s not so much the act of kissing as it is the exchange of saliva that can cause STD transmission. This happens most often with herpes, which may not always physically manifest itself before spreading. Kissing can also spread mononucleosis, colloquially called mono.

 

5. Food

Given the nature of STDs, there are not many that can be spread via food. In rare cases, however, food can cause hepatitis A to spread if a cook with the disease prepares food with dirty hands. Though this is a long shot, exercise caution by following safe food handling protocol.

 

6. Skin Contact

Even without engaging in what many would consider sexual contact, STD transmission is still possible with normal skin to skin contact. This is especially true for those who shave their groin area, which can cause minuscule tears in the skin.

 

7. Linens and Clothes

It’s possible for bacteria or infections that reside in towels, sheets or clothing worn by other people to infect the next person to make contact. Because of this, you should always be wary of using the same sheets, towels, or clothing as other people.

 

8. Sharing Razors

At some point down the line, everyone breaks their skin slightly with a razor. With infected blood, an STD could travel. Avoid this by simply using your own razor.

 

9. Blood Contact

These days, blood donors are thoroughly vetted to ensure that their blood is healthy. In fact, most facilities test every unit of blood that will be transfused. That being said, receiving a transfusion of HIV-infused blood will almost definitely cause an infection.

Additionally, contact with blood in other contexts can also cause HIV. For example, a medic without gloves who treats an HIV positive patient would be at risk.


No two STDs are exactly alike in the way that they spread from human to human. Unfortunately, it’s possible for STDs to spread in ways that are entirely unpredictable and unrelated to sexual contact. To fully prevent the spread of these diseases, be diligent in exercising extreme caution.