Can you get an STD from a human bite?

Human bites can seem scary, especially if the skin is broken and blood is involved. Many people know that sexually transmitted infections (STIs) can be passed on through certain bodily fluids, so it’s natural to wonder whether a bite could put you at risk of getting an STI.

Here’s what you need to know.

STIs are usually spread through sexual contact with an infected person. This can include vaginal sex, anal sex, oral sex, and, in some cases, skin-to-skin contact with an infected area. Some infections are transmitted through bodily fluids such as semen, vaginal fluids, and blood, while others can spread through direct contact with sores, ulcers, or infected skin. Sharing sex toys without cleaning them between uses can also spread infections.

To become infected, a pathogen usually needs a way to enter the body. This is why activities that involve exposure to blood, broken skin, mucous membranes, or infected bodily fluids present a greater risk than casual everyday contact.

While very unlikely in almost every case, there are some STIs that can technically be transmitted via a human bite.

Hepatitis B and Hepatitis C

The Hepatitis B virus (HBV) can be found in saliva, but it won’t spread through kissing, sharing utensils, or sneezing. The virus spreads primarily through blood, semen, and other body fluids entering the body of someone who isn’t infected.

But why is this? Studies comparing viral DNA levels in blood versus saliva find that patients with high viral loads in their blood tended to have low levels in saliva, and vice versa. The concentration of virus in saliva is generally too low to establish an infection through casual oral contact. Saliva also contains enzymes and proteins that can neutralise or degrade viruses, adding another layer of protection.

Hepatitis C is transmitted almost entirely through blood-to-blood contact, such as shared needles or, less commonly, sexual contact involving blood exposure. The virus has been detected in saliva, with one study finding HCV genetic material in 31% of saliva samples from infected patients, even when no visible blood was present in those samples. That sounds alarming, but epidemiological studies in humans suggest the infectious capacity of hepatitis C in saliva is very low.

Hepatitis A

Of the Hepatitis’s, this might be the one to worry about.

Hepatitis A spreads through the fecal-oral route, typically from contaminated food or water. But research has found something surprising: the virus is also shed in saliva during acute infection. One study detected Hepatitis A virus RNA in the saliva of five out of six acutely infected patients, and the viral sequences matched what was found in their blood.

Viruses appear in saliva during the infection’s incubation period, potentially detectable from just hours after exposure until several weeks after symptoms begin. Saliva from acutely infected patients could be infectious, meaning transmission through close oral contact during acute illness is at least plausible. That said, the fecal-oral route remains the dominant way Hepatitis A spreads, and saliva transmission, if it occurs, is likely uncommon.

HIV

Systematic reviews of HIV research over the years has shown that biting is an extremely rare mode of transmission for the virus. Of the currently known case reports, only a very small number reported instances where HIV transmission was highly plausible through a bite. In each case, the person with HIV had advanced disease and wasn’t on antiretroviral therapy and was therefore likely to have had a high viral load. These bites also caused deep wounds, and the infected person performing the bite had sores or wounds in their mouth.

So, most bites won’t transmit HIV, unless very specific circumstances are met.

Herpes

Herpes might seem like the most obvious infection that could be transmitted through a bite. After all, kissing is the most common transmission route for HSV-1.

However, there are no documented cases where a human bite has led to a Herpes infection. While technically possible, there remains no evidence for it.

Can I get an STI from being spat on?

The risk of getting an STI from someone spitting on you is extremely low. Most STIs aren’t spread through saliva alone, and there’s no evidence that infections such as HIV are transmitted through spitting.

Should I get a tetanus shot after a human bite?

Human bites are notorious for causing bacterial infections, even when the risk of an STI is low. If the bite has broken the skin, a healthcare professional may recommend a tetanus booster depending on your vaccination history. It’s important to seek medical advice promptly, especially if the wound is deep or shows signs of infection.

What signs of infection should I watch for after a human bite?

Even if you’re not worried about STIs, you should keep an eye out for signs that the wound is becoming infected. These include increasing pain, redness, swelling, warmth around the bite, pus, fever, or swollen lymph nodes. If any of these symptoms develop, seek medical attention as soon as possible.

Does the location of the bite make a difference?

Bites to the hands, face, joints, or areas with a rich blood supply are generally taken more seriously because they carry a greater risk of complications. Deep wounds and bites that draw blood are also more concerning than superficial bites that don’t break the skin.

If you’re worried about a human bite, you should visit your nearest hospital and seek treatment.

However, if you’re concerned about STIs, whether from your bite or another source, you should get tested. Testing will give you the information you need to make important decisions about your sexual health. Contact Better2Know today to book a test at a clinic near you.