What is a viral STI?

A viral STI is a sexually transmitted infection that’s caused by a virus. Unlike bacteria, viruses are not living organisms and need a host cell in order to replicate and survive.

Some of the most common viral STIs are HPV, herpes (often abbreviated as HSV), hepatitis, and HIV. Though they are all caused by viruses, each of these common STIs has a very different type of presentation. 

HPV can cause cauliflower-like warts on the skin or genitals, and precancerous cellular changes of the cervix or anus. HPV is usually diagnosed by a clinical exam or during a routine pap test. HPV is very common: studies show that more than three out of four people are infected with HPV at some point in their lives, although many will never know that they have the virus. 

A first-time outbreak of herpes usually involves a painful eruption of multiple small blisters called vesicles, sometimes accompanied by a fever or swollen lymph nodes. Subsequent outbreaks tend to be less dramatic, with one or more painful lesions preceded by an itchy or tingling sensation at the blister eruption site. Herpes is also often diagnosed by a clinical exam. Blood testing is available and can be a helpful tool in the diagnosis.

HIV has different stages and varying presentations. A newly infected person may experience a flu-like illness two-to-four weeks after exposure, including fever, sore throat, fatigue, and muscle aches, though not all patients have these symptoms, or they can be mild enough to go unnoticed. Many people are diagnosed during routine screening, which is usually done through a blood test. Rapid oral tests are also available. For people at risk for HIV, there is medication available to reduce the risk of getting infected, called PrEP (which stands for pre-exposure prophylaxis).

Hepatitis also has a varied presentation. There are three main hepatitis viruses, referred to as types A, B, and C. A person who gets infected with hepatitis A can become acutely ill, with fevers, abdominal pain, and jaundice. Hepatitis A can be spread through food and water, especially during travel or close personal contact. Hepatitis B can be passed from mother to child, or transmitted via injection drug use, or sexual contact. Symptoms can include fatigue, abdominal pain, and jaundice but most frequently, people are asymptomatic and are found to be infected through blood testing. Hepatitis C is spread most commonly through blood exposure, like with injection drug use. In terms of sexual risk, the highest risk is with receptive anal intercourse; hepatitis C is rarely transmitted through heterosexual contact.  

Most viral STIs are diagnosed either by a clinical exam (like HPV and herpes) or by blood tests (like hepatitis, HIV, and sometimes herpes).

Unfortunately, not all viral STIs can be cured. However, there are existing treatments for most of them.

For people who have HPV, HSV, or HIV—all of which are viruses that can live in your system chronically—treatment involves addressing the symptoms rather than the virus itself. For example, the treatment of genital warts can involve destroying the warts and then allowing your immune system time to clear the virus. HSV infections are similar in that it’s possible to treat outbreaks, but the virus itself can live in your system for a very long time—sometimes indefinitely. Hepatitis C infection is usually discovered through routine blood test screening and is treatable with oral medication. If not treated, it can cause severe liver disease, cirrhosis, and liver cancer. Hepatitis A is treated with supportive care and Hepatitis B is treated with pills or ongoing monitoring. HIV can be treated with antiviral medications that control and suppress the virus, but do not eliminate it entirely.

When it comes to prevention, there are existing vaccinations for some viral STIs, including HPV, hepatitis B (usually given at birth), and hepatitis A. If you have not been vaccinated for HPV or hepatitis B, it’s important to discuss these vaccinations with your healthcare provider.

If you're having any issues like lumps, bumps, or discharge, it’s a good idea to have your clinician check it out. Keep in mind that some people can live with a viral STI for months or even years without knowing that they have it, so if you’re sexually active (especially with multiple partners or partners with unknown statuses), it’s important to get tested on a regular basis.