Here Are the 27 Viruses Living in Your Semen

If you're very, very unlucky, that is.


You’re probably quite fond of your sperm, that innocent-looking yet powerful reproductive seed that glistens softly against the night sky. Bad news, though: Turns out it can be a disease-ridden cesspool.

Worryingly, we’re not even talking about the fact that there are carcinogens in your semen (by the way, there are carcinogens in your semen). No, we’re talking about something else. Specifically, this week, a new meta-analysis conducted by scientists at the University of Oxford discovered that, along with Zika, there are 26 other viruses that are able to live in human semen and go on to infect the bloodstream.

Let’s call it the “Other 27 Club,” a somewhat exclusive group that includes the viruses that cause Ebola, HIV, Hepatitis B and herpes. Though not all 27 viruses are capable of being transmitted from person to person, this sperm squad does have other consequences, such as reducing fertility or increasing the risk of acquiring an STD. Other viruses in your sperm, meanwhile, are capable of causing mutations in the DNA of sperm, which is great news for future generations.

Still, the authors of the study warn that far more research is needed to understand how and whether the viruses can be sexually transmitted, and exactly which viruses remain viable in semen, for how long and at what concentrations. But for now, here’s a breakdown of every virus that could be found in your sperm:

Name: Adenoviruses
What They Do: These viruses are a common cause of respiratory illness; most infections, however, aren’t severe.
Should I Panic?: Not just yet, as there’s no evidence of sexual transmission.

Name: Transfusion transmitted virus
What It Does: Not much, happily — TTV is believed to be asymptomatic.
Should I Panic?: Not unless you already have liver disease.

Name: Lassa fever virus
What It Does: A type of viral hemorrhagic fever, the Lassa virus is most commonly spread by rats in West Africa and is the cause of 5,000 deaths a year.
Should I Panic?: Possibly. It’s currently not known if Lassa can be transmitted sexually, but we do know that if it’s not treated early, it can be fatal.

Name: Rift Valley fever virus
What It Does: In humans, Rift Valley can cause fever, headache, muscle pains and liver abnormalities. It’s fatal in around 1 percent of cases.
Should I Panic?: Maybe. In the absolute worst case, Rift Valley can cause bleeding in the brain. If you’re one of the unlucky few, your chance of survival is a flip of the coin.

Name: Ebola virus
What It Does: Ebola is the cause of a severe and often fatal hemorrhagic fever.
Should I Panic?: Considering the mortality rate is between 83 and 90 percent, and that the virus can be passed on via human-to-human transmission, yes, you should panic.

Name: Marburg virus
What It Does: Another virus that causes an extremely dangerous hemorrhagic fever.
Should I Panic?: Yes, because this can definitely be passed along through sperm.

Name: GB virus C
What It Does: Formerly known as Hepatitis G, this virus isn’t known to cause diseases in humans.
Should I Panic?: Nope!

Name: Hepatitis C virus
What It Does: In humans, Hepatitis C virus is the cause of hepatitis C and some cancers, such as liver cancer and lymphomas.
Should I Panic?: Yes. Unlike Hep A and B, there’s no vaccine for Hep C.

Name: Zika virus
What It Does: Although Zika’s symptoms for adults are mainly fever, skin rashes and joint pains, during pregnancy Zika can cause congenital brain abnormalities in the child.
Should I Panic?: Most definitely, especially because Zika can survive in semen for up to six months.

Name: Hepatitis B virus
What It Does: Hep B virus is the cause of Hep B, a chronic liver disease with symptoms that include vomiting, yellowish skin, tiredness, dark urine and abdominal pain.
Should I Panic?: Not if you’re vaccinated.

Name: Cytomegalovirus
What It Does: A whole genus of viruses that can causes diseases that include mono and pneumonia.
Should I Panic?: The infection is typically unnoticed in healthy people, so unless your immune system is weak or compromised, you’ll be fine.

Name: Epstein Barr virus
What It Does: This virus can cause mono and is associated with certain forms of cancer, including Hodgkin lymphoma.
Should I Panic?: Chances are, you’ve already been affected with this version of the herpes virus, considering about 90 percent of all adults have evidence of previous infection. So unless you’re sick or dying, you shouldn’t have much to worry about.

Name: Human herpesvirus 8
What It Does: Also known as the Kaposi’s sarcoma-associated herpes virus, this virus appears as a skin cancer commonly occurring in AIDS patients.
Should I Panic?: Infection with this virus is thought to be lifelong, but as long as you have a healthy immune system, the virus will stay in check.

Name: Human herpesvirus 7
What It Does: If you’re healthy, not much.
Should I Panic?: No, because you’re probably part of the more than 95 percent of adults who have been infected by, but are immune to, HHV-7.

Name: Human herpesvirus 6
What It Does: Not much, unless you’re an infant.
Should I Panic?: Although it’s unknown if HHV-6 can be transmitted via semen, even in infants it generally only causes fever and rashes, so there’s not too much to worry about.

Name: Human simplex viruses 1 and 2
What It Does: Depending on which one you have (Herpes 1 is oral herpes, while herpes 2 is genital) you’re going to see blisters around your mouth or around your… well, you know.
Should I Panic?: Yes and no. While there’s no cure for either strain, there are plenty of ways to keep breakouts at a minimum.

Name: Varicella zoster virus
What It Does: Causes chicken pox.
Should I Panic?: This virus is likely to cause shingles if you’re over the age of 60, so wrap up whilst sexing it up at your local nursing home.

Name: Mumps virus
What It Does: This virus is the causative agent of mumps disease, characterized by swelling in your salivary glands.
Should I Panic?: Technically the virus can cause deafness, but you were almost certainly vaccinated against it as a kid.

Name: Adeno-associated virus
What It Does: Nothing. AAV is a small virus that currently isn’t known to cause any disease.
Should I Panic?: No.

Name: BK virus
What It Does: Not much unless you have a compromised immune system, in which case, you can expect a mild respiratory infection and fever.
Should I Panic?: Unless you have a weakened immune system as a result of a kidney transplant, significant consequences are uncommon. In other words, there are plenty of other viruses in your semen that deserve a greater portion of your panic.

Name: JC virus
What It Does: Another common disease that’s infected most people by the time they’re adults, JC is genetically similar to BK Virus.
Should I Panic?: Nope.

Name: Simian virus 40
What It Does: Some controversial research claims that SV40 could cause cancer in humans, but the detection methods used in the research are generally regarded as unreliable.
Should I Panic?: You’re probably better served saving your panicking for the next virus.

Name: HIV
What It Does: This virus is the cause of HIV infection, and over time, it can lead to AIDS.
Should I Panic: Of course you should, although it’s important to note that these days there are several treatments available to help monitor and manage the disease.

Name: Human T-cell lymphoma virus 1
What It Does: Implicated in a few different types of lymphoma, Human T-cell lymphoma virus is believed to occur via sexual contact, breast milk and blood transfusions.
Should I Panic?: Medscape says not: “The research in discordant couples showed that probability of sexual transmission is about 22 per 100,000 in the population.”

Name: Chikungunya virus
What It Does: Symptoms include fever and joint pain, but most people get better within a week.
Should I Panic?: Not really — the risk of death is roughly 1 in 1,000.

Name: Simian foamy virus
What It Does: This has been tentatively linked to several diseases, but without any real evidence.
Should I Panic?: Only if you’ve been bitten by a chimpanzee.