Mpox testing means swabbing an active skin lesion and running PCR to detect monkeypox virus DNA. There's no useful blood or antibody test for diagnosis, and you can't be tested before a sore appears, because the swab needs material from a rash, blister, or scab. Results usually come back within a few days CDC.
with the right treatment
testing, not symptoms, decides
| Item | Value |
|---|---|
| Curable? | yes — with the right treatment |
| Tested by | exam + lab |
| If you may have it | get tested — testing, not symptoms, decides |
How mpox is tested
Mpox is confirmed by detecting monkeypox virus DNA by PCR from a swab of a suspected lesion. PCR (polymerase chain reaction) copies and amplifies any viral genetic material in the sample, so even a small amount of virus shows up as a positive. The monkeypox virus is in the same family as smallpox, and the lab can confirm it directly from the skin.
The sample itself is the rash. A clinician — or sometimes you, with guidance — rubs a sterile swab firmly across the top of a lesion. They want cells and fluid from the sore, so the swab is pressed and rolled rather than dabbed lightly. It can sting on an open lesion, but it's over in seconds. If you have several spots, they may swab more than one to give the lab the best chance of a clear answer. The swab goes into a tube and is sent out for PCR. This isn't a rapid in-office strip test.
Blood tests don't diagnose active mpox. Antibody and blood-based tests can't reliably tell current infection from a past one or from smallpox vaccination, so the swab is the standard. With no lesion to swab, there's nothing to test.
When to test after exposure
The incubation period is 3–17 days, and people usually get sick within 21 days of contact CDC. During that early stretch, before any rash, there's no way to confirm mpox, because PCR needs lesion material. Some people feel flu-like symptoms first (fever, swollen lymph nodes, body aches), but you still wait for skin signs before a swab makes sense.
The rash is what triggers testing. As soon as you notice a new bump, blister, pimple-like spot, or sore, especially anywhere you had skin-to-skin or sexual contact, get swabbed. Don't wait for it to scab or spread. If you were exposed but have no lesion yet, watch closely through the window and ask about vaccination, which can still help shortly after exposure. For how timing works across infections, see our guide on when to test after exposure.
Who should get tested
Anyone with an unexplained rash or sores that could be mpox should be tested, particularly after close physical contact. The clade II strain behind the global outbreak that began in 2022 spread mainly through close skin-to-skin contact — including intimate and sexual contact — and affected mostly men who have sex with men. That epidemiology tells you who's at higher risk, but mpox isn't limited to any one group. Anyone in skin contact with an infected person can catch it.
- People with a new, unexplained rash or sores — especially in the genital, anal, or mouth area — after intimate contact.
- Anyone who had close skin-to-skin contact with someone diagnosed with mpox.
- Men who have sex with men with multiple or new partners during an active outbreak, if symptoms appear.
- People who are immunocompromised, who should test promptly because mpox can be more severe for them.
Because the rash can be mistaken for other things, testing also sorts out look-alikes. A single genital sore or cluster of blisters often raises the question of herpes versus mpox; the two can look similar early on, and only a swab settles it. We break down the visual and clinical differences in mpox vs herpes.
Getting tested: the visit and the cost
A mpox visit is short and centered on the rash. The clinician examines your skin, asks about contact and symptoms, swabs one or more lesions, and sends the swab to the lab. Like most sexual-health diagnoses — a urine cup, a self-collected swab, or a quick exam — the sample collection is fast, and results usually come back within a few days. You're typically asked to isolate from close contact while you wait, since mpox spreads through the rash.
Cost shouldn't be the barrier. Mpox swabbing and many STI services are free or low-cost at health departments, Planned Parenthood, and Title X clinics. If you're not sure where to go, you can get tested through a clinic near you, and our compare testing providers page lays out options side by side. Unlike a self-collected urine STI panel, an mpox swab generally needs an in-person lesion, so a hands-on visit is usually the route.
A common mistake is waiting to see if a sore clears on its own. Swabbing it early, while the lesion is fresh, gives a cleaner PCR result and lets you take steps sooner to avoid passing it to others. A diagnosis here is common and treatable. Clinics handle these every day, and it says nothing about you as a person.
Reading your results
PCR results are straightforward. A positive means monkeypox virus DNA was detected in the lesion, so you have mpox. A negative means it wasn't found; if your symptoms are convincing or worsening, your clinician may re-swab a different or newer lesion, since sampling a healing or scabbed-over spot can miss the virus. Results are usually available in a few days.
There's no number to interpret here. It's a yes or no on the virus, not a level. If the result is negative but your sores persist or change, push for a recheck and ask whether another condition, like herpes, should be tested at the same time.
If your result is positive
Most people recover fully from mpox, and the illness typically lasts 2–4 weeks; for severe cases or people who are immunocompromised, an antiviral called tecovirimat (TPOXX) may be used CDC, TPOXX. If a treatment course is recommended, finish all of it even once you feel better, and ask your clinician whether close contacts need evaluation. Keep lesions covered and isolate until they've fully healed.
When to see a clinician
See a clinician promptly if you have a new unexplained rash or sores after close or sexual contact, particularly during an outbreak. Seek care urgently if lesions are in the eyes, mouth, or rectum and very painful, if you can't eat or drink, or if you're immunocompromised — these situations can become serious and may need antiviral treatment. Call ahead so the clinic can prepare to swab safely and limit spread in the waiting room.