Mpox Testing: Who Should Get Tested and How It Works

Short answer: Get an mpox test if you have a new rash or sores that could be mpox, especially after close or intimate contact with someone who has it. CDC says testing is currently recommended only for people with a rash consistent with mpox, and a provider tests by swabbing the rash itself (CDC).

Mpox doesn't fit the usual STI testing playbook. It isn't part of a standard urine or blood STI panel, and only a healthcare provider can order the test. Testing is tied to symptoms, and it happens in a clinic. This guide covers when to get tested, how the test works, what to do while you wait, and how vaccination fits in.

What mpox is and how it spreads

Mpox is an illness caused by the monkeypox virus, which is in the same family as the smallpox virus. CDC says it spreads through close contact, including intimate contact, with a person who has it, through direct contact with contaminated materials, and through contact with infected animals (CDC). CDC also says most people recover fully within 2 to 4 weeks.

That's why mpox shows up in sexual health care even though it isn't only an STI. Anyone can get it through close contact.

Symptoms that should prompt testing

CDC lists a rash as the main sign. It can appear near the genitals or anus, and on the hands, feet, chest, face or mouth (CDC). It often starts as pimple-like bumps or blisters that may be painful or itchy, then goes through several stages, including scabs, before healing.

Other symptoms CDC describes can include:

• Fever or chills
• Swollen lymph nodes
• Exhaustion, muscle aches, backache, or headache
• Respiratory symptoms such as sore throat, congestion or cough

Flu-like symptoms often, but not always, come a few days before the rash. CDC's clinician guidance notes that the rash may be just a few lesions or even one, and that rectal pain or bleeding has often been reported (CDC). Symptoms usually start within 21 days of close contact. You don't need every symptom on the list. CDC advises seeing a provider for a new or unexplained rash, especially after close contact with someone who has mpox.

How the mpox test works

The standard test is a lab test (PCR) on material from the rash. CDC says the provider rubs a swab vigorously across the lesions and swabs more than one. It may be uncomfortable, but the lab needs enough material to detect the virus (CDC). CDC's clinician guidance calls for two swabs from each lesion, usually from 2 to 3 lesions, so there's extra material if more testing is needed (CDC).

Where to get tested

CDC says healthcare providers can order tests or send you to a lab, and your local health department can tell you about testing options in your community. It adds that tests through public health departments are usually free (CDC). Good places to start:

• Your primary care provider or another clinician you already see
• A public health clinic, which CDC suggests if you don't have a provider or insurance
• Your local health department, which can tell you where to go

Call ahead and say you have a rash that might be mpox, so the clinic can plan your visit. Until you've talked with a provider, CDC advises avoiding close or intimate contact and wearing a mask around others.

Why you may need syphilis and herpes tests too

A new rash or sore on the genitals, anus or mouth can have more than one cause, and it can be hard to tell them apart by looking. Syphilis, for example, causes a sore in, on or around the genitals, anus, rectum, lips or mouth that is usually painless, and later a rash that can show up on the palms or soles (CDC). Genital herpes also causes sores. So a clinician may suggest:

• A syphilis blood test. Our syphilis blood test guide explains how it works.
• A herpes test, often a swab of the sore. CDC's herpes testing page explains how swabs and blood tests are used.
• HIV testing, plus chlamydia and gonorrhea testing at the body sites involved.

It's fine to ask for these at the same visit. One swab doesn't rule out everything.

What to do while you wait for results

CDC says to take precautions so you don't spread the virus while you wait (CDC). Its prevention advice for people with mpox includes isolating at home, covering lesions and wearing a mask around others (CDC). In practice:

1. Stay home and avoid close contact with others when you can.
2. Cover the rash with clothing or bandages, and wear a mask, if you need to be around people.
3. Avoid sex and intimate contact until you get your result and talk with a clinician.
4. Don't share bedding, towels or clothing. CDC lists shared items and bedding as a way the virus spreads.
5. Wash your hands often.

If your test is positive, your clinician or health department will guide you on isolation. CDC says mpox can spread from when symptoms start until the rash has fully healed and a fresh layer of skin has formed (CDC).

Vaccination and prevention

The JYNNEOS vaccine is given as two doses, with the second due 4 weeks (28 days) after the first. CDC says the first dose gives some protection, but both are recommended for stronger protection, and a late second dose should still be given as soon as possible (CDC).

CDC recommends vaccination if you:

• Had a known or suspected exposure to someone with mpox, or a sex partner in the past 2 weeks who was diagnosed
• Are a gay, bisexual or other man who has sex with men, or are transgender or nonbinary, and in the past 6 months had a new STI diagnosis, more than one sex partner, sex at a commercial sex venue, or sex linked to a large commercial event or an area with ongoing spread
• Have a sex partner with any of those risks, or expect any of those situations
• Are traveling to a country with a clade I outbreak and expect sex with new partners, at a commercial venue or large event, or transactional sex

If you've had close contact with someone who has mpox, contact a clinician or your health department quickly about vaccination. Some insurance plans cover the vaccine, so check with yours.

Vaccination fits naturally with other sexual health care. If you're on PrEP, ask about it at your next visit. Our PrEP STI testing schedule covers the rest of that plan.

Clade I and clade II

Monkeypox virus has two main types, called clades. CDC says clade II caused the global outbreak that began in 2022 and is still circulating at low levels, including in the United States. Clade I has historically caused more severe disease, and clade I cases have been found in many countries, including the U.S. (CDC). For you, the test works the same way: a lesion swab ordered by a provider. Labs and health departments handle any clade-specific testing, and CDC's mpox pages have the current situation.

Disclaimer: This article is for informational purposes only and does not diagnose, prescribe, or replace individualized medical care. Testing and treatment decisions should be made with a qualified healthcare provider.