The honest answer first: there is no home test for plague. A rapid test does exist — a strip that detects a protein of the bacterium, the F1 antigen, and gives a result in 15 minutes. It is used by trained health workers, on fluid drawn from a bubo or on sputum from a person who is already ill. The World Health Organization says in as many words that it is not a screening test for the general population, and even in a clinic a positive strip still has to be confirmed in a laboratory.
Nobody can diagnose plague in themselves. What a person can do — and what in practice decides the outcome — is recognise the combination that makes plague possible, and act on it within hours.
Three questions.
- Exposure. In the last 10 days, was there any of this?
- Flea bites, in a place where plague exists in animals.
- Contact with a wild rodent, a rabbit or another wild animal, alive or dead — above all skinning or butchering one.
- A sick cat or dog that hunts.
- Dead rats or other rodents in or around the home.
- Travel to an area where plague has been reported.
- Close contact, in such an area, with a person who had a fever and a cough.
- Timing. Did the illness begin suddenly, within about a week of that?
- Signs. Is there a high fever with chills that came on within hours,
together with either of these?
- A painful swelling in the groin, the armpit or the neck.
- A cough with chest pain, shortness of breath or blood in the sputum.
A fever on its own, with no exposure, is almost never plague. A sudden fever with a painful swollen node, after an exposure, is plague until a doctor says otherwise.
What to do in the first hour.
- Get medical help now, not in the morning. Call your doctor or the emergency number — 112 across the European Union, the local emergency number elsewhere.
- Say the exposure, not only the symptoms. "I have a sudden high fever and a painful swelling in my groin, and four days ago I skinned a rabbit." A doctor who hears that will think of plague. A doctor who hears "I think I have flu" may not: plague is rare, and the World Health Organization's own manual says a high index of suspicion is needed to recognise it.
- Call ahead if you can, so that the clinic can receive you without a wait in a crowded room.
- If you are coughing: put on a medical mask, keep 2 metres from other people, and avoid public transport if there is any other way to travel.
- Do not take antibiotics on your own. The World Health Organization's advice to the public is explicit: no self-medication unless a health worker has prescribed it. Antibiotics taken before the examination can make the illness look milder and less obvious, and make it harder to confirm in the laboratory. If you have already taken something, say what and when.
- Do not squeeze or cut the swelling. The pus is infectious.
- Write down when the fever began, your temperature, where you have been in the last 10 days, which animals you touched, and who has been close to you since you fell ill. The doctor and the health authority will ask for exactly this.
What to watch for in somebody else. The same combination. And, for pneumonic plague, the speed: a person with fever and a cough who is visibly worse within hours and is coughing blood needs an ambulance — and the people around them need distance and masks.
Source. WHO, Questions and answers: Plague, https://www.who.int/news-room/questions-and-answers/item/plague ; WHO, Manual for plague surveillance, diagnosis, prevention and control (2024), sections 3, 4.3.1 and 6.1, https://www.who.int/publications/i/item/9789240090422 ; Jullien S., Dissanayake H. A., Chaplin M., "Rapid diagnostic tests for plague", Cochrane Database of Systematic Reviews 2020, Issue 6, https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD013459.pub2
What this is not. Reading, not medical advice and not a self-test. This page cannot tell you whether you have plague. It can only tell you when not to wait.