Plague still exists today. The bacterium Yersinia pestis persists in long-term cycles involving wild mammals and fleas, creating natural foci that can remain active even when no human case is reported. WHO states that animal plague is present on every continent except Oceania, while most human cases reported during 2019–2025 occurred in the Democratic Republic of the Congo and Madagascar.
That answer needs an important qualification: a country reporting no recent human cases is not necessarily free of plague ecology. Human case maps, animal surveillance maps and maps of potential natural foci measure different things.
Where are most human plague cases reported?
WHO reports that plague epidemics have occurred in Africa, Asia and South America. Since the 1990s, most reported human cases have been in Africa, particularly the Democratic Republic of the Congo and Madagascar. In Madagascar, bubonic plague cases are recorded nearly every year, usually during the September-to-April epidemic season.
This pattern describes reported human disease, not the complete geographic distribution of Y. pestis. Surveillance capacity, access to health care, laboratory confirmation and reporting practices all affect what enters an international dataset.
| Area | What current official sources say | What the statement does not mean |
|---|---|---|
| Democratic Republic of the Congo and Madagascar | Most human cases reported to WHO in 2019–2025 occurred in these countries | Every part of either country has equal risk |
| Africa, Asia and South America | Modern epidemics have occurred in all three regions | Every country in those regions has an active outbreak |
| Western United States | CDC records scattered rural cases and an average of about five reported human cases per year in recent decades | Plague is common across the entire United States |
| Countries with known natural foci | Wildlife, fleas and the bacterium can sustain a long-term local cycle | A human case is currently occurring |
What is a natural plague focus?
A natural focus is an ecological system in which Y. pestis persists among animal hosts and flea vectors over time. It is not a synonym for a human outbreak. Human risk can change when ecological conditions, animal die-offs, flea activity and contact between people, pets or wildlife change.
CDC describes an enzootic cycle, in which plague bacteria circulate at low levels among some rodent populations and their fleas. An epizootic is a noticeable outbreak among animals. Human exposure may become more likely during or shortly after an epizootic because infected fleas seek new hosts when susceptible rodents die.
This distinction is central to reading any plague map. A natural-focus layer shows ecological persistence; an outbreak marker should represent a dated event supported by a source. Plague Map keeps those layers separate so that a wildlife focus is not added to human case totals.
Does plague occur in the United States today?
Yes, but reported human disease is rare and geographically concentrated. CDC’s October 2026 update says an average of five human plague cases are reported each year in the United States. Most occur in the rural West, especially northern New Mexico and Arizona, with other areas including southern Colorado, California, southern Oregon and far western Nevada.
CDC says the last urban rat-associated plague epidemic in the United States occurred in Los Angeles in 1924–1925. The bacterium subsequently became established in rural wildlife cycles in parts of the West. Modern U.S. case patterns therefore differ from the port-city epidemics associated with the early twentieth century.
For more context, see why plague persists in the American West and the country and area data used by this site.
Why do plague maps disagree?
Two accurate maps can look different because they answer different questions. Before comparing them, check at least five things:
- Time window. A map of cases from 1970–2025 will not match a map limited to one year.
- Unit of observation. Human cases, animal detections, flea surveillance and ecological suitability are different datasets.
- Case definition. Suspected, probable and laboratory-confirmed cases should not be merged without labels.
- Geographic precision. Public reports may name a country, province, district or town; a plotted point may be only an approximation.
- Missingness. No public report may mean no case, incomplete surveillance, delayed reporting or data outside the map’s scope.
Our guide to reading the plague map explains the interface, while the methodology page documents status labels, coordinate precision and source tiers.
Does “not reporting” mean “plague-free”?
No. WHO explicitly warns that countries shown as not reporting human cases may still contain plague foci. A human case dataset is a record of detected and reported illness under defined criteria; it is not a direct census of bacteria in wildlife.
This is why Plague Map uses N/A instead of zero when a value is unavailable or cannot be established. Zero is a measured value. “Not reported” describes the evidence available to the dataset. Conflating the two creates false reassurance and misleading comparisons.
How should travelers interpret a plague map?
A world map is useful for context, but it cannot calculate an individual’s risk. Risk depends on a specific place, season, activities, animal or flea exposure, public-health notices and personal circumstances. A historical marker does not describe current danger, and a natural focus does not mean transmission is occurring everywhere inside a boundary.
Travelers should use current advice from the relevant national or local public-health authority. General precautions in areas with known plague ecology include avoiding contact with sick or dead animals, reducing flea exposure and keeping pets away from roaming rodents. See the site’s prevention guide for source-linked general information.
What this map can and cannot show
Plague Map can connect a dated public report to an approximate place, evidence status, source and revision history. It can show how known events relate to natural foci and historical records. It cannot prove that an unmarked area has no plague, display patient addresses, replace official surveillance or provide a real-time personal risk score.
The most responsible reading is therefore layered: use the map to find a record, open the event page, inspect the source and date, and note what remains unknown. Geography is the start of the question, not the end of the evidence.