Patient samples being tested for monkeypox in Spain.

A new analysis shows that at least two different types of monkeypox are circulating around the U.S., making it less likely that the disease can be stopped completely.

According to the Centers for Disease Control and Prevention, there have been 21 confirmed cases of monkeypox in the United States. The UK, Spain, and Portugal have the most reported cases of confirmed and suspected cases around the world. Five cases have been found in New York.

Monkeypox can cause a flu-like illness and a bumpy rash that can be seen from head to toe. It can take one to two weeks after exposure for symptoms to appear, and then they can remain up until their rash falls off. The long tail of exposure means that people may have been exposed to an illness weeks ago.

We are seeing alarming things now. There isn't a clear connection between reported cases and recent travel to areas in Africa where monkeys are endemic. Preliminary results from a genetic analysis of virus samples taken from US patients were reported by the CDC on Friday. Most of the cases were related to the strains found in Europe, but a few weren't. Two people who contacted monkeypox in the U.S. were related to both strains. The virus has been circulating in Nigeria for at least the last year.

All of this points to the fact that monkeypox has been spreading outside of Africa for a long time. It is likely to spread so quickly that it will cause many different chains of transmission that are harder to stop. It is possible that the virus could establish a permanent foothold in new areas of the world because it is native to rodents.

According to the early evidence, the virus hasn't become easier to transmit between humans in recent years, but it does seem to be spreading frequently through close contact during sex. At least 10 people have died of monkeypox this year in Africa, but the cases have been mild. There are vaccines that can be used for it. The worst case scenario of a second deadly epidemic is off the table. There is a chance that monkeypox will become a problem in more parts of the world.

The regional director of Europe at the World Health Organization, Hans Kluge, warned earlier this week that it may not be possible to completely eradicate monkeypox. It will take a significant and urgent reduction in exposures through clear communication, community led action, case isolation during the infectious period, and effective contact tracing and monitoring if that chance still exists.