The World Health Organization renamed the two known clades, or lineages, of the monkeypox virus Monday.
Director-General Tedros Adhanom Ghebreyesus said the lineages will be referred to going forward using Roman numerals.
"The clade formerly known as the Congo Basin or Central African clade will now be referred to as clade I, while the West African clade will be called clade II," he said during a news conference.
Subsequent lineages will be named using Roman numerals for the clade and lowercase letters will be used for the subclade.
The WHO has been in talks to rename the virus itself due to concerns about stigmatization.
The decision Monday comes as an outbreak of monkeypox spreads around the world with more than 35,000 cases reported to the global health agency.
In the United States, there are more than 12,600 cases across 49 states, the District of Columbia and Puerto Rico, according to the Centers for Disease Control and Prevention.
The majority of cases in the current outbreak have been reported during intimate contact among men who have sex with men, a group that includes people who identify as gay, bisexual, transgender and nonbinary.
However, the CDC has warned that anybody is at risk of monkeypox infection if they have skin-to-skin contact with a monkeypox patient or make contact with an infected person's lesions.
At least eight cases among children in six states and D.C. have been reported as well as one case among a pregnant woman.
To avoid infection, the CDC recommends limiting the number of sex partners, avoiding spaces with intimate sexual contact with multiple partners, using condoms and gloves during sexual contact and being fully clothed when attending events such as festivals and concerts.
Last week, researchers from Sorbonne University and Bichat-Claude Bernard University Hospital in France published a case report of a dog that developed monkeypox after being exposed to its owners, which were diagnosed with the disease.
The CDC has since updated its website to state dogs can be infected by humans. It's unknown if other pets, such as cats, hamsters, gerbils and guinea pigs, can be infected.