Since its initial outbreak in May 2022, the monkeypox virus has perplexed experts and researchers from all over because of its unusual behavior.

A study published in the scientific journal The Lancet Infectious Diseases found that newer monkeypox strains present more unique symptoms.

The symptoms in question are skin lesions, usually in the genital or anal area. The study, involving 54 diagnosed patients over 12 days in May 2022, revealed variation in the symptoms compared to past monkeypox outbreaks.

Monkeypox, a usually mild viral illness endemic in West and Central Africa, is typically characterized by fever, headache, sore throat, fatigue and a rash. However, the new study found that about 94% of patients had at least one skin lesion found in the vaginal or perianal area. And while most of the patients recovered by resting at home, five needed to be admitted due to pain or an infection in their skin lesions.

It is worth noting that the study also found that a quarter of the 54 individuals (all of whom identified as men who have sex with men) were HIV positive. Another quarter had another type of sexually transmitted disease (STI).

David Heymann, an epidemiologist, told Reuters that it's crucial to control the disease outbreak without stigmatizing the affected people.

"That includes working with populations at the greatest risk to try to help them understand how easy it is to prevent this infection – just by avoiding physical contact in the genital area [when a rash is present]," the infectious disease specialist said.

The study authors, affiliated with the Central London Community Healthcare NHS Trust and Imperial College Healthcare NHS Trust, said that case definitions should be further reviewed. This is mainly because monkeypox can reportedly "mimic" common STIs like syphilis and herpes.

Because monkeypox spreads via close contact, researchers are currently working to determine whether the disease can be transmitted via semen since that is the standard definition of sexual transmission.