Monkeypox has spent most of its evolutionary history living inside Central and Western Africa’s small mammals — squirrels, rats, mice, and the true reservoir host, which remains unknown. It didn’t evolve to be good at infecting humans. So catching it requires getting a hefty dose of the virus, what scientists call a “high inoculum.”
There are three ways you can be exposed to sufficient amounts of the virus to become infected: direct skin-to-skin contact with the lesions caused by the virus, touching contaminated objects, and close contact with respiratory secretions like saliva from a person with lesions in their mouth or throat. What’s clear from the epidemiological evidence so far is that the current monkeypox epidemic is being driven overwhelmingly by the first of these — in particular, close intimate contact between sexual partners.
What’s less clear is whether urine, feces, blood, semen, or vaginal fluids can spread the virus, the extent to which people without symptoms can infect others, and how much of a role inhaled respiratory particles are playing in transmission.
But many experts emphasized that while for most people the risk of contracting monkeypox right now is very low, public health officials should be taking this disease more seriously.
