Mpox is a viral illness that can spread between people and from animals to people. The virus is transmitted in several distinct ways, each involving contact with the virus from an infected individual, animal, or contaminated environment. This article explains the primary ways the mpox virus is transmitted.
Person-to-Person Transmission
The most frequent way mpox spreads between people is through close, personal contact with an infected individual. This occurs when a person comes into direct contact with the infectious rash, scabs, or body fluids of someone with mpox. The virus can enter the body through small breaks in the skin or through mucous membranes in the mouth, genitals, or eyes. A person with mpox is contagious from the onset of symptoms until their rash has completely healed and a new layer of skin has formed.
Intimate activities are a common scenario for this type of direct contact. Activities such as kissing, cuddling, and sexual contact involve significant skin-to-skin exposure, which facilitates the transfer of the virus. This can include oral, anal, and vaginal sex, or touching the genitals of a person with mpox. Bodily fluids, including saliva and semen, can also spread the virus during these close encounters.
Beyond direct skin contact, mpox can be transmitted through respiratory secretions. This pathway requires prolonged, face-to-face interaction, as casual conversations or walking past an infected person are not considered high-risk situations. Sustained close-range talking, coughing, or sneezing can expose someone to infectious droplets.
A pregnant person with mpox can pass the virus to their fetus through the placenta, which is known as vertical transmission. This can result in the baby being born with the infection, a condition called congenital mpox. Transmission can also occur during or after birth through close contact between the parent and the newborn.
Transmission from Contaminated Objects
The mpox virus can spread indirectly through contact with contaminated objects and surfaces, a process known as fomite transmission. When a person with an active mpox rash touches items, they can leave behind infectious viral particles. Another person who then touches these objects can become infected if the virus enters their body.
This mode of transmission is relevant in household or shared living situations. Items that can become contaminated include personal objects and fabrics used by an infected individual, such as:
- Bedding
- Towels
- Clothing
- Eating utensils
- Sex toys
The virus can remain viable on these surfaces, posing a risk to others.
This pathway is considered less common than direct person-to-person contact. The likelihood of transmission from a contaminated surface depends on factors like the amount of virus present and environmental conditions. It underscores the importance of not sharing personal items with someone who has mpox.
Animal-to-Human Transmission
Mpox is a zoonotic disease, meaning it can spread from animals to humans. This type of transmission occurs in regions where the virus is endemic, primarily in West and Central Africa. The virus circulates among wild animals, particularly rodents like squirrels and rats, which act as a natural reservoir.
Direct contact with an infected animal is a primary route for animal-to-human spread. A person can become infected if they are bitten or scratched by an animal carrying the virus. Handling infected animals or coming into contact with their blood, bodily fluids, or rash lesions can also lead to infection. This includes activities like hunting or processing wild game in areas where the virus is present.
Consuming meat from an infected animal is another risk factor. If the meat is not cooked thoroughly, the virus may survive and infect the person who eats it. Using other products from infected animals can also pose a risk. The 2003 mpox outbreak in the United States was linked to infected pet prairie dogs housed near mammals imported from Africa.