Fomite Transmission and STD Risk

Fomite transmission refers to the transmission of infectious diseases by objects. More specifically, it refers to the transmission of infectious diseases by germs left on objects. One common example of this is how the cold virus can be spread by people sneezing and touching door handles. Another is how food can become contaminated on uncleaned cutting boards.

Fomite transmission occurs when viruses or bacteria that remain on surfaces cause infections. This is as opposed to diseases being transmitted from person to person, in the air, in infected water, or in another manner. Some diseases are more likely to be transmitted by fomites than others.

Just because living pathogens can be found on surfaces does not necessarily mean that fomite transmission to humans can take place. The risk of fomite transmission varies depending on a number of factors. These include:

• the bacteria or virus involved
• how much bacteria/virus someone needs to be exposed to in order to become infectious
• the temperature and humidity of the room
• whether the surface is porous or non-porous

Other factors may also be involved.

There are many ways that fomites can end up on surfaces where they will pose a risk to others. Sneezing and coughing can disperse pathogens directly onto surfaces. Flushing a toilet may aerosolize them and lead to their presence on other surfaces. Even hand driers can spread bacteria around a room. However, the most important way that surfaces get infected is from hands.

People who don't wash their hands after sneezing or coughing. People who don't wash their hands after going to the bathroom. People who don't wash their hands after touching other, potentially contaminated surfaces. These can all lead to fomite transmission to surfaces and then to others.

The most important thing you can do to reduce fomite transmission is to wash your hands. If you have done anything that might have put you in contact with bodily secretions, wash your hands. If you have changed a diaper, or wiped your nose, wash your hands. If you sneeze, wash your hands. Washing your hands after touching dirty objects, like cutting boards, is also a good idea.

Surface cleaners also play a role in reducing the spread of infections. However, not all disinfectants work equally well at killing off all viruses and bacteria. Some pathogens are more susceptible to specific detergents than others. Still, regular cleaning of surfaces that come into contact with potentially infectious body fluids is a good way to reduce the risk of fomite transmission even if it is not 100 percent effective.

If you share a household with someone with an infectious disease and you are concerned about fomite transmission, start at the store. Read the label on the disinfectant you are using as a surface cleaner. Most of them will spell out which pathogens they are effective against. That way you can pick the disinfectant best suited to your needs. You don't want to accidentally spread an infection around your house instead of getting rid of it. So use the right cleaner, and change your rags often.

HPV has been found on numerous surfaces. It can be transmitted from hands to genitals. It's also likely HPV can be transmitted from surfaces, such as sex toys.

Hepatitis C, as well as the other hepatitis viruses, may also be transmitted by fomites. Fortunately, hepatitis A and hepatitis B are both preventable by vaccine. There are also new, more effective treatments for hepatitis C.

A number of other diseases can also be transmitted by fomites. In fact, fomite transmission is most often discussed in the context of respiratory diseases and gastrointestinal diseases. Some of the infections that can be transmitted by fomites include:

• Respiratory syncytial virus (RSV)
• Rhinovirus
• Influenza
• Coronavirus
• Rotavirus
• Adenovirus
• Norovirus
• Clostridium difficile (C. diff)
• Foot and mouth disease