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Overview of Disease Transmission and Universal Precautions

Infectious diseases have always been humanity’s companions and are spread in a myriad of ways. Direct contact infectious disease transmission occurs when there is physical contact between an infected person and a susceptible person, such as with a sexually transmitted disease or respiratory illness. Indirect contact transmission occurs when there is no direct human-to-human contact. Indirect contact occurs from a reservoir like a used surface or objects, or from vectors such as mosquitoes or ticks.

Direct contact infections spread when disease-causing microorganisms pass from the infected person to the healthy person via direct physical contact with blood or body fluids. Examples of direct contact are touching, kissing, sexual contact, contact with oral secretions, or contact with body lesions.

Indirect contact infections spread when an infected person sneezes or coughs, sending infectious droplets into the air. If healthy people inhale the infectious droplets, or if the expelled droplets land directly in their eyes, nose, or mouth, they risk becoming ill.

Droplets generally travel between three and six feet and land on surfaces or objects including tables, doorknobs, and telephones. Healthy people can breathe these directly or touch used objects with their hands, and then touch their eyes, nose, or mouth.

Universal precautions for pathogen control were initially developed for medical providers during the beginning of the HIV epidemic. Though pathogen control had been practiced in medicine since the 19th century, using universal precautions was a new approach because it starts with the assumption that everyone and all used materials are a potential risk for pathogen transmission. Starting from that assumption, universal precautions treat every situation, person, and all materials as if they are a potential risk for pathogen transmission.

REMINDER: Get Vaccinated

With few exceptions, harm reduction workers should be required to be vaccinated for all of the following:

  • COVID—annually
  • Influenza—annually
  • Tetanus—every 10 years
  • Hepatitis A—every 20 years
  • Hepatitis B—lifetime after third shot

Featured Hacks

These featured hacks highlight creative, practical solutions from harm reduction leaders on the ground. From DIY tools to clever workarounds, each one reflects the ingenuity, care, and real-world experience that keeps this movement alive. 

Though not all harm reduction organizations or programs are in need of universal precautions or OSHA considerations, most are. It’s important when setting up a harm reduction space to take into consideration the important and real risks of harm reduction work. This includes the potential for entry and exposure to blood-borne pathogens as well as airborne pathogens.
Generally, it’s important to use “person first language” when describing people who are marginalized due to some part of their identity being stigmatized, such as folks struggling with their substance use, people who do sex work, and folks living outside.