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Infectious Diseases

Infectious Disease information and resources for the MSK community, including clinicians, patients, and the general public.

Airborne (Aerosol)

Airborne transmission occurs when infectious agents (bacteria, viruses, etc) are carried in the air via aerosols (long-lasting particles). This type of transmission leads to extremely contagious diseases, since it requires no close contact with an infected person. Simply being in the same room as in infected individual can lead to infection.

  • Measles
  • Tuberculosis (TB)
  • Chickenpox (Varicella)
  • SARS/Covid-19 (SARS-Cov-1 and SARS-CoV-2)

Respiratory (droplet)

Respiratory transmission occurs when infectious agents are carried from an infected person's nose or mouth via coughing, sneezing, or through saliva and mucous. This type of transmission requires close but not necessarily direct contact with an infected person. If an infected person coughs or sneezes on or near you the respiratory droplets can either enter directly into the nose or mouth or land on unwashed hands and spread.

  • Flu (Influenza)
  • Whooping Cough (Petrussis)
  • RSV (Respiratory Syncytial Virus)
  • Common Colds (Rhinovirus, Adenovirus)

Formite (surface)

Formite transmission involves inanimate objects that are contaminated with an infectious agent. This can be things like doorknobs, telephones, handrails. Formites are usually nonporous hard surfaces that infectious agents can stay on until they are disinfected.

  • Adenoviruses
  • Noroviruses
  • Rotaviruses
  • Respiratory viruses (RSV, Rhinoviruses, Coronaviruses, Influenza)


Physical Contact

Direct contact transmission of diseases occur with direct physical (though NOT necessarily sexual) contact such as touching, hugging, kissing. It can also spread from sharing food, cups, and utensils.

  • Pink Eye (Conjunctivitis)
  • Mono (Mononucleosis)
  • Athlete's Foot (Tinea Pedis)
Sexual Contact

Sexually transmitted infections are diseases that are transmitted through sexual intercourse and other sexual activities. They are referred to as STDs (sexually transmitted diseases) or STIs (sexually transmitted infections).

  • HIV
  • Hepatitis B and C
  • Gonorrhea

Transfusion (blood)

Transfusion-transmitted infections (TTIs) are blood-borne infections that occur from the introduction of a pathogen via blood transfusion. This is why blood donor screenings (both questionnaires and laboratory testing) are a vital strategy to reduce these infectious diseases. There is also pathogen-reduction technology which can further decrease the risk of such transmission.

  • Staph Infection (Staphylococcus aureus)
  • Anaplasmosis (Anaplasma phagocytophilum)
  • Hepatitis (all)
  • Malaria
  • HIV

Trans-cutaneous (vector)

Vector-borne transmission occurs when a living organism carries a disease pathogen and passes it to another living organism. The disease does not infect or cause harm to the vector, but rather it simply passes it on to another organism. Vectors are often insects that feed on blood (mosquitos, fleas, ticks, etc.), they can pass the pathogen through the blood stream of the host; these diseases are often referred to as "Arboviruses", which are literally any virus that is spread through an arthropod. Some vector-borne diseases are spread by mammals and other animals as well, such as Rabies.

  • Malaria
  • West Nile Virus
  • Rabies
  • Plague (Yersinia pestis)

Enteric (fecal-oral)

Enteric (fecal-oral) transmission involves infectious agents that are spread via from the feces of an infected individual to the mouth another individual. Most enteric illnesses are caused by poor sanitation or hygiene. Sometimes enteric disease spreads when fecal particles are aerosolized, for example when flushing a toilet filled with diarrhea. Enteric diseases can also spread through contaminated food or water.

  • Polio (Poliomyelitis)
  • Norovirus (Gastroenteritis)
  • Rotavirus (Gastroenteritis)
  • Typhoid (Salmonella Typhi)

Food/waterborne transmission is a subset of enteric diseases that are spread through contaminated food and sources.
  • Cholera (Vibrio cholerae)
  • E.coli (Escherichia coli)
  • Listeria (Listeria monocytogenes)
  • Salmonella (Salmonella enterica)

Vertical (maternal-fetal)

Vertical transmission refers to a pathogen that is passed from mother to child either in utero (via the placenta), or during childbirth (via the mother's reproductive tract). It can be from a pre-existing disease or an infection that mother acquired while pregnant.  Oftentimes scheduled caesarians are required, especially when a mother has a sexually transmitted infection to decrease the risk of the infection passing to the child during a vaginal birth.

  • HIV
  • German Measles (Rubella)
  • Herpes Simplex Virus-2 (HSV-2)
  • Hand-Foot-and-Mouth Disease (Coxsackievirus)
  • Zika virus