Routes of Disease Transmission

Direct Contact Transmission

Transmission via direct physical contact between an infected host and a susceptible individual.

Indirect Contact / Fomites

Transmission through contact with contaminated non-living objects or surfaces.

Airborne Transmission

Transmission by inhaling infectious droplets or particles suspended in the air.

Faecal-Oral Transmission

Transmission via the ingestion of contaminated food, water, or faecal matter.

Vector-Borne Transmission

Transmission through the bite of an infected arthropod vector.

Maternal (Vertical) Transmission

Transmission from mother to offspring during pregnancy, childbirth, or breastfeeding.

Zoonosis

A disease that normally exists in animals but can be transmitted to infect humans.

Reverse Zoonosis (Anthroponosis)

A disease transmitted from humans to other animals.

Anthropozoonosis

A disease capable of being transmitted bidirectionally between humans and animals.

Direct Contact: Viral Example

Herpes simplex virus (HSV)

Direct Contact: Bacterial Example

Methicillin-resistant Staphylococcus aureus (MRSA)

Direct Contact: Fungal/Parasitic Example

Tinea infections (ringworm)

Fomite / Indirect: Viral Example

Influenza virus

Fomite / Indirect: Bacterial Example

Clostridium difficile (C. diff)

Fomite / Indirect: Fungal/Parasitic Example

Aspergillus species

Airborne / Droplet: Viral Example

Measles virus

Airborne / Droplet: Bacterial Example

Mycobacterium tuberculosis (TB)

Airborne / Droplet: Fungal/Parasitic Example

Histoplasma capsulatum

Maternal: Viral Example

Human Immunodeficiency Virus (HIV)

Maternal: Bacterial Example

Group B Streptococcus (GBS)

Maternal: Fungal/Parasitic Example

Candida species

Vector-Borne: Viral Example

Dengue virus

Vector-Borne: Bacterial Example

Borrelia burgdorferi (Lyme disease)

Vector-Borne: Fungal/Parasitic Example

Sporothrix schenckii

Faecal-Oral: Viral Example

Hepatitis A virus

Faecal-Oral: Bacterial Example

Salmonella species

Faecal-Oral: Fungal/Parasitic Example

Cryptosporidium parasite

Bubonic Plague

The most common form; transmitted via infected fleas moving from rodents to humans.

Septicemic Plague

Occurs secondary to bubonic plague or when bacteria enter directly through breaks in the skin.

Pneumonic Plague

The most deadly form; transmitted directly between humans through airborne respiratory droplets.