How is COVID-19 transmitted?

The COVID-19 virus is spread from person to person by a variety of methods. The spread of the COVID-19 virus primarily occurs by respiratory droplets and fomites. Let’s find out how this occurs.
When someone coughs or sneezes, small droplets of saliva and mucus are formed. These droplets also contain virus particles. These respiratory droplets can travel about 6 feet (2 meters) when someone sneezes or coughs. (1) If someone cough or sneezes vigorously, respiratory droplets can travel farther. These droplets can then be inhaled or land in someone nose, eyes or mouth and begin to multiply and cause serious infection.

Another method of transmission can occur though fomites. (1) A fomite is an inanimate object, such as a phone or pen, that has become contaminated with the COVID-19 virus. If someone coughs or sneezes on a phone or other object, this object becomes a fomite and can lead to transmission of the virus. Once another person touches the object, the virus then transfers to their hands. Afterwards, if this person then touches their nose, eyes or mouth; the virus can then replicate on these areas and spread to the lungs. This is way it remains important to disinfect surfaces and wash your hands frequently.

Airborne transmission of the COVID-19 virus is also a possibility. Airborne transmission allows the to COVID-19 virus to much further than 6 feet. Secretions and particles even smaller than respiratory droplet are lighter and can travel longer distances on indoor air currents. (2) Therefore, wearing a mask indoors is also useful in preventing the spread of the COVID-19 virus.

Finally, the COVID-19 virus has also been found and cultured from feces. () We know that the COVID 19 virus can also cause abdominal pain and diarrhea as this virus can inflammation of the intestine. Therefore, it is not surprising that the virus is found in stool. Yet, fecal to oral transmission, as seen in food borne illnesses, is not though to be a major route of transmission for the COVID-19 virus.
In all, the COVID-19 virus is primarily transmitted respiratory droplets. Fomite and airborne transmission are also a possibility, but appears to be less common. (1) Social distancing, frequent hand washing and wearing a mask outdoors and indoors are critical in preventing the spread of the virus.

ADDENDUM: The understanding of COVID 19 has changed over the course of the year. Fomites are no longer thought to be a main transmission mechanism for this infection. (Updated 10/22/21)

REFERENCES

1. Meyerowitz EA, Richterman A, Gandhi RT, Sax PE. Transmission of SARS-CoV-2: A Review of Viral, Host, and Environmental Factors. Ann Intern Med. 2020 Sep 17:M20-5008. doi: 10.7326/M20-5008. Epub ahead of print. PMID: 32941052; PMCID: PMC7505025.
2. Klompas M, Baker MA, Rhee C. Airborne Transmission of SARS-CoV-2: Theoretical Considerations and Available Evidence. JAMA. 2020 Aug 4;324(5):441-442. doi: 10.1001/jama.2020.12458. PMID: 32749495.
3. Wang W, Xu Y, Gao R, Lu R, Han K, Wu G, Tan W. Detection of SARS-CoV-2 in Different Types of Clinical Specimens. JAMA. 2020 May 12;323(18):1843-1844. doi: 10.1001/jama.2020.3786. PMID: 32159775; PMCID: PMC7066521.