Coronavirus disease is spread by direct and indirect routes. When an infected person coughs or sneezes, talks, or breathes, direct transmission occurs when virus particles in microscopic respiratory droplets are expelled into the air.
Indirect routes include your hand, which is why hand washing is critical.Touching contaminated surfaces and then your face is an easy way to get contaminated. Some people worry about indirect transmission by another potential route: via sweat, which would make the fluid 'infectious sweat'. If such a thing existed, it would create risk at gyms and other sports centers as exercise should lead to sweating, and infectious sweat could contaminate shared equipment.
Can sweat spread Covid-19?
That question is a concern for people who suffered hyperhidrosis, an excessive sweating production.
According to the International Hyperhidrosis Society, sweat "could actually help prevent the transmission of Covid-19." Experts like dermatologist Adam Friedman of the George Washington University, notes that "Sweat has some inherent antimicrobial activity." The sweat nitrate becomes acidified when it hits the skin, generating nitric oxide, which is one of the most potent broad-spectrum antimicrobial agents. In fact, gaseous nitric oxide is being currently studied as a potential treatment for some of the severe complications related to COVID-19."
But, recently, psychologist Ruth Propper of Montclair State University in New Jersey wrote a commentary article in which she suggested that one possible route of transmission may be via "infectious sweat." Propper argued that sweat could contain SARS-CoV-2 as its relative SARS-CoV-1 was detected in sweat glands (in a chinese scientists 2004 study) and because "other lethal viruses may be contagious via sweat." However, a biologist should have rejected Propper's work after peer review because it was full of idle conjecture.
How sweat can contribute to spread covid?
When you wipe the sweat from your brow during physical activity such as exercise or manual labour, you touch the area where respiratory droplets are most commonly found, a 'T-zone' around your eyes and nose, mouth and chin. You can infect objects like a door handle or free weights with virus particles by touching your face and then the surface. Another individual might then touch those contamination surfaces and infect themselves if they are not cleaned with disinfectant.
Covid-19 may be spread through sweating. Sweating will bring your hands into contact with the droplets released from your respiratory tract, and if you're uninfected, that region is also where a coronavirus can gain entry to your body. The implications of frequent face-touching during sweaty activities such as exercise are clear and is hard to consciously control and happens without you even realising. A 2020 review by epidemiologists at the University of Auckland in New Zealand revealed that face-touching happens far more often than you might think: on average, people touch the T-zone almost 69 times per hour.
However, according to Angela Ballard, RN with IHhS. “Perspiration would need to become mixed with virus-laden respiratory droplets or mucus from an infected person and then come into direct contact with another person's mouth, nose, or eye mucous membranes in order for a sweat-borne COVID-19 infection to occur.” But, risks of infection through touch are likely small, says a professor of cell biology with The Johns Hopkins University, as the amount of virus lingering on surfaces for long periods is less than 0.1% of the starting virus material.
In summary, there's no evidence that sweat, by itself, can transmit COVID-19. Some experts even think sweat can help prevent COVID-19 infection.
Tips to prevent Covid
It would probably be more effective to concentrate on maintaining vigilance about key principles experts have been emphasizing for months instead of worry about catching or spreading COVID-19 via sweat.
- Wash you hands often.
- Avoid touching your face.
- Wear a mask in public.
- Sanitize surfaces.
- Maintain physical distance