Gargling and Nasal Irrigation May Lessen Your Risk of Contracting and Spreading Coronavirus
By Dr. Sonia Ehrlich Sachs M.D., M.P.H.
In order to understand the myriad of health-related aspects of the current coronavirus epidemic, there are now innumerable research inquiries being undertaken all over the world. Hundreds of scientific groups are working on developing a vaccine, while other groups are busy developing effective drug treatments. As a medical doctor and a public-health practitioner, I follow some of that scientific literature. But in the short term, I am most keenly interested in scientific work that helps me understand how my family and I, living in densely populated New York City, can avoid getting infected, especially this fall and winter, as we face the oncoming second wave of increasing infections. So I follow the evidence-based recommendations for nonpharmaceutical interventions (NPIs), trying to prevent acquiring the virus.
NPIs are all of those activities that an individual can do -- and that policies should facilitate -- to prevent getting infected while we await the holy grail of an effective vaccine (which I doubt will solve all the problems in any event). Of course, the most important NPI is physical distancing, which carries the misnomer ‘social distancing.” Avoiding physical proximity to people is crucial in order to minimize sharing airborne droplets or the even smaller particles called aerosols, both of which are able to carry and transmit the virus from person to person. Even with physical distancing, one should not leave one’s home without a well-fitting face mask. The preferable type is the one with the highest particle filtration rate: the unavailable N95 that traps 95% of viral particles. Many types of facial covering prevent droplets from hitting the face, but only filtration masks, called respirators, also filter aerosol-borne virus. And of course proper handwashing with soap is crucial, since the virus can be transmitted between people via fomites, objects that people touch before or after touching one’s nose, mouth and eyes. There is a recent article (https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1517/5917611) showing that unlike the flu virus, which only survives on skin for two hours, this coronavirus survives for nine hours, which increases the risk of transmission, making frequent proper handwashing paramount.
Just a few days ago, I came across an article published by Indian scientists this month (https://www.sciencedirect.com/science/article/pii/S1550830720303128) suggesting an additional intervention that I will add to my own armamentarium of protective behaviors. It recommends what to do in case you suspect that you may have been exposed to someone who might have the virus. The article reviews some of the potential benefits of gargling and nasal irrigation with saline water, which is already a longstanding popular cleansing method used in traditional yoga. There is not yet a scientific, randomized controlled trial to prove that people who do this are less likely to get infected than people who don’t. But there are pieces of information that indicate that this might be an effective preventive measure.
This particular coronavirus enters mostly through the nose and mouth. It possibly also enters through the eyes, for which you can wear any type of glasses and/or a face shield, and not touch your eyes with unwashed hands. There is evidence that you can dislodge viral particles that have settled in your throat and nasopharynx by vigorous gargling and also by nasal washing, even if using just sterile water. The whirling pressure of the water might mechanically detach the virus from the nasopharyngeal epithelium and throat mucosa. Additionally, there is evidence that salt in the water, a normal saline solution, actually inhibits replication of many types of viruses. So it makes sense that gargling with salt water and using a neti pot, a small container with a long spout used to rinse the nasal cavities,would decrease retention and replication of an infective coronavirus particle. This procedure protects the person performing this type of cleansing from getting sick, and also lowers the chance of that person transmitting the virus to others.
There is no solid scientific evidence that gargling and nasal irrigation prevent or cure COVID-19, but there is compelling circumstantial evidence that it decreases the risk of contracting and spreading the virus. The reason I think it is worth doing these two simple procedures is that, if done correctly, there is no downside to performing them and yet, there is an important upside of potentially preventing the bug from gaining entry into one’s body and also from infecting others. So if I think I might have been exposed to someone with the virus, I will gargle and irrigate!
Sonia Ehrlich Sachs, M.D., M.P.H. is a pediatrician, an endocrinologist and public health specialist. She received a BA from Harvard University, an M.D. from the University of Maryland Medical School, and an M.P.H. from Harvard School of Public Health. Dr. Sachs practiced medicine for 20 years, 14 of which were at Harvard University Health Services in Cambridge, Massachusetts. At the Earth Institute, Columbia University, since 2005 she has led the design and implementation of low-cost primary health systems in low-income rural Africa and India. Her focus is on systems delivery, primarily for improvement of maternal and child health, at local and national scales. Sachs coordinated the health sector of the Millennium Villages Project, overseeing all health-related interventions and research. The Millennium Villages Project, in ten countries in sub-Saharan Africa, was an integrated rural development initiative, designed as a proof of concept, helping poor rural communities accelerate reaching the Millennium Development Goals, using a science-based, community led approach of integrated interventions that increase food production, increase access to health care, education, water, infrastructure and business development. Dr. Sachs was involved in the EI health team advisory to Haiti, India and Nigeria. She is the Director of the One Million CHW Campaign advocating for professionalized Community Health Workers, a cadre that is paid, supervised and supported by use of information communication technology. Sachs and her team currently advise the government of Ghana on the national scale up of Community Health Workers, including the national scale up of mobile health and telemedicine.