COVID-19: An Evolving Crisis
There are now almost 4 million total COVID-19 cases in the United States, with an average of about 66,920 new cases emerging daily within the past week [1]. Through the collaborative efforts of scientists, mathematicians, and medical health professionals, we’ve seen an influx of case studies and research articles in recent months detailing previously unknown symptoms, as well as more specific information on what to be aware of and how to protect ourselves from infection. In this blog post, we’ll highlight some of these recent developments and explore the scientific timeline of deciphering COVID-19 to help you navigate through this “new normal.”
New symptoms
After the pandemic was first reported back in December 2019, the common symptoms we kept hearing to watch out for were fever, coughing, trouble breathing, fatigue, and other flu-like symptoms. Some of these symptoms were features accounted for by the majority of COVID-19 patients during the incubation period of the virus, while others were extrapolated from existing knowledge of the pathology related to other coronaviruses. Over the past few months, the CDC has updated their list with a few other notable signs[2]:
- New loss of taste or smell
- Nausea or vomiting
- Diarrhea
- New confusion
- Inability to wake or stay awake
- Bluish lips or face
The CDC has also listed new complications that have been seen in COVID-19 patients. Initially, respiratory complications and worsening of existing medical conditions were the most common complications being widely reported; however, COVID-19 has recently been linked to the development of blood clots in the body, most notably in the veins and arteries of the lungs [3]. Additionally, some children have developed MIS-C, a condition where various body parts can become inflamed [4]. Reports of these symptoms and complications are just recently emerging due to the novelty of SARS-CoV-2, the virus responsible for the COVID-19 pandemic.
It’s very likely that there are details about the long-term effects of COVID-19 that have yet to be uncovered. Despite being more than 6 months since the virus was initially reported, we’re still relatively early along in the process of documenting all of the long-term complications related to COVID-19, which simply take time to observe, analyze, and report. For example, there have recently been reports of individuals not fully recovering, even months after being initially diagnosed with COVID-19 [5]. A significant number of patients are now experiencing post-viral syndrome, something not uncommon with viral diseases, where exhaustion and fatigue persist for months [6]. Addressing this, Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, has stated that some patients could develop long-term fatigue post-coronavirus infection [7][8]. However, the prevalence and longevity of this syndrome are yet to be determined.
Virus Transmission
In addition to the newly emerging symptoms, we are also learning more about the circumstances under which the virus is transmitted. A source of confusion earlier in the pandemic was the use of masks — when, how, and by whom do they need to be worn? The consensus initially seemed to be that only symptomatic individuals needed to wear masks. However, in recent months, it has become evident that asymptomatic and presymptomatic transmissions are possible, with reports of presymptomatic individuals being the most infectious [9][10][11]. We now know, definitively, that use of masks by the general public, not just people with symptoms, has a large impact on reducing the transmission and spread of the virus [12][13].
Another cloudy area that has become more clear in the past few months is the mechanism of transmission. There is growing evidence supporting the spread of the virus through aerosol transmission, i.e. by airborne microdroplets [12][13][14]. By now, almost everyone has probably become familiar with the recommendation to maintain at least 6 feet of distance with other people. This is merely a baseline, which should protect someone from an infected individual where the only mechanism of spreading the virus is through breathing. During regular breathing, most large droplets will quickly fall to the ground, and only a small number are aerosolized and spread through the air for short distances. However, when an infected individual sneezes or coughs, many more droplets are expelled and can travel up to 3m/10ft (coughing) and 7m/23ft (sneezing) [12].
If an infected individual comes into contact with another person outdoors, the virus-carrying aerosols are diluted by the constant flow of air. Indoors, especially in close proximity to others, it is much more likely that the aerosolized virus concentration would be high enough to infect another person, especially in poorly-ventilated areas. This includes public transportation, elevators, cruise ships, and even restaurants, where air recirculation measures are put into place to reduce the cost of energy consumption [14].
Everyday Recommendations
Now that we have all this new information, what do we make of it? What should we be doing in this “new normal” we’re presently experiencing? You’ll want to keep washing your hands frequently, especially after returning from a public area and before touching your face. Viruses have a heavy-duty protein coat to help protect their genetic material and replicate using our cells. This virus, however, has an outer layer of fatty molecules, which means it can be torn by soap or alcohol-based hand sanitizers (no need for antibacterial cleaners and sanitizers). This is just to highlight the importance of washing your hands, as the virus will literally die without its fatty layer [15].
Though becoming infected from touching possibly-contaminated surfaces is a lower risk than initially thought, it’s still not a bad idea to wipe down new items you bring into your home with some sort of disinfectant [16]. Avoid being indoors in a public space for an extended period of time and always wear a facemask when interacting with others to lower the risk of transmission and infection. Cloth face coverings are better at reducing transmission than they are at reducing infection, so if everyone is wearing a mask we’re all much less likely to become infected [17]. A study found that the best cloth face masks are those with multiple layers and have no gaps when worn (i.e. a properly fitted mask) [18].
Another piece of evidence supporting the use of masks is a recent case study by the CDC, which followed two hair stylists in Springfield, Missouri.They both developed symptoms while coming into work and saw a total of 139 clients over a period of 8 days. Both the stylists and the clients wore face coverings. 67 clients tested negative for the virus and the rest asserted they had developed no symptoms. Outside of work, one of the stylists had contact with 4 people all of whom developed symptoms, while the second had contact with 2- all without symptoms [19]. This is not to say that none of the clients became infected, because they might’ve been asymptomatic, but along with other evidence, we can still assume that face coverings likely contribute to preventing transmission of SARS-CoV-2.
Staying as far apart from others as possible is also highly recommended, as there are studies suggesting that the 6 feet rule might not be enough distance to prevent you from getting infected [20]. This is especially true when indoors and around people not wearing a facemask.
We’re a month into summer, so lakes and beaches are places we all want to be enjoying. The CDC recommends you avoid such public spaces if you are feeling ill, have received a positive test, or are waiting on results. Wear facemasks when you are out of the water, but maintain your distance even when swimming and floating. As always, stay hydrated, wash your hands, and stay safe!
Citations and Links
[1] United States. Dept. of Health and Human Services. Centers for Disease Control and Prevention. “Cases and Deaths in the U.S.”. 7/23/2020. Retrieved from https://www.cdc.gov/vaccines/vpd/vpd-vac-basics.html
[2]United States. Dept. of Health and Human Services. Centers for Disease Control and Prevention. “Symptoms of Coronavirus”. 5/13/2020. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html
[3]United States. Dept. of Health and Human Services. Centers for Disease Control and Prevention. “Similarities and Differences between Flu and COVID-19”. 7/10/2020. Retrieved from https://www.cdc.gov/flu/symptoms/flu-vs-covid19.htm#table
[4]United States. Dept. of Health and Human Services. Centers for Disease Control and Prevention. “Multisystem Inflammatory Syndrome (MIS-C)”. 5/29/2020. Retrieved from https://www.cdc.gov/mis-c/index.html
[5] Lowenstein, Fiona. “Covid-19 symptoms: no one knows why these patients keep relapsing”. June 4 2020. Retrieved from https://www.vox.com/2020/6/4/21274727/covid-19-symptoms-timeline-nausea-relapse-long-term-effects
[6]Perrin R, Riste L, Hann M et al. “Into the looking glass: Post-viral syndrome post COVID-19”. Medical Hypotheses 144 (2020). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7320866/pdf/main.pdf
[7] Citroner, George. “Fauci Warns About ‘Post-Viral’ Syndrome After COVID-19”. July 16 2020. Retrieved from https://www.healthline.com/health-news/fauci-warns-about-post-viral-syndrome-after-covid-19
[8] Berlinger J, McKeehan B, Kottasova I, Upright E, Wagner M, and Macaya M. CNN. “July 9 Coronavirus News”. July 10, 2020. Retrieved form https://edition.cnn.com/world/live-news/coronavirus-pandemic-07-09-20-intl/h_5125152a01f8c98d362cf15d6860ab37
[9] United States. Dept. of Health and Human Services. Centers for Disease Control and Prevention. “Evidence Supporting Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 While Presymptomatic or Asymptomatic” July 2020. Retrieved from https://wwwnc.cdc.gov/eid/article/26/7/20-1595_article
[10] Daniel P. Oran, AM, and Eric J. Topol, MD. “Prevalence of Asymptomatic SARS-CoV-2 Infection”. Annals of Internal Medicine. June 3 2020. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7281624/pdf/aim-olf-M203012.pdf
[11] He, Xi et al. “Temporal dynamics in viral shedding and transmissibility of COVID-19”. Nat Med. 2020 May;26(5):672–675. Retrieved from https://pubmed.ncbi.nlm.nih.gov/32296168/
[12]Zhang, Rhenyi et al. “Identifying airborne transmission as the dominant route for the spread of COVID-19”. PNAS. May 2020. Retrieved from https://www.pnas.org/content/117/26/14857
[13] Jayaweera, Mahesh et al. “Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy”. Environmental Research 188 (2020). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/pdf/main.pdf
[14]Morawska, Lidia et al. “How can airborne transmission of COVID-19 indoors be minimised?”. Environmental International. September 2020 (14). Retrieved from https://www.sciencedirect.com/science/article/pii/S0160412020317876
[15]Harrison, Sara. “All the ways to kill a Coronavirus (So Far)”. April 23 2020. Retrieved from https://www.wired.com/story/all-the-ways-to-kill-a-coronavirus-so-far/
[16]United States. Dept. of Health and Human Services. Centers for Disease Control and Prevention. “CDC updates COVID-19 transmission webpage to clarify information about types of spread”. May 22 2020. Retrieved from https://www.cdc.gov/media/releases/2020/s0522-cdc-updates-covid-transmission.html
[17] Chu, Derek et al. “Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis”. The Lancet. June 01, 2020. Retrieved from https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31142-9/fulltext
[18] Konda, Abhiteja et al. “Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks”. ACS Nano. April 21, 2020. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185834/pdf/nn0c03252.pdf
[19] Hendrix MJ, Walde C, Findley K, Trotman R. Absence of Apparent Transmission of SARS-CoV-2 from Two Stylists After Exposure at a Hair Salon with a Universal Face Covering Policy — Springfield, Missouri, May 2020. MMWR Morb Mortal Wkly Rep 2020;69:930–932. DOI: http://dx.doi.org/10.15585/mmwr.mm6928e2external icon.
[20] Qureshi, Zeshan et al. “What is the evidence to support the 2-metre social distancing rule to reduce COVID-19 transmission?”. CEBM. June 22, 2020 Retrieved from https://www.cebm.net/covid-19/what-is-the-evidence-to-support-the-2-metre-social-distancing-rule-to-reduce-covid-19-transmission/
