Over the last few decades, several new viruses have emerged as threats to human health around the globe. The most recent example is the 2019 novel coronavirus.
The virus itself is called SARS-CoV-2, and the disease it causes is called COVID-19 (short for Coronavirus Disease 2019). SARS-CoV-2 came to the attention of health authorities when it was identified as the cause of a small number of pneumonia cases in the city of Wuhan in Hubei province, China (WHO 2020). Since then, thousands of cases of COVID-19 illness have been identified in China, mainly in Hubei province, and international spread has been reported as travelers coming from China carry the virus worldwide (CDC 2020a).
Coronaviruses are a large group of related viruses that can cause many common human and animal infections (Li 2020). In humans, coronaviruses typically cause mild respiratory infections. Responsible for an estimated 10–30% of all upper respiratory tract infections, coronaviruses are among the most frequent causes of the common cold (Paules 2020). Over the last decade, new coronaviruses that cause potentially lethal respiratory diseases have emerged. These include severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses (Su 2016).
The SARS pandemic in the early 2000s, which lasted about nine months in 2002–2003, affected over 8,000 people in 29 world regions and caused a fatality in almost 10% of cases. MERS, on the other hand, has been smoldering mainly on the Arabian Peninsula since 2012, infecting approximately 2,400 people and having a case fatality rate of nearly 35% (Hui 2020; Killerby 2020). For perspective, the fatality rate of typical influenza viruses is much lower, reaching a maximum of about 0.2% in people over 75 years old; however, because of its high incidence, the number of deaths attributable to the flu worldwide averages between 291,000 and 646,000 annually (Iuliano 2018).
Although the characteristics of COVID-19 illness are still being elucidated, those most likely to contract the disease are those in direct contact with other infected individuals. The most common presentation is fever and cough followed by flu-like symptoms, with rapid progression to fulminant pneumonia and death mainly in those over 70 years old. So far, the case fatality rate is about 3% (Wang 2020). Experience with other new coronavirus outbreaks suggests those at greatest risk, in addition to the elderly, are likely to be those who are hospitalized, immunocompromised, or have a chronic disease (Hui 2020; Azhar 2019). In addition, healthcare workers have historically been at increased risk of developing and transmitting coronavirus infections (Judson 2019; Otter 2016).
Coronaviruses are highly adaptable and known to undergo host-switching. Several established human coronaviruses have evolved from bird or mammalian coronavirus origins (Corman 2018). For example, the human coronavirus associated with MERS is likely to have come from camels, though its origins may have been a bat coronavirus; the SARS coronavirus also appears to have originated in bats and was possibly transmitted by an intermediate mammalian host called a civet (Azhar 2019; Hui 2019). Although distinct from all other known coronaviruses, SARS-CoV-2 also appears to be closely related to a bat coronavirus (Chen 2020).
Once adapted to the human host, coronaviruses can become transmissible between humans. There are four possible routes of transmission: contact, droplet, aerosol, and oral-fecal (Shiu 2019).
- Contact. Direct contact is the most likely route of transmission for coronaviruses such as those associated with SARS, MERS, and the current COVID-19 outbreak (Killerby 2020). In these cases, the virus is transferred when an uninfected individual comes into direct contact with an infected person who is actively shedding virus.
- Droplet. In this form of viral spread, the virus is suspended in droplets emitted from the respiratory tract of an infected individual through a sneeze or cough and inhaled by nearby uninfected individuals. Another possibility is that droplets may land on or near uninfected individuals, be picked up by hands, and transferred to the respiratory tract through touching the nose, mouth, or eyes (Hui 2019).
- Aerosol. The aerosol route of transmission involves inhalation of airborne viruses, possibly at some distance from the infected person. Although this is less likely than direct contact or droplet transmission, studies in indoor environments and some case reports suggest this is a viable transmission route for SARS and MERS coronaviruses (Judson 2019; La Rosa 2013). Aerosol transmission appears to be an especially important concern in healthcare settings where aerosol-generating medical procedures may put healthcare workers and other patients at risk (Judson 2019).
- Oral-fecal. The oral-fecal route involves viruses being shed through the feces (usually in people with diarrhea), contaminating surfaces and ultimately hands that can then introduce the virus to the respiratory tract. This is an uncommon but documented route of transmission for coronaviruses such as the SARS virus (Hui 2019).
Below are some basic measures to consider in order to reduce your risk of contracting COVID-19 and other viral illnesses.
- Avoid air travel to affected regions. Avoiding contact with infected individuals is the best way to protect yourself from COVID-19. Since most of the cases are occurring in China at this time, the United States Centers for Disease Control and Prevention (CDC) has issued a travel warning that recommends avoiding non-essential travel to China (CDC 2020b).In addition, all air travel is associated with exposure to people and the infectious agents they carry. Outbreaks of infectious illnesses, including measles, influenza, SARS, and many others, aboard commercial flights have been documented (Mangili 2015; Hertzberg 2016). Therefore, avoiding air travel is a reasonable precaution for reducing your risk of viral infections in general, particularly if you have other vulnerabilities.
- Wash your hands. Frequent hand washing is an important strategy for protecting against all types of infectious diseases. Studies in office and healthcare settings have further demonstrated strategic use of alcohol-based surface disinfectants and hand sanitizers can reduce viral spread by 85–94% (Kurgat 2019; Reynolds 2019).
- Strengthen immunity. Optimal functioning of the immune system is vital for defending against all types of infections, from mild colds to dangerous influenza and life-threatening pneumonia. A nutrient-dense diet, regular exercise, adequate sleep, and stress management can all contribute to healthy immune function (Zapatera 2015).
- Disinfect surfaces. Coronaviruses can persist on inanimate surfaces like metal, glass, or plastic for up to nine days. Fortunately, coronaviruses can be inactivated with proper cleaning and disinfecting agents. Therefore, keeping surfaces clean and properly disinfected is important to limit the spread of infectious diseases caused by coronaviruses. A study published on February 6th, 2020 found that coronaviruses on inanimate surfaces can be inactivated within one minute through disinfection with 62%‒71% ethanol, 0.5% hydrogen peroxide, or 0.1% sodium hypochlorite (eg, bleach) (Kampf 2020).
Should you wear a mask?
As of March 2nd, 2020, the CDC does not recommend that people who are well to wear a facemask to reduce their chances of developing COVID-19. However, the Agency purposes an alternative suggestion, people who are sick or who have symptoms suggestive of COVID-19 wear a facemask to reduce the risk of spreading the infection to others (CDC 2020c). Facemasks are important in healthcare settings such as hospitals. One model of viral spread in a healthcare setting estimated facemasks could reduce flu (influenza) susceptibility by 3-10% (Blanco 2016).
Testing and Diagnosis
As is to be expected with newly emergent diseases, testing methods to confirm diagnoses are not always readily available. Fortunately, the CDC has been able to rapidly develop tests that can confirm a diagnosis of COVID-19. As of February 26th, 2020, tests should be available via CDC-designated facilities as needed to assess patients potentially affected by COVID-19 in the United States (CDC 2020).
Because there are no proven medical treatments for COVID-19 or other human coronaviruses, scientists are looking at both old and new antiviral drugs in search of effective therapies. Some, but not all, laboratory, animal, and preliminary human trials exploring the use of established antiviral medications against human coronaviruses have reported positive findings. Preliminary evidence from multi-center clinical trials conducted in China suggests chloroquine phosphate has clinical efficacy against COVID-19 (Gao 2020).
Remdesivir is another antiviral drug that has shown promise against SARS-CoV-2 in preliminary pre-clinical studies. It is a prodrug of an adenosine analog that has potent antiviral activity against many RNA virus families (Agostini 2018). 2018 in vitro study showed that remdesivir was efficacious against two strains of human endemic coronavirus (HCoV-OC43 and HCoV-229E) (Brown 2019). A drug screening study published on February 4th, 2020 showed remdesivir and chloroquine were both effective at inhibiting SARS-CoV-2 in vitro (Wang 2020). The Wall Street Journal published an article on January 31st indicating that the pharmaceutical company Gilead has entered into an agreement with Chinese health authorities to conduct priority clinical trials to assess the efficacy of remdesivir in patients infected with SARS-CoV-2 (Walker 2020).
On Feb. 25th, 2020, the U. S. National Institutes of Health (NIH) announced the commencement of the first clinical trial of remdesivir for COVID-19 in the United States. The trial is taking place at the University of Nebraska Medical Center in Omaha. This trial will help establish whether remdesivir can offer robust clinical benefits for COVID-19 patients (NIH 2020).
In the face of low efficacy and challenging adverse side effects of known medications, researchers are searching for new approaches. Immunotherapy using monoclonal antibodies could have a role in treating MERS, SARS, and other emerging coronavirus infections such as COVID-19 (Jin 2017), and novel compounds with anti-coronavirus activity are currently being developed and tested (Sheahan 2017).
Integrative Immune Support
There are many integrative options with well-established immune-modulating properties.
swift action to bolster your immune response might mitigate the likelihood of a severe disease course. At the first signs of an upper respiratory tract infection (eg, sneezing, coughing, feeling unwell, mild fever), make an appointment with your doctor. The following compounds can provide targeted immune support.
- Zinc Lozenges : Studies suggest the intake of one zinc lozenges every two waking hours, for example lozenges containing 18.75 mg of zinc acetate.8 lozenges daily should not be exceeded, and zinc lozenges in such doses should not be used for more than three consecutive days.
- Garlic: 9,000‒18,000 mg of a high-allic garlic supplement each day until discomfort subsides can be taken with food to minimize stomach irritation.
- Vitamin D: If you do not already maintain a blood level of 25-hydroxyvitamin D over 50 ng/mL, taking 50,000 IU of vitamin D the first day and for three more days can help increase the vitamin D blood level more quickly. A maintenance dose of around 5,000 IU of vitamin D each day can help maintain optimal vitamin D blood levels. If you already take around 5,000 IU of vitamin D every day, then there is probably no reason to increase your intake.
- Melatonin: 3‒50 mg at bedtime can support a more efficient immune response..
Talk to your doctor about prescribing cimetidine, a heartburn drug that has potent immune-enhancing properties. 800‒1,200 mg a day in divided doses are supported by scientific research to support the immune system.. Swift immune support activity might be optimal. Once viruses that cause respiratory infections infect too many cells, they replicate out of control and integrative strategies will not be effective. Below are a few additional integrative interventions that have shown beneficial immune-enhancing effects.
- Selenium. Selenium has important antioxidant, anti-inflammatory, and antiviral activities in the body, and deficiency is associated with increased risk of viral infection (Wrobel 2016). Probiotics. A growing body of evidence shows probiotic supplements with Bifidobacterium and Lactobacillus species can enhance antiviral immune activity (Lenoir-Wijnkoop 2019; Mousa 2017).
- Epigallocatechin gallate (EGCG). EGCG is a polyphenol from green tea. with broad antiviral effects,
Disclaimer and Safety Information
This information (and any accompanying material) is not intended to replace the attention or advice of a physician or other qualified health care professional. Anyone should first consult with and seek clearance from a physician or other qualified health care professional.