This update provides risk assessment and recommended actions for consideration in response to the current outbreak.
In the United States, at this point, people do not need to take any specific precautions aside from keeping abreast of the situation.
- Could this become a major international crisis?: Yes
- Is it likely?: No, but this is the most dangerous international health event since the 2004 SARS outbreak and bares many similarities. For the reasons outline below, it should not be ignored.
At this stage, widespread infection is limited to one region of China. There is no sustained transmission in the United States. Occasional US cases with traceable links to the original outbreak should be expected. Unless there is evidence of sustained person-to-person transmission in the US, however, this is not a significant individual threat.
Why is this virus so concerning?
This is a newly recognized type of virus. This novel virus, while still early in the characterization process:
- Does effectively infect humans
- Can (but, not always) cause significant disease
- Likely does have a primary animal vector that has not been identified (bats are suspected). Until the animal vector is identified, it is not possible to know if an infected animal shows signs of disease when infectious, or how to control or limit contact with infected animals.
- Does pass relatively easily between humans, although the exact mode of transmission is not yet determined. So far, it appears to be transmitted in a manner similar to influenza (infectious particles in body fluids of infected people), but determination has not yet been made as to how well the particles survive on airborne carriers (e.g., particles are blown into the air when an infected person sneezes) or on surfaces (e.g., table tops/doorknobs)
- And, until the virus is better characterized, there are few effective control measures short of quarantine of potentially infected people and isolation of those with suspected or known infection.
What will determine if the coronavirus becomes a problem I need to worry about?
Whether or not this local epidemic becomes a “pandemic” depends on the ability of the public health community to:
- Identify and control the non-human (animal) vector (carrier)
- Identify and quarantine or isolate affected people. The degree to which people are infectious, but still able to carry out their daily activities, is critical and not yet known. China is taking a relatively extreme step of limiting internal movement in the country to mitigate spread. Although approximately 5 million people, one-third of the population of the source city, Wuhan, left on holiday before the quarantine was initiated. The World Health Organization yesterday took the highly unusual step of recommending that all countries institute screening programs for all travelers from affected countries and instruct all such travelers to report to health authorities immediately if they develop any fever or flu-like symptoms within 14 days after arrival.
- Apply infection control measures to protect non-infected people. This depends on understanding where and how long the virus survives in the environment and will be one of the first important characterizations that the public health community will develop. If the infection characteristics are similar to influenza (as is likely), then fairly straightforward methods such as hand-washing/disinfection, frequent surface cleanings, keeping sick people out of public places, etc., will be effective in limiting the breadth of the epidemic.
- Develop countermeasures (vaccines and/or anti-viral drugs). This takes months to years unless an existing anti-viral is found to be effective (coronaviruses are typically not well controlled by existing anti-virals).
Are all viruses concerning?
Viruses are constantly evolving. These evolved viruses rarely cause us concern because they do not affect humans or even if they do, they do not easily pass from person to person, are controllable by a drug or vaccine, or only cause minimal illness. Often, we know what carries the disease (an animal or insect) and can control that carrier, or the disease is only transmissible when the affected person is obviously ill, making isolation easier to carry out.
So what do I need to do now?
As noted earlier, unless you are traveling internationally, no specific actions are needed. This is flu season, however, so the things you can do to reduce your risk of catching the flu would also reduce your risk of becoming infected with the coronavirus. At this point, in the exceeding low likelihood you could come into direct or indirect contact with an infected person:
- Wash your hands frequently and use hand-sanitizers routinely when touching public or semi-public surfaces
- Maintain your personal space in public areas. Airborne droplets that can carry viruses typically only travel a few feet before falling to the ground.
- Masks are more helpful in preventing infected people from transmitting disease rather than keeping healthy people from being infected. If you, your family members, or household staff have any signs of an upper respiratory infection, wearing a mask can greatly decrease viral transmission. The most common route of viral infection is not breathing in viral particles, but inoculating yourself (touching eyes, nose, mouth) after touching a contaminated surface. Masks may help you remember not to touch your face without washing or disinfecting your hands, first, so they do have value. Masks are generally useful for no more than one day or less (once damp or dirty they need to be exchanged).
- Clean and disinfect public and semi-public surfaces in your home and office regularly
- Various vitamins and other home remedies have not been shown to effectively limit infection although they may help your body minimize disease if you are infected. A balanced diet will help ensure your body is optimally situated to deal with infections, but no supplements have been shown to minimize infection. Studies on Vitamin C and E have found theoretical benefits but no actual real-life effects on preventing infections.
- Airflow on modern airplanes is designed to knock down and filter all airborne particles relatively efficiently. Applying the above guidelines (including wiping down your personal space on the plane, such as seat-back trays, armrests, and public reading material) when flying will help minimize your infection risk.