Editor's Note: (Dr. Leana S. Wen is an emergency physician and a visiting professor at George Washington University Milken Institute School of Public Health. Previously, she served as Baltimore's health commissioner. Follow on Twitter: @DrLeanaWen. View more opinion articles on CNN.)
(CNN) On Wednesday, the Centers for Disease Control and Prevention (CDC) said a new case of novel coronavirus, Covid-19, in California could be the first instance of "community spread" in the country. The news came a day after the CDC warned an outbreak of Covid-19 in the US is inevitable, stating that it's not a question of if, but when, it will happen.
At this point, the train has left the station for trying to contain the disease, and the CDC and other public health experts are preparing the US to switch to mitigating its impact.
Covid-19 will test our government's response and resiliency. How we weather the outbreak also hinges on our trust that the government has our best intentions at heart.
When Covid-19 was first discovered, US public health officials worked to contain the outbreak with quarantines and travel restrictions. This was an aggressive approach that some have criticized, but it has been effective in delaying disease transmission within the US. To date, only a very small number of confirmed cases of Covid-19 have been diagnosed in America.
The recent worldwide escalation of coronavirus cases has made clear that the containment approach alone will no longer work. There are now over 40 countries with Covid-19. Many have fragile health systems that are already overburdened. Community transmission is occurring within multiple countries—meaning that it's not just travelers bringing back the disease, but people in the community who are transmitting it to others.
There is also growing evidence that Covid-19 can be found in people with minimal or no symptoms, and that asymptomatic people can be contagious. Very likely, there are far more cases than are being detected all around the world. This will almost certainly get worse. Harvard University epidemiologist Dr. Marc Lipsitch provided a startling estimate: within the coming year, 40 to 70 % of people around the world could be infected with the virus that causes Covid-19.
Shutting down borders will no longer work. In fact, they can have unintended negative effects in the form of disrupting supply chains of medical equipment and life-saving medications. The initial containment efforts were necessary—and they worked. But when the disease reaches a much larger scale, the US will run out of capacity to keep on imposing quarantines, which won't be effective then either.
So what happens next? The CDC warned that "disruption to everyday life may be severe." We have seen this play out in China, Japan, Italy, Iran, Korea, and other countries with significant numbers of affected people. Mass gatherings have been postponed or changed, with conferences canceled and sporting events played with no live audience. Workers are telecommuting and students are staying home from school. If there are sudden clusters of Covid-19 community transmission in the US, these measures could be implemented here too.
Whether they do depends on our rapidly evolving understanding of the disease. New data are coming out every day about Covid-19, and one critical piece of information is exactly how deadly this disease is. At the moment, it appears that Covid-19 has a 2% fatality rate—lower than SARS and MERS (10% and 30-40%, respectively), but higher than influenza (0.1%). Given the lack of ongoing surveillance and high numbers of people who are not being tested and diagnosed, some public health experts predict that the actual fatality rate of Covid-19 is much lower than 2% and may be closer to 0.1%.
If that's the case, Covid-19 could be treated as we treat influenza. The flu is a serious seasonal illness that we work hard to prevent and treat. We develop flu vaccines and encourage everyone to obtain them. Those who get the flu and have mild symptoms self-isolate at home and avoid spreading it to others. Those who have much more severe symptoms get hospital care. There are some treatments available that reduce the severity of flu. Some people die from the flu, while the vast majority recover. It's a serious illness, but we don't close schools, restrict travel, and stop global economy because of it.
We don't yet know if the trajectory of Covid-19 will be mild, moderate, or severe. The CDC warnings are appropriate at this time, because our institutions and the American people need to be prepared for the next stage of this outbreak. Health departments and hospitals have pandemic response plans that they need to be reviewing and testing now. The federal government needs to make funding urgently available for local health departments, who are on the frontlines of the epidemic. Local public health does the work of outbreak preparedness and response every day. They know how to handle epidemics, but they need the resources to do their work. And all these institutions have to protect healthcare workers, without whom we have no chance of combating any epidemic.
We as the public can prepare ourselves too. Businesses and schools can prepare contingency plans. Families can formulate plans about telework and think through options for caring for the young and the elderly, should self-isolation be needed. Those with chronic illnesses can prepare to have a three-month supply of medications on hand. (Stockpiling other supplies is not recommended; the run on surgical masks—which have no proven value for everyday citizens—is making it hard for healthcare providers to access them.) Everyone can practice good hygiene: a simple measure like handwashing with soap and warm water reduces the likelihood of contracting respiratory viruses. And we should continue to follow the expert guidance of the CDC and local public health officials.
Finally, the US government must continue to be transparent. Outbreaks are quickly evolving situations. Constant reevaluation is the bedrock of good public health response, and changing course is actually a good thing—it means that officials are responding to new evidence and being nimble with their plans. Public health depends on public trust, and people must be able to trust that our government is following the guidance of experts and that they are being transparent and open with us.