With community spread of COVID-19 apparent in the U.S., the CDC should trigger a comprehensive and aggressive scale-up of health care capacity and infrastructure, with a pandemic preparedness mindset encompassing primary, secondary, and tertiary prevention strategies.
But effective design and implementation of infectious disease counter-measures requires a clear and precise understanding of the transmissibility, virulence, and of the disease, which is lacking for COVID-19. As well, the public health or epidemiological response will be driven by the needs of the particular locality and context, which vary considerably across more than 50 countries now affected by the virus. While there is a promising downward trend in the incidence or number of new cases in China, this continues to be an escalating epidemic, given the , and the sustained transmission of the COVID-19 virus within a number of those countries, including Iran, Italy, and South Korea.
At this stage of the epidemic in the U.S., emphasis should be given to primary prevention strategies, mainly health education and awareness messages and campaigns, designed to inform the public about risk of infection, symptoms, protective measures, and health care services, so as to facilitate the adoption of behaviors conducive to health, and reduce the likelihood of becoming infected. This needs to be carefully thought through in terms of differentiated and targeted messages with attention to research evidence about perceived threat (including personal health beliefs about susceptibility, and severity of disease). Conceptual frameworks such as the Health Belief Model and can be instructive in this regard.
The foremost primary prevention strategy is vaccination, but there is none as of yet, although efforts toward a and are advancing well. Secondary prevention or screening is aimed at early disease detection and intervention usually before the onset of symptoms but also for those with subclinical or mild disease. Notably, it has been reported that globally, of the COVID-19 cases had mild symptoms. Secondary prevention may therefore be particularly if, as a few reports suggest, asymptomatic cases may be able to transmit the virus.
Asymptomatic spread is a challenge to contact tracing and identifying transmission chains. In the COVID-19 context, the benefits of early testing (and disease detection) seem to outweigh the consequences of potential false negatives (from early testing), noting that follow-up testing and monitoring can be conducted, if the suspicion index is high and other criteria are met. Effective secondary prevention demands urgent expansion of healthcare services in terms of isolation and quarantine facilities and treatment, as well as diagnostic testing supplies and facilities, and this must be decentralized to allow for diagnostic testing at the local level.
Tertiary prevention strategies seek to treat and rehabilitate those with the clinical disease, toward reducing sequelae or complications and improving quality of life within a holistic or biopsychosocial framework. Above all, rapid and expanded surveillance is required so that COVID-19 cases and contacts can be quickly identified and contained, and appropriate interventions implemented. Reliable and valid surveillance data are also necessary for evaluating the interventions implemented.
Finally, continuing and emerging concerns center around the adequacy of the quarantine period for COVID-19, quality assurance of diagnostic testing, the need for stricter post-treatment monitoring, and possible -- those who have recovered from COVID-19 but may remain capable of transmitting the virus to others.
Rossi A. Hassad, PhD, MPH, is an epidemiologist and professor at Mercy College in Dobbs Ferry, New York. He is a member of the American College of Epidemiology, and a fellow and chartered statistician of the Royal Statistical Society.