The potential benefits of a universal testing approach include the ability to use Covid-19 status to determine hospital isolation practices and bed assignments, inform neonatal care, and guide the use of personal protective equipment. Access to such clinical data provides an important opportunity to protect mothers, babies, and health care teams during these challenging times. Diagnostic testing to identify persons infected with severe acute respiratory syndrome–related coronavirus-2 (SARS–CoV-2) infection is central to control the global pandemic of COVID-19 that began in late 2019. In a few countries, the use of diagnostic testing on a massive scale has been a cornerstone of successful containment strategies. In contrast, the United States, hampered by limited testing capacity, has prioritized testing for specific groups of persons.
The potential benefits of a universal testing approach include the ability to use COVID-19 status to determine hospital isolation practices and bed assignments, inform neonatal care, and guide the use of personal protective equipment. The CDC 2019 Novel Coronavirus (2019-nCoV) Real-Time Reverse Transcriptase (RT)-PCR Diagnostic Panel detects the SARS-CoV-2 virus in upper and lower respiratory specimens. Age and the presence of comorbid illnesses increase the risk for death among persons with COVID-19. The clinical manifestations of COVID-19 in children are less severe compared with adults, yet age younger than 1 year seems to increase the risk for critical illness. Current case-fatality rate estimates range from 0.6% to 7.2% by region and seem to be substantially higher than the 0.1% mortality rate of seasonal influenza. However, current estimates of COVID-19 case-fatality rates are probably inflated because of preferential testing in many countries of persons with severe manifestations, who are at risk for death. It is designed to be used with an existing RT-PCR testing instrument commonly used to test for seasonal influenza.
During the SARS-CoV-2 pandemic, state public health laboratories can authorize county or city laboratories in each state. These laboratories must be certified under the Clinical Laboratory Improvement Amendment (CLIA) to perform high complexity tests, have appropriate laboratory equipment and training, and demonstrate testing proficiency under their state laboratory’s stewardship in order to maintain their status as an IRR registered laboratory.
Although excellent tools exist for the diagnosis of symptomatic patients in well-equipped laboratories, important gaps remain in screening asymptomatic persons in the incubation phase, as well as in the accurate determination of live viral shedding during convalescence to inform decisions to end isolation. Many affluent countries have encountered challenges in test delivery and specimen collection that have inhibited rapid increases in testing capacity. These challenges may be even greater in low-resource settings. Urgent clinical and public health needs currently drive an unprecedented global effort to increase testing capacity for SARS–CoV-2 infection.
Laboratory-based molecular assays for detecting SARS–CoV-2 in respiratory specimens are the current reference standard for COVID-19 diagnosis, but point-of-care technologies and serologic immunoassays are rapidly emerging. Testing for the presence of the SARS-CoV-2 virus has been extensively discussed during the COVID-19 pandemic. The most sensitive tests measure the presence of the virus’ genetic material, RNA, in a patient’s sample, suggesting an ongoing infection. Early, massive deployment of SARS–CoV-2 diagnostics for case finding helped curb the epidemic in several countries. Urgent clinical and public health needs now drive an unprecedented global effort to increase testing capacity. The primary goal of epidemic containment is to reduce disease transmission by reducing the number of susceptible persons in the population or by reducing the basic reproductive number (R0). A huge effort is needed to scale up COVID-19 testing to a level required to ensure public safety. Many tests take several hours to complete and require extensive human labor as well as materials and equipment that are not universally available. This number is modulated by such factors as the duration of viral shedding, the infectiousness of the organism, and the contact matrix between infected and susceptible persons