CDC Provides Test Protocol for Novel Coronavirus

The CDC diagnostic test is a reverse transcriptase real-time PCR (rRT-PCR) assay developed for respiratory and blood serum samples. The protocol to make the assay has been made publicly available.

Specifically, if a person is identified with a travel history or contact that could have led to exposure, and also has a fever and respiratory illness, typically a health department is alerted. Through discussion with CDC, it is determined whether diagnostics are merited, and a sample is sent to CDC. All told 260 people in 26 states are currently or have been investigated for 2019-nCoV infection. To date, the agency has screened 2,400 people at five selected USA ports of entry. It is continuing to assess the public health situation as it evolves, she said, adding that CDC will likely be providing guidance on potential additional travel restrictions in the next few days.

The protocol specifies primers and probes, provides guidance on sample preparation, and advises performing rRT-PCR on the AB 7500 Fast DX thermal cycler (Thermo Fisher Scientific, Waltham, MA, USA). The agency's interim guidance for 2019-nCoV testing indicates biosafety precautions of using RNase Away or freshly prepared solution of 10% bleach for cleanup. In addition to the 11 cases confirmed positive in the USA using the rRT-PCR test, and167 cases confirmed negative, there are also 82 cases pending, which the agency said on its website includes specimens received and awaiting testing, as well as specimens en route to CDC.

Nancy Messonnier, MD, the director of the National Center for Immunization and Respiratory Diseases, said, “The time lag between the decision that a patient needs further laboratory testing and a test result is somewhere around a day, depending on geographically where that patient is being seen and how we can most efficiently ship. This is essentially a blueprint to make the test. Currently we are refining the use of this test so we can provide optimal guidance to states and laboratorians on how to use it.”

Related Links:
US Centers for Disease Control and Prevention
Thermo Fisher Scientific