Curative offers a PCR test using spit rather than swabs from the back of your nasal cavity. Initially only authorized for use on symptomatic patients, the company has requested the U.S. Food and Drug Administration expand its authorization for use on asymptomatic individuals.
According to company data, the spit test accurately identifies about 90% of positive cases when compared against a nasopharyngeal PCR test set to 35 cycle threshold (CT).
According to the FDA, that comparative CT is too low, and will produce too many false negatives. This, despite the scientific consensus, which states anything over 35 CTs is scientifically unjustifiable as it produces enormous amounts of false positives.
According to an April 2020 study, a CT of 17 must be used to obtain 100% confirmed real positives. Above 17 cycles, accuracy drops dramatically. At 33 cycles, the false positive rate is 80%. Beyond 34 cycles, the false positive rate reaches 100%.
Because the PCR test cannot discern between live virus and dead, noninfectious viral debris, the timing of the test is important. Recent research shows the median time from symptom onset to viral clearance confirmed by viral culture is seven days, whereas the PCR test continues to detect nonviable (noninfectious) SARS-CoV-2 for a median of 34 days.