Positive test results using a viral test (NAAT, antigen or other tests) in persons with signs or symptoms consistent with COVID-19 indicate that the person has COVID-19, independent of vaccination status of the person. ). Therefore, lower prevalence of positive test results over time and after asymptomatic infections might reflect lower infectiousness. Travelers have to consider the possibility of testing positive for COVID-19 while abroad. Information that identifies you personally (such as your name and date of birth) and matches your passport. The agency says, If you have recovered from COVID-19 but are not able to obtain documentation of recovery that fulfills the requirements, you will need to show a negative COVID-19 viral test result from a sample taken no more than one day before your flight to the US departs.. Overview of Testing for SARS-CoV-2, the virus that causes COVID-19 - CDC part 56; 42 U.S.C. The TCID50 value can also be considered a proxy for the Analytical Sensitivity or the Limit of Detection of a test. Sect. Many tests have had their expiration dates extended anywhere from 15 to 22 months. Two types of serologic tests have received EUAs from the FDA. All travelers coming to the U.S., vaccinated or not, must produce a negative COVID-19 test taken within one calendar day of their departure. False positive test results may occur due to cross-reactivity from pre-existing antibodies to other coronaviruses. "I tested positive this morning, going to be working from home. Epub December, 21, 2021. The type of test used is not the only reason why someone would continue to keep testing positive for COVID-19 for a while. Using a nasal swab to get a fluid sample, antigen tests can produce results in minutes. In fact, because each of these tests target multiple locations on the virus genome, they can be helpful in identifying new genetic variants before they become widespread in the population. Even after you're done masking, you may still need to test again within three months of a positive COVID-19 test, such as for travel. When Should You Test (and Possibly Retest) After Being Exposed to COVID-19? Sect 3501 et seq. What happens after the positive test depends entirely on the destination and, in some cases, your vaccination and booster status. Centers for Disease Control and Prevention. How do COVID-19 antibody tests differ from diagnostic tests? - MSN COVID testing guide: Here's everything you need to know - NPR Among 541 persons who received a primary vaccination series, 285 (52.7%) had a positive antigen test result, including 127 of 215 (59.1%) persons who had received a booster dose and 158 of 326 (48.5%) who had not received a booster dose.