A new antigen assay is similar in reliability (>95% positive, >97% negative) to rtPCR genetic detection method for determining the presence of coronavirus in your system, costs $30 and gives results in 15 minutes.
It is a so called “viral test” which is what the CDC requires for international arrivals. The new test was just approved by the U.S. FDA but guidance has yet been published on using the test for international travel. The developers (Ellume Australia) plan to deliver at least 20 million test kits to the U.S. in the first half of 2021.
Existing “rapid” or quick antibody test are NOT acceptable for travel to the U.S. since they do not test for the presence of the virus.
Taking the Antigen Test
The Ellume test kit is simple, fast and approved for ages 2 and up. According to the New York Times the included swab is inserted first in a nostril then in a microlab capsule and a few minutes later the results appear on your phone via bluetooth. Results can also be shared electronically with public health authorities.
Costa Rica Travel Testing
Testing at a hospital or health facility in Costa Rica costs between $100 and $285 (including 13% tax) and takes at least 12 hours (48 hours on average). Some hotels and resorts are already offering on site sampling for the convenience of their guests and hopefully (nearly) instant viral antigen testing at 3-8 times lower cost may soon just be another part of checkout.
The CDC requirement is to “Get tested with a viral test 1-3 days before you depart” and their definition of viral test states “A viral test checks specimens from your nose or your mouth (saliva) to find out if you are currently infected with SARS-CoV-2, the virus that causes COVID-19. Two types of viral tests can be used: 1) [the regular PCR test] 2) Antigen tests detect viral proteins…”
The Ellume antigen self test is not available in Costa Rica but there is no reason travelers could not bring one from home for use on their return trip. Taking the test in front of an airline agent should eliminate the uncertainties of other 24-48 hour self tests (did you really swab when you said you did and/or did you actually swab yourself or a stray dog?).
While there’s no obvious reason this test shouldn’t be accepted when departing Costa Rica we wouldn’t recommend being the first to try. Ideally the ICT (Costa Rican Tourism board) will purchase a hundred thousand tests, set up drive through instant testing in the parking lot of each airport and include the $20 (bulk discount) cost in the departure tax visitors already pay.