COVID vaccination efforts continue to gain momentum in the United States and around the world, but that does not mean that we are out of the pandemic forest yet. Regular testing remains an important factor in helping to slow the spread of the disease, but it usually requires a visit to your doctor or local clinic. Fortunately, this is no longer the case. In the past few months, the FDA has what it can be and return results in minutes instead of days.
If you took a COVID test in person last year, your nasal smear sample was probably diagnosed using a (real-time RT-PCR), which is among the most accurate and widely used laboratory methods to detect viral pathogens like Zika , Ebola and coronavirus.
Coronavirus contains only single-stranded RNA for genetic material that, unlike DNA, cannot be reproduced independently without the help of a host. As such, the virus must infect and redirect healthy cells to produce more of itself. RT – PCR simulates this process by first converting any coronavirus RNA present in a given sample into DNA – hence “” – and then creating billions of copies of the genetic material and tagging them with a fluorescent dye for identification.
The process is an offshoot of the more general PCR method, used to detect pathogens whose genetic material comes in the form of DNA and therefore does not need amplification. This process is sensitive and highly accurate, although time consuming, but allows pathologists to detect a coronavirus infection in its early stages, since only a small amount of initial RNA is required. Although the RT-PCR technique presents a low chance of external contamination, its capacity is limited, as it can only detect the coronavirus when it is currently present in a sample. This method cannot tell if someone has already been infected.
Some home tests rely on a similar process called isothermal amplification. Like PCR, isothermal amplification generates multiple copies of the coronavirus genetic material to aid in detection. Although AI is not as sensitive as the laboratory-based PCR method, it is more accurate than other home tests that look for antigens – bits of coronavirus proteins that elicit the body’s immune response.
For example, an antigen-based BinaxNOW test correctly detects the virus in symptomatic people. That number drops to just 35 percent in asymptomatic patients. Since antigen tests do not include a reverse transcription phase, they are faster and cheaper to perform than methods based on PCR and AI, but are less accurate and return higher rates of false negatives – especially among people who have been exposed recently.
The antigen method provides a general estimate of how contagious you are, Dr. Gigi Gronvall of Johns Hopkins University . “If you are positive about it, you really need to isolate,” she said.
So, if you we are asymptomatic, a PCR or similar molecular-based test should suffice. If you suddenly find that you can’t smell or taste anything, have a PCR or the most sensitive antigen-based test you can find. If your test is positive, regardless of the type of test you use, immediately isolate yourself and call a doctor.
So far, only a handful of home tests have obtained the FDA’s Emergency Use Authorization (USA). EUAs are unapproved medical treatments, tests or countermeasures that have been able to bypass the formal (and lengthy) FDA approval process in response to life-threatening health crises, such as the one we are currently facing.
Is the first home test available without a prescription. It is based on antigens and takes 15 minutes to return a result. You will need to clean your nose and then place the sample on a table analyzer along with some of the processing liquid. Once the device does its job, the results are transmitted via Bluetooth to your smartphone. This data is also shared through a secure, HIPAA-compliant cloud connection for health officials to assist in outbreak mapping. The test is expected to cost about $ 30, although the company has yet to announce where and when it will be available. Ellume’s test exhibited 96 percent accuracy in people aged 2 years and older during its clinical trial in the USA.
a $ 231.8 million deal with the Australian company for the purchase of 8.5 million test units. Ellume “will deliver 100,000 tests per month from the Australian plant until the US facility is built,” said a company representative. NPR. “At full capacity, the US facility will be able to produce up to 19 million tests per month. The 8.5 million tests for the US government are a part of the overall fabrication. “However, with one going so far as to characterize the effort as” saliva in the ocean “.
The will also be available soon over the counter, but unlike Ellume, it uses a nucleic acid amplification test (similar to PCR) for greater accuracy and generates results in 20 minutes. According to a recent one, “in prospective studies to evaluate the use of the Cue OTC Test, the results were 97.4% agreement for positive cases and 99.1% agreement for negative cases compared to the results of a laboratory test of highly sensitive USA PCR ”. The company has yet to announce price or availability.
it’s not just a bit of saying, it’s a whole process. After answering a series of screening questions through the digital health website eMed, Abbot will deliver a test to your home. Then, you will be connected to a “telehealth professional” who will guide you through the sample collection process. After placing your sample in the analyzer, you should get the results in about 15 minutes using the Navica smartphone app. The Abbot test costs $ 25 and is only available with a prescription.
It costs $ 50 and, like Cue, uses molecular technology. As with BinaxNOW, it requires a prescription, so your doctor will need to order it on your behalf. The Lucira test must be used by people aged 14 and over, it returns the results in 11 to 30 minutes.
If you don’t mind waiting for the results for a while, Amazon is selling. Each costs $ 110 and requires that you send it to the company’s LA lab for diagnosis. On the positive side, this test is based on saliva, so you won’t have to impale your nasal cavity with a cotton swab to collect your sample. The results will be available in 24 to 72 hours on the company’s web site.
Likewise, the CRL Rapid Response COVID-19 Saliva Test can cost $ 119 and returns results in just 24-48 hours. If your test is positive, the company will have a telemedicine representative to discuss the diagnosis and possible next steps.
Although all tests done entirely at home have shown an accuracy of more than 90% during their clinical tests, these numbers may fluctuate when ordinary people perform the tests on their own, so do not treat a negative result as a license to go out and get mixed up. “When manufacturers are preparing data to send to the FDA, they conduct studies under very specific and highly controlled conditions that optimize test performance,” said Kelly Wroblewski, director of infectious disease programs at the Association of Public Health Laboratories. .