PCR vs. rapid COVID-19 test: What’s the difference?

Getting examined if you happen to’re experiencing signs or have been uncovered to COVID-19 is step one in opposition to stopping the unfold of the virus.

When to check for COVID

Realizing when to check for COVID is vital.

• In case you have symptoms, check instantly.
• If you happen to had been uncovered to COVID-19 and will not be experiencing any signs, wait at the least 5 days after your publicity earlier than testing. If you happen to check too early, you might be extra prone to get an inaccurate outcome.

If you happen to check optimistic for COVID-19, isolate and take precautions to guard others from getting contaminated.

• Inform individuals you had current contact with that they could have been uncovered.
• Monitor your signs. In case you have expertise severe sickness, search emergency care instantly.
• Think about contacting your well being care supplier to find out about that you could be qualify to obtain. Remedy have to be began inside a number of days after you first develop signs to be efficient

Kinds of COVID-19 exams

There are two kinds of COVID-19 tests: the polymerase chain response (PCR) check and the antigen check, often called the speedy check. Each exams require a pattern from the affected person, normally a nasal swab.

PCR check

The way it works

The PCR check takes a pattern of ribonucleic acid (RNA) and “amplifies” it with the assistance of lab applied sciences. Amplifying RNA helps to make even small traces of the COVID-19 virus seen within the check pattern. Even you probably have a small hint of the virus in your system, the PCR check will detect it.

Advantages

“PCR exams are extra dependable and correct resulting from testing the precise genetic materials of the virus, eliminating the interference from different viruses,” mentioned Heather Seyko, a Laboratory Providers supervisor for OSF HealthCare.

Drawbacks

Whereas a PCR check is the popular technique of detecting COVID-19, it have to be carried out by a well being care supplier. These exams don’t produce quick outcomes, which implies you might be ready a couple of days to know if you happen to’re optimistic or destructive.

The Centers for Disease Control and Prevention notes whereas exams are finest used early in the midst of sickness to diagnose COVID-19, they’ll’t consider the length of infectiousness. PCR exams typically can keep optimistic for weeks after you’ve had COVID. It is because the PCR check is so delicate it may possibly detect even useless virus.

Antigen check

The way it works

The speedy check, referred to as an antigen check, checks for proteins which are discovered on the skin of the virus.

The antigen check mimics what antibodies do. Antibodies are the “good guys” that connect to the antigen protein (the “dangerous guys”) and combat the virus. Once you give your nasal swab pattern, it’s put right into a liquid after which onto a check strip.

The check strip acts like an antibody – if there are any COVID-19 antigen “dangerous guys” in your system, the molecules within the liquid will connect to these antigens, and a line will seem on the check strip. This implies you’re optimistic for COVID-19. If there are not any antigens detected in your system, the liquid doesn’t reply and no line will seem, typically which means you’re destructive for the virus.

Advantages

• Ends in about quarter-hour
• Simple sufficient to do by yourself at house. There’s at all times a little bit room for consumer error, however so long as you intently comply with the instructions, anybody can check themselves with an antigen check.
• Helps gradual the spread of contagious viruses like COVID-19 with faster outcomes

Drawbacks

“In contrast to the PCR check, the antigen check can solely decide you probably have an lively virus in your physique. The speedy check can’t detect small quantities of the virus or asymptomatic circumstances as precisely because the PCR check can,” Heather mentioned.

So how correct are house COVID-19 exams? The speedy check is much less correct and there’s a larger probability for a false destructive, not a false optimistic. The check solely picks up if the virus is lively in your physique, which means asymptomatic circumstances. If somebody doesn’t have any signs, these circumstances  are more durable to establish with the antigen check.

Selecting a PCR or antigen check

If you happen to’re visiting a well being care supplier to get examined, it’s doubtless you received’t get to decide on which check you get. That is for a couple of causes. First, it may simply be a matter of what check is available or in larger provide. Second, exams are chosen based mostly on likelihood of getting the virus.

“PCR can be chosen the place there’s a low chance of getting the virus, however we wish to be sure the affected person doesn’t have it. Antigen can be chosen if there’s a excessive likelihood the affected person has the virus (i.e. is experiencing signs), and we have to display the affected person as optimistic or destructive,” Heather mentioned.

Getting examined is a crucial a part of slowing the unfold of COVID-19. With extra correct outcomes, PCR exams are the popular strategy to go, however antigen exams work for speedy outcomes, as properly.

Antibody testing

Antibody testing can be obtainable and is designed to establish individuals who have recovered from the virus.

An antibody check may yield two outcomes:

• If you happen to check optimistic for antibodies, this implies you have got been beforehand contaminated with COVID-19, and you’ve got recovered. This doesn’t essentially imply you’re immune from contracting the virus once more.
• If you happen to check destructive for antibodies, this implies the lab couldn’t detect antibodies for COVID-19. This implies you’re nonetheless inclined to the virus.

Your supplier may advocate this blood check you probably have beforehand proven signs and wish to know in the event that they had been attributable to COVID-19.

Final Up to date: Might 30, 2023