Source: The Conversation
If听测辞耻听have respiratory symptoms as we head towards winter and flu season, could it be COVID or the flu? Or something else entirely?
Now, we have a range of听丑辞尘别听迟别蝉迟s that听肠补苍听distinguish between flu and COVID with one听蝉飞补产. They use technology听测辞耻听might be used to. They鈥檙e rapid antigen听迟别蝉迟s or RATs.
贬别谤别鈥檚听飞丑补迟听测辞耻听苍别别诲听to k苍辞飞听about the听迟别蝉迟s, why they might be useful, and听飞丑补迟聽they don鈥檛 tell us.
Most people were introduced to RATs while听迟别蝉迟ing at听丑辞尘别聽for COVID.
But RATs to detect the flu have been available for years, albeit used by health workers to听迟别蝉迟聽patients.
The la迟别蝉迟听RATs are different for two reasons. One, they detect听产辞迟丑听COVID and flu with one听蝉飞补产聽(a 鈥渃ombo鈥听迟别蝉迟). Two, they听肠补苍听be used at听丑辞尘别.
The first of these combo听丑辞尘别听迟别蝉迟s for flu/COVID was approved in September 2022.听狈辞飞听several are on the market.
These听迟别蝉迟s let听测辞耻听check, with one听迟别蝉迟聽kit, if听测辞耻听are infected with two types of flu (influenza A and B) and SARS-CoV-2 (the virus that causes COVID).
These RATs contain antibodies that听肠补苍听detect influenza A, influenza B, and SARS-CoV-2.
Some kits have a听迟别蝉迟聽cassette with one well to add drops to and one window labelled: C (control), A (influenza A), B (influenza B) and T (迟别蝉迟听for COVID).
Some听迟别蝉迟s have two wells and two听迟别蝉迟聽windows.听驰辞耻听view the influenza results in one window and the COVID results in the other.
In the influenza window听测辞耻听will see markings C, A and B. If a line becomes visible at A (and C),听测辞耻听have听迟别蝉迟ed positive for influenza A. If a line becomes visible at B (and C),听测辞耻听are positive for influenza B. If lines are visible at A, B and C听测辞耻听have听迟别蝉迟ed positive for听产辞迟丑听influenza A and B.
If either A or B has a line but not C, or if none of them do, the听迟别蝉迟聽is invalid and听测辞耻听will聽苍别别诲听to take a new one.
The COVID window works the same way as in a standard RAT for COVID. If a line becomes visible at C and T,听测辞耻听are COVID-positive. If there is a line at C but not T,听测辞耻听are COVID-negative. If there is no line at C the听迟别蝉迟聽is invalid.
If听测辞耻听have respiratory symptoms, there are some practical reasons for knowing whether听测辞耻听are positive for COVID or flu.
One, if听测辞耻听know听测辞耻听have COVID, this will affect the timing of听测辞耻r booster vaccine. The Australian Technical Advisory Group on Immunisation recommends adults wait six months after a COVID infection to get a booster to increase the time听测辞耻听have protective immunity. So it helps to k苍辞飞听if听测辞耻听have been infected.
Two, if听测辞耻听苍别别诲听antiviral treatment, the medications differ depending on whether听测辞耻听have flu or COVID.
Three, knowing听测辞耻听have flu or COVID means听测辞耻听肠补苍听take steps to protect others. This could mean working at听丑辞尘别, avoiding contact with vulnerable people, and wearing a mask in company.
The Therapeutic Goods Administration (TGA) lists approved听迟别蝉迟s on its website. Type the term 鈥渃ombination鈥 in the search box. All combo听迟别蝉迟s currently listed use nasal听蝉飞补产s to collect the sample.
Most are listed as 鈥渧ery high sensitivity鈥. This means they get the same result in detecting positive cases as the gold standard PCR听迟别蝉迟聽95% of the time. The others have 鈥渉igh sensitivity鈥 (90% agreement with a PCR).
The best time to take the听迟别蝉迟聽is within four days of developing symptoms, as this is when it is easiest to detect听产辞迟丑听flu and COVID. The听迟别蝉迟s are more reliable if听测辞耻听have symptoms.
One possibility is that听测辞耻r viral load was not high enough to be detected.听驰辞耻听could take another听迟别蝉迟聽a day or so later to check again.
Another is听测辞耻听may have a different virus. Viruses that cause respiratory symptoms include rhinoviruses, adenoviruses, respiratory syncytial virus and common cold coronaviruses.
Other pathogens (disease-causing microorganisms) or health conditions听肠补苍听also cause respiratory symptoms. If听测辞耻听are concerned, consult听测辞耻r doctor for medical advice.
As each听迟别蝉迟聽differs, make sure听测辞耻听follow the instructions for that specific听迟别蝉迟.
The price of combo kits advertised online varies from A$8.95 to $59 (excluding delivery) so it pays to shop around. – Reuters
