Five joint tests for respiratory diseases

The five-joint test for respiratory diseases is currently the most commonly used rapid joint screening project in clinical practice for high-risk respiratory infections. It can simultaneously detect five types of pathogens: influenza A virus, influenza B virus, respiratory syncytial virus, adenovirus, and Mycoplasma pneumoniae. The results can be obtained in the fastest 15 minutes. It can solve the core pain point of "unclear pathogens and inability to use targeted medication" in more than 80% of preliminary screenings for respiratory infections. It has now become a routine billing item for respiratory departments and pediatrics in most domestic hospitals in autumn and winter.

If you have been to the respiratory department or pediatrics department of a hospital in autumn and winter, you are most likely familiar with this test. After waiting in line for an hour or two, the doctor will probably prescribe this test first after listening to the lungs and asking about symptoms. He will take a long cotton swab and poke it twice in the throat or nose, then send it to the test window and wait for ten minutes for the report to come out. Director Zhang of the Department of Pediatrics at a tertiary A hospital I know talked to me last year, saying that during the peak period of respiratory infections in the autumn and winter of 2023, after their outpatient clinic adopted the five-component test as the first screening item for patients with fever and respiratory symptoms, the rate of irrational use of antibiotics dropped directly from 41% before to 14%. ”

However, not all practitioners think that the five-joint test is "omnipotent". Friends in the laboratory department have complained many times that the immunochromatographic principle used in the five-joint test is destined to be much lower than the single-pathogen nucleic acid test. Especially when the viral load is not high 24 hours before infection, the false negative rate can reach more than 20%. At the end of last year, I accompanied my niece to see a doctor. She had a fever of 39 degrees and was still coughing. The first five-part test was negative. The doctor asked and found out that she secretly drank half a cup of iced milk tea before coming, which washed away the pathogens in her throat. She waited two hours on an empty stomach and took another test, only to find out that she was positive for B flow. Many patients also complain about inconsistent pricing and huge differences in medical insurance coverage. In some places, it only costs thirty or forty to complete the employee medical insurance, while in other places it costs more than two hundred to pay for it all out of pocket. Many people feel that "it's just a cold, and spending two hundred to get tested is a waste of money."

In fact, there is absolutely no need to either deify or reject this test. If you only have a runny nose, a low-grade fever of over 37 degrees, and are in good spirits, there is no need to go to the hospital to join in the fun. The risk of cross-infection is higher than your own risk of a cold. But if you have a fever above 38.5 degrees for more than two days, you are coughing so much that you can't sleep at night, or there are susceptible people such as the elderly, pregnant women, and babies at home, it is still cost-effective to take a test - at least you know what the infection is. For mycoplasma, use Archie. For influenza A and B, oseltamivir is most effective within 48 hours. If it is a common viral infection, just go home and drink more water and rest. There is no need to take antibiotics blindly.

Oh, yes, one more thing to mention, don’t feel like you are “not trying to deal with anything” when you see that all five joint tests are negative. These five pathogens are only the most common, accounting for about 80% of clinical respiratory infections. There are also rhinovirus, parainfluenza virus, chlamydia pneumonia, and many other pathogens that are not within the detection range. If the symptoms continue to worsen, even if the five joint tests are all negative, you must follow the doctor’s advice for further examination. Don’t regret it if you develop pneumonia.

To put it bluntly, the five-component test is just a tool to help you quickly find out the cause of infection. It is not as bad as the "money-stealing" mentioned on the Internet, nor is it a god-level test that can detect everything. Whether you should do it or not, just listen to the doctor based on your own physical condition. After all, there is never a one-size-fits-all standard answer when it comes to illness.