Express tests: self-diagnosis
The stripe is red, the stripe is white...
Svetlana Ryabukhina, "AIF Health"
To diagnose yourself without leaving home is tempting, isn't it? And it's not fantastic. Express diagnostics is becoming more and more confident in our lives
On pharmacy shelves, you can find a lot of so-called express or quick tests (from the English word "fast"): pregnancy, sexually transmitted diseases, HIV, blood glucose levels that determine cholesterol levels, myocardial infarction… How do they work and can they be trusted?
Evgeny Zaraisky, Senior researcher at the Institute of Applied Mechanics of the Russian Academy of Sciences, Corresponding member of the Academy of Medical and Technical Sciences, tells.
Quickly and clearly
Express diagnostics opens up new opportunities for both patients and doctors. Its advantages are speed, visibility, ease of use. Quick tests do not require special equipment, trained medical personnel, they can be used in any conditions - at home, on a trip, on vacation ... With apparent simplicity, these tests are the product of the latest scientific achievements. The gold or polymer nanoparticles used in them are a good example of the use of nanotechnology in medicine.
For example, a test for myocardial infarction. This condition develops gradually. Heart pain, nausea may bother you. Should I limit myself to a validol tablet or call an ambulance? With the help of an express test, it is possible to determine whether a specific protein has formed in the body, which indicates the beginning of a lesion of the heart muscle. To do this, a drop of blood should be placed on a special strip soaked with a reagent. If the color has changed, it is an alarm signal.
Rapid tests are divided into two groups: biochemical and immunological. Biochemical ones are arranged simply – paper squares with dry reagents are pasted on polymer strips, which change their color under the action of substances contained in blood, saliva, urine or feces. In three to five minutes, you can determine the level of glucose in the blood, make a urine test for protein content… The nomenclature of biochemical tests is small – only about a dozen names, but they are sold in tens of millions. Determination of sugar and cholesterol in the blood are the most common methods of home diagnostics, only a thermometer is more popular.
The second group of quick tests, immunological, is much more diverse – it has several hundred names, most of which are based on the principle of immunochromatography, that is, binding diagnostic molecules with special antibodies and complexes of colored nanoparticles in the thickness of microporous membranes. The most famous representative of this group is a pregnancy test.
Popularity rating
This test was developed first and still leads in the number of sales. During pregnancy, a special hormone appears in the urine – chorionic gonadotropin, which is determined by express diagnostics. Two to three days before the expected start of menstruation, the test allows you to detect pregnancy in 80% of cases, and two to three days after the delay - in almost 100% of cases.
HIV tests were initially intended for compulsory tests – in places of detention, in the army. With the help of a special device, a drop of saliva is taken and placed on a special strip. These tests can be found in pharmacies, but they are not particularly popular. But tests for the content of drugs in urine turned out to be in demand: they are bought by parents who suspect that something is wrong with a teenage child. Tests can determine the presence of opiates, cocaine, marijuana, methamphetamine, amphetamines in the body. In addition to single-component tests (only for one drug), three- to six-component tests are also available.
Most of the express tests that are now on sale are imported. But the AMNI test developed in Russia for the leakage of fetal waters is now produced in the USA and sold all over the world, including in our country.
Screening tool
Expert tests open up great opportunities for large-scale screening studies. Tests are sent to your home, you conduct an examination, and the result is sent or taken to a doctor. In Sweden, such studies were conducted on chlamydia. Switzerland has a federal program for the prevention of intestinal cancer. People who have reached a certain age take rapid tests for hidden blood in the feces. This has significantly reduced the death rate from bowel cancer and stomach cancer.
Screening examinations are also widely used in the USA. People are sent home tests to determine protein in urine, blood sugar, hidden blood in feces, HIV. After sending the result to the laboratory, you can get data about your health in a week.
A test has already been developed to detect a prostate-specific antigen that causes a malignant tumor of the prostate gland in men. Detected in the early stages, this disease is almost always cured.
Undoubtedly, there will be other rapid tests in the future. Without leaving home, it will be possible to determine your hemoglobin, which is lowered in every fourth woman, which is why they quickly get tired, feel unwell. Meticulous Swedes have calculated that the rise of hemoglobin is only one gram (so in the text – VM :) gives an increase in labor productivity by 25%.
Diagnostics of the future
Despite all the advantages of express diagnostics, it is developing rather slowly in our country. Advertising and government support are necessary here, because oncological and cardiovascular diseases are a serious social problem. Take at least a test for myocardial infarction. It costs quite expensive – from 200 to 500 rubles, it is difficult to find it in pharmacies. And how many lives he could have saved! Such a test should be in the pocket of every person from the risk group (hypertensive patients, patients with angina pectoris). And it should cost a penny, and if a syringe with heparin is attached to it, anyone will be able to provide first aid to himself, prevent the development of a heart attack.
The same vital test, which is currently available only abroad, is for monitoring the level of prothrombin. Thrombosis affects one person in a thousand worldwide. It is because of thrombosis that sudden death occurs in 30-40% of cases. It is especially annoying when people die due to the development of thromboembolism after the most difficult, successfully performed operations.
Quick tests, which are produced by dozens of companies and used by thousands of laboratories, will become cheaper and more accessible, their quality will improve. And the day is not far off when they will become as familiar as a thermometer or a tonometer.
Important
Carefully read the instructions for the tests and follow them accurately, otherwise the result may be erroneous.
It should be borne in mind that some products and medications may affect the test result. For example, when taking a cough medicine containing codeine, the test result for opiates may be positive.
By the way
The reliability of express tests produced by reputable firms is 93-100%. Compare with the accuracy of the diagnoses that doctors make. Special studies have shown that a professor who has worked in this field of medicine for 20 years makes about 20% of erroneous diagnoses, an associate professor – 18%, a young specialist who has completed a residency – about 40%.
Portal "Eternal youth" http://vechnayamolodost.ru14.09.2009