Where can I donate blood for sterility. What is a blood test for sterility
A blood test for sterility is a clinical study aimed at identifying pathogenic bacteria in the blood. Allows you to diagnose severe diseases of various etiologies.
Attention! Correct diagnosis of bacterial infections allows you to prescribe effective drug therapy. In recent years, there has been a significant increase in the number of bacterial infections resistant to modern antibiotics. Scientists believe that this is due to the widespread misuse of antibacterial drugs.
Known antibacterial drugsWhat is a blood sterility test?
What does a general clinical analysis of blood sterility show? A sterility test is performed to detect a bacterial infection in the blood. Normally, blood is sterile, but some microbes can disrupt this state and lead to the development of diseases. In municipal and private clinics, a doctor, if a bacterial infection is suspected, writes out a referral for bacterial culture.
Bacteremia in the blood indicates the presence of diseases:
- Sepsis.
- Furunculosis.
- Meningitis.
- Myocarditis.
- Tuberculosis.
The study identifies staphylococcal, streptococcal, rod-shaped and other bacterial pathogens. Bakposev is an effective diagnostic technique that can identify the type of pathogenic microorganism. The main disadvantage of the method is a long period of study, which ranges from 4 to 15 days. Over such a period of time, an infectious pathogen can cause serious complications and lead to death. Therefore, drug therapy is started at the initial stages of infection, without waiting for the results of tests from the laboratory. In the Russian Federation, drugs of the penicillin series are prescribed first of all, but recently there has been more and more data on allergic reactions to this antibacterial agent.
Clinical blood test Often, blood sampling for sterility is carried out with resistance to first-line antibiotics. In such patients, bacteria with reduced sensitivity to antibacterial drugs are present. A prerequisite for blood culture for pathogenic pathogens is the postoperative period, suspicion of sepsis and bypass of the heart muscle. HIV-infected people are exposed to harmful microorganisms. Such patients have Mycobacterium tuberculosis in their blood.
Blood test for bacterial culture: preparation for the procedure
Biological material must be taken on an empty stomach and in the morning. Before the procedure, exclude the intake of fatty foods and excessive amounts of "fast" carbohydrates. Refuse to eat 12 hours before taking biological material and conducting a hemotest. Women during pregnancy and infants should avoid psycho-emotional, physical exertion.
The use of psychotropic substances and drugs is contraindicated. Tell your doctor in advance about taking medications. Failure to comply with the conditions increases the likelihood that the hemotest will show a false positive result.
Blood for sterility: rules for sampling biological material
Blood is taken for sterility from a vein at the bend of the elbow joint. In a newborn child, material for research is taken from a finger. The technique of blood sampling for sterility is performed according to WHO standards.
Algorithm of actions, how to take blood for sterility:
- The injection site is treated with an antiseptic (ethyl alcohol).
- The material is taken with a disposable syringe and in an environment where it is relatively sterile.
- After inserting the needle into the vein, 6-11 ml of blood is taken, which is placed in a special vial.
- The injection site is re-treated.
- Health workers deliver research material to the laboratory for research.
Subsequently, the material is placed in an in vitro environment where bacteria multiply. Modern tools determine the type of harmful microorganism and decipher the results of the study.
Technique for taking material from a vein Advice! When injected, there is a risk of infection or bleeding (especially if you have hemophilia or DIC). Therefore, it is important to sterilize the surface of the skin prior to blood sampling.
Preliminary test results can be obtained in the CMD in three days, and in Helix - in 5 days. The final result is in 8-15 days. Much depends on the type of pathogenic microorganism and the rate of its reproduction.
The video shows how a bacterial pathogen develops in the blood. Timely treatment and diagnosis of such disorders is a sure step towards recovery. It is important to contact your doctor in time if you experience "alarming" symptoms.
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A blood test for sterility has been used in medical practice for quite a long time, since it is considered the main way to determine the presence of pathogenic microorganisms in the blood. This is an integral part of any treatment, because it is precisely the sterility test that makes it possible to prescribe antibiotics to the patient. Testing will show if there are bacteria in the blood. It often happens that a person is healthy and does not need strong drugs. In the worst case, if the test is not carried out, the patient will be prescribed antibiotics, which should not be taken without reason. The test is intended to confirm the diagnosis, regulate treatment and speed up the recovery of the patient.
What is a blood test for sterility?
A blood test for sterility is a test of a blood sample taken from a patient. Such screening is needed to determine further treatment. An analysis is also prescribed if the patient has already undergone therapy with some kind of antibiotics, but the treatment did not help him. The test will help to more clearly determine the cause of the ineffectiveness of medicines. The analysis determines the presence of streptococcus bacteria, staphylococcus, Escherichia coli, yeast fungi.
Usually, the test is repeated several times at intermediate intervals. This helps to make sure exactly what the patient is sick with and determine his further treatment. It is prescribed for suspected specific diseases: sepsis; meningitis; pustular lesions of the skin.
The analysis determines the stage at which the bacteria exist. This may be the initial stage, development and strong activity of the infection. The test is performed to determine the cause of the patient's poor health. It is worth noting that this is a fairly effective method, since sometimes doctors cannot make an accurate diagnosis based only on the symptoms and complaints of the patient.
Who needs to get tested?
Decreased immunity and fever may not indicate a cold, but the development of an infectious disease. Therefore, people who feel a sharp decline in strength, accompanied by constant temperature fluctuations, should undergo a sterility test.
Testing is necessary in some specific cases:
- poor health of the patient;
- decreased immunity;
- suspected tuberculosis;
- suspected sepsis or meningitis;
- consistently high body temperature;
- ineffective antibiotic treatment;
- the patient is a blood donor.
Ineffective antibiotic treatment most often indicates that you are being treated for a misdiagnosis. In order not to injure the body with medications that will not help it in any way, it is necessary to donate blood for testing. It is possible that you have several types of bacteria, and the antibiotic only kills one of them. In this case, complex treatment is necessary.
If a person is a donor, then he definitely needs to undergo this analysis so as not to infect the recipient. Infections that are transmitted through the blood are very persistent, so the likelihood that they are transmitted by transfusion is very high.
How to prepare for the analysis?
The procedure is carried out in the laboratory. Doctors, through blood cultures on a certain medium, can see if you have bacteria in your body and how quickly they multiply. The types of bacteria are also determined. In order to donate blood for sterility, you need to follow only a few rules. First, do not drink alcohol and do not eat fatty foods. This applies to highly seasoned, spicy and peppery dishes. Second, don't smoke. These recommendations must be observed at least a few days before the procedure. You should stop smoking a few hours before taking a blood test.
Also, patients should refrain from eating at least eight hours before the procedure. Blood is taken in the morning on an empty stomach, as this significantly increases the chances of the reliability of the test results. The analyzes will be ready within 3-14 days (for donors, the verification period is longer).
Sterility Test Performance
Every person wants to have good health and know that he is not a carrier of any infection. Sterility testing is especially important for people who donate blood. A donation is great, but in this case you need to think not only about your own safety, but also about the safety of the recipient. Therefore, if you regularly donate blood, you also need to regularly undergo such control.
The effectiveness of a blood test for sterility has been proven by experts. The blood donor screening system has been improved, such as the introduction of third and fourth generation antibody assays and nucleic acid testing (NAT) 1, and the risk of transmission of clinically significant viral infections has been reduced. Apart from this, this simple check has reduced the risks for the transmission of bacterial infections. An ideal screening test should have extremely high diagnostic sensitivity, short testing times, and high clinical performance.
Bacterial detection systems used for screening blood components have long been used worldwide. Most countries use culture methods such as BacT/ALERT, BACTEC or Pall eBDS. These systems have high analytical sensitivity (less than 1 cfu/ml). The disadvantage of the method of checking the blood of donors is the duration of testing. Unlike patients who are tested several times in a row for their own treatment, donor blood is tested once. This check takes about seven days.
There are confirmed cases where, after screening blood donors for bacterial detection, false results have been reported due to sampling error. Based on the low concentration of bacteria in the final product, the residual probability that the volume of sample processed in the culture system did not contain bacterial colonies was still present although infected. This happens with insufficiently thorough and long-term blood tests.
Experimental bacteria detection systems have also been validated for routine blood screening. They will help detect staphylococcus, streptococcus, intestinal bacteria, yeast. A sterility test will help determine if an antibiotic that has been previously prescribed by your doctor is right for you or not. The advantage of high-speed bacteria detection systems is the short testing time, which allows the collection of test samples just before the patient is treated.
Department of Health of the Voronezh Region
BUZ VO "Voronezh Regional Clinical Hospital No. 1"
Blood test for sterility
at the present stage
Information and methodological letter for bacteriologists
Compiled by: chief freelance specialist in microbiological diagnostics
Department of Health of the Voronezh Region, Head of the Bacteriological Laboratory
BUZ VO VOKB No. 1 E.V. Bondarenko
Doctor-bacteriologist of BUZ VO VOKB No. 1 T.M. Paw
Blood is one of the most common biomaterial samples examined in a bacteriological laboratory. A blood test for sterility is the most important method of laboratory research in patients with certain indications.
Main indications for blood culture:
- fever (over 38°C)
- Hypothermia (less than 36 °C)
- Leukocytosis
- Granulocytopenia
Bacteria enter the bloodstream by exogenous (for example, during trauma) and endogenous (from the focus of infection) pathways.
Bacteremia: The presence of bacteria in the blood, confirmed by cultures
- Transient bacteremia, when there is a short-term release of microorganisms into the blood under the influence of factors such as physical activity, overheating, hypothermia. These events are usually asymptomatic.
- Intermittent bacteremia when there is a local focus of infection, such as pneumonia or intra-abdominal abscess.
- Ongoing bacteremia is manifested by intravascular
infection, such as infective endocarditis or septic thrombophlebitis.
Sepsis is a pathological process, which is based on the reaction of the body in the form of generalized (systemic) inflammation to an infection of various nature (bacterial, viral, fungal).
In the last decade, there has been an increase in cases of bacteremia and fungemia in the world. This is due to the development of invasive medical interventions, the aging of the population, an increase in the number of organ and bone marrow transplants, an increase in the number of more virulent and difficult-to-treat microorganisms, and a more aggressive nosocomial infection.
Risk factors that contribute to the penetration of bacteria into the bloodstream and the development of bacteremia:
- intravenous catheters
- bladder catheter
- any invasive procedures
- surgical interventions
- neutropenia
- therapy with antibiotics (empirical), corticosteroids, cytotoxic
Hemoculturing is currently the "gold standard" in the diagnosis of septicemia.
Principles of microbiological diagnostics
An accurate diagnosis is established only when pathogens are detected in the blood of patients. An important condition is timely sampling. For analysis, blood is used directly from a venous vessel. Sample collection from indwelling intravenous or intra-arterial catheters is allowed only in cases of suspected catheter-associated infection or inability to obtain it by venipuncture.
- Fever and chills begin about an hour after microorganisms enter the bloodstream
- Most often, blood is drawn as soon as possible after a bout of fever or chills when an infection is suspected.
- Blood sampling should be carried out, if possible, prior to the administration of antimicrobial therapy.
Blood volume is one of the most significant factors in increasing the sensitivity of blood culturing. It is believed that the risk of accidental contamination of 1 individual blood sample is 3% (0.03).
Then the probability of accidental contamination of 2 samples at the same time is: 0.03*0.03=0.0009=0.09%. Therefore, it is more informative to study 2 or more samples, each with a volume of at least 10 ml.
The recommended number of blood samples taken depending on the suspected disease according to MU 4.2.2039-05 Technique for collecting and transporting biomaterials to microbiological laboratories :
1) Acute sepsis, meningitis, meningocococemia, osteomyelitis, arthritis, acute pneumonia, pyelonephritis 2 samples from two vessels or two sections of a blood vessel before starting antibiotic therapy
2) Fever of unknown origin 4 first 2 samples from different blood vessels (two sections of the vessel), then after 24-36 hours 2 more samples
3) If you suspect the presence of endocarditis and sluggish sepsis: in case of exacerbation, 2 samples from two vessels during the first 1-2 hours of body temperature rise (not at the peak of temperature!) Before starting therapy; in subacute and sluggish course, first 3 samples with an interval of 15 minutes. and more. If all samples are negative, on the second day after sowing, another 3 samples are collected.
4) in patients with endocarditis receiving antibiotics, collect 2 separate samples within three days
5) In patients whose therapy includes antibiotics, 6 samples are collected within 48 hours; samples should be collected immediately before the next dose of the drug
6) with fever of unknown origin, first 2 samples from different blood vessels, then 2 more samples after 24-36 hours
The minimum set of media for blood cultures under the terms of Order 535:
“Double medium” - 1.7-2% nutrient agar (150 ml) slant in a vial and 150 ml of a semi-liquid medium prepared in nutrient broth with the addition of 15 g of glucose and 0.15 g of agar.
“ Sterility control medium” is a standard thioglycol medium to which 15-20 g of yeast extract and agar 4.25-5 g per 1 liter are added, 0.001 g of resazurin is added to the medium as an indicator of anaerobiosis.
Necessary equipment for taking blood:
- Vials with nutrient media.
- 70o ethyl alcohol;
- 2% or 5% tincture of iodine
- venous tourniquet
- rubber (latex, vinyl) gloves
- alcohol lamp (only when using vials with media made in the laboratory)
Blood sampling technique. Collection of blood samples for culture is carried out by 2 people at the patient's bedside or in the treatment room.
Disinfect the skin area over the vessel chosen for puncture: treat the skin with a swab moistened with 70% ethyl alcohol, then with another swab moistened with 1-2% iodine solution or another disinfectant approved for use for these purposes in the prescribed manner, in circular motions , starting from the center, within 30 s; wait until the treated area dries. It is not allowed to palpate the vessel after skin treatment before the introduction of the needle;
When working with double medium vials: collect 10 ml of blood from adults with a sterile syringe, 5 ml from children; open the vial over the flame of the spirit lamp; inject blood into the vial from the syringe, after removing the needle; burn the neck and cork of the vial in the flame of an alcohol lamp, close the vial with a cork; carefully, so as not to soak the stopper of the vial, mix its contents in a circular motion.
Visual signs of growth of blood cultures during blood cultures
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macroscopic |
Possible microorganisms |
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streptococci, staphylococci, Listeria spp., Clostridia, Bacillus spp. |
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clouding |
Aerobic Gram(-) coli, Staphylococcus aureus, Bacteroides spp. |
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Gas formation |
Aerobic gram(-) sticks, anaerobes |
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Film formation |
Pseudomonas spp., Bacillus spp., yeast cells |
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Flaking |
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Visible colonies ("smoky") |
Staphylococcus, streptococcus |
Reasons for negative results:
Local infection (the body's defenses keep the infection in one place)
Irrelevant sampling time (probability of missing intermittent bacteremia)
Too little material received
Patient taking antibiotics
Identification of isolated bacteria in bacteremia:
- Significant and common- S.aureus, S.pneumoniae, E.coli and other enterobacteria, P.aeruginosa, C.albicans
- significant- S.pyogenes, S.agalactiae, L.monocytogenes, N.meningitidis, N.gonorrhoeae, H.influenzae, B.fragilis group, Candida spp, Cryptococcus neoformans
- Contaminants or not? ( depends on specific cases ) - KOS, viridescent streptococci, Propionibacterium acnes, Acinetobacter calcoaceticus, Clostridium spp., Corynebacterium spp., Bacillus spp.
Additional criteria in favor of the clinical significance of the isolate:
Fast culture isolation - within the first 48 hours
Isolation of monoculture
Isolation of the same type of microorganism in different samples
Isolation of the same type of microorganism from blood and other loci
In addition to manual methods, there are methods of automated blood culturing, which are more modern, more sensitive. The most famous series of bacteriological analyzers for blood culture for sterility is BDBACTEC.
The Bactec instrument is designed to accelerate the detection of bacteria and fungi in clinical blood samples. Blood samples are taken from patients and inoculated directly into the original culture medium vials, then - as soon as possible - placed in the workstations of the BD Bactec™ 9000 Series instruments. The presence of microorganisms in the blood is determined using highly sensitive fluorescent technology based on the indication of CO into the nutrient medium by growing and rapidly dividing microorganisms. With the BD BACTEC system, 90% of positive results are detected within the first 24 hours of incubation, which allows timely initiation of empiric antibiotic therapy or changes to the current drug regimen. Timely bacteriological diagnosis of bacteremia significantly reduces the incidence of septic shock and increases the survival rate of patients.
Vials for blood culture are available in several types. The following are most commonly used:
- Aerobic Culture Medium Vials
- Vials with medium for the cultivation of anaerobes
- Vials with the medium for the cultivation of children's blood
Designed to study small blood volumes up to 3 ml, also contain latex particles
- Vials with selective medium for the detection of yeasts and fungi
Vacuum blood sampling is used using a butterfly needle blood sampling system. The vacuum draws blood through the BD VacutainerTM needle directly from the vein into the BD VacutainerTM tubes and BD BactecTM vials and immediately mixes with the culture medium.
Traditionally, blood sampling is carried out simultaneously in aerobic (BD BACTEC™ PLUS+ Aerobic/F) and anaerobic (BD BACTEC™ PLUS+ Anaerobic/F) vials. The alternative set consists of: a) an aerobic bottle and an additional aerobic bottle; b) anaerobic and/or Mycosis IC/F and/or Myco F/Lytic flasks (both types of flasks are for cultivation of hemocultures of fungi).
Optimal blood volume for blood culture
- Children:
- Neonates 1-2 ml blood/vial (allowable blood volume for culture is 0.5-5 ml)
- Children 2-5 ml/vial
- Teenagers 10-20 ml/vial
- Adults:
Simultaneously 20-30 ml (10 ml per vial) of blood 2 or 3 times within 24 hours
| STEP 1 |
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| STEP 2 |
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| STEP 3 |
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| STEP 4 |
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With proper blood sampling, contamination is no more than 2-3% of all blood cultures. The use of BD VacutainerTM blood collection kits significantly reduces the degree of contamination of cultures.
In the presence of growth of a microorganism in the vial, the analyzer notifies laboratory personnel using a light indication on the front panel of the instrument, as well as using an audible indication. Thus, it is not necessary to inoculate from all vials, the inoculation is done purposefully from the positive vial.
Scope of research and micro-landscape during hemoculturing in bacteriological laboratories of healthcare facilities of the Voronezh region.
The total number of blood samples for testing for sterility in the Voronezh region was 12515. In 2013, this number was much less: 8406. The share of these tests for medical institutions is shown in the table:
The total number of positive cultures from blood samples in the region was 1245, which amounted to 9.95%, in 2013 808, which amounted to 9.6%.
Microlandscape of isolated cultures:
The following cultures were most often isolated from the blood: S. aureus - 165, coagulase-negative staphylococci - 639 (the bulk - S. epidermidis - 478), Enterococcus faecalis - 74, Pseudomonas sp - 59, Klebsiella - 54, E. coli - 31, Enterococcus faecium 36. Among fungi of the genus Candida, C. albicans and C. glabrata were most often identified.
In a small amount stood out: Enterobacter-18, Ps. aeruginosa 20, Acinetobacter 17, Streptococcus spp 20.
Cultures such as Str.viridans, Str. β-haemolyticus, Str pyogenes, Proteus mirabilis, Proteus vulgaris, Candida tropicalis, Candida krusei.
All bacteriological laboratories in the Voronezh region, with the exception of two, examine blood for sterility by manual methods. Bacteriological analyzers "Baktek" are available in the bacteriological laboratories of the Voronezh Regional Clinical Hospital No. 1 and in the laboratory of the Perinatal Center 1k. As a result of the analysis of microbiological monitoring for 2011-2014 in these laboratories, an increase in the number of microbial cultures was noted. Before the use of hardware technology, the inoculation of microorganisms from the blood in 2010-2012 ranged from 6 to 10%, in the study using "BD Bactec 9050" in 2013 - 24.7%, in 2014 - 26.9% in adult patients and in newborns in 2013 - 17.5%, in 2014 - 20.3%.
Literature
1. "Guide to medical microbiology" edited by A.S. Labinskaya, N.N. Kostyukova, Moscow, 2013
2. "Methods of clinical laboratory research". Reference manual edited by V.V. Menshikov. Volume 3 Clinical microbiology. M, 2009.
3. "Laboratory" magazine for doctors №5 2014
4. "Clinical Microbiology" P.R. Marie, I.R. Shay, short guide, translated from English, Moscow, 2006
5. Clinical Microbiology and Antimicrobial Chemotherapy
2013, volume 15 (4).
The delivery of a blood test for sterility makes it possible to determine the presence of various types of infectious processes in the body. How this happens, read on.
Blood for sterility is donated in cases where it is required to detect the presence of various types of pathogenic bacteria in the blood. In this case, the analysis makes it possible to identify various infectious diseases occurring in the body. This allows you to diagnose the occurrence of tumors and other pathological processes at an early stage.
A blood test for sterility is always prescribed for people who have a weak immune system.
The main indications for a blood test include:
- repeated sharp rises in temperature;
- after surgical operations;
- after the use of artificial valves on the heart;
- if prolonged catheterization was used;
- if there is a suspicion of blood poisoning;
- when diagnosing meningitis.
Sterility testing can be used as a prophylactic if there is a risk of developing infectious diseases. In this case, bakposev will be carried out, allowing you to make or, on the contrary, remove diagnoses. This makes it possible to test the sensitivity of the infection to the antibiotics used for treatment or to develop a new course of therapeutic measures.
Blood culture itself for sterility is carried out in cases where it will be necessary to identify the presence of various types of bacteria in it, including pathogens. Thanks to this, it is possible to detect the development of an infectious disease at an early stage. A blood test makes it possible to determine the presence of microorganisms, the presence of which in a healthy body is very limited or completely unacceptable. These include: streptococci, Pseudomonas aeruginosa, Staphylococcus aureus, various types of enterobacteria and even yeast fungi.
A sterility test can show the possibility of infection with such a dangerous bacterium as Staphylococcus epidermidis.
It is detected after repeated testing, with bacteriological culture. Such cultures will be of great value when examining samples taken from patients who have a weakened immune system. This is especially important in cases where a survey of patients diagnosed with HIV infection is carried out. This is due to the fact that mycobacterium tuberculosis is most often detected in them.
What results can the analysis show?
Any microflora that has entered the blood or found in it as a result of a sterility test can cause or indicate the presence of infectious processes in the body. Moreover, with the help of blood, it will spread throughout the body, affecting organs and tissues. This can make it more difficult to identify the root cause and the site of infection. Conducting a study allows not only to identify microorganisms, but also to establish the stage at which the disease is located.
A blood test for sterility is performed in order to find out about the presence of bacteremia. Doctors recommend donating blood for sterility immediately before the therapy process, being careful not to get the wrong result.
A blood test for sterility is done in order to determine the presence of bacteremia, indicating the presence of serious diseases. Indications for such an analysis are the determination of pathogenic microorganisms in the blood.
Examples of such microorganisms are streptococci, Pseudomonas aeruginosa, Staphylococcus aureus, yeast fungi and enterobacteria. For example, to detect infection with Staphylococcus epidermidis, multiple testing must be performed.
These types of studies are very important for sick people with low immunity. For example, HIV-infected patients may be carriers of Mycobacterium tuberculosis.
In order to determine the type of bacteria, pathogens are carefully studied. If during the analysis it is revealed that microorganisms enter the body, then it is necessary to determine what risk they carry for internal infection of all organs. Treatment, the appointment of the necessary studies and analyzes is already carried out by a specialist, using the already available data from the diagnostics.
Blood culture for sterility is one of the types of tests that are part of the standard list of services of many clinics and medical laboratories. This analysis is prescribed only when it becomes impossible to establish the exact cause. In most cases, the analysis is done in cases where the patient has a high temperature for a long time and does not subside, and this happens for no particular reason. In addition, the analysis is prescribed for suspected sepsis or meningitis.
Carrying out this analysis helps to determine the bacteria contained in the blood. It can be both dangerous and opportunistic bacteria, which can also be the cause of the disease. In addition to the fact that by conducting an analysis it is possible to establish the presence of a certain bacterium, it is also possible to determine the stage at which the disease is located.
In addition to the necessary information about the presence of certain bacteria in the blood, the results of the analysis contain information about sensitivity to antibiotics. After conducting this analysis, the doctor will be able to determine the exact diagnosis and prescribe the correct treatment.
When do you need to take an analysis? Before the analysis, you must adhere to the most standard rules - do not drink alcohol for a couple of days, do not eat fatty foods, try to stop smoking, at least a couple of hours before the analysis. Medications are prescribed after the analysis.
Sterility analysis is a microbiological type examination carried out in the presence of diseases that are directly related to the penetration of microorganisms into the blood stream. In the normal healthy state of a person, blood is sterile. With the help of this blood test, the presence of microbes in it that enter it during complications of purulent-septic diseases, manipulations. A blood test is also prescribed for patients with an unclear fever of a long duration, as well as for people with low immunity.
If blood cultures are performed to determine the sensitivity of the body to a variety of antibiotics, then the analysis will help determine the type of pathogen and prescribe appropriate antibiotics for treatment. In this case, the analysis will help determine the ineffective use of previous antibiotic drugs; the presence of meningitis or sepsis, as well as pustular skin lesions.
The main purpose of conducting a sterility test is to confirm or refute the presence of bacteria and microorganisms in human blood, followed by the selection of adequate and effective treatment using antibiotics suitable for the body.
The causes of sepsis or bacteremia in human blood can be the weakening of the patient's body or the presence of any type of microorganisms, in particular opportunistic pathogens. Most often, pathogenic microorganisms are detected during sowing, including streptococci, Staphylococcus aureus, Pseudomonas aeruginosa, intestinal bacteria, enterobacteria, yeast fungi, and so on.
During the analysis, special attention should be paid to the fact that in 3% of cases, epidermal staphylococcus aureus (contaminated skin microflora) can act as a blood culture. That is why its clinical significance is determined only after multiple studies.
If non-sterile blood is detected during the analysis, it is necessary to remember the danger of infection of absolutely any organ in the human body. To identify the location of the affected area, it is necessary to conduct a complete examination of the body for damage. After determining the affected organ, it is necessary to seek advice from a narrow-profile specialist who will be able to make an accurate diagnosis and prescribe the correct treatment. But in most cases, the blood is still sterile.
The correctness of the blood test for sterility. It is necessary to conduct an analysis in the presence of typhoid fever, sepsis, meningitis, as well as other infections that are accompanied by fever. The analysis is prescribed at different periods of the disease, it is best if the analysis is done at the initial stage of the disease or during its peak (pronounced bacteremia).
During the study, it is necessary to take blood from a vein at the elbow bend. In young children, blood is taken from the finger, heel, earlobe in a smaller amount. Blood for analysis is taken only after careful treatment of the skin, following all the rules of asepsis, using a disposable sterile syringe.
For analysis, it is necessary to take 5-10 ml of blood, which is inoculated into a vial with 50-100 ml of medium. For this analysis, a vial with a nutrient medium, which is obtained in laboratories, is used. A blood test is performed on liquid nutrient media.
The procedure for transfusing blood into a vial from a syringe must be carried out over a flame from an alcohol lamp, after removing the needle. And only after that the vial with blood can be sent to the laboratory. Before moving the vial to the laboratory for research, it must be placed in a thermostat.
An important point is the fact that the earlier the seeding from the onset of the disease, the greater the possibility of obtaining a positive result, and vice versa, the later, the less chance. At normal temperatures, a positive result is very rare.
In order to increase the number of positive blood culture results, it is possible to inject 1 ml of a 0.1% adrenaline solution subcutaneously (in the absence of contraindications) approximately 20 minutes before the analysis.
This procedure will serve to reduce the spleen and release pathogens into the bloodstream. Preliminary results can be obtained as early as 3 days after seeding, and the final result is known only after 10 days.
