The analysis for typhoid how and where the blood is taken
Typhoid is an acute infectious disease caused by bruchnotifozna wand. Route of transmission – nutritional, mechanism – fecal-oral. The pathogen causes bacteremia (a large number bruchnotifozna sticks in the blood), high toxicity, damage to the lymphatic apparatus of the small intestine, liver and spleen (organs increased in size). Diagnostic analysis for typhoid the first days of illness is difficult. This is due to the fact that infection can occur in atypical or latent form. Therefore, any kind of fever, irrespective of its intensity, diagnosis for typhoid do 5 days in a row.
Characteristics and peculiarities of causative agent of typhoid fever
Infection causing pathogen of the genus Salmonella is Salmonella typhi. It is a mobile gram-negative Bacillus, which lives in conditions of oxygen. She is not able to form spores, but very stable in the environment. In the water, the typhoid Bacillus is still viable from 1 to 5 months. In the stool she is active for 25 days.
With moderate cooling, such as in the refrigerator, the microorganism in dairy products is not only preserved, but also capable of reproduction within a month. High temperature is detrimental affect of the pathogen. When boiling typhoid Bacillus perishes instantly. If you heat water to 60°C, the microorganism will die in 4-5 minutes. Under direct sunlight it also loses viability.
Typhoid Bacillus is very sensitive to chemical disinfectant substances. When exposed to chloramine, corrosive sublimate, Lysol disinfected it for a few minutes.
Typhoid Bacillus has a complex antigenic structure. But for diagnostic purposes, use only two antigenic complex: O-antigen (heat-stable somatic), and Vi-antigen (heat-labile flagellar). The pathogen is capable of forming L-shape, which contribute to the development of bacterial carriage and relapse of typhoid fever.
Differential diagnosis of the disease
According to the clinical picture of typhoid fever are similar to other infectious diseases. Therefore, it is important to distinguish it manifested symptoms of diseases such as typhus, brucellosis, influenza, meningococcal, fever (Coxiella).
The distinctive symptoms of typhoid fever:
- acute onset of illness only in 1/3 of cases;
- sleep disturbance, weakness and headache increasing gradually;
- the skin becomes pale and dry;
- confusion reactions;
- intoxication progresses gradually;
- the body temperature rises slowly but tolerated difficult, patients do not sweat, the skin remains dry;
- it slows, slightly decreases blood pressure, auscultation heart sounds are muffled;
- appears soft, moist cough that goes in early bronchitis;
- abdomen distended, rumbling hear, which are localized in the right upper quadrant (liver area).
Early detection of typhoid sticks
For the detection of typhoid fever in the early stages of the disease using seed blood draw a blood culture. This is because infectious disease is accompanied by intense bacteremia the first days of the disease in the late period of the disease the number of typhoid Bacillus in the blood becomes much less.
For isolation of the pathogen taken from the patient's blood is put on a special nutrient medium – mesopatamia broth.
To study pass venous blood from the cubital vein in the amount of 10-15 ml, all patients with high fever. In some cases with suspected typhoid fever the blood culture may hold at the normal temperature of the patient. Blood sown immediately after collection and sent to the lab.
How much is the analysis? Preliminary data can be obtained in two days. The final result is known within 4-5 days. To confirm the diagnosis, study on blood culture 2-3 times.
To improve the quality of the planting and growth of a microorganism, for 20 minutes before blood sampling, the patient is administered epinephrine. Blood cultures should be performed before initiation of antibiotic therapy, otherwise analysis results will be unreliable.
Serological research methods
Serology is specific diagnostic methods for the detection of the pathogen. Their goal is the detection of antibodies in serum. When typhoid antibodies are produced for 6-8 day of the disease.
Phragmites (reaction of indirect hemagglutination)
This method of determination of antigens and antibodies with red blood cells, which are able to precipitate in the presence of antigens. Pre-antibodies and antigens adsorbed and stored in that form on the surface of red blood cells.
Phragmites for typhoid is conducted in the complex diagnosis with other tests, a search of the sources of contamination in the event of a disease outbreak. Preparing to study:
- blood taken from the cubital vein;
- the capture of material should be done on an empty stomach;
- the interval between the last meal and blood donation at least 8 hours.
Phragmites bruchnotifozna diagnostics detects Vi - and O-antibodies. For a positive resultminimum diagnostic titers should be for Vi-antibody – 1:80 for O-antibody – 1:200.
TPPA (reaction passive hemagglutination)
This is a research method that detects serum antibodies specific to the pathogen of the disease.
TPPA-test for antibodies in typhoid fever becomes positive by the end of the second week of illness. For the reliability of the results of the blood test for typhoid was repeated after 5 days. If the infection is acute, the titles grow.
Blood for the TPPA on typhoid fever taken in the morning on an empty stomach from the cubital vein. The positive diagnostic value of credits for Vi-antibody – 1:40 for O-antibody – 1:200.
For diagnostic purposes can be used by other serological methods:
- IFM – immunofluorescence microscopy;
- The enzyme linked immunosorbent assay;
- the reaction of coagglutination.
The clinical study of blood
When typhoid mandatory make a General analysis of blood. Main indicators:
- leukopenia – white blood cell count below normal;
- aneozinofiliya – absence of one type of white blood cell – eosinophils;
- relative lymphocytosis – indicates a decline in body resistance;
- high or moderate ESR (erythrocyte sedimentation rate);
- leukocytosis – an abnormally high number of neutrophils – white blood cells that are produced by immune system in response to acute inflammation, in typhoid fever is a bacteremia;
- thrombocytopenia – reduction in platelets responsible for blood clotting.
A common blood test to take for admission to a hospital, and several times during treatment.
Bacteriological examination of feces (coproculture)
This diagnostic method is not often used, as typhoid Bacillus appears in Calais before the end of the 2nd week or early 3rd week of the disease. Mostly this method is used to survey people on the carriage. Also bacteriological analysis of feces for typhoid do for sanknizhki the childcare workers, food, water.
As a charge material:
- 3-4 hours before taking the cal need to take 30 g of magnesium salt to the stool to make it softer.
- The material for investigation should be taken only from the liquid portion.
- If Kale is detected admixture of blood, pus, mucus, be sure to collect for analysis.
- Number of Kal – 10-15 g, collect wood or plastic with a sterile spatula and placed in a jar with a wide mouth.
Better seeding immediately at the bedside. If it is not possible to immediately deliver it to the laboratory, the feces contribute in a special preservative.
Bacteriological examination of urine (urinoculture)
In urine samples typhoid Bacillus is detected on 3-4 week of illness. Rules of urine collection for examination:
- to conduct a thorough toilet of the external genitalia;
- in severely ill urine collected with a catheter;
- the required amount of urine to 40-50 ml.
Urine transported to the laboratory. For sowing use the sediment. To get it, the material tsentrifugirujut, and then seeded on solid media.
Bacteriological examination of bile (biokultura)
To receive a portion of bile for analysis, the patient is doing duodenal intubation. For better discharge of the patient bile into the duodenum through a probe enter solution of magnesia with a volume of 40-50 ml. In test tubes to collect three portions – A, b, C, each with a volume of 5-10 ml.
Bile is seeded in bottles with a nutrient broth. If the bile contains flakes or other inclusions, for research it is not suitable. The crops are placed in thermostats at a constant temperature of 37°C and grow the culture for 20 hours.
Analysis of typhoid fever with a positive result confirms the presence of infection in the body. Negative indicators say about the absence of disease or its early period. If the test results false-positive, this may indicate cross-reactions with other infections. Invalid response can also be when taking antibiotics.