Helminths igg ifa best. Instruments and reagent kits for ELISA of Russian production Kundelsky R.V., Ph.D.

DRUGS

EVALUATION OF A NEW ELISA TEST SYSTEM

"Rotavirus-antigen-ELISA-BEST"

12Zhirakovskaya E.V., 3Ignatiev G.M., 3Indikova I.N., 12Tikunova N.V.

1 Federal State Scientific Institution SSC VB "Vector" of Rospotrebnadzor, Koltsovo settlement, Novosibirsk Region;

2 Institute of Chemical Biology and Fundamental Medicine, Novosibirsk;

3 State Institute for Standardization and Control of Medical Biological Preparations named after L.A. Tarasevichag Moscow

The results of testing the sensitivity, specificity and reproducibility of a new set of reagents "Rotavirus-antigen-ELISA-BEST" developed in JSC "Vector-Best" (Novosibirsk) are presented. The data obtained make it possible to predict the diagnostic reliability of the results when using this test system to detect group A rotavirus antigen in clinical material.

Keywords: ELISA test system, efficiency, rotavirus A

Group A rotaviruses (family Reoviridae, genus Rotavirus) are the most common cause of severe gastroenteritis in young children worldwide. Immunocompromised adults also often get sick. Rotavirus infection (RVI) is a highly contagious disease with multiple ways distribution. The source of infection is a person with a manifest or asymptomatic form of the disease, as well as a virus carrier. Among children and adults, RVI can manifest itself in the form of sporadic cases, local group diseases, outbreaks and is widespread. The fecal-oral mechanism of transmission of this infection is realized by food (milk and dairy products, children food), water and contact-household ways.

The diagnosis of rotavirus gastroenteritis according to the clinical picture, especially with sporadic morbidity, presents a certain difficulty, since the symptoms characteristic of this infection differ little from the symptoms of other acute intestinal infections (AII) of various etiologies. Differential Diagnosis in patients with rotavirus gastroenteritis, it is carried out both with food toxic infections and with other viral (noroviruses, astroviruses, adenoviruses, coronaviruses, Coxsackie enteroviruses and ECHO) and bacterial (salmonellosis, dysentery, cholera, yersiniosis, opportunistic microorganisms) etiology. Unfortunately, not all specialized medical institutions RF diagnoses rotavirus infection.

Diagnostic methods in RVI, they are aimed at detecting whole virions, viral antigen or virus-specific RNA in feces. A promising approach to the direct detection of viruses both in clinical material and in objects environment, is a reverse transcription method - by polymerase chain reaction(RT-PCR) . AT last years test systems are created based on modern scientific developments with combination various methods detection of rotaviruses: multiplex PCR with hybridization-fluorescence detection of amplification products "by the end point"; end-point immuno-PCR (IPCR) with real-time detection; quantitative RT-PCR with real-time detection. In research laboratories, electron microscopy is used to quickly detect rotaviruses. However, all of the above methods are quite laborious and require expensive instruments and highly qualified personnel. Therefore, when carrying out laboratory diagnostics in hospitals and outpatient settings, preference is given to methods based on the detection of viral antigen in feces using enzyme-linked immunosorbent assay (ELISA) with mono- and polyponic antibodies to rotaviruses. This method is available for practical laboratories, is easy to set up and allows you to quickly get the result.

The purpose of this work is to study the diagnostic efficiency of a new set of reagents "Rotavirus-antigen-ELISA-BEST" developed in JSC "Vector-Best", Novosibirsk.

^September-December

Materials and methods

The material of the study was the samples of faeces of children early age with a diagnosis of AII and without clinical manifestations intestinal infection who were hospitalized in the departments of intestinal infections and respiratory infections MUZ "Children's city clinical Hospital No. 3 "Novosibirsk. Fecal samples were collected in disposable sterile plastic containers in a volume of 2-3 ml upon admission of patients to the hospital department and stored at -20 °C for 15 days. Longer storage of the material was carried out at -70 °C.

A panel of 104 fecal samples previously tested for the presence of AII pathogens was used in the work. Of them:

30 samples in which only group A rotaviruses were detected by ELISA and RT-PCR; genotyping by RT-PCR showed that fecal samples contained rotaviruses of the genotype PG1 (18 samples), PG2 (4 samples), PG3 (3 samples), PG4 (2 samples), PG4 (1 sample), PG9 (1 sample) , PG3 (1 sample);

14 samples in which only noroviruses of the second genotype were detected by RT-PCR, which was confirmed by determining the nucleotide sequence of the 5" region of the capsid gene located on the norovirus genome in the region of 5085-5485 h.;

15 samples in which only astroviruses were detected by RT-PCR, which was confirmed by determining the nucleotide sequence of the 5" region of the capsid gene located on the astrovirus genome in the region of 4526 - 4955 bp; 15 samples in which PCR method only adenoviruses were detected;

30 fecal samples (control) from children without clinical manifestations of intestinal infection, hospitalized in the respiratory department of the hospital; preliminary analysis did not reveal the above viral pathogens in these samples.

Testing of samples for the presence or absence of rota-, noro-, astro- and adenoviruses was carried out by RT-PCR using commercial kits registered in the Russian Federation "AmpliSense No virus 1, 2 genotypes - 306/322", "AmpliSense Astrovirus -165", "AmpliSense Adenovirus - 462", "AmpliSense Rotavirus - 290" (manufactured by the Central Research Institute of Epidemiology, RF). The study of samples was carried out in accordance with the instructions for use of the respective kits of reagents during the expiration date. Samples positive for rotavirus were genotyped by RT-PCR. The determination of the presence or absence of the rotavirus antigen was also carried out by ELISA using a commercial test system IDEIA™ Rotavirus, (DakoCytomation, UK) in accordance with the instructions for the kit.

When testing the kit of reagents "Rota-virus-antigen-ELISA-BEST" all the above samples (104) were encrypted and tested three times with the test kit. After completion of the tests, the samples were decoded and the results analyzed.

Results and discussion

The sensitivity of the kit of reagents "Rotavirus-antigen-ELISA-BEST" was evaluated by the number of matches positive results(in %) testing of samples using the tested test system and comparators. At the same time, it was found that when using the kit of reagents "Rotavirus-antigen-ELISA-BEST", all 30 samples with confirmed presence of rotavirus A were positive (Table 1). Therefore, the sensitivity of the test set of reagents for the detection of rotavirus A was 100%. It should be noted that the panel included samples with seven different rotavirus genotypes, and all of them were successfully detected by the Rota virus - antigen - AND FAB EST reagent kit.

The specificity of the test system was assessed by the number of coincidences of negative results (in %) of testing samples using the tested test system with data from preliminary studies. To assess specificity, the panel used included 30 samples in which no viral pathogens were detected, as well as 14 samples in which only noroviruses of the second genotype were detected using the RT-PCR method, 15 samples in which RT-PCR detected only astroviruses; 15 samples in which only adenoviruses were detected by PCR. It was determined that in 69 out of 74 negative samples, the values of optical densities when detected by the Rotavirus-antigen-ELISA-BEST reagent kit for the presence of rotavirus A did not exceed the background values, that is, the values obtained as a result of measuring the optical density in control negative samples. Two samples containing astroviruses, one sample - norovirus of the second genotype, one sample - adenovirus and two samples in which none of the above viral pathogens was detected, showed positive optical density values. It should be noted that in samples in which none of the viral pathogens had previously been detected, positive signals were registered only in one of the repeated studies (Table 2). Thus, the specificity of the kit of reagents "Ro-tavirus-antigen-ELISA-BEST" was 93.2%.

During the tests, the reproducibility of the results obtained using the test set of reagents "Rotavirus-antigen-ELISA-BEST" on clinical material was evaluated - all samples were examined three times in different experiments to determine the variation in the results. In almost all cases, similar results were obtained: the test system detected all negative and positive samples in the same way. The exception was two samples in which none of the viral pathogens had previously been detected: in one of the repeats for both samples, the optical density values exceeded the ODcrit. It should be noted that the excess was insignificant (Table 2). Thus, the reproducibility of the results was 98.8%.

The results of the tests showed that the tested set of reagents "Rotavirus-antigen-IFA-BEST" in terms of its diagnostic efficiency - specificity, sensitivity and reproducibility - is comparable to the diagnostics available in the Russian Federation.

using the test kit "Ro-tavirus-antigen-ELISA-BEST" for the detection of group A rotavirus antigen in clinical material.

Literature

1. Bogomolov B.P. // "Infectious diseases: emergency diagnosis, treatment, prevention". - M., New diamed. - 2007.

2. Vasiliev B.Ya., Vasil'eva R.I., Lobzin Yu.V.// "Acute intestinal diseases. Rotaviruses and rotavirus infection. - S.-Pb., Lan. - 2000.

3. Zhirakovskaya E.V., Tikunov A.Yu., Bodnev O.A., et al.// "BIOpreparations". - 2008 - No. 2. - p. 15 - 18.

4. Zhirakovskaya E.V., Maleev V.V., Bodnev A.S. and others // JMEI - 2008 - No. 4. - With. 12 - 16.

5. Ignatyuk T.E., Golutvin I.A., Nasikan N.S., et al. // Problems of Virology. - 2003. - v. 48. - No. 6. - p. 1721.

6. Novikova N.A., Fedorova O.F., Epifanova N.V., Chup-rova A.B. // "Issues of Virology". - 2007. - v.52. -№ 3 - with. 19-23.

7. A. T. Podkolzin, A. A. Mukhina, G. A. Shipulin, et al.//

"Infectious Diseases". - 2004. - v. 2. - No. 4. - p. 85-91.

8. Podkolzin A.T., Fenske E.B., Abramycheva N.Yu., et al.// Therapeutic archive. - 2007. - v. 79. - No. 11. -p. 10-16.

9. Sergevnin V.I., Voldshmidt N.B., Sarmometov E.V., et al. // “Epidemiology and infectious diseases". -2004.-No. 6.-p. 17-20.

10. Sergevnin V.I., Voldshmidt N.B., Sarmometov E.V., et al. // Hygiene and sanitation. - 2007. - No. 1. - p. 56-58.

11. Arcangeletti M.C., De Conto E, Pinardi F., at al. // Acta Biomed. Ateneo. Parmense. - 2005.-V. 76(3). - P. 165-170.

12. Gladstone B.P., Iturriza-Gomara M., Ramani S., at al. // Epidemiol. Infect. - 2008. V. 136(3). - P. 399-405.

13. Min B.S., NohYJ., Shin J.H., atal. //J. Virol. methods. -2006. - V. 137(2). - P. 280 - 286.

14. Santos N., Honma S., Timenetsky Mdo C., at al. //J. Clin. microbiol. - 2008. V. 46 (2). - P. 462 - 469.

15 Schets F.M., van Wijnen J.H., Schijven J.F., at al. //Appl. Environ. microbiol. - 2008. - V. 74 (7). - P. 2069 - 2078.

16. Stockman L.J., Staat M.A., Holloway M., at al. // J. Clin. microbiol. - 2008. - V. 46 (5). - P. 1842 - 1843.

Evaluation of the sensitivity and specificity of the kit of reagents "Rotavirus-antigen-ELISA-BEST"

Table 1

No. No. Number of samples Detection results with comparison drugs IDEIA Rotavirus Astro-PCR Hopo 2-PCR Adeno-PCR Detection results with the Rotavirus-antigen-ELISA-BEST kit

1. 30 30 0 0 0 30

2. 15 0 15 0 0 2

3. 14 0 0 14 0 1

4. 15 0 0 0 15 1

Evaluation of the specificity of the kit of reagents "Rotavirus-antigen-ELISA-BEST> -

table 2

PCR AmpliSense

rotavirus rotavirus rotavirus rotavirus

0,443 1,306 0,676 0,418

Rotavirus-antigen-IFA-BEST CJSC "Vector-Best"

OPCrit OPCrit OPCrit

0,250 0,263 0,251

> 4,000 > 4,000 > 4,000 3,926 > 4,000 3,939

> 4,000 > 4,000 > 4,000

£September

December 2009

AmpliSense

rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus rotavirus astrovirus astrovirus astrovirus astrovirus astrovirus astrovirus astrovirus

IDEA Rotavirus DakoCytomation RPC = 0.150

0,401 0,322 1,659 0,566 0,518 1,278 1,285 0,809 1,160 0,407 0,218 0,703 1,889 1,069 1,302 0,879 1,842 0,747 0,793 1,013 1,124 0,670 0,726 0,683 0,814 0,997 0,206 0,052 0,050 0,034 0,040 0,048 0,040

Rotavirus-

OPcrit 0.250

> 4,000 3,933 3,987 3,918 3,853 3,972

> 4,000 3,864 3,879 3,897 3,800

> 4,000 3,981

> 4,000 3,713

> 4,000 4.000

> 4,000 3,989

> 4,000 3,872 0,088 0,103 0,230 0,240 0,268 1,819 0,062

antigen-ELISA-BEST "Vector-Best"

OPcrit OPcrit 0.263 0.251

> 4,000 > 4,000

> 4,000 > 4,000 3,821 3,899

> 4,000 3,964 3,845 3,923 3,962 3,871

> 4,000 3,929

> 4,000 3,881 3,884 > 4,000

> 4,000 > 4,000 3,800 3,851 3,818 >4,000

> 4,000 > 4,000

> 4,000 3,995

> 4,000 > 4,000

> 4,000 > 4,000 3,837 3,839

> 4,000 > 4,000

> 4,000 3,986

> 4,000 > 4,000

> 4,000 3,998

> 4,000 > 4,000

> 4,000 3,823 0,063 0,073 0,054 0,061 0,255 0,250 0,256 0,244 0,278 0,560 1,117 1,235 0,052 0,052

astrovirus astrovirus astrovirus astrovirus astrovirus astrovirus astrovirus astrovirus norovirus norovirus norovirus norovirus norovirus norovirus norovirus norovirus norovirus norovirus norovirus norovirus norovirus norovirus adenovirus adenovirus adenovirus adenovirus adenovirus adenovirus adenovirus adenovirus adenovirus adenovirus adenovirus

IDEA Rotavirus DakoCytomation OIIKpHT = 0.150

0,043 0,043 0,041 0,052 0,040 0,046 0,041 0,040 0,037 0,039 0,030 0,045 0,032 0,030 0,037 0,042 0,034 0,039 0,043 0,043 0,045 0,039 0,050 0,034 0,050 0,043 0,050 0,042 0,041 0,042 0,038 0,047 0,039

PoTaBHpyc-aHTHreH-HOA-EECT 3AO "BeKTop-EecT"

OnKpHT OnKpHT OIIKpHT

0,250 0,263 0,251

0,115 0,075 0,082

0,053 0,046 0,058

0,233 0,198 0,189

0,144 0,105 0,128

0,243 0,062 0,073

0,043 0,040 0,046

0,069 0,043 0,041

0,143 0,044 0,058

0,220 0,206 0,230

3,475 2,577 2,405

0,223 0,247 0,240

0,232 0,236 0,231

0,048 0,042 0,041

0,121 0,085 0,093

0,132 0,111 0,174

0,122 0,052 0,063

0,061 0,044 0,054

0,073 0,035 0,048

0,089 0,046 0,046

0,047 0,043 0,044

0,041 0,039 0,044

0,083 0,046 0,038

0,168 0,074 0,097

0,247 0,118 0,099

0,248 0,251 0,242

0,243 0,259 0,250

0,054 0,048 0,055

0,048 0,040 0,037

0,058 0,045 0,046

0,053 0,045 0,049

0,069 0,058 0,065

0,912 0,344 0,379

0,089 0,037 0,042

December 2009

PCR AmpliSense

adenovirus adenovirus adenovirus adenovirus negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative negative

IDEA Rotavirus DakoCytomation RPC = 0.150

0,040 0,044 0,039 0,041 0,260 0,044 0,046 0,042 0,047 0,041 0,039 0,048 0,055 0,035 0,039 0,040 0,041 0,033 0,046 0,049 0,048 0,038 0,039 0,029 0,037 0,036 0,043 0,043 0,039 0,042 0,034 0,037 0,041 0,036

Rotavirus - antigen - ELISA-BEST CJSC "Vector-Best"

OPCrit O P Crit OPCrit

0,250 0,263 0,251

0,105 0,042 0,043

0,046 0,143 0,133

0,227 0,045 0,042

0,065 0,068 0,054

0,125 0,039 0,042

0,196 0,191 0,182

0,209 0,170 0,154

0,316 0,071 0,073

0,058 0,043 0,049

0,171 0,056 0,061

0,049 0,060 0,064

0,047 0,062 0,065

0,058 0,047 0,066

0,073 0,072 0,066

0,188 0,120 0,109

0,180 0,074 0,072

0,057 0,063 0,058

0,047 0,060 0,047

0,162 0,146 0,143

0,248 0,248 0,260

0,063 0,066 0,104

0,247 0,223 0,251

0,054 0,053 0,070

0,242 0,240 0,248

0,073 0,061 0,103

0,066 0,065 0,064

0,108 0,123 0,192

0,072 0,067 0,071

0,079 0,079 0,087

0,104 0,079 0,164

0,169 0,150 0,162

0,140 0,166 0,146

0,114 0,133 0,131

Treatment of helminthiases in children is extremely important, since the consequences of this may be a lag in the development of physical and mental, pathological processes internal organs and systems, even death. In addition, helminth infestations are highly contagious, which is why they spread so easily in preschool and school institutions. From this it is clear how important timely treatment helminthiasis in children.

The first signs of helminths in children

Worms are opportunistic pathogens human body, worms for which humans are the definitive host. Moreover, in this issue The owner's age doesn't matter. different types helminthiases can be observed both in children and in adult patients.

How dangerous is helminthiasis for a child?

As mentioned earlier, helminths in children can cause serious illness and pathologies, as a result of which mental and physical development slows down. Possible Complications each type of helminthiasis can be completely different, for example:

Therefore, children's helminthiases require even more attention, timely medical attention, long-term observation in a specialist, and prevention.

Main symptoms in children

Symptoms of helminthiasis in a child can be different, depending on the type of worms:

1. Ascaris immediately manifest itself as an allergic reaction, fever and nausea in the child. The first appearances are usually bright, but quickly subside. Then the following symptoms may occur:

colic and dysbacteriosis and newborns;
in babies under 1 year old, pain in the navel, problems with stools, allergies and diathesis;
older children have sleep problems, restless behavior, nightmares;
for children 3-7 years old, nausea, fever, coughing and abdominal pain, rash are characteristic.

2. Enterobiosis, the causative agent of which are pinworms, manifests itself as an erased clinical picture. And only after 1 month you can notice the following symptoms:

in newborns, inflammation, swelling and redness of the anus, refusal to eat, crying at night, lack of appetite;
children under one year old have the same symptoms, as well as severe itching of the anus at night (from 11 pm to 1 am), girls suffer from inflammation of the genital organs;
in older children, pain in the abdomen near the navel, sleep disturbance, itching in the buttocks.

3. The symptoms of Toxocariasis are difficult to recognize except small temperature body and allergic reactions(rash, hives, itching and swelling). After infection, a cough may occur, which later causes pneumonia or bronchitis, especially in the smallest patients.

Trichinosis suggests mild signs in newborns, otherwise the following signs are observed:

feverish state;
swelling of the face;
muscle pain;
allergic reactions;
children 5 years of age and older may have enlarged tonsils, spleen, rash, and sore throat.

It is most difficult to diagnose the symptoms of helminthiasis in children 2 years and younger, since the child cannot explain his behavior and condition. Therefore, for any atypical manifestations and behavior of the child, it is better to show the doctor.

What needs to be done first?

Worms that have been found in feces a child is the most important sign of the disease, after which you should immediately seek help from a doctor. No helminth treatment can be successful without proper diagnosis. Survey methods in this case should be comprehensive, including the following procedures:

taking a scraping from the anus;
study of the child's feces;
blood analysis;
muscle biopsy in rare cases with suspected trichinosis;
serological blood test;
x-ray, ultrasound, tomography;
ELISA to detect antibodies in the blood.

Treatment Methods

Treatment of helminthiasis in children should be comprehensive, well thought out, scheduled with exact dosages and frequency of drug administration. This is due to the fact that drugs with toxic components are used for the anthelmintic effect, which means that irrational use can lead to side effects. In addition, at home it is appropriate folk treatment medicinal plants.

Folk remedies

Modern treatment with folk remedies for such diseases for children involves 4 effective ways:

Any method of home treatment should be discussed with your doctor in advance. It must be remembered that for herbs and folk remedies contraindications are provided in the form of individual intolerance.

Medical treatment

With enterobiasis and ascariasis, drugs such as Pirantel and Mebendazole are usually used. Reception of Pirantel is appropriate at a dose of 10 mg of the substance per kilogram of weight from pinworms, and 5 mg / kg from roundworms. Mebendazole is taken twice a day at 50 mg for children 2-3 years old for three days in a row, twice for 100 mg for three days in a row for children over 3 years old, after 3 weeks the therapy is repeated.
With toxocariasis, Mebendazole is prescribed in a different dose - for children 2 years and older, 100 mg twice a day for 14-10 days.
Treatment of trichinosis accepts Mebendazole 5 mg per kilogram of weight, after which the dose is divided into three doses per day. The course of treatment is 1 week under the strict supervision of a physician.

Prevention of helminthiases

washing hands immediately after contact with animals, after the street and sandboxes, going to the toilet and before eating;
eating only clean foods;
properly conducted heat treatment of meat and fish products;
drinking boiled water;
observance of personal hygiene and sanitation;
regular deworming of pets;
preventive deworming in children aged 2 years and older.

Blood test for toxocara

Features of human infection with toxocariasis

Carriers of infection are dogs, rarely cats. Toxocara eggs are shed in faeces stray dogs. Once on the ground, in water or lingering on the fur of an animal, they are introduced into a healthy organism in various ways.

Reaction to an intruder

From medical statistics it is known that adults are less likely to become infected with toxocariasis, unless their occupation is at risk. Children are much more likely to get an infection.

The most common symptoms of toxocariasis are:

Fever without signs of any disease.
Temperature rise.
Growing and fading pain in the head or abdomen.
The appearance of a skin rash that cannot be eliminated.
Puffiness of the face.
An increase in the level of eosinophils in the blood, revealed in the general analysis.

To make an accurate diagnosis, an immunological analysis for toxocara is prescribed. The presence of protein compounds in the blood that carry the genetic information of the helminth (antigens) provokes immunity to produce antibodies of the igg class. This is the first sign of infection with toxocariasis.

Preliminary diagnostics

The initial stage of the patient's history is collective. Before sending a patient to take a blood test for toxocariasis, it is necessary to study the history of the disease and make a preliminary examination.

Primary diagnosis:

Investigation of aggravating circumstances that could provoke infection - specific work with animals or the presence of pet, earthworks in potentially dangerous areas, children playing in dog walking areas.
Physical examination of the patient. Survey skin for subcutaneous invasion with toxocars, eyelids and eyeballs, palpation.
Appointment of a detailed blood test. During infection with toxocariasis, a significant increase in some indicators is characteristic - eosinophils (70–80%), lymphocytes, ESR. While the level of hemoglobin drops markedly.
Taking liver samples. In severe invasion, the load on the liver is affected, which is manifested by a strong jump in bilirubin.

It is impossible to obtain direct confirmation of toxocara invasion using conventional tests (blood, coprogram, smear). Duodenal examination is also uninformative, as it is difficult for the migrating nature of the larvae.

After receiving the results of the preliminary examination, indicating possible infection toxocars, and differentiation of the alleged diagnosis from diseases with similar symptoms, the patient is assigned to undergo an ELISA for toxocariasis.

Linked immunosorbent assay

The main purpose of this study is to confirm the presence of toxocars in the human body. Antibodies to these helminths are found in the blood plasma, so it is taken from a vein.

Toxocara analysis requires some preparation:

Do not eat fatty and heavy foods the day before the procedure.
Do not drink sugary, carbonated and alcoholic drinks during the day before visiting the laboratory.
Give fasting tests.
Do not use medicines on the previous day and the day on which the analysis is scheduled.

It should be noted that this very informative method of detecting invasion can be affected by some circumstances. A false positive result may occur if the patient has:

Oncological diseases.
Tuberculosis of the lungs.
Severe liver pathologies.
autoimmune syndrome.
Antiphospholipid syndrome.
Pregnancy.

In this case, it will not be possible to obtain a 100% confirmatory analysis, since under the listed circumstances, the protective system also produces immunoglobulins (antibodies). It is necessary to carry out additional diagnostics and differentiate toxocariasis from the listed factors.

The concentration of immunoglobulins (titer) of the IgG class reaches the maximum possible value after 2-3 months from the onset of invasion. The more severe the infection, the higher this rate.

ELISA results

To make a diagnosis, enzyme immunoassay is carefully studied, the results obtained are compared with reference values. The norm is an antibody titer of 1:100 with a positivity index of less than 0.9.

Numerical values of titles

The results obtained can be negative, positive, weakly positive, or questionable. The number of antibody titers depends on the severity of the invasion and the duration of its occurrence.

Analysis transcript:

AT titer up to 1:100 - the result is negative. Toxocara larvae were not found in the patient's body.
AT titer up to 1:400 - the result is weakly positive. The patient has a weak invasion or develops an ocular form of toxocariasis. In some cases, the indicator indicates a recent infection.
AT titer up to 1:600 - the result is positive. Man is suffering clinical form helminthiasis, the detection of which requires immediate therapy.
AT titer up to 1:800 - the result is positive. It speaks of a severe invasion of a progressive nature and a high degree of probability of the development of a pathological process of internal organs.

With rare exceptions, the study of ELISA reveals a neglected form of invasion with an admixture of helminthiases of a different origin. In this case, the total antibodies may be higher than 1:800.

Positivity coefficient

At enzyme immunoassay for toxocariasis with a titer of 1:400 - 1:600 to differentiate invasion from side factors, the obtained indicators are compared with the reference value. The difference between these figures is commonly called the index or the positivity coefficient.

Usually, in the form of the conducted ELISA, one indicator is opposite the other. The first is the norm, the second can mean:

Up to 0.9 - the result is negative. Toxocara larvae were not found.
0.9-1.1 - the result is doubtful. In this case, a re-diagnosis is assigned.
1.1-2.2 - the result is slightly positive. A person is a carrier with a weak invasion.
2.2-4.2 - the result is positive. Toxocariasis moderate has been developing for a long time.
Over 4.4 - the result indicates the peak of helminthic invasion or a recent helminthiasis.

CP with a result of 4.4 and a detected increase in eosinophilia by 10% may indicate the development eye shape toxocariasis and the presence of antibodies to cross-invasion, total to toxocariasis.

The immune response and the optical density of antibodies (positivity coefficient) depend on the degree of infection with Toxocara and the place of their localization. The lowest titer and CP indicator allows only to assume the absence of helminths, but not to assert this.

The information presented cannot serve as a source for self-diagnosis or self-treatment. The results of the ELISA, together with a preliminary examination, can only tell a specialist about the presence of a problem. In the Invitro laboratory, blood diagnostics are carried out with high accuracy, the result of the analysis is accompanied by comments from specialists about the positivity coefficient. This greatly helps the doctor to make a more accurate diagnosis.

Leading Russian manufacturers In the segment of reagent kits for diagnosing infections: - CJSC Vector-Best, Novosibirsk; - LLC NPO Diagnostic Systems, N.Novgorod; - CJSC "Ecolab", Elektrogorsk MO. In the field of diagnostic kits not infectious diseases and physiological conditions: - Alkor-Bio LLC, St. Petersburg; - CJSC Vector-Best, Novosibirsk; - Hema-Medica LLC, Moscow. In the segment of reagents for laboratory diagnostics of allergies: - Alkor-Bio LLC, St. Petersburg; - CJSC Vector-Best, Novosibirsk; - NPO Immunoteks LLC, Stavropol. Production of laboratory equipment: - OOO Pikon, Moscow

Assessment of the degree of possible import substitution according to the nomenclature of tests Nomenclature of analytes, units Approved for use in the Russian Federation Produced in the Russian Federation Degree of possible import substitution Infectious disease markers % Non-infectious disease markers and indicators of physiological conditions % Allergy markers % Total: %

Assessment of the degree of import substitution in terms of the market volume of products for tablet ELISA Market segments Market volume in the Russian Federation, mln. Sales volume of domestic manufacturers, million rubles Share of import substitution Infectious disease markers % Non-communicable disease markers and indicators of physiological conditions % Allergy markers % Equipment50051% Total: %

Assessment of the degree of import substitution in terms of the volume of the market for products for immunochemical methods as a whole Market segments Market volume in the Russian Federation, mln. Sales volume of domestic manufacturers, million rubles Share of import substitution Infectious disease markers % Non-communicable disease markers and indicators of physiological conditions % Allergy markers % Equipment % Total: %

Problems of domestic producers in the industry: The ELISA method is becoming obsolete. There is a gradual replacement of domestic IF reagents with imported chemiluminescent ones; The existing public procurement system stimulates either the purchase of the cheapest goods or imported products with unique characteristics; One of the main reasons for the insufficient development of domestic manufacturers of automatic equipment and the localization of the production of imported products is the customs administrative barrier; The main problem of recent times is the collapse of the system state registration new products in RZN. The admission of new products to the market has practically stopped and those foreign manufacturers that have previously registered with long lists continue to have an advantage over domestic ones; The main reason for the technological backwardness is the inability to obtain the right to produce compatible products for modern equipment; The low degree of consolidation of domestic manufacturers and constant price wars among themselves do not make it possible to develop advanced products and compete with leading players on an equal footing, including in foreign markets.

Suggestions: Within the framework of the FCC, introduce a non-competitive procedure for public procurement of medical devices with subsequent itemized publication. Determination of financing limits based on the average market price will give certain advantages to domestic producers, will allow limiting the consumption of expensive imported reagents and more effectively control the development of budget funds; Promote the enlargement and consolidation of domestic manufacturers in order to concentrate resources on the development of modern products and enter international market. A non-competitive public procurement procedure will quickly leave only truly competitive enterprises on the market; Allocate state funds to stimulate, on the principles of public-private partnership, the development of a range of tests sufficient to ensure the biological safety of the country; Customs exemptions should be for components, not for finished products; Harmonize the registration system with the European one, where medical devices With low level potential risks are registered on the basis of a declaration of conformity.

Number of definitions 96 (48 in duplicates)
Format of the working tablet: stripped 12x8, breaking 1 well.
Sensitivity: 1.5 U/ml.
Measuring range: 0-400 U/ml.
The volume of the test sample is not more than 25 µl.
Standardization of the conditions for carrying out an enzymatic reaction with a chromogen in a thermostatically controlled shaker at 37ºС.
Set composition:
1. Striped plate 12 x 8 holes, ready for use - 1 pc.
2. Ready-to-use calibration samples (0-400 U/ml) stained with varying degrees intensity depending on the concentration - 6 vials.
3. Control sample - 1 vial.
4. One-component conjugate, ready for use, not requiring dilution - 1 vial.
5. Serum dilution solution - 1 vial.
6. Substrate chromogenic, one-component - solution of tetramethylbezidine plus (TMB+) ready for use, not requiring dilution - 1 vial.
7. Phosphate-saline buffer solution with twin - 2 bottles.
8. Stop reagent, ready for use - 1 vial.
9. Film for gluing the tablet - 1 pc.
10. Stencil for constructing a calibration graph - 1 pc.
11. Tray for the reagent - 2 pcs.
12. Pipette tips for 5-200 µl - 16 pcs.
The packaging of the tablet is a teak "zip-lock" package.
The stability of the FST-T working solution is at least 5 days at a temperature of +2...8°C.
Store the set at +2...8°C. Expiration date - 1 year from the date of production.
Registered in Roszdravnadzor.