The indirect hemagglutination reaction in the diagnosis of trichinosis

An indirect hemagglutination test (IHAT) for trichinosis using a Melcher's antigen was evaluated and compared with a precipitin test (PT) and a bentonite flocculation test (BFT). One hundred and forty eight serum samples from patients from the whole country confirmed or suspected to have trichinosis by clinical or epidemiological evidences were studied: 117 (79.1%) samples resulted positive by IHAT, 138 (93.2%) by PT and 65 (43.9%) by BFT. Sixty three serum samples from patients with strong clinical suspect of trichinosis presented the PT and the BFT positive and were compared with the IHAT for sensitivity study. IHAT was positive in 60 (95.2%) serum samples. In order to determine the specificity of IHAT 25 serum samples from healthy volunteers and 124 serum samples from individuals with other parasitoses, such as cysticercosis (48), hydatidosis (45) and fascioliasis (31) were studied. The specificity, using a titre > or = 1:16 as a possible diagnostic value was 96%. The use of IHAT with RP and BFT in the diagnosis of human trichinosis is discussed.     

Detection of HBs antigen by hemagglutination inhibition tests; experiment with standardization]

The standarization of a reagent for automated detection of HBs antigen by an inhibition of the hemagglutination reaction is described. Its advantages are its specificity, its fast efficiency, its low cost. But, its handling is delicate and requires a good technicity.     

Use of the indirect hemagglutination test in the study of ornithosis. I. Hemosensitizing activity of ornithosis phosphlipid antigen and a method of performing tests with it]

A possibility was shown of using the phospholipid group-specific antigen of the ornitosis causative agent in the capacity of a hemosensitin for conducting the indirect hemagglutination test (IHAT). There was revealed a direct proportional relationship between the sensitizing activity and the complement fixing properties of the antigens obtained. A method of sorption of this antigen on the tannin-treated erythrocytes and the optimal parameters of conducting the test with it were elaborated. A sufficiently high sensitivity and specificity of the IHAT was revealed as a result of parallel titration of hetero-and homologous sera in the complement fixation test and in the IHAT. The suggested test can be successfully used for the diagnosis of ornithosis.     

The characteristics of detecting the tick-borne encephalitis virus antigen in the ELISA and indirect hemagglutination reaction by means of scanning electron microscopy

The surface of polystyrene plates was studied at different stages of the enzyme immunoassay (EIA) and the passive hemagglutination (PHA) test by the method of scanning electron microscopy in the detection of tick-borne encephalitis (TBE) virus antigen. The study revealed that in the process of EIA larger antigens were washed away from the plate surface. The objects detected on the polystyrene surface were identified as conglomerations of the virions of TBE virus, but whole virions were shown to play no decisive role in EIA. The conclusion was made that, due to some specific features of this method, EIA was more sensitive in reaction with small antigens (individual glycoproteids, their small complexes). And, respectively, the PHA test was more sensitive in reaction with large antigenic complexes (whole virions, their conglomerations, immune complexes).     

Serologic diagnosis of intestinal yersiniosis. The design of a stable erythrocyte preparation for the indirect hemagglutination reaction

Nine types of erythrocyte diagnostica of serovars O3 and O9, differing in the methods of obtaining sensitins and the physical state of erythrocytes, were put on trial. The preparations were used for the titration of hyperimmune sera and blood sera obtained from about 500 healthy persons, 300 patients with Yersinia enteric infection and 300 patients with other diseases. Freeze-dried diagnostica, when compared with liquid ones, were found to be less sensitive, but more stable and specific. Sensitins isolated by the methods of Westphal ad Boivin showed the highest degree of specificity. The authors believe freeze-dried sheep red blood with activated Boivin's antigen adsorbed onto them to be the optimal preparation for use in the passive hemagglutination (PHA) test. The preparation was found to retain its serological activity for as long as 2-3 years. The titer 1:160 (1:200) in the PHA test is recommended as the minimal diagnostic indicator. Erythrocyte diagnosticum is more sensitive, specific and stable than bacterial one. Since 1984 dried Yersinia erythrocyte diagnostica (serovars O3 and O9) have gone into quantity production at the Leningrad Research Institute for Vaccines and Sera.     

Use of the indirect hemagglutination reaction in studying ornithosis infection. III. The diagnostic value of the IHR with an ornithosis erythocytic diagnosticum]

In both experimental and clinical conditions the passive hemagglutination test (PHAT with the use of an ornithosis erythrocytic diagnostic preparation was found to be sufficiently sensitive and specific as compared with the complement fixation test (CFT), a routine testing method. The study of the dynamics of immune response in infected animals and ornithosis patients allowed to regard the PHAT as a comparatively early method of serological analysis. Hemagglutinins were also found to circulate in the patients' blood sera only for a short time (on the average for 1 1/2--2 months). The CFT and the PHAT with erythrocytic diagnostic preparation, used in combination, will make it possible not only to diagnose ornithosis in patient more effectively, but also to differentiate between the cases of infection and anamnestic reaction.20