Serodiagnosis of Trichomonas vaginalis infection by the indirect fluorescent antibody test.

The indirect fluorescent antibody test was used to detect antibodies to Trichomonas vaginalis in 200 antenatal patients. A total of 104 (52%) gave a positive reaction with antigen prepared from cultures of trichomonas isolated from seven of the patients. Antitrichomonal antibody was detected at a 1/4 dilution in 90% of patients with proven trichomoniasis, while the highest dilution at which antibody was detected was 1/32. IgG rather than IgM appeared to be the antibody class involved. Of those patients with no demonstrable trichomonal infection, 17% gave positive reactions at 1/4 dilution, while 64% had no demonstrable antibody. One of 30 children under 11 years of age gave a positive reaction.     

Modification of the indirect haemagglutination test for amoebiasis

Optimal conditions for carrying out the indirect haemagglutination test with sheep erythrocytes were studied using the microtitre system. The age of the erythrocytes, concentration of reagents, time and temperature of tanning, sensitization, and incubation are described with reference to replication of titres. Sera from patients with amoebic colitis were used to evaluate the test conditions.     

Sensitized chick cells in the indirect haemagglutination test for echinococcosis

An indirect haemagglutination (IHA) test was performed with chick red blood cells (RBC) on sera from 26 confirmed cases of echinococcosis and 45 control sera. The results were compared with those obtained in an IHA test with sheep RBC on the same batches of sera; both tests were equally sensitive. The chick cells settled quickly and the results could be determined within 30-45 min. Heterophilic antigen was not a problem. This study also showed that chick cells stabilised by the double-aldehyde method, could be sensitised with the antigen and then stored at 4 degrees C for up to 31 days before use in the IHA test without loss of sensitivity. The use of sensitised double-aldehyde stabilised (DAS) chick cells in IHA tests provides a rapid diagnostic test in echinococcosis.     

Evaluation of stabilised cells in the indirect haemagglutination test for echinococcosis

We have evaluated the use of sheep red-blood cells stabilised in various ways in indirect haemagglutination tests on the sera of 21 surgically confirmed cases of echinococcosis, and on control sera. Tests with Double-Aldehyde-Stabilised cells-treated sequentially with pyruvic aldehyde, tannic acid and glutaraldehyde-were more sensitive than tests with the cells treated only with formaldehyde, glutaraldehyde or pyruvic aldehyde, and subsequently tanned.     

Serodiagnosis of tsutsugamushi fever (scrub typhus) by the indirect immunoperoxidase technique.

The indirect immunoperoxidase technique was assessed for the serodiagnosis of tsutsugamushi fever (scrub typhus). The antigens were peritoneal smears prepared from mice infected intraperitoneally with the Karp, Kato, and Gilliam strains of Rickettsia tsutsugamushi. Treatment of the mice with cyclophosphamide apparently increased the number of the rickettsiae, and it minimized the exudate that interfered with the specific staining. The rickettsiae were seen as clusters in the juxtanuclear region of the mesothelial cells and also as free particles outside of the cells. By the indirect immunoperoxidase technique, the sera from all of the patients (49 samples from 30 patients) were positive for the R. tsutsugamushi antibody. The antibody titers (immunoglobulin G [IgG] and IgM) determined by the indirect immunoperoxidase technique correlated with those determined by the indirect immunofluorescence technique. Thus, the indirect immunoperoxidase technique was useful for quantifying both IgG and IgM antibodies to the rickettsia.     

Comparative study of three tests (dye test, indirect haemagglutination test, latex agglutination test) for the detection of antibodies to Toxoplasma gondii in human sera.

An evaluation has been made of a commercial latex agglutination test, Toxotest-MT (TMT) (Eiken, Japan), for the detection of antibodies to Toxoplasma gondii in human sera. In qualitative studies, 878 sera were examined in both the TMT and dye test (DT) and 96.6% agreement was found, In quantitative studies 339 sera were titrated in the TMT and DT, with 337 of these sera also titrated in the indirect haemagglutination test (IHAT). Agreement between the DT and TMT was best, 78% of the sera showing titres within +/- 1 dilution in the two tests. The IHAT and TMT gave 66% agreement, while the DT and IHAT showed least agreement, 40.9%. The results suggest that the pattern of antigenic determinants to which antibody levels are measured are different in the three test systems. The TMT is a better substitute for the DT than the IHAT.     

A haemagglutination test for staphylococcal anti-leucocidin

A haemagglutination test using tanned erythrocytes sensitized with the fast and slow moving components of the Panton-Valentine staphylococcal leucocidin is described. From the results obtained it is suggested that this test could be useful in the diagnosis of deep-seated staphylococcal lesions.     

Simplified method for the rubella haemagglutination inhibition screening test.

A modification of the rubella haemagglutination inhibition (HAI) test in which both pretreatment and serum titration are carried out in wells of the same microtitre plate saves time, labour, and materials and gives results comparable to a conventional HAI procedure.     

Serodiagnosis of the infection caused by the influenza C virus using immunoenzyme analysis

Serological studies employing enzyme immunoassay and HI tests suggest that influenza C viruses not only play an etiological role in respiratory diseases but can also take part in exacerbation of a number of chronic diseases predominantly affecting children.     

Automatic technique for titration of influenza virus haemagglutination inhibitors

An automatic method, utilizing the AutoAnalyzer, for titration of influenza virus haemagglutination inhibitors is described. The titres obtained compare favourably with those obtained by densitometric methods. So far, the technique has not proved superior to the densitometric methods in either speed of operation or in reproducibility but various developments are suggested to effect this.