RBPT positive samples demonstrated variable SAT titres; diagnostic titres were detected in only 10 samples.
Moreover, most researchers establish diagnostic titres of STA test as ≥1 160, which was not the endpoint for this study (16, 20, 23, 24).
Serological confirmation of infection was obtained for 232 (63.6%) patients; 154 patients had diagnostic antibody titre on admission, while 78 showed a 4-fold titre elevation after two weeks.
In conjunction with a compatible clinical presentation, SAT titres above 1 160 are considered diagnostic (19); however, in endemic areas, a titre of 1 320 as cutoff may make the test more specific.
A 4-fold or greater increase in serologic titres was considered diagnostic for M. pneumoniae, C. pneumoniae, or L. pneumophila.
Anti-mitochodrial antibodies (AMA) and anti-smooth muscle antibodies (SMA) were tested by an indirect immunofluorescence (IIFL) assay of Nova Lite TM IFAA) on Mouse Kidney & Stomach substrate (Inova Diagnostics, San Diego CA, Inc) and a titre of ≥1/40 was considered positive, according to the manufacture' s instructions.
For the detection and quantification of t-TGA antibodies, commercially available ELISA kit was used (IMMCO Diagnostics, Buffalo, NY); a t-TGA titre of >25 U/mL was considered as positive for CD.
A total of 2,259 serum samples of travellers returning from dengue endemic countries were screened for the prevalence of dengue-antibodies and further analyzed to evaluate the diagnostic value of positive dengue antibody titres (IgM and IgG) in single serum samples.
The diagnostic sensitivity of Widal TO test at titre ≥1/400 was 84.09 % and specificity was 52.65 %.
Microscopic agglutination test (MAT) is the standard reference serological test and a four-fold or greater change in antibody titres in paired acute and convalescent sera is considered diagnostic as well as a single finding of a high titre together with clinical signs.
