Metagenomic Approach to Characterizing Disease Epidemiology in a Disease-Endemic Environment in Northern Thailand

Takhampunya, Ratree; Korkusol, Achareeya; Pongpichit, Chalermpol; Yodin, Komsan; Rungrojn, Artharee; Chanarat, Nitima; Promsathaporn, Sommai; Monkanna, Taweesak; Thaloengsok, Sasikanya; Tippayachai, Bousaraporn; Kumfao, Naruemon; Richards, Allen L.; Davidson, Silas A.

Immunofluorescence Assay (IFA) Scrub typhus and typhus group and spotted fever group of rickettsial diseases IFA tests were used to detect groupspecific IgM antibodies against scrub typhus orientiae, and murine typhus and the spotted fever group of rickettsiae. The Rickettsia Screen IFA IgM Antibody Kit was used following the manufacturers' instruction (Fuller Laboratories, Fullerton, CA, United States). The assay is intended for the simultaneous detection and semi-quantitation of IgM human antibody to both typhus group (TG) and spotted fever group (SFG) rickettsiae. An O. tsutsugamushi IFA IgM Antibody Kit (Fuller) included 4 strains (Boryong, Gilliam, Karp, and Kato) in one well. Positive reaction appears as bright staining (at least 1+) of positive control cut-off level in any of the four antigens areas. Bartonella henselae and Anaplasma phagocytophilum IFA tests were conducted for the detection of human IgG antibodies from serum using commercial kits [B. henselae IFA Human IgG Antibody Kit, A. phagocytophilum (HGA) IFA IgG Antibody Kit, Fuller]. Serum screening dilutions for B. henselae and A. phagocytophilum were 1:64 and 1:80, respectively.