Volume 24, Number 2—February 2018
Scrub Typhus Outbreak in Chonburi Province, Central Thailand, 2013
||Clinical signs and symptoms||Symptom onset to collection, d†
||Test results for O. tsutsugamushi, IgM/IgG‡|
*ID, patient identification number; IFA, indirect fluorescence antibody assay; ND, not determined; + positive; –, negative.
†Time from onset of signs and symptoms to first blood collection.
‡Karp, Kato, and Gilliam genotypes. Tests were performed on September 27 (round 1), October 4 (round 2), and October 7 (round 3). Positivity cutoff titer for initial screening was 1:50 and the diagnostic criteria were established as a >4-fold increase in the titer of IgM or IgG in paired serum samples. If only 1 serum sample was available, titer of 1:50 to <1:400 was determined as recent or previous infection and titer >1:400 as active infection.