Table. Serologic data and risk factors of volunteers that showed positive reactivity in rickettsial IFA, New Zealand*.

Volunteer no.	IFA serologic titers				WB and cross-adsorption results	Risk factors in the past 4 years
	ARRL kit†		Focus kit‡			Flea or animal contact	Traveled overseas
	Rickettsia typhi		R. typhi	R. rickettsii
4	Neg		64	64	Indeterminate§	Rat, cat, dog	Yes
5	Neg		Neg	64	Indeterminate	Cat, dog	Yes
8	Neg		Neg	128	Neg¶	Flea, rat, cat, dog	Yes
9	Neg		Neg	64	Indeterminate	Flea, cat, dog	Yes
16	Neg		Neg	128	Indeterminate	Rat, cat, dog	Yes
17	Neg		Neg	128	R. felis	Rat, cat, dog	Yes
18	128		64	64	Neg	Cat, cow, hen	Yes
19	128		Neg	64	Indeterminate	Cat, dog	Yes
21	Neg		64	256	R. felis	Flea, cat, dog, possum	Yes
22	Neg		Neg	64	Neg	Cat, dog	Yes
23	256		Neg	Neg	Neg	Rat, cat, dog	No
25	Neg		Neg	128	Indeterminate	None	Yes

*IFA, indirect immunofluorescence assay; ARRL, Australian Rickettsial Reference Laboratory; WB, Western blot; neg, negative.
†The cutoff titer for seropositivity was 128 as recommended by the manufacturer.
‡According to kit instructions, endpoint titers ≥64 and <256 indicate either past infection or early response to a recent infection, and ≥256 are considered presumptive evidence of recent or current infection.
§Serum samples that still reacted with R. typhi and R. felis after cross-adsorption were classified as indeterminate responses.
¶Serum samples that showed no specific reactions to R. typhi and R. felis in the WB assay were classified as negative for R. typhi and R. felis..