Volume 18, Number 1—January 2012
Rickettsia felis Infections, New Zealand
|Volunteer no.||IFA serologic titers
||WB and cross-adsorption results||Risk factors in the past 4 years
||Flea or animal contact||Traveled overseas|
|Rickettsia typhi||R. typhi||R. rickettsii|
|4||Neg||64||64||Indeterminate§||Rat, 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|
|21||Neg||64||256||R. felis||Flea, cat, dog, possum||Yes|
|23||256||Neg||Neg||Neg||Rat, cat, dog||No|
*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..