Volume 14, Number 5—May 2008
Dispatch
Fatal Rickettsia conorii subsp. israelensis Infection, Israel
, Avi Keysary‡, Judith Sandbank*, Ronit Zaidenstein*, Avi Itzhaki*, Carmela Strenger‡, Moshe Leitner‡, Christopher D. Paddock§, and Marina E. Eremeeva§Table
Diagnostic tests performed to identify spotted fever in the patient*
| Day after disease onset | Assay | Specimen(s) tested | Result | Laboratory |
|---|---|---|---|---|
| 7 |
IFA
PCR |
Serum
Serum |
IgM<100, IgG<100
Negative |
IIBR†
IIBR |
| 11 (autopsy) | IFA | Serum | IgM = 64, IgG<32 | CDC‡ |
| PCR | Serum sediment Liver, muscle, skin, lung, kidney Liver, muscle, skin | Rickettsia conorii subsp. israelensis Spotted fever group rickettsiae R. conorii subsp. israelensis | CDC IIBR§ CDC¶ | |
| IHC stain# | Brain, kidney | Positive | CDC | |
| Cell culture** | Liver, lung | Negative | IIBR |
*IFA, immunofluorescent assay; Ig, immunoglobulin; IIBR, Institute for Biological Research; CDC, Centers for Disease Control and Prevention; IHC, immunohistochemical.
†IFA performed (6). Cutoff values for IgM and IgG are 100.
‡IFA performed (7). Cutoff values for IgM and IgG are 64.
§Nested PCR for 17-kDa protein gene (8).
¶Nested and semi-nested PCR for 17 kDa protein gene and recombinant outer membrane protein A gene fragment, respectively, followed by sequencing (9).
#Three-micron sections cut from formalin-fixed, paraffin-embedded brain and kidney tissue samples were stained by using an immunoalkaline phosphatase technique with a hyperimmune rabbit anti–Rickettsia rickettsii antibody at a dilution of <500 (3).
**Homogenized samples from lung and liver were applied by centrifugation onto monolayer of Vero cells culture in 24-well plates and incubated for 2 weeks at 35°C in 5% CO2 atmosphere incubator.
