RICKETTSIA SIBERICA
Rickettsia siberica, known as North Asian tick typhus when first described in 1960, is found in Siberia and western China. Another species Rickettsia mongolotimonae was described in 1993, then reclassified in 2005 as a subspecies of R. siberica based upon genomic studies. This subspecies has a much broader range, including Asia, Africa and Europe.The table, below, describes some of the clinical differences between these subspecies.
| Characteristic | R. siberica siberica | R. siberica mongolitimonae |
| Outbreak season for humans | Spring |
Spring and summer |
| Clinical characteristic | |
|
| Headache | 55% |
100% |
| Fever | 100 | Yes |
| Rash | 78 | 100 |
| Enlarged lymph nodes | 55 | Yes |
| Lymphangitis | 44 | 4 |
| Eschar | 89 | 77 |
| Multiple eschars | 22 | 0 |
| Fatal outcome | 0 | Rare |
- Yu X, Jin Y, Fan M, Xu G, Lui Q, Raoult D, Genotypic and antigenic identification of two new strains of spotted fever rickettsiae isolated from China. J Clin Microbiol 1993; 31:83-88.
- Fournier PE, Tissot-Dupont H, Gallais H, Raoult D. Rickettsia mongolotimonae: a rare pathogen in France. Emerg Infect Dis 2000; 6:290-292.
- Fournier PE, Gouriet F, Brouqui P, Lucht F, Raoult D. Lymphangitis-associated rickettsiosis, a new rickettsiosis caused by Rickettsia siberica mongolotimonae: seven new cases and review of the lierature. Clin Infect Dis 2005; 5:1435-1444.
- Fournier PE, Yong Z, Raoult D. Proposal to create subspecies of Rickettsia siberica and an emended description of Rickettsia siberica. Ann NY Acad Sci 2006, 1078:597-606.