Rickettsia helvetica

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Rickettsia helvetica
Scientific classification
Domain: Bacteria
Phylum: Proteobacteria
Class: Alphaproteobacteria
Order: Rickettsiales
Family: Rickettsiaceae
Genus: Rickettsia
Species: R. helvetica
Binomial name
Rickettsia helvetica
Beati, Peter, Burgdorfer, Aeschlirnami & Raoult, 1993 [1]

Rickettsia helvetica, previously known as the Swiss Agent, is a bacterium found in Dermacentor reticulatus and other ticks which has been implicated as a suspected but unconfirmed human pathogen.[2][3][4] First recognized in 1979 in Ixodes ricinus ticks in Switzerland (hence the designation helvetica) as a new member of the spotted fever group of Rickettsia, the Rickettsia helvetica bacterium was eventually isolated in 1993.[5] Although R. helvetica was initially thought to be harmless in humans and many animal species, some individual case reports suggest that it may be capable of causing a non-specific fever in humans.[3][4][6] In 1997 a man living in eastern France seroconverted to Rickettsia 4 weeks after onset of an unexplained febrile illness.[7] In 2010, a case report indicated that tick-borne R. helvetica can also cause meningitis in humans.[8]

Molecular evidence suggests that in Croatia as many as 10% of Dermacentor reticulatus ticks are infected with R. helvetica.[9]

Signs and symptoms[edit]

Erythema migrans or rash was observed at all combinations of seroreactivity, with symptoms including fever, muscle pain, headache and respiratory problems[10]

The spots (erythema migrans) are described as red spots, much lesser in size than those seen in lyme disease, but sometimes there are no spots at all according to http://www.gp.se/nyheter/sverige/1.1067910-fastingar-sprider-flacktyfus (Interview Kenneth Nilsson, Swedish co-author of previous citation).


In 80 healthy Swedish blood donors, approximately 1% were seroreactive for Rickettsia spp., interpreted as past infection. In a prospective study of Swedish recruits who trained in the coastal areas, 8.9% showed seroconversion[10]


Broad band antibiotics are available, it is likely that phenoxymethylpenicillin is sufficient as the drug of choice.[citation needed]

See also[edit]


  1. ^ Xue-Jie Yu & David H. Walker (2005). "Genus I. Rickettsia da Rocha Lima 1916, 567". In Don J. Brenner; Noel R. Krieg; George M. Garrity & James T. Staley. The proteobacteria, Part 3. Bergey's Manual of Systematic Bacteriology. 2 (2 ed.). Springer. pp. 96–114. ISBN 978-0-387-24145-6. 
  2. ^ Piller, Charles (October 12, 2016). "The ‘Swiss Agent’: Long-forgotten research unearths new mystery about Lyme disease". Retrieved December 19, 2016. 
  3. ^ a b Parola, P.; Davoust, B.; Raoult, D. (2005). "Tick- and flea-borne rickettsial emerging zoonoses". Veterinary Research. 36 (3): 469–492. PMID 15845235. doi:10.1051/vetres:2005004. 
  4. ^ a b Walker, D. H. (2007). "Rickettsiae and Rickettsial Infections: The Current State of Knowledge". Clinical Infectious Diseases. 45: S39–S44. PMID 17582568. doi:10.1086/518145. 
  5. ^ Beati, L.; Péter, O.; Burgdorfer, W.; Aeschlimann, A.; Raoult, D. (1993). "Confirmation that Rickettsia helvetica sp. nov. Is a distinct species of the spotted fever group of rickettsiae". International Journal of Systematic Bacteriology. 43 (3): 521–526. PMID 8102245. doi:10.1099/00207713-43-3-521. 
  6. ^ Dobler, G.; Wölfel, R. (2009). "Typhus and other rickettsioses: Emerging infections in Germany". Deutsches Arzteblatt international. 106 (20): 348–354. PMC 2689634Freely accessible. PMID 19547738. doi:10.3238/arztebl.2009.0348. 
  7. ^ Fournier, P. E.; Grunnenberger, F.; Jaulhac, B.; Gastinger, G.; Raoult, D. (2000). "Evidence of Rickettsia helvetica infection in humans, eastern France". Emerging Infectious Diseases. 6 (4): 389–392. PMC 2640907Freely accessible. PMID 10905974. doi:10.3201/eid0604.000412. 
  8. ^ Nilsson, K.; Elfving, K.; Pahlson, C. (2010). "Rickettsia helvetica in Patient with Meningitis, Sweden, 2006". Emerging Infectious Diseases. 16 (3): 490–492. PMC 3322002Freely accessible. PMID 20202426. doi:10.3201/eid1603.090184. 
  9. ^ Dobec, M.; Golubic, D.; Punda-Polic, V.; Kaeppeli, F.; Sievers, M. (2009). "Rickettsia helvetica in Dermacentor reticulatus ticks". Emerging Infectious Diseases. 15 (1): 98–100. PMC 2660705Freely accessible. PMID 19116063. doi:10.3201/eid1501.080815. 
  10. ^ a b Lindblom, A.; Wallménius, K.; Nordberg, M.; Forsberg, P.; Eliasson, I.; Påhlson, C.; Nilsson, K. (2012). "Seroreactivity for spotted fever rickettsiae and co-infections with other tick-borne agents among habitants in central and southern Sweden". European Journal of Clinical Microbiology & Infectious Diseases. 32 (3): 317–323. PMC 3569577Freely accessible. PMID 22961007. doi:10.1007/s10096-012-1742-3.