Experimental infection of dogs with a Brazilian strain of Rickettsia rickettsii

Clinical and laboratory findings

Eliane M. Piranda, João Luis H Faccini, Adriano Pinter, Tais Saito, Richard C. Pacheco, Mitika K. Hagiwara, Marcelo B. Labruna

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

The bacterium Rickettsia rickettsii is the etiological agent of an acute, severe disease called Rocky Mountain spotted fever in the United States or Brazilian spotted fever (BSF) in Brazil. In addition to these two countries, the disease has also been reported to affect humans in Mexico, Costa Rica, Panama, Colombia and Argentina. Like humans, dogs are also susceptible to R. rickettsii infection. However, despite the wide distribution of R. rickettsii in the Western Hemisphere, reports of R. rickettsii-induced illness in dogs has been restricted to the United States. The present study evaluated the pathogenicity for dogs of a South American strain of R. rickettsii. Three groups of dogs were evaluated: group 1 (G1) was inoculated ip with R. rickettsii; group 2 (G2) was infested by R. rickettsii-infected ticks; and the control group (G3) was infested by uninfected ticks. During the study, no clinical abnormalities, Rickettsia DNA or R. rickettsii-reactive antibodies were detected in G3. In contrast, all G1 and G2 dogs developed signs of rickettsial infection, i.e., fever, lethargy, anorexia, ocular lesions, thrombocytopenia, anemia and detectable levels of Rickettsia DNA and R. rickettsii-reactive antibodies in their blood. Rickettsemia started 3-8 days after inoculation or tick infestation and lasted for 3-13 days. Our results indicate that a Brazilian strain of R. rickettsii is pathogenic for dogs, suggesting that canine clinical illness due to R. rickettsii has been unreported in Brazil and possibly in the other South American countries where BSF has been reported among humans.

Original languageEnglish (US)
Pages (from-to)696-701
Number of pages6
JournalMemorias do Instituto Oswaldo Cruz
Volume103
Issue number7
StatePublished - Nov 2008
Externally publishedYes

Fingerprint

Rickettsia rickettsii
Dogs
Infection
Rickettsia
Fever
Ticks
Brazil
Rickettsia Infections
Tick Infestations
Rocky Mountain Spotted Fever
Panama
Costa Rica
Lethargy
Colombia
Antibodies
DNA
Argentina
Anorexia
Acute Disease
Mexico

Keywords

  • Brazil
  • Dog
  • Rickettsia rickettsii
  • Spotted fever
  • Tick

ASJC Scopus subject areas

  • Microbiology (medical)

Cite this

Piranda, E. M., Faccini, J. L. H., Pinter, A., Saito, T., Pacheco, R. C., Hagiwara, M. K., & Labruna, M. B. (2008). Experimental infection of dogs with a Brazilian strain of Rickettsia rickettsii: Clinical and laboratory findings. Memorias do Instituto Oswaldo Cruz, 103(7), 696-701.

Experimental infection of dogs with a Brazilian strain of Rickettsia rickettsii : Clinical and laboratory findings. / Piranda, Eliane M.; Faccini, João Luis H; Pinter, Adriano; Saito, Tais; Pacheco, Richard C.; Hagiwara, Mitika K.; Labruna, Marcelo B.

In: Memorias do Instituto Oswaldo Cruz, Vol. 103, No. 7, 11.2008, p. 696-701.

Research output: Contribution to journalArticle

Piranda, EM, Faccini, JLH, Pinter, A, Saito, T, Pacheco, RC, Hagiwara, MK & Labruna, MB 2008, 'Experimental infection of dogs with a Brazilian strain of Rickettsia rickettsii: Clinical and laboratory findings', Memorias do Instituto Oswaldo Cruz, vol. 103, no. 7, pp. 696-701.
Piranda, Eliane M. ; Faccini, João Luis H ; Pinter, Adriano ; Saito, Tais ; Pacheco, Richard C. ; Hagiwara, Mitika K. ; Labruna, Marcelo B. / Experimental infection of dogs with a Brazilian strain of Rickettsia rickettsii : Clinical and laboratory findings. In: Memorias do Instituto Oswaldo Cruz. 2008 ; Vol. 103, No. 7. pp. 696-701.
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