Experimental infection of dogs with a Brazilian strain of Rickettsia rickettsii: clinical and laboratory findings
Mem. Inst. Oswaldo Cruz
; 103(7): 696-701, Nov. 2008. graf, tab
Article
in English
| LILACS, Sec. Est. Saúde SP
| ID: lil-498380
Responsible library:
BR1.1
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.
Full text:
Available
Collection:
National databases
/
Brazil
Database:
LILACS
/
Sec. Est. Saúde SP
Main subject:
Rickettsia rickettsii
/
Ticks
/
DNA, Bacterial
/
Rocky Mountain Spotted Fever
/
Dog Diseases
Type of study:
Diagnostic study
/
Prognostic study
Limits:
Animals
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Mem. Inst. Oswaldo Cruz
Year:
2008
Document type:
Article
/
Project document
Institution/Affiliation country:
Superintendência de Controle de Endemias/BR
/
Universidade Federal Rural do Rio de Janeiro/BR
/
Universidade de São Paulo/BR