Evaluation of the diagnosis of Ehrlichia canis in dogs from Costa Rica, using blood smears and molecular technique

Authors

  • Luis Ernesto Romero Pérez Laboratorio de Diagnóstico y Control de Calidad. Ministerio de Agricultura y Ganadería (MAG). San Salvador, El Salvador
  • Gaby Dolz Wiedner Programa de Investigación en Medicina Poblacional. Escuela de Medicina Veterinaria. Universidad Nacional., Costa Rica
  • Juan José Romero Zúñiga Programa de Investigación en Medicina Poblacional. Escuela de Medicina Veterinaria. Universidad Nacional, Costa Rica
  • Ana Meneses Guevara Laboratorio de Análisis Clínico. Escuela de Medicina Veterinaria. Universidad Nacional, Costa Rica
  • Mauricio Jiménez Soto Hospital Especies Menores y Silvestres. Escuela de Medicina Veterinaria. Universidad Nacional, Costa Rica
  • Lizbeth Salazar Sánchez Centro de Investigación en Hematología y Trastornos Afines. Universidad de Costa Rica (UCR), San José, Costa Rica

Keywords:

Ehrlichia canis, blood smear, PCR, dogs, Costa Rica

Abstract

The objective of this study was to compare the results of the diagnosis of Ehrlichia canis in blood of dogs from the Central Valley of Costa Rica, using blood smears and the polymerase chain reaction (PCR). For this purpose, 300 blood samples of dogs suspected of suffering ehrlichiosis were used. Samples were obtained from different veterinary clinics and had been previously analyzed using blood smears, nested PCR, and, in some cases, the serological technique. In addition, the following information was obtained from each blood sample: geographical location of the veterinary clinic and data from the dog such as race, age, sex, and clinical signs.
Of the total 300 samples analyzed, 147 (49.0%) were positive for E. canis, using a nested PCR, while 178 (59.3%) were reported with inclusions using blood smears. However, only 103 (57.9%) of the positive cases using blood smear resulted in the molecular diagnosis of E. canis; while of the 122 negative samples (no inclusions) 44 (36.0%) were positive using the PCR technique. Blood smear testing showed a sensitivity of 70.1% and a specificity of 51.0%; positive and negative predictive values were 57.9% of 63.9%, respectively, compared with the PCR technique. The logistic regression analysis showed a positive association (p<0.05) with the presence of inclusions, but not for age or sex, while highly significant differences were detected using the Student’s T-Test in the average hematocrit and hemoglobin variables between PCR positive and PCR negative dogs. Of the 30 samples previously evaluated by serological tests, 25.0% of seropositive cases and 36.4% of seronegative cases were positive in the molecular diagnosis of E. canis. Low levels of hematocrit and hemoglobin, together with clinical signs and inclusions detected in blood samples, represent a strong indication of ehrlichiosis infection.
However, a molecular technique is required to confirm the diagnosis.

References

Aguirre, E., A. Sainz, S. Dunner, I. Amusategui, L. López, F. Rodrígues-Franco, I. Luaces, O. Cortés, and M. A. Tesouro. 2004. First isolation and molecular characterization of Ehrlichia canis in Spain. Vet. Parasitol. 125:365-372.

Beaufils, J. P., J. Martin-Granel, and P. Jumelle. 1995. Diagnostic cytologique des ehrlichioses canines. Prat. Méd. Chir. Anim. Comp. 30:189-195.

Breitschwerdt, E. B., B. C. Hegarty, and S. I. Hancock. 1998. Sequential evaluation of dogs naturally infected with Ehrlichia canis, Ehrlichia chaffeensis, Ehrlichia equi, Ehrlichia ewingii, or Bartonella vinsonii. J. Clin. Microbiol. 36: 2645-2651.

Castro, M. B., R. Z. Machado, L. P. T. Aquino, A. C. Alessi, and M. T. Costa. 2004. Experimental acute canine monocytic ehrlichiosis: clinicopathological and immunopathological findings. Vet. Parasitol. 119:73-86.

Dagnone, A. S., H. S. de Morais, M. C. Vidotto, F. S. Jojima, and O. Vidotto. 2003. Ehrlichiosis in anemic, thrombocytopenic, or tick-infested dogs from a hospital population in South Brazil. Vet. Parasitol. 117:285-290.

Dawson, J. E., B. E. Anderson, D. B. Fishbein, J. L. Sanchez, C. S. Goldsmith, K. H. Wilson, and W. Duntley. 1991. Isolation and characterization of an Ehrlichia sp. from a patient diagnosed with human ehrlichiosis. J. Clin. Mirobiol. 29:2741-2745.

Dawson, J. E., K. L. Biggie, C. K. Warner, K. Cookson, S. Jenkins, J. F. Levine, and J. G. Olson. 1996. Polymerase chain reaction evidence of Ehrlichia chaffeensis, an etiologic agent of human ehrlichiosis, in dogs from southeast Virginia. Am. J. Vet. Res. 57:1175-1179.

Dumler, J. S., A. F. Barbet, C. P. Bekker, G. A. Dasch, G. H. Palmer, S. C. Ray, Y. Rikihisa, and F. R. Rurangirwa. 2001. Reorganization of genera in the families´ Rickettsiaceae and Anaplasmataceae in the order Rickettsiales:

unification of some species of Ehrlichia with Anaplasma, Cowdria with Ehrlichia and Ehrlichia with Neorickettsia, descriptions of six new species combinations and designation of Ehrlichia equi and ‘HE agent’ as subjective synonyms of Ehrlichia phagocytophila. Int. J. Syst. Evol. Microbiol. 51:2145-2165.

Elias, E. 1991. Diagnosis of ehrlichiosis from the presence of inclusion bodies or morulae of E canis. J. Small. Anim. Pract. 33:540-543.

Felek, S., A. Unver, R. W. Stich, and Y. Rikihisa. 2001. Sensitive detection of Ehrlichia chaffeensis in cell culture, blood and tick specimens by reverse transcription-PCR. J. Clin. Microbiol. 39:460-463.

Harrus, S., T. Waner, I. Aizenberg, J. E. Foley, A. M. Poland, and H. Bark. 1998a. Amplification of ehrlichial DNA from dogs 34 months after infection with Ehrlichia canis. J. Clin. Microbiol. 36:73-76.

Harrus, S., T. Waner, I. Aizenberg, and H. Bark. 1998b. Therapeutic effect of doxycycline in experimental subclinical canine monocytic ehrlichiosis: Evaluation of a 6-week course. J. Clin. Microbiol. 36:2140-2142.

Harrus, S., T. Waner, H. Bark, F. Jongejan, and A. W. C. A. Cornelissen. 1999. Recent advances in determining the pathogenesis of canine monocytic ehrlichiosis. J. Clin. Microbiol. 37:2745-2749.

Harrus, S., M. Kenny, L. Miara, I. Aizenberg, T. Waner, and S. Shaw. 2004. Comparison of simultaneous splenic sample PCR with blood sample PCR for diagnosis and treatment of experimental Ehrlichia canis infection. Antimicrob. Ag. Chemother. 48:4488-4490.

Hori-Oshima, S., G. L. Tinoco, S. A. Barreras, M. Moro, and J. Viñasco. 2006. Detección de Ehrlichia canis mediante ELISA y PCR en perros de Mexicali, Baja California. En: VII Congreso Nacional de Parasitología Veterinaria. Set. 28 -30. Asociación Mexicana de Parasitólogos Veterinarios, A.C., México.

Iqbal, Z., W. Chaichanasiriwithaya, and Y. Rikihisa. 1994. Comparison of PCR with other tests for early diagnosis of canine ehrlichiosis. J. Clin. Microbiol. 32:1658-1662.

Keysary, A., T. Waner, M. Rosner, C. K. Warner, J. E. Dawson, R. Zass, K. L. Biggie, and S. Harrus. 1996. The first isolation, in vitro propagation, and genetic characterization of Ehrlichia canis in Israel. Vet. Parasitol. 62:331-340.

Kocan, A., G. Crowder Levesque, L. C. Whitworth, G. L. Murphy, S. A. Ewing , and R. W. Barker. 2000. Naturally ocurring Ehrlichia chaffeensis infection in coyotes from Oklahoma. Emerg. Infect. Dis. 6:477-480.

Lakshmanan, B., L. John, S. Gomathinayagam, and G. Dhinakarraj. 2007. Molecular detection of Ehrlichia canis from blood of naturally infected dogs in India. Vet. Archiv. 77:307-312.

Liddell, A. M., S. L. Stockham, M. A. Scott, J. W. Sumner, C. D. Paddock, M. Gaudreault-Keener, M. Q. Arens, and G. A. Storch. 2003. Predominance of Ehrlichia ewingii in Missouri dogs. J. Clin. Microbiol. 41:4617-4622.

Lockhart, J. M., W. R. Davidson, D. E. Stallknecht, J. E. Dawson, and E. W. Howerth. 1997. Isolation of Ehrlichia chaffeensis from wild white-tailed deer (Odocoileus virginianus) confirms their role as natural reservoir hosts. J. Clin. Microbiol. 35:1681-1686.

López, J., A. Castillo, M. Muñoz, and S. Hildebrandt. 1999. Hallazgo de Ehrlichia canis en Chile, informe preliminar. Arch. Med. Vet. 31:211-214.

Meneses, A. 1995. First report of canine ehrlichiosis in Costa Rica. Vet. Rec. 137:46-47.

Murphy, G. L., S. A. Ewing, L. C. Whitworth, J. C. Fox, and A. A. Kocan. 1998. A molecular and serologic survey of Ehrlichia canis, E. chaffeensis, and E. ewingii in dogs and ticks from Oklahoma. Vet. Parasitol. 79:325-339.

Mylonakis, M. E., A. F. Koutinas, C. Billinis, L. S. Leontides, V. Kontos, O. Papadopoulos, T. Rallis, and A. Fytianou. 2003. Evaluation of cytology in the diagnosis of acute canine monocytic ehrlichiosis (Ehrlichia canis): a comparison between five methods. Vet. Microbiol. 91:197-204.

Neer, T. M., E. B. Breitschwerdt, R. T. Greene, and M. R. Lappin. 2002. Consensus statement on ehrlichial disease of small animals from the infectious disease study group of the ACVIM. J. Vet. Intern. Med. 16:309-315.

Ndip, L.M., R. N. Ndip, S. N. Esemu, V. L. Dickmu, E. B. Fokam, D. H. Walker, and J. W. McBride. 2005. Ehrlichial infection in Cameroonian canines by Ehrlichia canis and Ehrlichia ewingii. Vet. Microbiol. 111:59-66.

Pérez, M., Y. Rikihisa, and B. Wen. 1996. Ehrlichia canis-like agent isolated from a man in Venezuela: antigenic and genetic characterization. J. Clin. Microbiol. 34:2133-2139.

Pérez, M., M. Bodor, C. Zhang, Q. Xiong, and Y. Rikihisa. 2006. Human infection with Ehrlichia canis accompanied by clinical signs in Venezuela. Ann. NY. Acad. Sci. 1078: 110-117.

Rímolo, M. 2006. Prevalencia serológica y citológica de la ehrlichiosis canina en Costa Rica. Tesis de grado. Universidad Nacional, Heredia, Costa Rica.

Rodríguez-Vivas, R. I., R. E. F. Albornoz, and G. M. E. Bolio. 2005. Ehrlichia canis in dogs in Yucatán, Mexico: seroprevalence, prevalence of infection and associated factors. Vet. Parasitol. 127:75-79.

Romero, L. E., A. I. Meneses, L. Salazar, M. Jiménez, J. J. Romero, D. M. Aguiar, M. B. Labruna, and G. Dolz. 2011. First isolation and molecular characterization of Ehrlichia canis in Costa Rica, Central America. Res. Vet. Sc. 91:95-97.

Sáinz, A., S. Delgado, I. Amusategui, M. A. Tesouro, and P. Cármenes. 1996. Seroprevalence of canine ehrlichiosis in Castilla-León (north–west Spain). Prev. Vet. Med. 29:1-7.

Standaert, S.M., T. Yu, M. A. Scott, J. E. Childs, C. D. Paddock, W. L. Nicholson, J. Singleton Jr, and M. J. Blaser. 2000. Primary isolation of Ehrlichia chaffeensis from patients with febrile illnesses: clinical and molecular characteristics. J. Infect. Dis. 181:1082-1088.

Waner, T. and S. Harrus. 2000. Canine monocytic ehrlichiosis. [en línea]. Consultado 16 Octubre del 2007. http://www.ivis.org.

Waner, T., S. Harrus, F. Jongejan, H. Bark, A. Keysary, and A. W. Cornelissen. 2001. Significance of serological testing for ehrlichial diseases in dogs with special emphasis on the diagnosis of canine monocyitic ehrlichiosis caused by Ehrlichia canis. Vet. Parasitol. 95:1-15.

Wen, B., Y. Rikihisa, J. M. Mott, R. Greene, H. Y. Kim, N. Zhi, G. C. Couto, A. Unver, and R. Bartsch. 1997. Comparison of nested PCR with inmunofluorescent-antibody assay for detection of Ehrlichia canis infection in dogs treated with doxycycline. J. Clin. Microbiol. 35:1852-1855.

Weiser, G.M., M. A. Thrall, R. Fulton, E. R. Beck, L. A. Wise, and J. L. Steenhouse. 1991. Granular Lymphocytosis and Hyperproteinemia in dogs with chronic ehrlichosis. J. Am. Anim. Hosp. Assoc. 27:84-88.

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Published

2013-11-20

How to Cite

Evaluation of the diagnosis of Ehrlichia canis in dogs from Costa Rica, using blood smears and molecular technique. (2013). Ciencias Veterinarias, 28(1), 23-36. https://www.revistas.una.ac.cr/index.php/veterinaria/article/view/5425

How to Cite

Evaluation of the diagnosis of Ehrlichia canis in dogs from Costa Rica, using blood smears and molecular technique. (2013). Ciencias Veterinarias, 28(1), 23-36. https://www.revistas.una.ac.cr/index.php/veterinaria/article/view/5425

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