Parasitology



Domestic dogs and cats as sources of Trypanosoma cruzi infection in rural northwestern Argentina


R. E. GÜRTLER a1c1, M. C. CECERE a1, M. A. LAURICELLA a2, M. V. CARDINAL a1, U. KITRON a3 and J. E. COHEN a4
a1 Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
a2 Instituto Nacional de Parasitología “Dr. Mario Fatala Chaben”, Paseo Colón 568, 1032 Buenos Aires, Argentina
a3 Division of Epidemiology and Preventive Medicine, Department of Veterinary Pathobiology, University of Illinois, Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61802, USA
a4 Laboratory of Populations, Rockefeller and Columbia Universities, 1230 York Ave. Box 20, New York NY 10021-6399, USA

Article author query
gurtler re   [PubMed][Google Scholar] 
cecere mc   [PubMed][Google Scholar] 
lauricella ma   [PubMed][Google Scholar] 
cardinal mv   [PubMed][Google Scholar] 
kitron u   [PubMed][Google Scholar] 
cohen je   [PubMed][Google Scholar] 

Abstract

The reservoir capacity of domestic cats and dogs for Trypanosoma cruzi infection and the host-feeding patterns of domestic Triatoma infestans were assessed longitudinally in 2 infested rural villages in north-western Argentina. A total of 86 dogs and 38 cats was repeatedly examined for T. cruzi infection by serology and/or xenodiagnosis. The composite prevalence of infection in dogs (60%), but not in cats, increased significantly with age and with the domiciliary density of infected T. infestans. Dogs and cats had similarly high forces of infection, prevalence of infectious hosts (41–42%), and infectiousness to bugs at a wide range of infected bug densities. The infectiousness to bugs of seropositive dogs declined significantly with increasing dog age and was highly aggregated. Individual dog infectiousness to bugs was significantly autocorrelated over time. Domestic T. infestans fed on dogs showed higher infection prevalence (49%) than those fed on cats (39%), humans (38%) or chickens (29%) among 1085 bugs examined. The basic reproduction number of T. cruzi in dogs was at least 8·2. Both cats and dogs are epidemiologically important sources of infection for bugs and householders, dogs nearly 3 times more than cats.

(Received December 30 2005)
(Revised April 7 2006)
(Accepted May 24 2006)
(Published Online October 11 2006)


Key Words: surveillance; host-feeding; incidence; triatomine bugs; Chagas disease; Trypanosoma cruzi; Triatoma infestans; dogs; cats; infectiousness.

Correspondence:
c1 Departamento de Ecología, Genética y Evolución, FCEN-UBA, Ciudad Universitaria, 1428 Buenos Aires, Argentina. Tel: +54 11 4576 3318. Fax: +54 11 4576 3384. E-mail: gurtler@ege.fcen.uba.ar


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