Strong Host-Feeding Preferences of the Vector Triatoma infestans Modified by Vector Density: Implications for the Epidemiology of Chagas Disease
| Autor: | Leonardo A. Ceballos, Ricardo E. Gürtler, Raúl Stariolo, Paula Ordóñez-Krasnowski, Uriel Kitron, Leonardo Lanati |
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| Rok vydání: | 2009 |
| Předmět: |
Male
Infectious Diseases/Epidemiology and Control of Infectious Diseases Chagas disease Veterinary medicine animal structures RC955-962 030231 tropical medicine Public Health and Epidemiology/Infectious Diseases medicine.disease_cause law.invention Random Allocation 03 medical and health sciences Dogs 0302 clinical medicine law Arctic medicine. Tropical medicine parasitic diseases Infestation Triatoma infestans medicine Animals Chagas Disease Triatoma Trypanosoma cruzi 030304 developmental biology 2. Zero hunger 0303 health sciences biology Host (biology) fungi Infectious Diseases/Protozoal Infections Public Health Environmental and Occupational Health medicine.disease biology.organism_classification Insect Vectors 3. Good health Infectious Diseases Transmission (mechanics) Ecology/Population Ecology Infectious Diseases/Neglected Tropical Diseases Vector (epidemiology) Cats Female Public aspects of medicine RA1-1270 Chickens Research Article |
| Zdroj: | PLoS Neglected Tropical Diseases, Vol 3, Iss 5, p e447 (2009) PLoS Neglected Tropical Diseases |
| ISSN: | 1935-2735 |
| DOI: | 10.1371/journal.pntd.0000447 |
| Popis: | Background Understanding the factors that affect the host-feeding preferences of triatomine bugs is crucial for estimating transmission risks and predicting the effects of control tactics targeting domestic animals. We tested whether Triatoma infestans bugs prefer to feed on dogs vs. chickens and on dogs vs. cats and whether vector density modified host choices and other vital rates under natural conditions. Methodology Two host choice experiments were conducted in small caged huts with two rooms between which bugs could move freely. Matched pairs of dog–chicken (six) and dog–cat (three) were assigned randomly to two levels of vector abundance and exposed to starved bugs during three nights. Bloodmeals from 1,160 bugs were tested by a direct enzyme-linked immunosorbent assay. Principal Findings Conditional logistic regression showed that dogs were highly preferred over chickens or cats and that vector density modified host-feeding choices. The relative risk of a bug being blood-engorged increased significantly when it fed only on dog rather than chicken or cat. Bugs achieved higher post-exposure weight at higher vector densities and successive occasions, more so if they fed on a dog rather than on a cat. Conclusions Our findings strongly refute the hypothesis that T. infestans prefers to blood-feed on chickens rather than dogs. An increase in dog or cat availability or accessibility will increase the rate of bug feeding on them and exert strong non-linear effects on R 0. When combined with between-dog heterogeneities in exposure, infection, and infectiousness, the strong bug preference for dogs can be exploited to target dogs in general, and even the specific individuals that account for most of the risk, with topical lotions or insecticide-impregnated collars to turn them into baited lethal traps or use them as transmission or infestation sentinels based on their immune response to Trypanosoma cruzi or bug salivary antigens. Author Summary Chagas disease is a complex zoonosis with more than 150 mammalian host species, nearly a dozen blood-sucking triatomine species as main vectors, and 9–11 million people infected with Trypanosoma cruzi (its causal agent) in the Americas. Triatoma infestans, a highly domesticated species and one of the main vectors, feeds more often on domestic animals than on humans in northern Argentina. The question of whether there are host-feeding preferences among dogs, cats, and chickens is crucial to estimating transmission risks and predicting the effects of control tactics targeting them. This article reports the first host choice experiments of triatomine bugs conducted in small huts under natural conditions. The results demonstrate that T. infestans consistently preferred dogs to chickens or cats, with host shifts occurring more frequently at higher vector densities. Combined with earlier findings showing that dogs have high infection rates, are highly infectious, and have high contact rates with humans and domestic bugs, our results reinforce the role of dogs as the key reservoirs of T. cruzi. The strong bug preference for dogs can be exploited to target dogs with topical lotions or insecticide-impregnated collars to turn them into baited lethal traps or use them as transmission or infestation sentinels. |
| Databáze: | OpenAIRE |
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