RESUMEN
Dirofilaria immitis is a widespread mosquito-borne parasite that causes dirofilariasis, a commonly diagnosed disease of dogs that is rarely reported in cats and humans. A mosquito survey was conducted in Itacoatiara in the State of Rio de Janeiro, from March 1995 to February 1996, using canine, feline and human baits. A total of 3,667 mosquitoes were dissected for D. immitis larvae, representing 19 species and 10 genera. From those, Ae. scapularis, Ae taeniorhynchus, Cx. quinquefasciatus, Cx. declarator, Cx. saltanensis and Wy. bourrouli were found infected with D. immitis parasites, and among those only the first three harbored infective larvae. The majority of larvae were found in the Malpighian tubules (889/936), and larval melanization was observed in the two Aedes species. In descending order, the best vectors were Ae. scapularis. Ae. taeniorhynchus, and Cx. quinquefasciatus which alternate seasonally in importance. Cx. quinquefasciatus is suggested to be a vector to cats. The potential transmission of D. immitis parasites by these three vectors to man is discussed.
Asunto(s)
Culicidae/parasitología , Dirofilaria immitis/aislamiento & purificación , Insectos Vectores/parasitología , Animales , Brasil , Gatos , Culicidae/clasificación , Dirofilaria immitis/crecimiento & desarrollo , Perros , Conducta Alimentaria , Femenino , Humanos , Insectos Vectores/clasificación , Estaciones del AñoRESUMEN
Heartworm, a chronic fatal mosquito-borne canine disease, is frequently diagnosed in dogs from the State of Rio de Janeiro, where its prevalence is 29.7% in the city of Niterói. Nevertheless it is rarely detected in cats (0.8%) from the same state. Dogs are the primary source of infection to mosquitoes. because cats either do not demonstrate microfilaremia or it is too low and transient for transmission. A mosquito survey was conducted in Itacoatiara, Niterói, from March 1995 to February 1996, using canine, feline and human baits. A total of 21 mosquito species (3,888 females) was collected and biting frequency was higher at dusk. The four species collected most frequently (88.9%) were: Aedes taeniorhynchus (30% of the total catch; with the peak in May/June); Culex quinquefasciatus (22.5%; August/October); Aedes scapularis (19.4%; August, October/November and January) and Culex declarator (17%; November/January). Human baits were attractive to these species and dogs were significantly more attractive to them than cats. Ae. taeniorhynchus, Cx. quinquefasciatus, Ae. scapularis, Cx. declarator and Cx. nigripalpus are the most likely mosquito species to transmit Dirofilaria immitis parasites to dogs and may transit the parasite to humans. It is also suggested that the vector to cats belongs to the games Culex.
Asunto(s)
Culicidae/parasitología , Dirofilaria immitis/patogenicidad , Dirofilariasis/epidemiología , Dirofilariasis/transmisión , Perros/parasitología , Conducta Alimentaria , Animales , Brasil/epidemiología , Gatos , Femenino , Humanos , Insectos Vectores , Distribución Normal , Prevalencia , Lluvia , Estaciones del Año , TemperaturaRESUMEN
Seventeen field isolates of Arcobacter species were recovered in Brazil from aborted porcine fetal livers (n = 3), kidneys (n = 2), and thoracic fluid (n = 1). Arcobacter species were also recovered from uterine and oviductal tissues (n = 5) and a placenta from sows with reproductive problems. These isolates were initially presumed to be Arcobacter cryaerophilus on the basis of aerobic growth at 30 degree C, indoxyl acetate hydrolysis, catalase and oxidase reactions, growth on MacConkey agar, sensitivity to 3.5% sodium chloride, and susceptibility to nalidixic acid (40 mg/ml). The isolates were confirmed as Arcobacter using polymerase chain reaction, and were classified as A. cryaerophilus 1A (24%), A. cryaerophilus 1B (71%), and A. butzleri (6%) using restriction fragment length polymorphism.