Evaluation of Larval Development of Dirofilaria immitis in Different Populations of Aedes aegypti and Aedes albopictus

Abstract

Dirofilaria immitis is an important nematode parasite commonly known as heartworm. This filarioid is transmitted by culicid vectors and primarily affects dogs, but other animals may also become infected, such as wild carnivores, cats and humans. The aim of the present study was to assess the development of D. immitis larvae in different culicid populations under laboratory conditions. Adult females of populations of Aedes aegypti from the city of Recife (P1), the city of Campinas (P2) and the Rockefeller strain from the Centers for Disease Control (P3) and one population of Aedes albopictus from Recife (P4) were fed for two hours with infected dog blood containing 2,000 microfilariae/ml of D. immitis. After artificial feeding, the specimens were maintained under controlled conditions. Ten females from each population were dissected daily over 14 days. The infection ratio and vector efficiency index were calculated and D. immitis development from L 1 to L 3 was assessed. The larvae in P1, P2, P3 and P4 reached the third stage in 11, 10, 14 and 9 days, respectively. The vector efficiency index was 53.8%, 20.0%, 7.4% and 25.2% in P1, P2, P3 and P4, respectively. The findings demonstrate that D. immitis larvae develop in all culicid populations studied herein. Based on mosquito mortality, development time and VEI the A. albopictus population from Recife (P4) demonstrated the best performance as vector. This is the second report of D. immitis development in A. albopictus from Brazil. The present data reinforce the role of this species as vector of D. immitis in an area where greater importance has long been given to A. aegypti.

Occurrence of immature forms of culicids (Insecta: Diptera) in the northeastern region of Brazil

“…This species presents great epidemiological importance due to its capacity to be a vector for various arboviruses (TAIPE-LAGOS;NATAL, 2003). Moreover, S. (S.) albopicta is a potential vector for the dengue virus, which causes epidemic disease throughout Brazil, and for D. immitis, the etiological agent of canine dirofilariasis, which also has a zoonotic nature (CARVALHO et al, 2013). This culicid species was detected in traps in all three environments (domestic, peridomestic and forest), thus confirming its capacity to colonize a wide variety of artificial breeding grounds, without necessarily abandoning its natural ecotopes (GOMES et al, 1999).…”

“…arboviruses, protozoa and helminths) (CARVALHO et al, 2013;DIBO et al, 2011;FORATTINI, 2002;PINTO et al, 2011). In Brazil, the state of Pernambuco is considered an endemic area for several pathogens transmitted by mosquitoes.…”

“…For example, human filariasis, caused by Wuchereria bancrofti, has been a serious sanitary problem in Recife (the state capital) and adjacent areas for a long time (FONTES et al, 2012;MEDEIROS et al, 2006). Similarly, canine filariasis caused by Dirofilaria immitis, a parasite with zoonotic potential, is frequently reported in northeastern region of Brazil, including the state of Pernambuco (ALVES et al, 1999;CARVALHO et al, 2008CARVALHO et al, , 2013LANGONI, 2009).…”