[Morphological and molecular identification of canine filariae in a semi-rural district of the Metropolitan Region in Chile].

INTRODUCTION

To date, there has been no definitive confirmation of the presence of zoonotic dirofilariasis in dogs in Chile.

OBJECTIVES

To study the presence of dirofilarias in blood samples from dogs collected in a semi-rural district near Santiago and to compare their frequency in dogs with and without dermatological manifestations.

METHODS

We examined 100 blood samples for dog filariae infections using microscopic methods (modified Knott technique). 50 dogs presented dermatological symptoms or signs compatible with filarial infections and 50 were asymptomatic. ITS-2 and 12s rDNA gene amplification by PCR and sequencing were performed in samples microscopically positive for microfilariae. Results. We observed microfilariae in 22 dogs (22%). Of these, 16/50 (32%) were symptomatic and 6/50 (12%) were asymptomatic (p = 0.02). Morphologically, the majority of micro-filariae were similar to Dirofilaria repens, although many had a bigger size than previously described. Nucleotide sequencing of the amplified genes showed no more than 95% homology with the D. repens sequences available for comparison. D. reconditum and D. dracunculoides infections were also identified.

CONCLUSIONS

These features might indicate the presence of new species of Dirofilaria or a D. repens close related variant in Chile.