Canine Brugia malayi microfilarial excretory/secretory protein-based antibody assay for the diagnosis of brugian filariasis in dogs.

Brugian filariasis is reported in dogs in Kerala, India. Antibody detection kits are not available worldwide, for detection of Brugian filariasis in dogs. A study was carried out to develop Indirect plate ELISA using excretory secretory antigen isolated from canine brugian microfilariae and compare the sensitivity and specificity with that of blood smear examination. Identification of microfilariae was done by acid phosphatase staining using Naphthol AS-TR method and Polymerase Chain Reaction for Hha 1 repeat sequence. The microfilariae were identified as Brugia malayi. Isolation of brugian microfilariae from canine blood was done by gradient centrifugation method. The isolated microfilariae were maintained in RPMI-1640 media. The pooled media was then concentrated to obtain excretory secretory protein (ESP). This ESP was used to develop Indirect ELISA. The sensitivity and specificity of the plate ELISA developed was 84 and 100 per cent respectively when compared with blood smear examination. This is the first report of successful isolation of ESP from Brugia malayi microfilariae from dogs and standardization of plate ELISA using the antigen.

Comparison of efficacy of ivermectin and diethylcarbamazine against naturally infected Brugia malayi microfilaria in dogs.

Filarial parasites like Brugia pahangi and Brugia malayi can infect dogs. Adults of Brugia genus resides in the lymphatic system and microfilariae, in blood. There are increasing reports of detection of B. malayi microfilariae in dogs. A study was undertaken to compare the efficacy of repeated oral dosing of ivermectin (IVT) and diethylcarbamazine (DEC), individually and in combination against naturally infected B. malayi microfilariae in dogs. The species of the microfilariae was confirmed by acid phosphatase staining and polymerase chain reaction. The three treatment groups were 200 mcg/kg body weight IVT daily for 14 days (I), 6.6 mg/kg body weight DEC daily for 14 days (II) and IVT and DEC together in the same dose for a period of 5 days (III). Microfilarial status of the peripheral blood was assessed on the 0th, 7th, 14th and 21st day. Haematological parameters were measured on day zero and on the 21st day. Though, all the three treatment groups showed a reduction in the microfilarial concentration through the study period, complete absence of detectable microfilaremia was not noticed in any of the three groups by 21st day. Among the haematological parameters, statistically significant difference was observed in the post-treatment means of haemoglobin levels of group III when compared with group II. Since group III regime (IVT + DEC) was shorter and just as effective as the longer ones, it is considered superior to the other two.