The efficacy of a single-oral-dose administration of ivermectin and diethylcarbamazine on the treatment of feline Brugia malayi.

The combination of ivermectin and diethylcarbamazine (DEC) have been shown to be superior to either drug alone for the suppression of Brugia malayi in humans, but their efficacy against infection with B. malayi in cats has never been investigated. Fourteen asymptomatic microfilaremic (1-200 microfilariae/20 microl blood) cats received oral doses of ivermectin (400 microg/kg body weight) and DEC (6 mg/kg body weight) as a single treatment. A two-month post-treatment examination revealed that 87-100% of the microfilariae in each subject had been cleared, with two of the subjects being amicrofilaremic. A further reduction in microfilarial levels was observed until the final follow-up, at 8 months post-treatment, when the mean clearance rate was 99% and 12 out of the 14 subjects (86%) were amicrofilaremic. The combination of ivermectin and DEC demonstrated a microfilaricidal effect superior to that of either drug used alone, both in the initial rapid clearance of microfilariae, and in sustaining the effect for 8 months. This finding has important implications for the control of brugian lymphatic filariasis in the cat reservoir.

Determination of dengue virus serotypes in Thailand using PCR based method.

A reverse transcriptase-polymerase chain reaction (RT-PCR) and a single-tube multiplex PCR assay was modified for typing of dengue virus in different geographical areas of Thailand during 2000-2001. A set of primers (D1 and D2) was used to generate the RT-PCR product of 511 bp in size which subsequently underwent a single-tube multiplex PCR amplification using the highly specific primers for each of the dengue virus serotypes (D1, TS1, TS2, TS3 and DEN4). The PCR products of 482, 119, 290 and 392 bp in size were generated for dengue virus serotypes 1, 2, 3, and 4, respectively. Each set of specific primers showed no amplification of non-specific and non-target PCR products from human genomic DNA. The method was applied for investigation of 637 human blood samples in Thailand during 2000-2001 and found that 71, 43, 28, and 43 patients were classified as having a single infection with serotypes 1, 2, 3, and 4, respectively. Multiple infections with two or more dengue virus serotypes were also detected.