Treatment of primate platynosomosis: A word of caution about the use of praziquantel in marmosets.

BACKGROUND: The successive reports of Platynosomum illiciens in Neotropical captive primates have increased interest in platynosomosis; however, its treatment is little known. METHODS: Callithrix penicillata (n = 10) naturally and chronically infected with P. illiciens were treated with praziquantel (25 mg/kg BW, three s.c. doses at 24 hours intervals), and coproparasitological tests performed over 67 days. The proportions of primates with a reduction in fecal egg counts (FEC) or negative results progressively increased after treatment, and at the last fecal tests, marmosets were negative. RESULTS AND CONCLUSIONS: Although all primates tolerated the initial days of study well, 40% (4/10) of them died between the 8th and 16th days after the onset of treatment. Clinical signs and necropsies indicated the occurrence of hepatic involvement, biliary obstruction, and cholangitis. Marmosets with a higher previous FEC were more likely to die after treatment. Use of praziquantel should be considered carefully on a case-by-case basis.

Eurytrema pancreaticum: the in vitro effect of praziquantel and triclabendazole on the adult fluke.

The efficacy and tolerance of the 80 microg/ml praziquantel (PZQ) and 40 microg/ml triclabendazole (TCZ) against adult stage Eurytrema pancreaticum in vitro were investigated at 3, 12, and 15 h incubation. Motility of the flukes and histopathological changes were studied. Sudden paralysis and death were observed after exposed to PZQ as early as 3h incubation. In contrast, the TCZ treated flukes showed active mobility at all intervals. By light microscopic examination, severe damages in various organs such as tegument, muscle, and testes were observed early at 12h incubation of these drugs. PZQ caused more severe damage to flukes than TCZ. There were vigorous contraction of musculature, progressive shrinkage of circular and longitudinal muscles, vacuolization and disintegration of the tegument disrupting the worms' outer surface including detachment of spines in the PZQ treatment. The cells in testes were slightly increased in size and followed by degeneration leaving several hollow spaces. The uterus and vitelline glands remained unaffected. The direct observation of the fluke motility and light microscopic study highly suggested that PZQ was more effective than TCZ treatment for the eurytremiasis infection.