Parasitology

Research Article

An evaluation of melarsomine hydrochloride efficacy for parasitological cure in experimental infection of dairy cattle with Trypanosoma evansi in Thailand

MARC DESQUESNESa1a2, KETSARIN KAMYINGKIRDa2, TIMOTHÉE VERGNEa1, NACHAI SARATAPHANa3, RODTIAN PRANEEa4 and SATHAPORN JITTAPALAPONGa2 c1

a1 Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Montpellier, F-34000 France

a2 Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, 10900 Thailand

a3 Department of Livestock Development (DLD)/Bureau of Biology for Livestock Production (BBLP), Pathumthani, Thailand

a4 Department of Livestock Development (DLD) Chang Mai, Thailand

SUMMARY

Melarsomine hydrochloride can cure Trypanosoma evansi infection in camels at a dose of 0·25 mg/kg, but at that dose relapses occur in cattle. In our study, the efficacy of an intramuscular injection of melarsomine hydrochloride at 0·5 mg/kg was assessed in 3 normal and 3 splenectomized dairy cattle experimentally infected with a stock of T. evansi from Thailand. The animals were monitored for 5 months by haematocrit centrifugation, blood- or cerebrospinal fluid-mouse inoculation, polymerase chain reaction, the card agglutination test (CATT) for T. evansi, and the enzyme-linked immunosorbent assay‑T. evansi. Parasitological and DNA tests became and remained negative just after treatment. By the end of the experiment, CATT was negative and ELISA scores were below or very close to the cut-off value. One of the splenectomized cattle died from anaplasmosis during the experiment, but tested negative for surra. It was concluded that the parasites had been cleared from the cattle, and melarsomine hydrochloride at 0·5 mg/kg can be recommended for treatment against T. evansi infection in dairy cattle in Thailand. Further work is necessary to validate the efficacy of the treatment in the event of confirmed CSF-infection.

(Received January 30 2011)

(Revised March 18 2011)

(Revised April 20 2011)

(Accepted April 20 2011)

(Online publication July 18 2011)

Correspondence:

c1 Corresponding author: Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, 10900 Thailand. Tel: +66 (0) 8 49 40 72 68. Fax: +66 (0) 29 42 86 84. E-mail: fvetspj@yahoo.com

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