Purine nucleoside phosphorylase (PNP) and lactate dehydrogenase (LDH) from Plasmodium parasites are two potential targets for novel anti-malarial compounds. Whereas these enzymes have been well-characterised from the Plasmodium falciparum parasite, information on these enzymes from the similarly prevalent species, Plasmodium vivax, is very limited. This hinders the development of effective common anti-malarial compounds.