An in vitro system for assessing the sensitivity of Plasmodium vivax to chloroquine

In vitro Anti-Malarial Drug Susceptibility of Temperate Plasmodium vivax from Central China

“…Although assay conditions may have had some slight variations between different studies and may not be directly comparable with results from other studies, 31,32,34 the same technique has been used to evaluate in vitro drug susceptibility of P. vivax parasites in Thailand and South Korea. 33,35 These studies detected similar sensitivities to some drugs (artesunate and CQ) but dramatic differences to others (e.g., quinine, pyrimethamine, and mefloquine), which could be explained by difference in malaria epidemiology and antimalarial drug use history in these countries.…”

“…In recent years, renewed interests in culturing P. vivax led to improvement of an ex vivo procedure and adaptation of this technique for in vitro drug assays. [30][31][32] These assays, based on schizont maturation, have been used to evaluate drug sensitivity of tropical P. vivax isolates from southeast Asia and temperate-zone isolates from South Korea. [33][34][35] We present the first in vitro evaluation of drug sensitivity of P. vivax clinical isolates from a temperate malarious region of central China.…”

Neglect of Plasmodium vivax malaria

“…The expense and risk of such work usually requires solid preclinical studies as a foundation. Recent improvements with in vitro assays of drug activity against P. vivax (a rare example of a significant advance in research on this parasite) [60][61][62][63] at least offer the means of investigation of therapies in which the parasite can be obtained with relative ease. Despite evidence of resistance to CQ, and a reasonable forecast of further deterioration, clinical investigation of alternative treatments for vivax malaria resistant to CQ rarely occurs.…”

Assessment of in vitro sensitivity of Plasmodium vivax fresh isolates

“…Through the removal of leukocytes and enrichment of the growth media, it is now possible to culture P. vivax from ring stage to schizont stage. This has enabled the successful development of the two in vitro test systems for assessing P. vivax sensitivity to antimalarials by Tasanor and Russell et al [7,8] . Either assay method relies on the microscopic examination, but with different assay end points (schizont maturation and growth inhibition, respectively).…”

“…The schizont maturation inhibition assay has been used as a standard for assessing sensitivity of P. vivax to antimalarial drugs but it poses a constraint with regard to the absence of P. vivax intravascular sequestration of the higher stages of intraerythrocytic schizogony. The test system previously reported by our group based on growth inhibition [7] reflects the age composition of the parasite population and its progression over the duration of the drug response test. Both methods however, suffer from the requirement of highly experienced and skilled microscopists and extensively labour-intensive work.…”