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

Abstract

Abstract. In the face of recent increase of Plasmodium vivax malaria in central China, we conducted a study to evaluate in vitro susceptibility of temperate-zone P. vivax parasites to antimalarial drugs. During 2005During -2006, in vitro drug susceptibility was measured for 42 clinical P. vivax isolates by using a schizont maturation inhibition technique. Geometric means of 50% inhibitory concentrations (IC 50 s) and 95% confidence intervals (CIs) were 10.87 (4.50-26.26) ng/mL for chloroquine, 4.21 (1.88-9.42-8) ng/mL for mefloquine, 11.82 (6.20-22.56) ng/mL for quinine, 0.13 (0.09-0.20) ng/mL for artesunate, 18.32 (8.08-41.50) ng/mL for pyrimethamine, and 17.73 (10.29-30.57) ng/mL for piperaquine. The IC 50 for chloroquine was lower than those obtained from isolates from Thailand and South Korea, suggesting that chloroquine remained effective against P. vivax malaria in central China. The results further indicated that temperate-zone P. vivax isolates from China were more susceptible to chloroquine, quinine, and mefloquine than isolates from Thailand.

Multistage inhibitors of the malaria parasite: Emerging hope for chemoprotection and malaria eradication

“…Researchers have also evaluated drugs 4 , 23 , and 25 on other human malaria species such as P. vivax , and these compounds exhibited IC 50 values of 0.60 nM, 4.90 nM, and 17.0 nM, respectively. It has been previously reported that drug molecules active against both P. falciparum and P. vivax show good correlation and have great clinical value . This investigation provides the first systematic evaluation of current and future malaria treatments against various life stages of three Plasmodium species, P. falciparum , P. vivax , and P. yoelii .…”

In Vitro Susceptibility of Plasmodium vivax to Antimalarials in Colombia

“…Such results suggest that derivatives of artemisinins have been effective against this type of parasite. However, an IC 50 of 32.6 nM was found for artesunate in Thailand in 2011 and an IC 50 of 21.0 nM was found for this antimalarial in a Brazilian region in 2014, which suggests a susceptibility loss of P. vivax to this antimalarial in two different geographic regions (Table 5) (9,19,21,22,36,38). In this study, when the isolates were classified according to the initial parasitic stages, IC 50 s of 0.3 nM for AS in group 1 and 1.4 nM in group 2 were found (Table 3).…”

Prevalence of Drug Resistance-Associated Gene Mutations in Plasmodium vivax in Central China

“…The tools that are used to monitor drug efficacy include clinical trials, in vitro studies, and molecular markers for detection, each of which made important contributions to a more complete understanding of anti-malarial drug resistance. In a previous study, the susceptibility of P. vivax to anti-malarial drugs was observed by in vitro testing [4], though further investigations are needed to assess the predictive value of molecular markers in central China.…”

“…1). A total of 26 P. vivax single infection samples were selected for this study, including 8 samples collected in Bengbu, Anhui Province during 2005-2006, which had shown lower susceptibility to chloroquine in a previous in vitro study [4], as well as 18 further samples collected in Suining, Jiangsu Province during 2008. The history of anti-malarial drugs used in these 2 sites was similar, and Suining is located in the border of the 2 provinces.…”

“…In a previous study, we investigated anti-malarial susceptibility of P. vivax in this temperate-zone by in vitro testing [4], and a variety of anti-malarial drugs with potential clinical use in China were tested. The results indicated that for P. vivax isolates from this area, the IC 50 s of chloroquine were lower than those of isolates from South Korea and Thailand.…”