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Clinical Trial
. 2015 Dec;59(12):7411-9.
doi: 10.1128/AAC.00791-15. Epub 2015 Sep 21.

Confirmed Plasmodium Vivax Resistance to Chloroquine in Central Vietnam

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Free PMC article
Clinical Trial

Confirmed Plasmodium Vivax Resistance to Chloroquine in Central Vietnam

Pham Vinh Thanh et al. Antimicrob Agents Chemother. .
Free PMC article

Abstract

Plasmodium vivax resistance to chloroquine (CQ) is currently reported in almost all countries where P. vivax is endemic. In Vietnam, despite a first report on P. vivax resistance to chloroquine published in the early 2000s, P. vivax was still considered sensitive to CQ. Between May 2009 and December 2011, a 2-year cohort study was conducted in central Vietnam to assess the recommended radical cure regimen based on a 10-day course of primaquine (0.5 mg/kg/day) together with 3 days of CQ (25 mg/kg). Here we report the results of the first 28-day follow-up estimating the cumulative risk of P. vivax recurrences together with the corresponding CQ blood concentrations, among other endpoints. Out of 260 recruited P. vivax patients, 240 completed treatment and were followed up to day 28 according to the WHO guidelines. Eight patients (3.45%) had a recurrent P. vivax infection, at day 14 (n = 2), day 21 (n = 1), and day 28 (n = 5). Chloroquine blood concentrations, available for 3/8 recurrent infections (days 14, 21, and 28), were above the MIC (>100 ng/ml whole blood) in all of these cases. Fever and parasitemia (both sexual and asexual stages) were cleared by day 3. Anemia was common at day 0 (35.8%), especially in children under 10 years (50%), and hemoglobin (Hb) recovery at day 28 was substantial among anemic patients (median change from day 0 to 28, +1.7 g/dl; interquartile range [IQR], +0.7 to +3.2). This report, based on CQ blood levels measured at the time of recurrences, confirms for the first time P. vivax CQ resistance in central Vietnam and calls for further studies using standardized protocols for accurately monitoring the extent and evolution of P. vivax resistance to chloroquine in Vietnam. These results, together with the mounting evidence of artemisinin resistance in central Vietnam, further highlight the increasing threat of antimalarial drug resistance to malaria elimination in Vietnam.

Figures

FIG 1
FIG 1
Study profile.
FIG 2
FIG 2
(A) Median hemoglobin (Hb) concentration at days 0, 14, and 28 (n = 224 patients with ACPR); (B) relative Hb change (between day 0 and day 14) according to baseline Hb values (cutoff for anemia, Hb concentration of <11.0 g/dl) (n = 240). Relative Hb change on day 14 (%) by linear regression: (i) anemia group, coefficient β = −10.00; 95% CI, −12.81 to −7.19; P < 0.001; (ii) nonanemia group, β = −6.46; 95% CI, −7.41 to −5.51; P < 0.001. A significant interaction was found between Hb change at day 14 and anemia status at day 0 (interaction term β = −5.99; 95% CI, −8.87 to −3.11; P < 0.001).

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References

    1. Guerra CA, Howes RE, Patil AP, Gething PW, Van Boeckel TP, Temperley WH, Kabaria CW, Tatem AJ, Manh BH, Elyazar IR, Baird JK, Snow RW, Hay SI. 2010. The international limits and population at risk of Plasmodium vivax transmission in 2009. PLoS Negl Trop Diseases 4:e774. doi:10.1371/journal.pntd.0000774. - DOI - PMC - PubMed
    1. Roberts L, Enserink M. 2007. Malaria. Did they really say ... eradication? Science 318:1544–1545. - PubMed
    1. Price RN, Tjitra E, Guerra CA, Yeung S, White NJ, Anstey NM. 2007. Vivax malaria: neglected and not benign. Am J Trop Med Hyg 77:79–87. - PMC - PubMed
    1. Baird JK. 2004. Chloroquine resistance in Plasmodium vivax. Antimicrob Agents Chemother 48:4075–4083. doi:10.1128/AAC.48.11.4075-4083.2004. - DOI - PMC - PubMed
    1. Baird JK. 2009. Resistance to therapies for infection by Plasmodium vivax. Clin Microbiol Rev 22:508–534. doi:10.1128/CMR.00008-09. - DOI - PMC - PubMed

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