BackgroundTreatment failure of chloroquine for P. vivax infections has reached high levels in the eastern provinces of Indonesia, however, in vitro characterization of chloroquine resistance and its associated molecular profile have yet to be determined.MethodsUsing a modified schizont maturation assay we investigated the in vitro chloroquine susceptibility profile and molecular polymorphisms of P. vivax isolates collected from Papua, Indonesia, where high levels of clinical chloroquine treatment failure have been reported, and from Thailand, where chloroquine treatment is generally effective.ResultsThe geometric mean chloroquine IC50 for P. vivax isolates from Papua (n = 145) was 312 nM [95%CI: 237–411 nM] compared to 46.8 nM [95%CI: 34.7–63.1 nM] from Thailand (n = 81); p<0.001. Correlating with the known clinical efficacy of the area, a cut off for chloroquine resistance was defined as 220nM, a level exceeded in 13.6% (11/81) of Thai isolates and 65% (94/145) of Papuan isolates; p<0.001. Several sequence polymorphisms in pvcrt-o and pvmdr1, and difference in pvmdr1 copy number were identified. A Y976F mutation in pvmdr1 was present in 96% (123/128) of Papuan isolates and 25% (17/69) of Thai isolates; p<0.001. Overall, the geometric mean chloroquine IC50 in isolates with the Y976F mutation was 283 nM [95%CI: 211–379], compared to 44.5 nM [95%CI: 31.3–63.4] in isolates with the wild type; p< 0.001. Pvmdr1 amplification occurred in 23% (15/66) of Thai isolates compared to none (0/104) of Indonesian isolates (p<0.001), but was not associated with increased chloroquine resistance after controlling for geographical location.Conclusions In vitro susceptibility testing of P. vivax discriminates between populations with differing levels of clinical efficacy of chloroquine. The pvmdr1 polymorphism at Y976F may provide a useful tool to highlight areas of emerging chloroquine resistance, although further studies defining its clinical correlates are needed.

In Papua, Indonesia, the antimalarial susceptibility of Plasmodium vivax (n ‫؍‬ 216) and P. falciparum (n ‫؍‬ 277) was assessed using a modified schizont maturation assay for chloroquine, amodiaquine, artesunate, lumefantrine, mefloquine, and piperaquine. The most effective antimalarial against P. vivax and P. falciparum was artesunate, with geometric mean 50% inhibitory concentrations (IC 50 In vitro drug susceptibility assays assess antimicrobial activity in the absence of the confounding effects of the host. Although such assays have become useful for monitoring the antimalarial resistance of Plasmodium falciparum, the assay has been of limited use with P. vivax. This is in part a consequence of a perception of the importance of antimalarial drug resistance with P. vivax, compounded by difficulties in standardizing a field-based assay. Over the last decade, a number of clinical studies have demonstrated the emergence of highgrade chloroquine resistance in Papua, Indonesia, and Papua, New Guinea (1, 18, 21), and its spread to other regions of Asia (6) and South America (20). However, assessment of the clinical efficacy of antimalarial drugs against P. vivax infection is confounded by the occurrence of both reinfections and relapses, making the attributable fraction of recurrent infections due to intrinsic parasite resistance difficult to gauge (2, 3, 10). To confirm the emergence of the spread of antimalarial drug resistance of P. vivax and to investigate alternative antimalarial drugs, it is critical that a standardized in vitro assay be developed and validated. The aim of this study was to define the in vitro susceptibility profiles of a range of antimalarial drugs and to investigate the confounding factors that modulate the derived estimate of drug efficacy. MATERIALS AND METHODS Field location and sample collection. Between March 2004 and May 2007,Plasmodium isolates were collected from patients attending malaria clinics in Timika, located in the southern part of Papua province, Indonesia. Timika is a region of endemicity for multidrug-resistant strains of P. vivax and P. falciparum, with a risk of treatment failure of 65% within 28 days after chloroquine monotherapy for P. vivax malaria and 48% failure after multidrug therapy with chloroquine-sulfadoxine-pyrimethamine for P. falciparum malaria (16). In 2004, treatment guidelines were changed accordingly to recommend an artemisinin combination therapy for both P. falciparum and P. vivax infection, precluding further clinical studies of the use of chloroquine monotherapy in this region (15). Patients with symptomatic malaria who presented to an outpatient facility were recruited into the study if they were singly infected with P. falciparum or with P. vivax, with a parasitemia of between 2,000 l Ϫ1 and 80,000 l Ϫ1 . Patients treated with antimalarials in the previous 3 weeks were excluded from this study. Venous blood (5 ml) was collected by venipuncture and, after the host white blood cells were removed using a CF11 column, 2 ml of packed infected red bl...

Amplification of pvmdr1 and single-nucleotide polymorphisms are correlated with susceptibility of P. vivax to multiple antimalarial drugs. Chloroquine and mefloquine appear to exert competitive evolutionary pressure on pvmdr1, similar to that observed with pfmdr1 in Plasmodium falciparum.

BackgroundA practical and simple regimen for all malaria species is needed towards malaria elimination in Indonesia. It is worth to compare the efficacy and safety of a single dose of artemisinin-naphthoquine (AN) with a three-day regimen of dihydroartemisinin-piperaquine (DHP), the existing programme drug, in adults with uncomplicated symptomatic malaria.MethodsThis is a phase III, randomized, open label using sealed envelopes, multi-centre, comparative study between a single dose of AN and a three-day dose of DHP in Jayapura and Maumere. The modified WHO inclusion and exclusion criteria for efficacy study were used in this trial. A total of 401 eligible adult malaria subjects were hospitalized for three days and randomly treated with AN four tablets single dose on day 0 or DHP three to four tablets single daily dose for three days, and followed for 42 days for physical examination, thick and thin smears microscopy, and other necessary tests. The efficacy of drug was assessed by polymerase chain reaction (PCR) uncorrected and corrected.ResultsThere were 153 Plasmodium falciparum, 158 Plasmodium vivax and 90 P. falciparum/P. vivax malaria. Mean of fever clearance times were similar, 13.0 ± 10.3 hours in AN and 11.3 ± 7.3 hours in DHP groups. The mean of parasite clearance times were longer in AN compared with DHP (28.0 ± 11.7 hours vs 25.5 ± 12.2 hours, p = 0.04). There were only 12 PCR-corrected P. falciparum late treatment failures: seven in AN and five in DHP groups. The PCR uncorrected and corrected on day −42 of adequate clinical and parasitological responses for treatment of any malaria were 93.7% (95% Cl: 90.3–97.2) and 96.3% (95% Cl: 93.6–99.0) in AN, 96.3% (95% Cl: 93.5–99.0) and 97.3% (95% Cl: 95.0–99.6) in DHP groups. Few and mild adverse events were reported. All the abnormal haematology and blood chemistry values had no clinical abnormality.ConclusionAN and DHP are confirmed very effective, safe and tolerate for treatment of any malaria. Both drugs are promising for multiple first-line therapy policies in Indonesia.

Reports of potential drug-resistant strains ofPlasmodium malariaein western Indonesia raise concerns that chloroquine resistance may be emerging inP. malariaeandP. ovale. In order to assess this,in vivoandin vitroefficacy studies were conducted in patients with monoinfection in Papua, Indonesia. Consecutive patients with uncomplicated malaria due toP. ovaleorP. malariaewere enrolled in a prospective clinical trial, provided with supervised chloroquine treatment, and followed for 28 days. Blood from patients withP. malariaeorP. ovaleparasitemia greater than 1,000 per microliter underwentin vitroantimalarial drug susceptibility testing using a modified schizont maturation assay. Of the 57 evaluable patients in the clinical study (P. malariae,n= 46;P. ovale,n= 11), none had recurrence with the same species during follow-up. The mean parasite reduction ratio at 48 h was 86 (95% confidence interval [CI], 57 to 114) forP. malariaeand 150 (95% CI, 54 to 245) forP. ovale(P= 0.18). One patient infected withP. malariae, with 93% of parasites at the trophozoite stage, was still parasitemic on day 4.In vitrodrug susceptibility assays were carried out successfully for 40 isolates (34 infected withP. malariaeand 6 withP. ovale). TheP. malariaeinfections at trophozoite stages had significantly higher chloroquine 50% effective concentrations (EC50s) (median, 127.9 nM [range, 7.9 to 2,980]) than those initially exposed at the ring stage (median, 14.0 nM [range, 3.5 to 27.0];P= 0.01). The EC50for chloroquine inP. ovalewas also higher in an isolate initially at the trophozoite stage (23.2 nM) than in the three isolates predominantly at ring stage (7.8 nM). Chloroquine retains adequate efficacy againstP. ovaleandP. malariae, but its marked stage specificity of action may account for reports of delayed parasite clearance times.

Primaquine is an effective anti-hypnozoite drug for Plasmodium vivax and Plasmodium ovale. However, it can trigger erythrocyte hemolysis in people with glucose 6-phosphate dehydrogenase (G6PD) deficiency. In a previous report from South Central Timor (SCT), Indonesia, we described the prevalence of Vanua Lava, Chatham, and Viangchan variants; in this study, other G6PD variants (Kaiping, Coimbra, Gaohe, Canton, and Mahidol) were subsequently analyzed. For clarity, all of these results are described together. The 381 DNA samples from the previous study during 2013-2014 were analyzed for G6PD variants by using PCR-restriction fragment length polymorphism (RFLP). The prevalence of G6PD deficiency in SCT was 6.3% (24/381 cases), including 4.2% (16/381 cases), 0.5% (2/381 cases), and 1.6% (6/381 cases) for Coimbra, Kaiping, and Vanua Lava variants, respectively. No other variants were found in this population. A significant association was found between ethnicity and the distribution of G6PD Kaiping in female subjects. A positive association was shown between G6PD activity and heterozygous females carrying Coimbra genotype, hemizygous males carrying Vanua Lava, Plasmodium falciparum infection in female subjects, and P. vivax infection in male subjects. Further molecular analysis of heterozygous females, particularly in malaria-endemic areas, is needed for mapping distribution of G6PD deficiency status in Indonesia.

Di Indonesia, malaria Plasmodium vivax resisten klorokuin mengkhawatirkan. Beberapa negara lain juga sudah melaporkan kasus P.vivax resisten klorokuin. Oleh sebab itu, dibutuhkan obat antimalaria alternatif. Ini merupakan penelitian prospektif dan uji perbandingan efikasi terapeutik klorokuin 25 mg basa/kg bb untuk 3 hari (CQ3, n=75), CQ3 plus sulfadoksin-pirimetamin (SP1) berdasarkan dosis pirimetamin 1,25 mg/kg bb dosis tunggal (CQ3+SP1, n=84) dan amodiakuin 25 mg basa/kg bb 3 hari (AQ3, n=83) pada penderita anak dan dewasa dengan malaria vivaks simptomatik. Dalam penelitian ini digunakan sistem penilaian WHO yang terbaru. PCR untuk genotyping juga dilakukan untuk memastikan kesembuhan radikal. Efikasi terapeutik dari CQ3, CQ3+SP1 dan AQ3 pada hari ke 14

Malaria still become one of major health burden in Indonesia especially in remote areas of east Indonesia. Golden standard of malaria parasite detection is still microscopic © 2017 Jurnal Teknologi Laboratorium ABSTRAKMalaria masih menjadi salah satu masalah kesehatan di Indonesia terutama di daerah bagian timur Indonesia. Gold standard pemeriksaan malaria sampai saat ini adalah teknik pemeriksaan mikroskop dengan cahaya putih (polikromatis) bersumber dari lampu halogen atau