Determination of antimalarial drugs in pharmaceutical formulations and human blood by liquid chromatography: a review.

Malaria is a life-threatening disease being treated by oral medication. This is the best treatment to reduce morbidity and mortality, prevent disease progression to the most severe form, lower the transmission of the disease and hinder the appearance of strains resistant to antimalarials. According to the World Health Organization, the most common antimalarial drugs are chloroquine, primaquine, mefloquine, lumefantrine, artemether, and artesunate in single dosage forms or fixed-dose combination. Within this context, the present review aims to show the evolution of different analytical methods that have been applied to the determination of these antimalarial drugs in pharmaceutical formulations and human blood by liquid chromatography in the last 10 years, along with statistical analyses of the methods.

Tratamiento de infección por virus hepatitis C con nuevos antivirales en pediatría: a propósito de un caso / Treatment of hepatitis C virus infection with new direct-acting antivirals agents in pediatrics. Case report

La infección por virus de la hepatitis C en pediatría se produce principalmente por transmisión vertical. La historia natural en niños consiste en alta tasa de eliminación espontánea, infección asintomática o cambios histológicos mínimos. Las complicaciones suelen observarse en la adolescencia o en la edad adulta. El tratamiento clásico con interferón pegilado y ribavirina presenta efectos adversos, es de duración prolongada y logra una respuesta virológica sostenida (RVS) en el 50 % de los pacientes con infección por genotipo 1. Los nuevos antivirales de acción directa se encuentran disponibles para su indicación a partir de los 12 años, con excelente tolerancia y alta tasa de RVS. Se sugiere conducta terapéutica expectante en pacientes asintomáticos hasta acceder a la medicación. Reportamos el caso de un adolescente con hepatitis C crónica sin cirrosis que recibió tratamiento durante 12 semanas con ledipasvir/sofosbuvir y se logró una RVS.

Hepatitis C virus infection in children occurs mainly through vertical transmission. The natural history at this age consists in a high rate of spontaneous clearance, asymptomatic infection, or minimal histological changes. Disease complications are commonly seen in adolescence or adulthood. The classic treatment with pegylated interferon and ribavirin presents adverse effects, prolonged duration and achieves sustained viral response (SVR) in 50 % of patients with genotype 1 infection (the most frequent). New direct-acting antiviral treatments have been available in recent years for their indication from 12 years of age with excellent tolerance and a high SVR rate. Expectant therapeutic behavior is suggested in asymptomatic patients until they can access to them. We report the case of an adolescent with chronic hepatitis C without cirrhosis who received 12 weeks treatment with ledipasvir/sofosbuvir, achieving SVR.

Resistance-associated substitutions and response to treatment in a chronic hepatitis C virus infected-patient: an unusual virological response case report.

BACKGROUND: Direct-Acting agents (DAAs) target and inhibit essential viral replication proteins. They have revolutionized the treatment of Hepatitis C virus (HCV) infection reaching high levels of sustained virologic response. However, the detection of basal resistance-associated substitutions (RASs) to DAAs in naïve patients could be important in predicting the treatment outcome in some patients exhibiting failures to DAA-based therapies. Therefore, the aim of this work was to evaluate the presence of RASs as minority variants within intra-host viral populations, and assess their relationship to response to therapy on a multiple times relapser patient infected chronically with HCV. CASE PRESENTATION: A male HCV infected-patient with a genotype 1a strain was evaluated. He had previously not responded to dual therapy (pegylated interferon-α plus ribavirin) and was going to start a direct-acting agent-based therapy (DAAs). He showed no significant liver fibrosis (F0). Viral RNA was extracted from serum samples taken prior and after therapy with DAAs (sofosbubir/ledipasvir/ribavirin). NS5A and NS5B genomic regions were PCR-amplified and the amplicons were sequenced using Sanger and next-generation sequencing (NGS) approaches. RASs were searched in in-silico translated sequences for all DAAs available and their frequencies were determined for those detected by NGS technology. Sanger sequencing did not reveal the presence of RASs in the consensus sequence neither before nor after the DAA treatment. However, several RASs were found at low frequencies, both before as well as after DAA treatment. RASs found as minority variants (particularly substitutions in position 93 within NS5A region) seem to have increased their frequency after DAA pressure. Nevertheless, these RASs did not become dominant and the patient still relapsed, despite perfect adherence to treatment and having no other complications beyond the infection (no significant fibrosis, no drug abuse). CONCLUSIONS: This report shows that some patients might relapse after a DAA-based therapy even when RASs (pre- and post-treatment) are detected in very low frequencies (< 1%) within intra-host viral populations. Increased awareness of this association may improve detection and guide towards a personalized HCV treatment, directly improving the outcome in hard-to-treat patients.

Improvement in Liver Stiffness in Pediatric Patients with Hepatitis C Virus after Treatment with Direct Acting Antivirals.

OBJECTIVES: To assess the degree of liver stiffness using transient elastography in Egyptian children infected with hepatitis C virus (HCV) at baseline and 1 year after achievement of sustained virologic response (SVR) with direct acting antivirals. STUDY DESIGN: This prospective study included children infected with HCV who received treatment with sofosbuvir/ledipasvir and achieved SVR. At baseline and 1 year after achievement of SVR, the extent of hepatic fibrosis was assessed by transient elastography using FibroScan to measure liver stiffness, in addition to noninvasive markers including aspartate aminotransferase/platelet ratio index (APRI) and fibrosis-4 (FIB-4) index. RESULTS: The study included 23 cases that had variable degrees of fibrosis at baseline; their ages ranged between 10 and 18 years. At baseline, 13 patients had F1; 3 patients had F1-F2; 1 patient had F2; 3 patients had F3; 2 had F3-F4; and 2 patients with F4. One year after achievement of SVR, there was a statistically significant improvement in liver stiffness, APRI, and FIB-4 index (P = .03, <.001, .02, respectively). In 13 patients (56.5%), the liver stiffness improved; in 7 patients, it was stationary; and the remaining 3 patients showed mild increase in liver stiffness that was, however, associated with improvement in APRI and FIB-4 index. Comorbid conditions and previous treatment with interferon were not associated with increased liver stiffness 1 year after SVR. CONCLUSIONS: Egyptian children infected with HCV genotype 4 achieved significant regression in liver stiffness after treatment with direct acting antivirals.

Changes in Liver Stiffness and Noninvasive Fibrosis Scores in Egyptian Adolescents Successfully Treated with Ledipasvir-Sofosbuvir for Chronic Hepatitis C Virus Infection.

OBJECTIVE: To assess changes in noninvasive liver fibrosis measurements after chronic hepatitis C eradication by direct-acting antivirals in Egyptian adolescents. STUDY DESIGN: Liver stiffness measurement (LSM), by vibration-controlled transient elastography and noninvasive fibrosis scores (Firbosis-4, aspartate aminotransferase-platelet ratio index), was obtained before and 12 months after eradication with ledipasvir-sofosbuvir. The primary outcome was a more than 30% decrease in LSM with resulting fibrosis stage regression for initial fibrosis of F2 or higher and nonprogression of F0-F1, using the Ishak score (F0-F6). The secondary outcome was change in noninvasive fibrosis scores after treatment. RESULTS: Analyzing 85 patients, the median baseline LSM was 5.8 (IQR, 4.2-6.5) and at follow-up 5.1 kPa (IQR, 4-6 kPa) (P = .045); 62 (73%) met the primary outcome, 16 patients (19%) experienced regression, and 46 (54%) nonprogression of LSM. Of 18 with initial fibrosis of F2 0r higher, 13 regressed to F0-F1 and 2 from F6 to F5, 1 unchanged at F3, and 1 increased to F3 and 1 to F4. Among 67 patients with a baseline fibrosis of F0-F1, 62 were unchanged and 5 increased-4 to F2 and 1 to F3. Although 23 (27%) had a more than 30% LSM increase, only 7 (8%), with associated comorbidities (4 ß-thalassemia, 3 hepatic steatosis), had increased fibrosis stage. The median baseline FIB-4 and aspartate aminotransferase-platelet ratio index scores were 0.34 (IQR, 0.22-0.47) and 0.35 (0.24-0.57), and at follow-up 0.3 (IQR, 0.22-0.34) and 0.2 (0.18-2.8) (P < .001, <.001), respectively. CONCLUSIONS: Chronic hepatitis C eradication by direct-acting antiviral agents in Egyptian adolescents was associated with nonprogression or regression of liver fibrosis, by noninvasive fibrosis measurements, at 12 months after treatment in the majority of cases.

Effects of Age on Treatment of Chronic Hepatitis C with Direct Acting Antivirals.

INTRODUCTION AND AIM: Data on the efficacy and tolerance of interferon-free treatment in chronic hepatitis C (CHC) in elderly patients are limited in phase II-III trials. MATERIAL AND METHODS: A prospective cohort of adult patients with CHC treated in French general hospitals. RESULTS: Data from 1,123 patients, distributed into four age groups, were analyzed. Of these, 278 were > 64 years old (fourth quartile) and 133 were > 73 years old (tenth decile). Elderly patients weighed less, were more frequently treatment-experienced women infected with genotype 1b or 2, while they less frequently had genotype 3 or HIV coinfection, but had more frequent comorbidities and drug consumption. Half of the patients had cirrhosis, whatever their ages. The main treatment regimens were sofosbuvir/ledipasvir (37.8%), sofosbuvir/daclatasvir (31.8%), sofosbuvir/simeprevir (16.9%), sofosbuvir/ribavirin (7.8%); ribavirin was given to 24% of patients. The overall sustained virological response (SVR) rate was 91.0 % (95% CI: 89.292.5%) with no difference according to age. Logistic regression of the independent predictors of SVR were albumin, hepatocellular carcinoma and treatment regimen, but not age. The rate of severe adverse events (66 in 59/1062 [5.6%] patients) tended to be greater in patients older than 64 years of age (21/261,8.1%), but the only independent predictors of SAE by logistic regression were cirrhosis and baseline hemoglobin. Patient-reported overall tolerance was excellent in all age groups, and patient-reported fatigue decreased during and after treatment, independent of age. CONCLUSIONS: The high efficacy and tolerance of interferon-free regimens is confirmed in elderly patients in real-life conditions.

Multicenter Experience using Ledipasvir/Sofosbuvir ± RBV to Treat HCV GT 1 Relapsers after Simeprevir and Sofosbuvir Treatment.

INTRODUCTION AND AIM: Approximately 10%-15% of patients with hepatitis C genotype 1 (HCV GT1) experience virological relapse after all-oral antiviral regimen using simeprevir (SMV) and sofosbuvir (SOF). The efficacy and safety of treating such relapsers using ledipasvir/sofosbuvir (LDV/SOF) with/without ribavirin (RBV) has been limited. OBJECTIVE: Report the virological response and safety of LDV/SOF with/without RBV for 12-24 weeks in treating HCV GT1 relapsers after SMV + SOF. MATERIAL AND METHODS: Patients treated with standardized clinical protocol utilizing LDV/SOF with/without RBV at three transplant centers were retrospectively reviewed. RESULTS: Forty-five patients (29% post-LT, 82% male, 13% non-white, 73% subtype 1a, 86% IL28B CT/TT, 78% F3-4) started LDV/SOF with/without RBV at a median of 22 weeks (range 7-55 weeks) after the last dose of SMV+SOF treatment. Thirty-seven patients received LDV/SOF for 24 weeks (24/37 patients with RBV) and eight patients received LDV/SOF for 12 weeks (5/8 patients with RBV). RBV dose was adjusted for renal function. Sixteen patients who were RBV-ineligible received LDV/SOF without RBV for 12 or 24 weeks. SVR 12 was achieved in 96% (43/45) of patients. Baseline viral load, RBV use, or GT1 subtype did not impact SVR 12. Minimal adverse events were reported in those without RBV; 45% of patients who received RBV developed significant anemia requiring RBV dose reduction and/or discontinuation. In LT recipients, minimal immunosuppression dose adjustments were required and no biopsy-proven acute rejection occurred. CONCLUSIONS: Treatment with LDV/SOF with/without RBV for 12-24 weeks was very well tolerated and resulted in high SVR 12 rates (96%) in HCV GT1 relapsers to SMV + SOF treatment.

K13 Propeller Alleles, mdr1 Polymorphism, and Drug Effectiveness at Day 3 after Artemether-Lumefantrine Treatment for Plasmodium falciparum Malaria in Colombia, 2014-2015.

High treatment failure rates for Plasmodium falciparum malaria have been reported in Colombia for chloroquine, amodiaquine, and sulfadoxine-pyrimethamine. Artemisinin combination therapies were introduced in 2006 in Colombia, where artemether-lumefantrine (AL) is currently used to treat uncomplicated P. falciparum malaria. Artemisinin (ART) resistance was initially observed in Southeast Asia as an increased parasite clearance time, manifesting as a positive thick-blood smear on day 3 after treatment (D3 positivity). Recently, mutations in the propeller domain of the P. falciparumkelch13 gene (K13 propeller) have been associated with ART resistance. In this study, we surveyed AL effectiveness at D3 and molecular markers of drug resistance among 187 uncomplicated P. falciparum cases in 4 regions of Colombia from June 2014 to July 2015. We found that 3.2% (4/125) of patients showed D3 positivity, 100% (163/163) of isolates carried wild-type K13 propeller alleles, 12.9% (23/178) of isolates had multiple copies of the multidrug resistance 1 gene (mdr1), and 75.8% (113/149) of isolates harbored the double mutant NFSDD mdr1 haplotype (the underlining indicates mutant alleles). These data suggest that ART resistance is not currently suspected in Colombia but that monitoring for lumefantrine resistance and AL failures should continue.

Efficacy of Different Primaquine Regimens to Control Plasmodium falciparum Gametocytemia in Colombia.

Treatment against Plasmodium falciparum malaria includes blood schizonticides to clear asexual parasites responsible for disease. The addition of gametocytocidal drugs can eliminate infectious sexual stages with potential for transmission and the World Health Organization recommends a single dose (SD) of primaquine (PQ) to this end. The efficacy of PQ at 0.75 mg/kg to suppress gametocytemia when administered in single or fractionated doses was evaluated. A clinical controlled study with an open-label design was executed; three groups of 20 subjects were studied sequentially. All subjects were treated with the standard dose of artemether-lumefantrine plus the total dose of 0.75 mg/kg of PQ administered (without previous G6PD testing) in three different ways: Group "0.75d-3" received 0.75 mg/kg on day 3; Group "0.50d-1 + 0.25d-3" received 0.50 mg/kg on day 1 and 0.25 mg/kg on day 3; Group "0.25d-1,2,3" received 0.25 mg/kg on days 1, 2, and 3. Subjects were evaluated on days 1, 4, and 7 by thick smear microscopy and quantitative polymerase chain reaction to determine the carriage of immature and mature gametocytes. There were no adverse events. The three schemes caused a marked reduction (75-85%) in prevalence of gametocytes on day 4 compared with day 1, but only the group that received 0.75 mg/kg on day 3 maintained the reduced gametocyte burden until day 7. None of the three treatments were able to clear gametocyte carriage on days 4 or 7, but the group that received the SD had the lowest prevalence of gametocytes (15%). Further studies are needed to establish a PQ regimen with complete efficacy against gametocytes.

Baseline in vivo, ex vivo and molecular responses of Plasmodium falciparum to artemether and lumefantrine in three endemic zones for malaria in Colombia.

Background: Colombia began using artemisinin-based combination therapies for the treatment of uncomplicated Plasmodium falciparum malaria in 2006. It is necessary to implement resistance surveillance to antimalarial drugs in order to promptly detect changes in parasite susceptibility. The aim of this study was to establish a susceptibility baseline of P. falciparum to artemether-lumefantrine using three monitoring tools. Methods: Patients with uncomplicated malaria treated with artemether-lumefantrine underwent clinical and parasitological follow-up over 28 days. Ex vivo test was performed using the microtest technique for chloroquine, arthemeter, dihydroartemisinin and lumefantrine. Pfmdr1 copy number and polymorphisms in Pfk13, Pfatp6, Pfcrt and Pfmdr1 genes were analyzed. Results: From a total of 150 screened patients, 49 completed follow-up for 28 days. All treated patients had adequate clinical and parasitological responses. Parasitic clearance showed a drastic reduction of parasite biomass at 24 hours and complete elimination at 48 hours. One hundred eleven isolates were processed, all exhibited high susceptibility to artemisinins and a slight decrease in susceptibility to lumefantrine. No genetic polymorphisms associated with resistance to artemisinin were found. Conclusion: This study generated a susceptibility baseline in response to therapy with Coartem (artemether-lumefantrine) with numerical reference values, which will allow data comparison with future studies to systematically monitor changes in the parasite and to provide an early alert to the health authorities.

Persistence of Virologic Response after Liver Transplant in Hepatitis C Patients Treated with Ledipasvir / Sofosbuvir Plus Ribavirin Pretransplant.

INTRODUCTION: Recurrence of HCV infection in patients with chronic hepatitis C virus (HCV) at the time of liver transplantation is nearly universal and reduces the likelihood of graft and patient survival. MATERIALS AND METHODS: We evaluated outcomes of 17 patients (16 with HCV genotype 1 and 1 with genotype 4) who received up to 12 or 24 weeks of ledipasvir/sofosbuvir plus ribavirin prior to or up to the time of liver transplant in the SOLAR-1 and SOLAR-2 trials. In all patients, HCV RNA was < 15 IU/mL prior to transplant. At screening, 6 patients were Child-Pugh-Turcotte (CPT) class B and 11 were CPT class C. Seven patients underwent transplant prior to completing assigned treatment, with 4 treated for < 12 weeks. The primary endpoint was posttransplant virologic response 12 weeks after transplant (pTVR12) in patients with HCV RNA < 15 IU/mL at their last measurement prior to transplant. RESULTS: Overall, 94% (16/17) achieved pTVR12. All who achieved pTVR12 received at least 11 weeks of treatment. The single patient who did not achieve pTVR12 discontinued study drug on day 21 and underwent liver transplant the following day. The patient had HCV RNA < 15 IU/mL at post-transplant week 2 but died 15 days post-transplant because of multi-organ failure and septic shock. CONCLUSION: Among a small population of HCV patients with decompensated cirrhosis, virologic response to ledipasvir / sofosbuvir plus ribavirin prior to liver transplantation was maintained after transplantation, even if treatment was stopped early. Administration of ledipasvir / sofosbuvir plus ribavirin before liver transplant can prevent post-transplant HCV recurrence.

Combination of Ledipasvir and Sofosbuvir for Treatment of Hepatitis C Virus Genotype 1 Infection: Systematic Review and Meta-Analysis

ABSTRACT Background and aim. The combination of Sofosbuvir (SOF) and Ledipasvir (LDV) has been lead to considerable enhancement of treatment of hepatitis C virus (HCV) genotype 1 infection. A meta-analysis of the currently available studies was undertaken with the aim to evaluate the antiviral efficacy of SOF/LDV therapy for 12 or 24 weeks with or without Ribavirin (RBV) in patients with HCV genotype 1 infection. Material and methods. In this meta-analysis, we searched databases including PubMed, Scopus, Science Direct and Web of Science using appropriate keywords. All papers which evaluated the efficacy of combination therapy of SOF/LDV with or without RBV for 12 or 24 weeks among patients with HCV genotype 1 infection were included. Results. The 20 published articles were assessed for eligibility and finally 10 articles pooling 2248 participants were included in this meta-analysis. Pooled SVR12 for four SOF/LDV regimens were 95% (95%CI = 93%-97%) for 12 weeks of treatment with SOF/LDV, 97% (95%CI = 95%-98%) for 24 weeks of treatment with SOF/LDV, 96% (95%CI = 94%-97%) for 12 weeks of treatment with SOF/ LDV/RBV and 98% (95%CI = 97%-99%) for 24 weeks of treatment with SOF/LDV/RBV. Only in treatment regimen of SOF/LDV for 12 weeks, cirrhosis had a significant effect on the SVR12 (OR = 0.21, 95%CI = 0.07-0.66). Furthermore, NS5A resistance-associated substitutions at baseline were associated with decrease in the rate of SVR (OR = 0.31, 95%CI = 0.2-0.5). Conclusions. The Interferon-free regimen of SOF/LDV for 12 or 24 weeks with or without RBV is highly effective for treatment of patients with HCV genotype 1 infection.

Successful Posttransplant Treatment of Hepatitis C With Ledipasvir-Sofosbuvir in HIV+ Kidney Transplant Recipients.

BACKGROUND: Ledipasvir-sofosbuvir is effective at eradicating hepatitis C virus (HCV) infection in the general population and in HCV-monoinfected kidney transplant recipients, but there are no data to guide its use in human immunodeficiency virus/HCV coinfected kidney transplant patients. METHODS: We treated 6 human immunodeficiency virus/HCV coinfected kidney transplant recipients with ledipasvir-sofosbuvir at our 2 centers. All were infected with genotype 1 and 66% had received kidneys from HCV+ donors. RESULTS: All patients cleared the virus while on therapy and 100% have achieved a sustained virologic response at 12 weeks after completion of ledipasvir-sofosbuvir. Tacrolimus dosing required adjustment during and after ledipasvir-sofosbuvir therapy but antiretroviral regimens did not. CONCLUSIONS: Ledipasvir-sofosbuvir was well tolerated. Although all patients in our series were treated posttransplant, the ideal timing of HCV therapy in this population is unknown, and the impact of HCV clearance on posttransplant outcomes is yet to be determined.

Use of HCV+ Donors Does Not Affect HCV Clearance With Directly Acting Antiviral Therapy But Shortens the Wait Time to Kidney Transplantation.

BACKGROUND: Hepatitis C virus (HCV) infection is prevalent in the renal transplant population but direct acting antiviral agents (DAA) provide an effective cure of HCV infection without risk of allograft rejection. METHODS: We report our experience treating 43 renal transplant recipients with 4 different DAA regimens. RESULTS: One hundred percent achieved a sustained viral response by 12 weeks after therapy, and DAA regimens were well tolerated. Recipients transplanted with a HCV+ donor responded equally well to DAA therapy those transplanted with a kidney from an HCV- donor, but recipients of HCV+ organs experienced significantly shorter wait times to transplantation, 485 days (interquartile range, 228-783) versus 969 days (interquartile range, 452-2008; P = 0.02). CONCLUSIONS: On this basis, we advocate for a strategy of early posttransplant HCV eradication to facilitate use of HCV+ organs whenever possible. Additional studies are needed to identify the optimal DAA regimen for kidney transplant recipients, accounting for efficacy, timing relative to transplant, posttransplant clinical outcomes, and cost.

Cost-effectiveness of new antiviral regimens for treatment-naïve U.S. veterans with hepatitis C.

UNLABELLED: Recently approved, interferon-free medication regimens for treating hepatitis C are highly effective, but extremely costly. We aimed to identify cost-effective strategies for managing treatment-naïve U.S. veterans with new hepatitis C medication regimens. We developed a Markov model with 1-year cycle length for a cohort of 60-year-old veterans with untreated genotype 1 hepatitis C seeking treatment in a typical year. We compared using sofosbuvir/ledipasvir or ombitasvir/ritonavir/paritaprevir/dasabuvir to treat: (1) any patient seeking treatment; (2) only patients with advanced fibrosis or cirrhosis; or (3) patients with advanced disease first and healthier patients 1 year later. The previous standard of care, sofosbuvir/simeprevir or sofosbuvir/pegylated interferon/ribavirin, was included for comparison. Patients could develop progressive fibrosis, cirrhosis, or hepatocellular carcinoma, undergo transplantation, or die. Complications were less likely after sustained virological response. We calculated the incremental cost per quality-adjusted life year (QALY) and varied model inputs in one-way and probabilistic sensitivity analyses. We used the Veterans Health Administration perspective with a lifetime time horizon and 3% annual discounting. Treating any patient with ombitasvir-based therapy was the preferred strategy ($35,560; 14.0 QALYs). All other strategies were dominated (greater costs/QALY gained than more effective strategies). Varying treatment efficacy, price, and/or duration changed the preferred strategy. In probabilistic sensitivity analysis, treating any patient with ombitasvir-based therapy was cost-effective in 70% of iterations at a $50,000/QALY threshold and 65% of iterations at a $100,000/QALY threshold. CONCLUSION: Managing any treatment-naïve genotype 1 hepatitis C patient with ombitasvir-based therapy is the most economically efficient strategy, although price and efficacy can impact cost-effectiveness. It is economically unfavorable to restrict treatment to patients with advanced disease or use a staged treatment strategy. (Hepatology 2016;63:428-436).

Temporal and seasonal changes of genetic polymorphisms associated with altered drug susceptibility to chloroquine, lumefantrine, and quinine in Guinea-Bissau between 2003 and 2012.

In 2008, artemether-lumefantrine was introduced in Guinea-Bissau, West Africa, but quinine has also been commonly prescribed for the treatment of uncomplicated Plasmodium falciparum malaria. An efficacious high-dose chloroquine treatment regimen was used previously. Temporal and seasonal changes of genetic polymorphisms associated with altered drug susceptibility to chloroquine, lumefantrine, and quinine have been described. P. falciparum chloroquine resistance transporter (pfcrt) K76T, pfmdr1 gene copy numbers, pfmdr1 polymorphisms N86Y and Y184F, and pfmdr1 sequences 1034 to 1246 were determined using PCR-based methods. Blood samples came from virtually all (n=1,806) children<15 years of age who had uncomplicated P. falciparum monoinfection and presented at a health center in suburban Bissau (from 2003 to 2012). The pfcrt K76T and pfmdr1 N86Y frequencies were stable, and seasonal changes were not seen from 2003 to 2007. Since 2007, the mean annual frequencies increased (P<0.001) for pfcrt 76T (24% to 57%), pfmdr1 N86 (72% to 83%), and pfcrt 76+pfmdr1 86 TN (10% to 27%), and pfcrt 76T accumulated during the high transmission season (P=0.001). The pfmdr1 86+184 NF frequency increased from 39% to 66% (from 2003 to 2011; P=0.004). One sample had two pfmdr1 gene copies. pfcrt 76T was associated with a lower parasite density (P<0.001). Following the discontinuation of an effective chloroquine regimen, probably highly artemether-lumefantrine-susceptible P. falciparum (with pfcrt 76T) accumulated, possibly due to suboptimal use of quinine and despite a fitness cost linked to pfcrt 76T. (The studies reported here were registered at ClinicalTrials.gov under registration no. NCT00137514 [PSB-2001-chl-amo], NCT00137566 [PSB-2004-paracetamol], NCT00426439 [PSB-2006-coartem], NCT01157689 [AL-eff 2010], and NCT01704508 [Eurartesim 2012].).

Evidence of an increased incidence of day 3 parasitaemia in Suriname: an indicator of the emerging resistance of Plasmodium falciparum to artemether

The emerging resistance to artemisinin derivatives that has been reported in South-East Asia led us to assess the efficacy of artemether-lumefantrine as the first line therapy for uncomplicated Plasmodium falciparum infections in Suriname. This drug assessment was performed according to the recommendations of the World Health Organization in 2011. The decreasing number of malaria cases in Suriname, which are currently limited to migrating populations and gold miners, precludes any conclusions on artemether efficacy because adequate numbers of patients with 28-day follow-up data are difficult to obtain. Therefore, a comparison of day 3 parasitaemia in a 2011 study and in a 2005/2006 study was used to detect the emergence of resistance to artemether. The prevalence of day 3 parasitaemia was assessed in a study in 2011 and was compared to that in a study in 2005/2006. The same protocol was used in both studies and artemether-lumefantrine was the study drug. Of 48 evaluable patients in 2011, 15 (31%) still had parasitaemia on day 3 compared to one (2%) out of 45 evaluable patients in 2005/2006. Overall, 11 evaluable patients in the 2011 study who were followed up until day 28 had negative slides and similar findings were obtained in all 38 evaluable patients in the 2005/2006 study. The significantly increased incidence of parasite persistence on day 3 may be an indication of emerging resistance to artemether.

Trouble from the tropics: challenges in managing malaria in Rhode Island.

The authors present a case of severe falciparum malaria diagnosed in a traveler after he returned to Rhode Island from a visit to the Dominican Republic. They then review aspects of the case pertinent to our local practice environment that make diagnosis and management especially challenging.

Evidence of an increased incidence of day 3 parasitaemia in Suriname: an indicator of the emerging resistance of Plasmodium falciparum to artemether.

The emerging resistance to artemisinin derivatives that has been reported in South-East Asia led us to assess the efficacy of artemether-lumefantrine as the first line therapy for uncomplicated Plasmodium falciparum infections in Suriname. This drug assessment was performed according to the recommendations of the World Health Organization in 2011. The decreasing number of malaria cases in Suriname, which are currently limited to migrating populations and gold miners, precludes any conclusions on artemether efficacy because adequate numbers of patients with 28-day follow-up data are difficult to obtain. Therefore, a comparison of day 3 parasitaemia in a 2011 study and in a 2005/2006 study was used to detect the emergence of resistance to artemether. The prevalence of day 3 parasitaemia was assessed in a study in 2011 and was compared to that in a study in 2005/2006. The same protocol was used in both studies and artemether-lumefantrine was the study drug. Of 48 evaluable patients in 2011, 15 (31%) still had parasitaemia on day 3 compared to one (2%) out of 45 evaluable patients in 2005/2006. Overall, 11 evaluable patients in the 2011 study who were followed up until day 28 had negative slides and similar findings were obtained in all 38 evaluable patients in the 2005/2006 study. The significantly increased incidence of parasite persistence on day 3 may be an indication of emerging resistance to artemether.