An ultrasensitive reverse transcription polymerase chain reaction assay to detect asymptomatic low-density Plasmodium falciparum and Plasmodium vivax infections in small volume blood samples.

BackgroundHighly sensitive, scalable diagnostic methods are needed to guide malaria elimination interventions. While traditional microscopy and rapid diagnostic tests (RDTs) are suitable for the diagnosis of symptomatic malaria infection, more sensitive tests are needed to screen for low-density, asymptomatic infections that are targeted by interventions aiming to eliminate the entire reservoir of malaria infection in humans.MethodsA reverse transcription polymerase chain reaction (RT- PCR) was developed for multiplexed detection of the 18S ribosomal RNA gene and ribosomal RNA of Plasmodium falciparum and Plasmodium vivax. Simulated field samples stored for 14 days with sample preservation buffer were used to assess the analytical sensitivity and specificity. Additionally, 1750 field samples from Southeastern Myanmar were tested both by RDT and ultrasensitive RT-PCR.ResultsLimits of detection (LoD) were determined under simulated field conditions. When 0.3 mL blood samples were stored for 14 days at 28 °C and 80% humidity, the LoD was less than 16 parasites/mL for P. falciparum and 19.7 copies/µL for P. vivax (using a plasmid surrogate), about 10,000-fold lower than RDTs. Of the 1739 samples successfully evaluated by both ultrasensitive RT-PCR and RDT, only two were RDT positive while 24 were positive for P. falciparum, 108 were positive for P. vivax, and 127 were positive for either P. vivax and/or P. falciparum using ultrasensitive RT-PCR.ConclusionsThis ultrasensitive RT-PCR method is a robust, field-tested screening method that is vastly more sensitive than RDTs. Further optimization may result in a truly scalable tool suitable for widespread surveillance of low-level asymptomatic P. falciparum and P. vivax parasitaemia

Artemether-Lumefantrine Pharmacokinetics and Clinical Response Are Minimally Altered in Pregnant Ugandan Women Treated for Uncomplicated Falciparum Malaria.

Artemether-lumefantrine is a first-line regimen for the treatment of uncomplicated malaria during the second and third trimesters of pregnancy. Previous studies have reported changes in the pharmacokinetics and clinical outcomes following treatment with artemether-lumefantrine in pregnant women compared to nonpregnant adults; however, the results are inconclusive. We conducted a study in rural Uganda to compare the pharmacokinetics of artemether-lumefantrine and the treatment responses between 30 pregnant women and 30 nonpregnant adults with uncomplicated Plasmodium falciparum malaria. All participants were uninfected with HIV, treated with a six-dose regimen of artemether-lumefantrine, and monitored clinically for 42 days. The pharmacokinetics of artemether, its metabolite dihydroartemisinin, and lumefantrine were evaluated for 21 days following treatment. We found no significant differences in the overall pharmacokinetics of artemether, dihydroartemisinin, or lumefantrine in a direct comparison of pregnant women to nonpregnant adults, except for a statistically significant but small difference in the terminal elimination half-lives of both dihydroartemisinin and lumefantrine. There were seven PCR-confirmed reinfections (5 pregnant and 2 nonpregnant participants). The observation of a shorter terminal half-life for lumefantrine may have contributed to a higher frequency of reinfection or a shorter posttreatment prophylactic period in pregnant women than in nonpregnant adults. While the comparable overall pharmacokinetic exposure is reassuring, studies are needed to further optimize antimalarial efficacy in pregnant women, particularly in high-transmission settings and because of emerging drug resistance. (This study is registered at ClinicalTrials.gov under registration no. NCT01717885.)

Prevalence and seroprevalence of Plasmodium infection in Myanmar reveals highly heterogeneous transmission and a large hidden reservoir of infection.

Malaria incidence in Myanmar has significantly reduced over recent years, however, completeness and timeliness of incidence data remain a challenge. The first ever nationwide malaria infection and seroprevalence survey was conducted in Myanmar in 2015 to better understand malaria epidemiology and highlight gaps in Annual Parasite Index (API) data. The survey was a cross-sectional two-stage stratified cluster-randomised household survey conducted from July-October 2015. Blood samples were collected from household members for ultra-sensitive PCR and serology testing for P. falciparum and P. vivax. Data was gathered on demography and a priori risk factors of participants. Data was analysed nationally and within each of four domains defined by API data. Prevalence and seroprevalence of malaria were 0.74% and 16.01% nationwide, respectively. Prevalent infection was primarily asymptomatic P. vivax, while P. falciparum was predominant in serology. There was large heterogeneity between villages and by domain. At the township level, API showed moderate correlation with P. falciparum seroprevalence. Risk factors for infection included socioeconomic status, domain, and household ownership of nets. Three K13 P. falciparum mutants were found in highly prevalent villages. There results highlight high heterogeneity of both P. falciparum and P. vivax transmission between villages, accentuated by a large hidden reservoir of asymptomatic P. vivax infection not captured by incidence data, and representing challenges for malaria elimination. Village-level surveillance and stratification to guide interventions to suit local context and targeting of transmission foci with evidence of drug resistance would aid elimination efforts

Pregnancy outcomes and risk of placental malaria after artemisinin-based and quinine-based treatment for uncomplicated falciparum malaria in pregnancy: a WorldWide Antimalarial Resistance Network systematic review and individual patient data meta-analysis.

BACKGROUND: Malaria in pregnancy, including asymptomatic infection, has a detrimental impact on foetal development. Individual patient data (IPD) meta-analysis was conducted to compare the association between antimalarial treatments and adverse pregnancy outcomes, including placental malaria, accompanied with the gestational age at diagnosis of uncomplicated falciparum malaria infection. METHODS: A systematic review and one-stage IPD meta-analysis of studies assessing the efficacy of artemisinin-based and quinine-based treatments for patent microscopic uncomplicated falciparum malaria infection (hereinafter uncomplicated falciparum malaria) in pregnancy was conducted. The risks of stillbirth (pregnancy loss at ≥ 28.0 weeks of gestation), moderate to late preterm birth (PTB, live birth between 32.0 and < 37.0 weeks), small for gestational age (SGA, birthweight of < 10th percentile), and placental malaria (defined as deposition of malaria pigment in the placenta with or without parasites) after different treatments of uncomplicated falciparum malaria were assessed by mixed-effects logistic regression, using artemether-lumefantrine, the most used antimalarial, as the reference standard. Registration PROSPERO: CRD42018104013. RESULTS: Of the 22 eligible studies (n = 5015), IPD from16 studies were shared, representing 95.0% (n = 4765) of the women enrolled in literature. Malaria treatment in this pooled analysis mostly occurred in the second (68.4%, 3064/4501) or third trimester (31.6%, 1421/4501), with gestational age confirmed by ultrasound in 91.5% (4120/4503). Quinine (n = 184) and five commonly used artemisinin-based combination therapies (ACTs) were included: artemether-lumefantrine (n = 1087), artesunate-amodiaquine (n = 775), artesunate-mefloquine (n = 965), and dihydroartemisinin-piperaquine (n = 837). The overall pooled proportion of stillbirth was 1.1% (84/4361), PTB 10.0% (619/4131), SGA 32.3% (1007/3707), and placental malaria 80.1% (2543/3035), and there were no significant differences of considered outcomes by ACT. Higher parasitaemia before treatment was associated with a higher risk of SGA (adjusted odds ratio [aOR] 1.14 per 10-fold increase, 95% confidence interval [CI] 1.03 to 1.26, p = 0.009) and deposition of malaria pigment in the placenta (aOR 1.67 per 10-fold increase, 95% CI 1.42 to 1.96, p < 0.001). CONCLUSIONS: The risks of stillbirth, PTB, SGA, and placental malaria were not different between the commonly used ACTs. The risk of SGA was high among pregnant women infected with falciparum malaria despite treatment with highly effective drugs. Reduction of malaria-associated adverse birth outcomes requires effective prevention in pregnant women

SECURITY OF HEALTHCARE SYSTEM USING ROLE-BASED ACCESS CONTOL

Today, security is recognized as an absolute need in application development. The healthcare sector deals with very sensitive data, patient’s medical records need to be kept confidential; hence, security is very important. Role Based Access Control (RBAC) is increasingly used for ensuring security and privacy in complex organizations such as healthcare institutions. This papers is implemented the database security system by using RBAC for the patient treatment information. In this system, the employees of the hospital such as Head of Hospital, Doctors, Sisters, Nurses, Lab staffs and others are defined their role and access right for each role in order to access the treatment information. To improve better security within the system, this system can also control to the sensitive data by controlling attributes using RBAC. The main concept underlying this system uses the RBAC to control unauthorized access to patient medical information

Phase I/II evaluation of the prophylactic antimalarial activity of pafuramidine in healthy volunteers challenged with Plasmodium falciparum sporozoites

We evaluated the causal prophylactic antimalarial activity of a single oral dose of pafuramidine (DB289), an experimental prodrug of active metabolite DB75, in a randomized, double-blind, placebo-controlled, outpatient study. Sixteen healthy volunteers were dosed and challenged in a single cohort. Subjects were randomly assigned to one of three treatment arms: 100 mg pafuramidine eight days before challenge, 100 mg pafuramidine the day before challenge,or placebo. Challenge was by the bites of Plasmodium falciparum-infected Anopheles gambiae. Malaria developed in 15 persons but did not develop in one person in the day-8 pafuramidine treatment arm. Plasma levels of DB75 were lower than expected, and as intended were too low to provide suppressive prophylaxis at the earliest appearance of erythrocytic parasites. We conclude that a single dose of 100 mg pafuramidine does not adequately protect non-immune individuals against P. falciparum and shows no clinically or statistically significant evidence of causal prophylactic activity. Copyright © 2009 by The American Society of Tropical Medicine and Hygiene

Efavirenz-Based Antiretroviral Therapy Reduces Artemether-Lumefantrine Exposure for Malaria Treatment in HIV-Infected Pregnant Women.

BackgroundThe choice of malaria treatment for HIV-infected pregnant women receiving efavirenz-based antiretroviral therapy must consider the potential impact of drug interactions on antimalarial exposure and clinical response. The aim of this study was to investigate the effects of efavirenz on artemether-lumefantrine (AL) because no studies have isolated the impact of efavirenz for HIV-infected pregnant women.MethodsA prospective clinical pharmacokinetic (PK) study compared HIV-infected, efavirenz-treated pregnant women with HIV-uninfected pregnant women in Tororo, Uganda. All women received the standard 6-dose AL treatment regimen for Plasmodium falciparum malaria with intensive PK samples collected over 21 days and 42-days of clinical follow-up. PK exposure parameters were calculated for artemether, its active metabolite dihydroartemisinin (DHA), and lumefantrine to determine the impact of efavirenz.ResultsNine HIV-infected and 30 HIV-uninfected pregnant women completed intensive PK evaluations. Relative to controls, concomitant efavirenz therapy lowered the 8-hour artemether concentration by 76% (P = 0.013), DHA peak concentration by 46% (P = 0.033), and day 7 and 14 lumefantrine concentration by 61% and 81% (P = 0.046 and 0.023), respectively. In addition, there were nonsignificant reductions in DHA area under the concentration-time curve0-8hr (35%, P = 0.057) and lumefantrine area under the concentration-time curve0-∞ (34%, P = 0.063) with efavirenz therapy.ConclusionsPregnant HIV-infected women receiving efavirenz-based antiretroviral therapy during malaria treatment with AL showed reduced exposure to both the artemisinin and lumefantrine. These data suggest that malaria and HIV coinfected pregnant women may require adjustments in AL dosage or treatment duration to achieve exposure comparable with HIV-uninfected pregnant women

An In Silico Analysis of Malaria Pre-Erythrocytic-Stage Antigens Interpreting Worldwide Genetic Data to Suggest Vaccine Candidate Variants and Epitopes

Failure to account for genetic diversity of antigens during vaccine design may lead to vaccine escape. To evaluate the vaccine escape potential of antigens used in vaccines currently in development or clinical testing, we surveyed the genetic diversity, measured population differentiation, and performed in silico prediction and analysis of T-cell epitopes of ten such Plasmodium falciparum pre-erythrocytic-stage antigens using whole-genome sequence data from 1010 field isolates. Of these, 699 were collected in Africa (Burkina Faso, Cameroon, Guinea, Kenya, Malawi, Mali, and Tanzania), 69 in South America (Brazil, Colombia, French Guiana, and Peru), 59 in Oceania (Papua New Guinea), and 183 in Asia (Cambodia, Myanmar, and Thailand). Antigens surveyed include cell-traversal protein for ookinetes and sporozoites, circumsporozoite protein, liver-stage antigens 1 and 3, sporozoite surface proteins P36 and P52, sporozoite asparagine-rich protein-1, sporozoite microneme protein essential for cell traversal-2, and upregulated-in-infectious-sporozoite 3 and 4 proteins. The analyses showed that a limited number of these protein variants, when combined, would be representative of worldwide parasite populations. Moreover, predicted T-cell epitopes were identified that could be further explored for immunogenicity and protective efficacy. Findings can inform the rational design of a multivalent malaria vaccine