11 research outputs found
Age-Specific Risk of Severe Disease with P. falciparum, P. vivax, and Mixed Infections in Children <10 y
<p>Age-Specific Risk of Severe Disease with P. falciparum, P. vivax, and Mixed Infections in Children <10 y</p
Age-Specific Prevalence of Parasitaemia among Presumptive Malaria Cases
<p>Age-Specific Prevalence of Parasitaemia among Presumptive Malaria Cases</p
Mosaic Plot of SM by Species in Children < 5 y
<p>Horizontal, species; vertical, proportion of SM.</p
Proportion of SM Cases with Each of the Main Defining Clinical or Laboratory Features among Children <5 y Infected with P. vivax, P. falciparum, and Mixed Species (Venn Diagram)
<p>Proportion of SM Cases with Each of the Main Defining Clinical or Laboratory Features among Children <5 y Infected with P. vivax, P. falciparum, and Mixed Species (Venn Diagram)</p
Distribution of parasite life cycle stages in the two <i>Plasmodium falciparum</i> cultures used in the present study.
<p>Panel A: The <i>ring stage culture</i> contained early rings, late rings and some early trophozoites of the first generation after synchronization. The <i>schizont stage culture</i> was on the verge of the first and second life cycles where most of the schizont stages have already turned to early ring stages of the second generation following invasion. Therefore, the ring stage culture contained only the hemozoin present in the parasites up to the early trophozoite stage, while the schizont stage culture had the entire hemozoin content formed during one generation of parasites with the largest portion produced by schizonts. Panel B: Light microscopy images of Giemsa stained thin blood films containing infected red blood cells with parasites in different stages of maturity (taken from these two cultures). In both panels the labels ER, LR, ET, LT, ES and LS correspond to early-ring, late-ring, early-trophozoite, late-trophozoite, early-schizont and late-schizont stages, respectively.</p
Using the hemozoin conversion rates reported in the literature for the different parasite stages (rings: 3â5%, trophozoites: 15â20%, and schizonts: 50â70%) [20]â[22], [29], [30] and the stage distribution of the parasites (Fig. 1), we estimated the hemozoin content of culture A (ring stage culture) and culture B (schizont stage culture).
<p>The lower and upper values of the hemozoin content correspond to the lower and upper values of the conversion rates quoted above. Note that the cultures have different parasite densities. We also estimated the hemozoin concentration of the two cultures based on MO signal using the conversion factor c<sub>HZ</sub>â=â1 ng/<i>”</i>L â â=â1.4% between the hemozoin concentration and the low-frequency (âŒ1 Hz) MO signal previously determined for artificial hemozoin crystals suspended in blood <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096981#pone.0096981-Butykai1" target="_blank">[15]</a>.</p
Magneto-optical (MO) detection of parasitemia in synchronized <i>Plasmodium falciparum</i> cultures.
<p>Panel A: Red and blue curves show the frequency dependent MO signal for samples from the ring and schizont stage cultures, respectively, with various levels of parasite density given in <i>”</i>L<sup>â1</sup> units on the right of the respective curves. The green curves shows the signal from uninfected reference samples. Data plotted with triangles and diamonds are the residual signal from freshly hemolyzed uninfected blood and water, respectively. The frequency scale corresponds to the rotation speed of the magnetic field. Panel B: Red and blue squares in panel B are the MO signal values measured at 20 Hz â indicated by a vertical solid line in panel A â for the dilution series prepared from the original ring and schizont stage cultures, respectively. Solid and open squares correspond to the duplicate samples labeled as samples #1 and samples #2. Triangles indicate the results obtained by remeasuring samples #1 with 24 h delay. The solid lines following the trend of the MO signal at higher parasite densities for ring (red line) and schizont (blue line) samples are guides for the eye. For ring and schizont stage samples with parasite densities lower than 10 parasites/<i>”</i>L and 1 parasites/<i>”</i>L, respectively, the MO signal does not further decrease. The green horizontal line shows the residual MO signal of uninfected blood, which is the mean detection limit of our method. The 95% confidence levels of this mean detection limit for the ring and schizont stage samples are indicated by red and blue dashed lines, respectively. Correspondingly, for ring and schizont stage samples with parasite density higher than 40 parasites/<i>”</i>L and 10 parasites/<i>”</i>L, respectively, the diagnosis is positive with a confidence of at least 95%. The background signal for freshly hemolyzed uninfected blood and water are also shown by dark and light grey lines. All these horizontal indicators are also shown in panel A for reference. The upper horizontal scale shows the corresponding levels of parasitemia.</p
Additional file 4: of Infection of Anopheles aquasalis from symptomatic and asymptomatic Plasmodium vivax infections in Manaus, western Brazilian Amazon
Table S4. Plasmids dilutions containing the sequence of the respective PCR product were used both as assay standards and to determine the limit of detection (LoD) of each assay. Generation of the plasmids is described in [35, 38]. (DOC 29 kb
Additional file 1: of Infection of Anopheles aquasalis from symptomatic and asymptomatic Plasmodium vivax infections in Manaus, western Brazilian Amazon
Table S1. PCR setup of Plasmodium-specific qPCR (QMAL) and P. vivax specific qPCR based on detection of 18S rRNA genes and RT-qPCR detecting pvs25 transcripts. For sequences of primers and probes see [35, 38]. (DOC 31 kb
Additional file 3: of Infection of Anopheles aquasalis from symptomatic and asymptomatic Plasmodium vivax infections in Manaus, western Brazilian Amazon
Table S3. Data from each membrane feeding assay of Anopheles aquasalis performed with samples from symptomatic and asymptomatic individuals of Plasmodium vivax. (DOC 151 kb