Absolute and relative levels of cytokines in study participants.

<p>Plasma levels of TNF-∝, IFN-γ, IL-4, IL-10, IL-12 and TGF-β for 75 samples from symptomatic malaria patients and apparently healthy controls had been previously reported <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044394#pone.0044394-Gonalves1" target="_blank">[23]</a> and here are combined with IL-6, sTNFRI and sTNFRII measurements in these same samples and a complete analysis of additional samples. Data are expressed as median (interquartile range) unless stated otherwise and compared across three or four groups with Kruskal-Wallis tests (continuous variables) or χ² tests (proportions); <i>P</i> values for this comparison across groups are presented in the right-hand column. When comparisons across groups showed statistical significance, further pairwise comparisons were made using Mann-Whitney tests (continuous variables) or χ² tests (proportions). Values with different superscripts across a row indicate pairwise comparisons with statistical significance at the 5% level. The same value may have more than one superscript. When pairs of values across a row share one superscript (either the only or one of the superscripts associated with them), no statistically significant difference was found.</p

Demographic, hematologic and clinical characteristics of study participants.

<p>Clinical and laboratory data from 75 symptomatic malaria patients and apparently healthy controls had been previously reported <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044394#pone.0044394-Gonalves1" target="_blank">[23]</a> and here are combined with additional subjects living in the same areas. Data are expressed as median (interquartile range) unless stated otherwise and compared across three to five groups with Kruskal-Wallis tests (continuous variables) or χ² tests (proportions); <i>P</i> values for this comparison across groups are presented in the right-hand column. Only when comparisons across groups showed statistical significance, further pairwise comparisons were made using Mann-Whitney tests (continuous variables) or χ² tests (proportions). Values with different superscripts across a row indicate pairwise comparisons with statistical significance at the 5% level. The same value may have more than one superscript. When pairs of values across a row share one superscript (either the only or one of the superscripts associated with them), no statistically significant difference was found. Anemia was defined when hemoglobin concentration was below the following cut-off values: 120 g/l for adolescents aged 12–14 years and non-pregnant women, and 130 g/l for men aged ≥ 15 years. Thrombocytopenia was defined when the platelet count was below 150×10⁹/l.</p>*<p>Number of subjects  = 27 for hemoglobin measurements and platelet counts.</p>§<p>Number of subjects  = 11 for hemoglobin measurements and platelet counts.</p

Cytokine levels in acute-phase and convalescence blood samples from <i>P. vivax</i>-infected study participants.

<p>Levels of TNF-∝, IFN-γ, IL-4, IL-10, IL-12 and TGF-β in 22 paired samples had been reported previously <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044394#pone.0044394-Gonalves1" target="_blank">[23]</a> and were combined here with those for 17 additional pairs. Data are expressed as median (interquartile range) and were compared using Wilcoxon tests.</p

Severity of 13 malaria-associated symptoms in Amazonians with uncomplicated infection with <i>Plasmodium vivax</i> (A; n = 84), <i>P. falciparum</i> (B; n = 27) or both species (C; n = 11), diagnosed by thick-smear microscopy and confirmed by real-time PCR.

<p>Symptoms are abbreviated as follows: fever  =  Fev; chills  =  Chi; sweating  =  Swe; headache  =  Hea; myalgia  =  Mya; arthralgia  =  Art; abdominal pain  =  Abd; nausea  =  Nau; vomiting  =  Vom; dizziness  =  Diz; cough  =  Cou; dyspnea  =  Dys; diarrhea  =  Dia. Each bar segment represents the proportion of subjects reporting a given symptom as absent (no shading), mild (light gray), moderate (dark gray) or severe (black).</p

Proportion of <i>P.vivax</i> infections diagnosed during 8 consecutive cross-sectional surveys in Remansinho, Brazil, that were symptomatic (black bar segments) and asymptomatic (white bar segments) according to parasite density estimated by quantitative PCR.

<p>The bar widths are proportional to the number of cases within each parasite density class. A total of 129 <i>P. vivax</i> infections were classified according to the presence of symptoms and parasite density.</p

Kaplan-Meier estimates of the proportion of <i>P. vivax</i>-infected (continuous black line) and uninfected (continuous red line) asymptomatic subjects who remained free of slide-confirmed clinical vivax malaria over the follow-up period.

<p>Dashed lines represent the respective 95% confidence intervals. The small vertical tick-marks indicate the occurrence of a slide positive case of <i>P.vivax</i>, corresponding to the right censoring of the individual survival time. A Cox proportional hazards model revealed no significant difference, between the two groups, in overall risk of vivax malaria episodes, after controlling for potential confounders (hazard ratio = 1.07; 95% CI, 0.52–2.22, <i>P</i> = 0.840).</p

Correlation between length of residence in Amazonia (in years), a proxy of cumulative exposure to malaria, and the probability of having a <i>P. vivax</i> infection (continuous red line) and a clinical vivax malaria episode (continuous black line).

<p>Lines represent median individual probabilities derived from the final (fully adjusted) mixed-effects logistic regression models; the shaded area surrounding the lines represent interquartile ranges.</p

Venn diagram showing the proportion of <i>P. vivax</i> infections diagnosed by quantitative PCR during 8 consecutive cross-sectional surveys in Remansinho, Brazil, that were asymptomatic, subpatent (i.e., missed by conventional microscopy) and agametocytemic.

<p>The latter group comprises infections with no <i>pvs25</i> gene transcripts detected by quantitative reverse transcriptase PCR; note that all agametocytemic infections were both asymptomatic and subpatent.</p

Number of malarial infections diagnosed by conventional microscopy (CM) and quantitative real-time PCR (qPCR), according to the presence or absence of malaria-related symptoms, during 8 consecutive cross-sectional surveys in the population of Remansinho, Brazil (2010–13).

<p>Dates of cross-sectional surveys were: survey 1 1, March–May, 2010; survey 2, May–July, 2010; survey 3, October–November, 2010; survey 4, March–April, 2011; survey 5, October–November, 2011; survey 6, April–May, 2012; survey 7, October–November, 2012; survey 8, April–May, 2013. Polyethylene bed-nets treated with 2% permethrin (Olyset Net) were distributed to the entire study population in August, 2012.</p><p>Number of malarial infections diagnosed by conventional microscopy (CM) and quantitative real-time PCR (qPCR), according to the presence or absence of malaria-related symptoms, during 8 consecutive cross-sectional surveys in the population of Remansinho, Brazil (2010–13).</p