Chloroquine Alone or in Combination for Malaria in Children in Malawi

Clinical malaria episode was defined as at least one symptom of malaria and a positive malaria smear. The number of clinical malaria episodes (not including the initial malaria episode) reported by participants during follow up is presented as the number per Person Years at Risk (PYAR).

Adequate clinical and parasitologic response (ACPR) was defined as the absence of parasitemia at Day 28 and without previously meeting any of the criteria of early treatment or late clinical failure.

Adequate clinical and parasitologic response (ACPR) was defined as the absence of parasitemia at Day 28 and without previously meeting any of the criteria of early treatment or late clinical failure.

Adequate clinical and parasitologic response (ACPR) was defined as the absence of parasitemia at Day 28 and without previously meeting any of the criteria of early treatment or late clinical failure.

Adequate clinical and parasitologic response (ACPR) was defined as the absence of parasitemia at Day 28 and without previously meeting any of the criteria of early treatment or late clinical failure.

Adequate clinical and parasitologic response (ACPR) was defined as the absence of parasitemia at Day 28 and without previously meeting any of the criteria of early treatment or late clinical failure.

A case of severe malaria included one or more of the following: Hemoglobin ≤5 g/dL; prostration; respiratory distress; bleeding; recent seizures, coma or obtundation (Blantyre coma score < 5); inability to drink, or persistent vomiting. All cases were then adjudicated by a panel of investigators prior to analysis.

Hemoglobin values were assessed from blood collected at the last study visit at one year after enrollment. Group means are stratified by participants 3 years of age and under, and over 3 to 5 years of age.

Hemoglobin values were assessed from blood collected at the last study visit at one year after enrollment. Group means are stratified by participants 3 years of age and under, and over 3 to 5 years of age.

Creatine values were assessed from blood draws at Day 0 and Day 14 of each malaria episode. Samples that were below the limit of detection were reported as 44.2 micromoles/liter, equivalent to the lower limit of detection.

Creatine values were assessed from blood draws at Day 0 and Day 14 of each malaria episode. Samples that were below the limit of detection were reported as 44.2 micromoles/liter, equivalent to the lower limit of detection.

Creatine values were assessed from blood draws at Day 0 and Day 14 of each malaria episode. Samples that were below the limit of detection were reported as 44.2 micromoles/liter, equivalent to the lower limit of detection.

Creatine values were assessed from blood draws at Day 0 and Day 14 of each malaria episode. Samples that were below the limit of detection were reported as 44.2 micromoles/liter, equivalent to the lower limit of detection.

Creatine values were assessed from blood draws at Day 0 and Day 14 of each malaria episode. Samples that were below the limit of detection were reported as 44.2 micromoles/liter, equivalent to the lower limit of detection.

Creatine values were assessed from blood draws at Day 0 and Day 14 of each malaria episode. Samples that were below the limit of detection were reported as 44.2 micromoles/liter, equivalent to the lower limit of detection.

Creatine values were assessed from blood draws at Day 0 and Day 14 of each malaria episode. Samples that were below the limit of detection were reported as 44.2 micromoles/liter, equivalent to the lower limit of detection.

Creatine values were assessed from blood draws at Day 0 and Day 14 of each malaria episode. Samples that were below the limit of detection were reported as 44.2 micromoles/liter, equivalent to the lower limit of detection.

Creatine values were assessed from blood draws at Day 0 and Day 14 of each malaria episode. Samples that were below the limit of detection were reported as 44.2 micromoles/liter, equivalent to the lower limit of detection.

Creatine values were assessed from blood draws at Day 0 and Day 14 of each malaria episode. Samples that were below the limit of detection were reported as 44.2 micromoles/liter, equivalent to the lower limit of detection.

ALT values were assessed from blood draws at Day 0 and Day 14 of each malaria episode.

ALT values were assessed from blood draws at Day 0 and Day 14 of each malaria episode.

ALT values were assessed from blood draws at Day 0 and Day 14 of each malaria episode.

ALT values were assessed from blood draws at Day 0 and Day 14 of each malaria episode.

ALT values were assessed from blood draws at Day 0 and Day 14 of each malaria episode.

ALT values were assessed from blood draws at Day 0 and Day 14 of each malaria episode.

ALT values were assessed from blood draws at Day 0 and Day 14 of each malaria episode.

ALT values were assessed from blood draws at Day 0 and Day 14 of each malaria episode.

ALT values were assessed from blood draws at Day 0 and Day 14 of each malaria episode.

ALT values were assessed from blood draws at Day 0 and Day 14 of each malaria episode.

A basic age-appropriate neurological examination was conducted on Day 28 of each malaria illness episode and also at Days 112 and 224, and at 1 year. Subjects were were counted as a "change from 'normal' to 'abnormal' " if they had the 'normal' (or not-applicable) response for the initial day 28 exam and an 'abnormal' response at their last exam. If a subject did not have an exam at 1 year then the last available exam that was not associated with an illness episode (either Day 112 or 224) was used.

The presence of parasites with the mutation pfCRT 76T was measured with filter paper specimens collected at the time of enrollment and with successful parasite DNA amplification using pyrosequencing.

Participants were enrolled in the study at the time of the initial episode of malaria. If the participant presented with a subsequent episode of malaria at any time during the one year of follow-up, the presence of parasites with the mutation pfCRT 76T was measured with filter paper specimens collected at the time of enrollment and with successful parasite DNA amplification using pyrosequencing.

Participants were enrolled at the time of initial malaria episode and treated. Subsequent to treatment, subjects were monitored for the occurrence of new and recrudescent malaria infections, which were distinguished by analysis of the infecting parasites using merozoite surface protein-2 polymorphic gene length variation.

Participants were enrolled at the time of initial malaria episode and treated. Subsequent to treatment, participants who subsequently suffered new malaria episodes were monitored for the additional occurrence of new and recrudescent malaria infections, which were distinguished by analysis of the infecting parasites using merozoite surface protein-2 polymorphic gene length variation.

The cumulative hazard of having a malaria attack within one year for those participants who travelled and slept in rural areas (outside the city) versus those who did not was calculated and is presented as a life table to display the number of subjects at risk, the number with first clinical episode and the number censored at each time point. Participants are right-censored at the time of first malaria episode. Participants who did not develop malaria during follow-up or were lost to follow-up were censored at the time of their last visit.

The Global Positioning System (GPS) was used to establish the coordinates of participants' homes. The distribution of these coordinates was analyzed for evidence of clustering, or occurring closer together than would be expected on the basis of chance. Nearest Neighbor Index is a ratio of the observed mean distance over the expected mean distance. If the index is less than 1, the pattern exhibits clustering. If the index is greater than 1, the trend is toward dispersion.

1727 non-zero concentration measurements from 479 participants were pooled and used for population pharmacokinetic modeling in Monolix413s. Compartmental population pharmacokinetic modeling was used due to highly sparse data. The model was parameterized in terms of absorption rate constant for chloroquine (Ka), apparent clearance for chloroquine (CL/F, with F as the unknown oral bioavailability), apparent volume of distribution of the central and peripheral compartments for chloroquine (Vd/F), and the inter-compartmental clearance for chloroquine (Q/F). Only these primary population pharmacokinetic parameters could be estimated using the type of data collected. The best-fit population PK model was then used to estimate individual parameter estimates to derive Tmax and half-life.

1727 non-zero concentration measurements from 479 participants were pooled and used for population pharmacokinetic modeling in Monolix413s. Compartmental population pharmacokinetic modeling was used due to highly sparse data. The model was parameterized in terms of absorption rate constant for chloroquine (Ka), apparent clearance for chloroquine (CL/F, with F as the unknown oral bioavailability), apparent volume of distribution of the central and peripheral compartments for chloroquine (Vd/F), and the inter-compartmental clearance for chloroquine (Q/F). Only these primary population pharmacokinetic parameters could be estimated using the type of data collected. The best-fit population PK model was then used to estimate individual parameter estimates to derive Cmax in nanograms per milliliter (ng/mL).