Clonality of P. falciparum infection was assessed as described previously. 32 Bacteraemia with metabolically active
Streptococcus pneumoniae and non-Typhoid Salmonella (NTS) was determined using quantitative PCR on cDNA. 33 Statistical analyses were performed using PASW statistics 18 (SPSS Inc.), GraphPad Prism (GraphPad Software Inc.) and the R-statistical software (R Foundation). Data was log10 transformed for parametric analyses Selumetinib molecular weight to achieve normality, except sequestered biomass (comprising positive and negative values) which was analyzed with non-parametric methods. Unpaired t-tests and likelihood-ratio tests were used to compare means and medians, respectively, of groups. Confounding by age, prior
antimalarial treatment and clonality of infection was assessed by quantile regression (“quantreg” package, R-statistical software): a model including only intercept was compared by means of likelihood-ratio tests to models with any combination of the above covariates or interaction terms. Correlation was assessed using Spearman’s rank correlation coefficient. click here To allow for the multiplicity of tests resulting from multiple responses and multiple comparisons within a response, a false discovery rate (FDR) of 5% was assumed, using the Benjamini and Hochberg approach. 34 Power of likelihood-ratio tests for detecting an X-fold difference in medians was determined by bootstrapping (10,000 replicates):
re-sampled data from the distribution of sequestered-parasite N-acetylglucosamine-1-phosphate transferase biomass estimates was compared with a similar sample to which (X − 1) times the median sequestered biomass was added. Sensitivity analyses assessed the range within which each model parameter could be varied without rejection of the null hypothesis of equal median sequestered biomass among groups. In addition, the effect of joint variation in the parameters was assessed by sampling 10,000 candidate values from uniform distributions within the limits defined for each individual parameter, determining the frequency with which the likelihood-ratio test did not reject the null hypothesis. The effect of parameter variation on the Spearman’s rank correlation between lactate and sequestered biomass was assessed identically. Complete clinical and laboratory data (Fig. 1) were available from 296 children (Tables 1 and 2), 127 (42.9%) with SM, of whom 5 died (Fig. 2). Children with SM were younger, more anaemic and thrombocytopaenic, and had higher blood lactate, parasitaemia, parasite density, plasma PfHRP2 concentrations, circulating parasite biomass, and total parasite biomass (calculated from PfHRP2 concentration) than children with UM (Table 2 and Fig. 3A).