has 2 genes encoding xanthine dehydrogenase (XDH). We analyzed and gene expression by real-time quantitative PCR in tissues from sugar- and blood-fed females. Differential and gene expression was observed in tissues dissected throughout a time course. We next exposed females to blood meals supplemented with allopurinol, a well-characterized XDH inhibitor. We also tested the effects of injecting double-stranded RNA (dsRNA) against XDH1, XDH2, or both. Disruption of XDH by allopurinol or XDH1 by RNA interference significantly affected mosquito survival, causing a disruption in blood digestion, excretion, oviposition, and reproduction. XDH1-deficient mosquitoes showed a persistence of serine proteases in the midgut at 48 h after blood feeding and a reduction in the uptake of vitellogenin by the ovaries. Surprisingly, analysis of the fat body from dsRNA-XDH1-injected mosquitoes fell into 2 groups: one group was characterized by a reduction of the XDH1 transcript, whereas the other group was characterized by an up-regulation of several transcripts, including XDH1, glutamine synthetase, alanine aminotransferase, catalase, superoxide dismutase, ornithine decarboxylase, glutamate receptor, and ammonia transporter. Our data demonstrate that XDH1 plays an essential role and that XDH1 has the potential to be used as a metabolic target for vector control.-Isoe, J., Petchampai, N., Isoe, Y. E., Co, K., Mazzalupo, S., Scaraffia, P. Y. Xanthine dehydrogenase-1 silencing in mosquitoes promotes a blood feeding-induced adulticidal activity.

Key Points Question Are plasma tau levels associated with long-term neurocognitive impairment in pediatric cerebral malaria or severe malarial anemia? Findings In this cohort study of 467 children in Uganda, including children with cerebral malaria and severe malarial anemia as well as asymptomatic community children, plasma tau levels were higher in children with cerebral malaria or severe malarial anemia compared with asymptomatic community children. Plasma tau levels were associated with increased mortality and worse neurocognitive outcomes in children with cerebral malaria at younger than 5 years. Meaning These findings suggest that plasma tau may serve as a brain injury biomarker in 2 clinically diverse forms of pediatric severe malaria and may identify children at risk of developing long-term neurocognitive impairment following cerebral malaria.

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There are conflicting data about level and duration of Abs to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children after symptomatic or asymptomatic infection. In this human population, we enrolled adults and children in a prospective 6-mo study in the following categories: 1) symptomatic, SARS-CoV-2 PCR + (SP + ; children, n 5 8; adults, n 5 16), 2) symptomatic, PCR À , or untested (children, n 5 27), 3) asymptomatic exposed (children, n 5 13), and 4) asymptomatic, no known exposure (children, n 5 19). Neutralizing Abs (nAbs) and IgG Abs to SARS-CoV-2 Ags and spike protein variants were measured by multiplex serological assay. All SP + children developed nAb, whereas 81% of SP + adults developed nAb. Decline in the presence of nAb over 6 mo was not significant in symptomatic children (100 to 87.5%; p 5 0.32) in contrast to adults (81.3 to 50.0%; p 5 0.03). Among children with nAb (n 5 22), nAb titers and change in titers over 6 mo were similar in symptomatic and asymptomatic children. In children and adults, nAb levels postinfection were 10-fold lower than those reported after SARS-CoV-2 mRNA vaccination. Levels of IgG Abs in children to SARS-CoV-2 Ags and spike protein variants were similar to those in adults. IgG levels to primary Ags decreased over time in children and adults, but levels to three spike variants decreased only in children. Children with asymptomatic or symptomatic SARS-CoV-2 infection develop nAbs that remain present longer than in adults but wane in titer over time and broad IgG Abs that also wane in level over time. However, nAb levels were lower postinfection than those reported after immunization. ImmunoHorizons, 2022, 6: 408-415.