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Artemisinin resistance in Plasmodium falciparum is conferred by mutations in the kelch 13 (K13) gene. In Rwanda, K13 mutations have increased over the past decade, including mutations associated with delayed parasite clearance. We document artemisinin resistance in P. falciparum patient isolates from Rwanda carrying K13 R561H, A675V, and C469F mutations.

Artemisinin resistance in Plasmodium falciparum is associated with nonsynonymous mutations in the Kelch 13 (K13) propeller domain. We found that 12.1% (8/66) of clinical P. falciparum isolates from Huye district, Rwanda, exhibited K13 mutations, including R561H, a validated resistance marker. K13 mutations appear to be increasing in this region.

Malaria parasites have coevolved with their human and mammalian hosts. These Plasmodium species invade the iron-rich environment of red blood cells. Zhang et al. found that the iron transporter ferroportin persists on the surface of mature mammalian red blood cells. Red blood cells are at risk of oxidative damage if their hemoglobin releases its iron; ferroportin is thus important to expel this iron. The authors also found that the transporter can deprive malaria parasites of the iron they need for proliferation. The Q248H mutation in the human ferroportin gene enhances ferroportin expression during development and seems to provide protection against malaria. This effect may explain the enrichment of the Q248H mutation among African populations. Science , this issue p. 1520 Ferroportin exports free iron from mature erythrocytes to protect cells from oxidative damage and the malaria parasite. Malaria parasites invade red blood cells (RBCs), consume copious amounts of hemoglobin, and severely disrupt iron regulation in humans. Anemia often accompanies malaria disease; however, iron supplementation therapy inexplicably exacerbates malarial infections. Here we found that the iron exporter ferroportin (FPN) was highly abundant in RBCs, and iron supplementation suppressed its activity. Conditional deletion of the Fpn gene in erythroid cells resulted in accumulation of excess intracellular iron, cellular damage, hemolysis, and increased fatality in malaria-infected mice. In humans, a prevalent FPN mutation, Q248H (glutamine to histidine at position 248), prevented hepcidin-induced degradation of FPN and protected against severe malaria disease. FPN Q248H appears to have been positively selected in African populations in response to the impact of malaria disease. Thus, FPN protects RBCs against oxidative stress and malaria infection.

Strongyloidiasis is caused by a neglected nematode, manifesting as chronic intestinal infection with potentially severe manifestations. The disease is an emerging problem in non-endemic countries affecting travelers and migrants. Diagnosis of strongyloidiasis is hampered by the lack of standardization and absence of a gold standard. Since adequate direct methods to detect the motile larvae in stool samples are not widely available, other techniques such as serology have been developed. We evaluated three commercial ELISA kits (DRG Instruments, IVD Research, and Bordier Affinity Products) to detect IgG antibodies against Strongyloides stercoralis assays utilizing serum samples from travelers with microscopically confirmed strongyloidiasis (n = 50) and other imported helminthic infections (n = 159) as well as healthy controls (n = 50). The DRG, IVD, and Bordier assays showed sensitivities of 58.0%, 64.0%, and 56.0%, respectively. Specificity values were 96.0%, 96.0%, and 92.0% in healthy controls, and 67.3%, 62.9%, and 76.7% in cases with other helminth infections, respectively. Cross-reactions were mostly observed in cases with other nematodes (37.5%, 42.5%, and 20.0%, respectively), but also in trematode (33.3%, 38.1%, and 19.0%, respectively) and in cestode infections (25.0%, 30.0%, and 32.5%, respectively). The study demonstrates the diagnostic limitations of serological assays to detect or exclude cases of strongyloidiasis in returning travelers, who frequently present with recent or acute infections.

Human blood samples serve as the gold standard for molecular surveillance of the malaria parasite Plasmodium falciparum . However, these samples may not accurately reflect the parasite population and come with logistical constraints and ethical requirements. Using blood-fed mosquitoes as a sample basis could overcome these challenges. We developed and validated DNA extraction methods and PCR assays, allowing for P. falciparum detection from whole mosquitoes and sequencing of drug resistance genes. PCRs were consistently positive on mosquito samples mimicking field conditions, i.e., with low P. falciparum infection (2000× dilution of a single oocyst-infected mosquito) or after a blood-meal with low parasitemia (250× dilution of 1% parasite density). Antimalarial drug resistance genes PfK13 and PfMDR1 could be sequenced from these samples, and markers of resistance could be detected in samples reflecting a mutated minority parasite population of ≥ 25%. Pools of 20 mosquitoes allowed for the detection of a single infected mosquito. We applied our protocol on 50 field-caught Anopheles mosquitoes from DR Congo. Five out of eight mosquito pools were P. falciparum positive, providing good sequencing reads for PfK13 and PfMDR1. Our presented method has the potential to facilitate surveillance, e.g., on drug resistance, leveraging the promising properties of xenomonitoring .

In the earlier phases of the COVID-19 pandemic, studies in Germany and elsewhere found an overall reduction in health-related quality of life (HRQoL) among students. However, there is little evidence on later pandemic stages as well as socioeconomic influencing factors. We aimed to (1) describe HRQoL in a Berlin student cohort at two time points in mid-2021, and to (2) analyze the effects of household income and education. We assessed HRQoL of students from 24 randomly selected primary and secondary schools in Berlin, Germany, with the KIDSCREEN-10 index in June and September 2021. To adjust for non-response bias, inverse probability weighting was applied. The potential effects of both household income and education (lower vs. higher) were estimated in generalized linear mixed models, based on prior assumptions presented in directed acyclic graphs. Our cohort comprised 660 students aged 7–19 years. In June 2021, 11.3% [95% CI = 9.0% - 14.0%] reported low HRQoL, whereas in September 2021, this increased to 13.7% [95% CI = 11.1% - 16.5%], with adolescent girls more frequently reporting low HRQoL at both time points (20% [95% CI = 17.1% - 23.3%] and 29% [95% CI = 25.5% - 32.5%]) compared to boys and younger children. While there was no statistically significant total effect of lower household income on HRQoL, a negative effect of lower household education was statistically significant ( β = -2.15, SE 0.95, 95% CI = -4.01 to -0.29, p = 0.024). In summary, students’ HRQoL in mid-2021 was better than that documented in other studies conducted at pandemic onset using KIDSCREEN-10. Female adolescents reported low HRQoL more often, and lower household education significantly reduced children’s HRQoL. Support strategies for psychosocial wellbeing should consider socioeconomically disadvantaged children as important target groups.

Adult-onset diabetes mellitus (here: aDM) is not a uniform disease entity. In European populations, five diabetes subgroups have been identified by cluster analysis using simple clinical variables; these may elucidate diabetes aetiology and disease prognosis. We aimed at reproducing these subgroups among Ghanaians with aDM, and establishing their importance for diabetic complications in different health system contexts. We used data of 541 Ghanaians with aDM (age: 25–70 years; male sex: 44%) from the multi-center, cross-sectional Research on Obesity and Diabetes among African Migrants (RODAM) Study. Adult-onset DM was defined as fasting plasma glucose (FPG) ≥ 7.0 mmol/L, documented use of glucose-lowering medication or self-reported diabetes, and age of onset ≥ 18 years. We derived subgroups by cluster analysis using (i) a previously published set of variables: age at diabetes onset, HbA1c, body mass index, HOMA-beta, HOMA-IR, positivity of glutamic acid decarboxylase autoantibodies (GAD65Ab), and (ii) Ghana-specific variables: age at onset, waist circumference, FPG, and fasting insulin. For each subgroup, we calculated the clinical, treatment-related and morphometric characteristics, and the proportions of objectively measured and self-reported diabetic complications. We reproduced the five subgroups: cluster 1 (obesity-related, 73%) and cluster 5 (insulin-resistant, 5%) with no dominant diabetic complication patterns; cluster 2 (age-related, 10%) characterized by the highest proportions of coronary artery disease (CAD, 18%) and stroke (13%); cluster 3 (autoimmune-related, 5%) showing the highest proportions of kidney dysfunction (40%) and peripheral artery disease (PAD, 14%); and cluster 4 (insulin-deficient, 7%) characterized by the highest proportion of retinopathy (14%). The second approach yielded four subgroups: obesity- and age-related (68%) characterized by the highest proportion of CAD (9%); body fat-related and insulin-resistant (18%) showing the highest proportions of PAD (6%) and stroke (5%); malnutrition-related (8%) exhibiting the lowest mean waist circumference and the highest proportion of retinopathy (20%); and ketosis-prone (6%) with the highest proportion of kidney dysfunction (30%) and urinary ketones (6%). With the same set of clinical variables, the previously published aDM subgroups can largely be reproduced by cluster analysis in this Ghanaian population. This method may generate in-depth understanding of the aetiology and prognosis of aDM, particularly when choosing variables that are clinically relevant for the target population.

Background During the COVID-19 pandemic, children and adolescents worldwide have disproportionally been affected in their psychological health and wellbeing. We conducted a cohort study among German school children, aiming at assessing levels of general anxiety disorder (GAD) and identifying associated factors in the second pandemic year. Methods A cohort of 660 students from 24 Berlin schools was recruited to fill in questionnaires including the GAD-7 tool on anxiety symptoms at three time points between June and September 2021. To adjust for non-random attrition, we applied inverse probability weighting. We describe reported GAD levels stratified by time point, sex, and school type and report odds ratios from univariate logistic regression. Results In total, 551 participants (83%) filled in at least one questionnaire at any time point. At the first time point in June 2021, 25% of the children and adolescents reported anxiety symptoms with a GAD-7 score ≥ 5, decreasing to 16% in August 2021 directly after the summer holidays and rising again to 26% in September 2021. The majority of reported anxiety levels belonged to the least severe category. Being female, attending secondary school, coming from a household with lower education or with lower income level, and being vaccinated against COVID-19 were significantly linked with reporting anxiety symptoms. Preceding COVID-19 infection and anxiety were negatively associated. Conclusion Overall, anxiety in school children was lower in mid-2021 than in the first pandemic year, but still double compared to pre-pandemic data. Reporting of anxiety symptoms during the second pandemic year was especially high in females and in secondary school students. Policy makers should pay additional attention to the mental health status of school children, even as the pandemic situation might stabilize.

The cyclic GMP-AMP synthase (cGAS)-STING pathway is central for innate immune sensing of various bacterial, viral and protozoal infections. Recent studies identified the common HAQ and R232H alleles of TMEM173/STING, but the functional consequences of these variants for primary infections are unknown. Here we demonstrate that cGAS- and STING-deficient murine macrophages as well as human cells of individuals carrying HAQ TMEM173/STING were severely impaired in producing type I IFNs and pro-inflammatory cytokines in response to Legionella pneumophila, bacterial DNA or cyclic dinucleotides (CDNs). In contrast, R232H attenuated cytokine production only following stimulation with bacterial CDN, but not in response to L. pneumophila or DNA. In a mouse model of Legionnaires' disease, cGAS- and STING-deficient animals exhibited higher bacterial loads as compared to wild-type mice. Moreover, the haplotype frequency of HAQ TMEM173/STING, but not of R232H TMEM173/STING, was increased in two independent cohorts of human Legionnaires' disease patients as compared to healthy controls. Our study reveals that the cGAS-STING cascade contributes to antibacterial defense against L. pneumophila in mice and men, and provides important insight into how the common HAQ TMEM173/STING variant affects antimicrobial immune responses and susceptibility to infection. ClinicalTrials.gov DRKS00005274, German Clinical Trials Register.

Plasmodium falciparum malaria remains a significant public health concern in Tanzania, particularly among children under 5 years of age. The emergence and spread of partial artemisinin resistance in East Africa add to this concern. Specific mutations in the P. falciparum kelch-13 (Pfk13) and multidrug drug resistance 1 (Pfmdr1) genes are associated with artemisinin resistance and lumefantrine tolerance, respectively. The emergence of antimalarial drug resistance may be associated with unstable transmission in sub-Saharan Africa (SSA). Time-trends of Pfk13 and Pfmdr1 mutations as well as the multiplicity of infection (MOI) as a proxy for transmission intensity were investigated. Between 2016 and 2022, 173 P. falciparum PCR-positive samples were collected from febrile inpatient and outpatient children aged 3 months to 18 years at selected health facilities in Mwanza, Tanzania. Pfk13 and Pfmdr1 were amplified by PCR and Sanger-sequenced. Polymorphic Pfmsp1 and Pfmsp2 allelic markers were genotyped by nested PCR in 168 samples to assess MOI. Among 143 samples successfully sequenced for Pfk13, 7.0% (10/143) exhibited non-synonymous mutations including the WHO-validated artemisinin resistance marker R561H in 1.4% (2 patients, 2022). As for Pfmdr1, the wild-type N86 allele was observed in 100% (97/97) of isolates, and about half (55/97) carried the wild-type Y184 allele. The mean multiplicity of infection (MOI) was 1.5, and did not change significantly over time. Single-genotype and polyclonal infections were observed in 59.3% (80/135), and 40.7% (55/135) respectively. This study from Mwanza, Tanzania demonstrates the presence of a validated artemisinin resistance marker Pfk13 R561H in 2022 and suggests increased lumefantrine tolerance. MOI as a proxy marker of endemicity was low and stable over the six years of observation. The detection of these resistance markers reinforces the need for continuous genetic surveillance to sustain the efficacy of antimalarial therapies in paediatric patients.