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Children with severe acute malnutrition (SAM) are at high risk of infectious mortality and morbidity during and after hospital discharge. This risk persists despite nutritional and prophylactic antibiotic interventions among children with SAM, implicating persistent deficits in their immune defenses. Here we test the hypothesis that innate immune cells from children (0-59 months) hospitalized with SAM in Zambia and Zimbabwe (n=141) have distinct capacity to respond to bacteria relative to adequately-nourished healthy controls from the same communities (n=92). Neutrophils and monocytes from SAM inpatients had a higher capacity to bindE. colibut lower monocyte activation and pro-inflammatory mediator secretion in response toE. colilipopolysaccharide (LPS) or heat-killedSalmonella typhimurium(HKST) than controls. Bacterial binding capacity differentiated children with SAM from controls after adjusting for clinical and demographic heterogeneity and normalized with duration of hospital treatment. Wasting severity, HIV status, and age group were associated with LPS and HKST-induced cytokine secretion, monocyte activation, and myeloperoxidase secretion, respectively. Bacterial binding capacity and monocyte activation during hospitalization were associated with higher odds of persistent SAM at discharge; a risk factor for subsequent mortality. Thus, SAM shifts anti-bacterial innate immune cell function, favoring bacterial containment over pro-inflammatory activation upon challenge, which contributes to persistent health deficits among hospitalized children.TEASERChildren with severe acute malnutrition have distinct anti-bacterial innate immune cell function compared to healthy children which persists during their hospitalization and contributes to persistent wasting.

Environmental enteropathy is a major contributor to growth faltering in millions of children in Africa and South Asia. We carried out a longitudinal, observational and interventional study in Lusaka, Zambia, of 297 children with stunting (aged 2–17 months at recruitment) and 46 control children who had good growth (aged 1–5 months at recruitment). Control children contributed data only at baseline. Children were provided with nutritional supplementation of daily cornmeal-soy blend, an egg and a micronutrient sprinkle, and were followed up to 24 months of age. Children whose growth did not improve over 4–6 months of nutritional supplementation were classified as having non-responsive stunting. We monitored microbial translocation from the gut lumen to the bloodstream in the cohort with non-responsive stunting (n = 108) by measuring circulating lipopolysaccharide (LPS), LPS-binding protein and soluble CD14 at baseline and when non-response was declared. We found that microbial translocation decreased with increasing age, such that LPS declined in 81 (75%) of 108 children with non-responsive stunting, despite sustained pathogen pressure and ongoing intestinal epithelial damage. We used confocal laser endomicroscopy and found that mucosal leakiness also declined with age. However, expression of brush border enzyme, nutrient transporter and mucosal barrier genes in intestinal biopsies did not change with age or correlate with biomarkers of microbial translocation. We propose that environmental enteropathy arises through adaptation to pathogen-mediated epithelial damage. Although environmental enteropathy reduces microbial translocation, it does so at the cost of impaired growth. The reduced epithelial surface area imposed by villus blunting may explain these findings., Studying the intestinal pathology of undernourished children in Zambia with persistent stunting reveals that adaptation to pathogen exposure in early life may explain why children with stunting do not respond well to nutrient supplementation.

Background Children discharged from hospital following management of complicated severe acute malnutrition (SAM) have a high risk of mortality, especially HIV-positive children. Few studies have examined mortality in the antiretroviral therapy (ART) era. Objectives Our objectives were to ascertain 52-wk mortality in children discharged from hospital for management of complicated SAM, and to identify independent predictors of mortality. Methods A prospective cohort study was conducted in children enrolled from 3 hospitals in Zambia and Zimbabwe between July 2016 and March 2018. The primary outcome was mortality at 52 wk. Univariable and multivariable Cox regression models were used to identify independent risk factors for death, and to investigate whether HIV modifies these associations. Results Of 745 children, median age at enrolment was 17.4 mo (IQR: 12.8, 22.1 mo), 21.7% were HIV-positive, and 64.4% had edema. Seventy children (9.4%; 95% CI: 7.4, 11.7%) died and 26 exited during hospitalization; 649 were followed postdischarge. At discharge, 43.9% had ongoing SAM and only 50.8% of HIV-positive children were receiving ART. Vital status was ascertained for 604 (93.1%), of whom 55 (9.1%; 95% CI: 6.9, 11.7%) died at median 16.6 wk (IQR: 9.4, 21.9 wk). Overall, 20.0% (95% CI: 13.5, 27.9%) and 5.6% (95% CI: 3.8, 7.9%) of HIV-positive and HIV-negative children, respectively, died [adjusted hazard ratio (aHR): 3.83; 95% CI: 2.15, 6.82]. Additional independent risk factors for mortality were ongoing SAM (aHR: 2.28; 95% CI: 1.22, 4.25), cerebral palsy (aHR: 5.60; 95% CI: 2.72, 11.50) and nonedematous SAM (aHR: 2.23; 95% CI: 1.24, 4.01), with no evidence of interaction with HIV status. Conclusions HIV-positive children have an almost 4-fold higher mortality than HIV-negative children in the year following hospitalization for complicated SAM. A better understanding of causes of death, an improved continuum of care for HIV and SAM, and targeted interventions to improve convalescence are needed.

PURPOSE We investigated the association between gastric cancer and environmental and dietary exposures. In addition, we explored probable mechanistic pathways for the influence of biomass smoke on gastric carcinogenesis. PATIENTS AND METHODS The study was conducted in Lusaka, Zambia. Questionnaires were used to collect data on risk factors, whereas enzyme-linked immunosorbent assays and high-performance liquid chromatography were used to measure biologic exposures. Study data were analyzed using contingency tables and logistic regression. RESULTS We enrolled 72 patients with gastric adenocarcinoma and 244 controls. Gastric cancer was positively associated with rural residence (odds ratio [OR], 2.9; 95% CI, 1.5 to 5.3), poverty (OR, 4.2; 95% CI, 1.9 to 9.1), and daily consumption of processed meat (OR, 6.4; 95% CI, 1.3 to 32) and negatively associated with consumption of green vegetables (OR, 0.2; 95% CI, 0.1 to 0.5). Gastric cancer was also associated with biomass smoke exposure (OR, 3.5; 95% CI, 1.9 to 6.2; P < .0001), an association that was stronger for intestinal-type cancers (OR, 3.6; 95% CI, 1.5 to 9.1; P = .003). Exposure to biomass smoke in controls was associated with higher urinary levels of 8-isoprostane ( P < .0001), 8-hydroxydeoxyguanosine ( P = .029), and 1-hydroxypyrene ( P = .041). Gastric cancer was not associated with biochemical measures of current exposure to aflatoxins or ochratoxins. CONCLUSION In Zambia, exposure to biomass smoke, daily consumption of processed meat, and poverty are risk factors for gastric cancer, whereas daily consumption of green vegetables is protective against gastric cancer. Exposure to biomass smoke was associated with evidence of oxidative stress and DNA damage, suggesting mechanistic plausibility for the observed association, and the association was restricted to intestinal-type gastric cancer.

IntroductionLittle is known about specific bacterial characteristics of Helicobacter pylori (H. pylori) infection influencing gastric carcinogenesis in Zambia. The aim of this study was to evaluate the associations between pre-selected H. pylori antibodies with gastric cancer, premalignant lesions and active gastritis. MethodsThis was cross-sectional study with multiple comparisons of patients with gastric cancer (GC), gastric premalignant (GP) lesions and active or chronic gastritis. A fluorescent bead-based antibody multiplex serology assay was used to quantify antibodies to thirteen immunogenic H. pylori antigens. Logistic regression models were used to examine the associations.ResultsIncluded were 295 patients with: 59 GC, 27 GP lesions, 48 active and 161 chronic gastritis. Overall, 257/295 (87%) were H. pylori positive. H. pylori seropositivity was not associated with sex, age, body mass index, socio-economic status, HIV infection, alcohol consumption or cigarette smoking (p-values all above 0.05). When compared to the patients with chronic gastritis, the presence of catalase and cinnamyl alcohol dehydrogenase (Cad) antibodies was positively associated with GP lesions (OR 3.53; 95% CI 1.52-8.17 and OR 2.47; 95% CI 1.08-5.67 respectively). However, seropositivity to Cad antibodies was significantly lower in GC patients (OR 0.28; 95% CI 0.09-0.83). Compared to chronic, active gastritis was significantly associated with (p

Background Schistosoma mansoni is hyperendemic in many rural areas of Zambia where up to 77% of people are positive for infection via serologic evaluation. Zambia also has a high prevalence of HIV infection. Individually, S. mansoni and HIV infection impair gastrointestinal barrier integrity and induce inflammation, but the effects of coinfection are not well understood. We set out to test the hypothesis that HIV would exacerbate intestinal barrier failure in patients with S. mansoni infection. Methods Adults attending medical outpatient clinics in Kaoma, Western Province, Zambia, were enrolled in a case-control study to determine the relative contributions of schistosomiasis and HIV to microbial translocation (measured as soluble CD14 [sCD14] and lipopolysaccharide binding protein [LBP]) and inflammation (measured as CRP). Results Among 152 adults evaluated, 74 (49%) were HIV-seropositive, 45 (29%) were shedding schistosome ova (Kato-Katz), 120 (81%) were seropositive for schistosome antibodies (i.e. prior or current infection, with or without egg shedding) and 16 (11%) were HIV/schistosome coinfected (defined by Kato-Katz). HIV infection was associated with higher circulating sCD14 concentrations (p=0.003 by Kruskal–Wallis test), but schistosomiasis was not. HIV infection was associated with greater exposure to schistosomes assessed serologically (OR=2.48, 95% CI 1.05 to 5.86; p=0.03), but reduced likelihood of egg shedding (OR 0.47, 95% CI 0.21 to 1.01; p=0.03). Conclusions There was no evidence for a compounding or synergistic effect of coinfection on microbial translocation that appeared to be correlated with HIV infection. Further studies are needed to understand how the increase in LBP secondary to HIV infection may decrease schistosome egg excretion in coinfected individuals.

Environmental enteropathy (EE) is a subclinical condition of the small intestine that is highly prevalent in low- and middle-income countries. It is thought to be a key contributing factor to childhood malnutrition, growth-stunting, and diminished oral vaccine responses. While EE has been shown to be the by-product of recurrent enteric infection, its full pathophysiology remains unclear. Here, we mapped the cellular and molecular correlates of EE severity by performing high-throughput single-cell RNA-sequencing on 33 small intestinal biopsies from 11 adults with EE from Lusaka, Zambia (8 HIV-negative, 3 HIV-positive), 6 adults without EE in Boston, USA, and 2 adults from Durban, South Africa, which we complemented with published data from 3 additional South African adults from the same clinical site. By using these data to reanalyze previously-defined bulk-transcriptomic signatures of reduced villus height and decreased plasma LPS levels in EE, we found that these signatures may be driven by an increased abundance of surface mucosal cells – a gastric-like subset previously implicated in epithelial repair in the gastrointestinal tract. In addition, we identified several cell subsets whose fractional abundances associate with histologically determined EE severity, small intestinal region, and HIV infection. Furthermore, by comparing distal duodenal EE samples with those from three control cohorts, we identified dysregulated WNT and MAPK signaling in the EE epithelium and a T cell subset highly expressing a transcriptional signature of tissue-resident memory cells but with increased pro-inflammatory cytokine expression in the EE cohort. Altogether, our work illuminates epithelial and immune correlates of EE and provides new molecular targets for intervention.One Sentence SummaryUsing single-cell RNA-sequencing, we characterize the pathophysiology of environmental enteropathy (EE) – a highly prevalent condition of the small intestine that is thought to be a primary cause of global growth-stunting cases and a key contributing factor to childhood malnutrition and diminished oral vaccine responses – to derive insights into the epithelial and immune correlates of disease severity, suggesting new therapeutic targets for future investigation.