Health-care workers (HCWs) are at the frontline of response to coronavirus disease 2019 (COVID-19), being at a higher risk of acquiring the disease and, subsequently, exposing patients and others. Searches of 8 bibliographic databases were performed to systematically review the evidence on the prevalence, risk factors, clinical characteristics, and prognosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among HCWs. A total of 97 studies (all published in 2020) met the inclusion criteria. The estimated prevalence of SARS-CoV-2 infection from HCWs’ samples, using reverse transcription–polymerase chain reaction and the presence of antibodies, was 11% (95% confidence interval (CI): 7, 15) and 7% (95% CI: 4, 11), respectively. The most frequently affected personnel were nurses (48%, 95% CI: 41, 56), whereas most of the COVID-19–positive medical personnel were working in hospital nonemergency wards during screening (43%, 95% CI: 28, 59). Anosmia, fever, and myalgia were the only symptoms associated with HCW SARS-CoV-2 positivity. Among HCWs positive for COVID-19 by reverse transcription–polymerase chain reaction, 40% (95% CI: 17, 65) were asymptomatic at time of diagnosis. Finally, severe clinical complications developed in 5% (95% CI: 3, 8) of the COVID-19–positive HCWs, and 0.5% (95% CI: 0.02, 1.3) died. Health-care workers suffer a significant burden from COVID-19, with those working in hospital nonemergency wards and nurses being the most commonly infected personnel.

Iron metabolism and anemia may play an important role in multiple organ dysfunction syndrome in Coronavirus disease 2019 (COVID-19). We conducted a systematic review and meta-analysis to evaluate biomarkers of anemia and iron metabolism (hemoglobin, ferritin, transferrin, soluble transferrin receptor, hepcidin, haptoglobin, unsaturated iron-binding capacity, erythropoietin, free erythrocyte protoporphyrine, and erythrocyte indices) in patients diagnosed with COVID-19, and explored their prognostic value. Six bibliographic databases were searched up to August 3rd 2020. We included 189 unique studies, with data from 57,563 COVID-19 patients. Pooled mean hemoglobin and ferritin levels in COVID-19 patients across all ages were 129.7 g/L (95% Confidence Interval (CI), 128.51; 130.88) and 777.33 ng/mL (95% CI, 701.33; 852.77), respectively. Hemoglobin levels were lower with older age, higher percentage of subjects with diabetes, hypertension and overall comorbidities, and admitted to intensive care. Ferritin level increased with older age, increasing proportion of hypertensive study participants, and increasing proportion of mortality. Compared to moderate cases, severe COVID-19 cases had lower hemoglobin [weighted mean difference (WMD), − 4.08 g/L (95% CI − 5.12; − 3.05)] and red blood cell count [WMD, − 0.16 × 10¹²/L (95% CI − 0.31; − 0.014)], and higher ferritin [WMD, − 473.25 ng/mL (95% CI 382.52; 563.98)] and red cell distribution width [WMD, 1.82% (95% CI 0.10; 3.55)]. A significant difference in mean ferritin levels of 606.37 ng/mL (95% CI 461.86; 750.88) was found between survivors and non-survivors, but not in hemoglobin levels. Future studies should explore the impact of iron metabolism and anemia in the pathophysiology, prognosis, and treatment of COVID-19.

Akkermansia muciniphila and Faecalibacterium prausnitzii are highly abundant human gut microbes in healthy individuals, and reduced levels are associated with inflammation and alterations of metabolic processes involved in the development of type 2 diabetes. Dietary factors can influence the abundance of A. muciniphila and F. prausnitzii, but the evidence is not clear. We systematically searched PubMed and Embase to identify clinical trials investigating any dietary intervention in relation to A. muciniphila and F. prausnitzii. Overall, 29 unique trials were included, of which five examined A. muciniphila, 19 examined F. prausnitzii, and six examined both, in a total of 1444 participants. A caloric restriction diet and supplementation with pomegranate extract, resveratrol, polydextrose, yeast fermentate, sodium butyrate, and inulin increased the abundance of A. muciniphila, while a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols decreased the abundance of A. muciniphila. For F. prausnitzii, the main studied intervention was prebiotics (e.g. fructo-oligosaccharides, inulin type fructans, raffinose); seven studies reported an increase after prebiotic intervention, while two studies reported a decrease, and four studies reported no difference. Current evidence suggests that some dietary factors may influence the abundance of A. muciniphila and F. prausnitzii. However, more research is needed to support these microflora strains as targets of microbiome shifts with dietary intervention and their use as medical nutrition therapy in prevention and management of chronic disease.

Chagas disease (CD) is a neglected tropical disease, endemic in Latin America, but due to migration and environmental changes it has become a global public health issue. To assess the global prevalence and disability-adjusted life years due to CD using findings from the Global Burden of Disease Study 2019. The Global Burden of Disease data was obtained from the Global Burden of Disease Collaborative Network; results were provided by the Institute for Health Metrics and Evaluation. The prevalence and disability-adjusted life-years (DALYs) were described at a global, regional, and national level, including data from 1990 to 2019. Globally, CD prevalence decreased by 11.3% during the study period, from 7,292,889 cases estimated in 1990 to 6,469,283 in 2019. Moreover, the global DALY rate of CD decreased by 23.7% during the evaluated period, from 360,872 in 1990 to 275,377 in 2019. In addition, significant differences in the burden by sex, being men the most affected, age, with the elderly having the highest burden of the disease, and sociodemographic index (SDI), with countries with the lowest SDI values having the highest prevalence of the disease, were observed. Finally, the prevalence trends have followed different patterns according to the region, with a sustained decrease in Latin America, compared to an increasing trend in North America and Europe until 2010. The global burden of CD has changed in recent decades, with a sustained decline in the number of cases. Although the majority of cases remain concentrated in Latin America, the increase observed in countries in North America and Europe highlights the importance of screening at-risk populations and raising awareness of this neglected tropical disease.

Background: Creatinine is the most widely used test to estimate the glomerular filtration rate (GFR), but muscle mass as key determinant of creatinine next to renal function may confound such estimates. We explored effects of 24‐h height‐indexed creatinine excretion rate (CER index) on GFR estimated with creatinine (eGFR_Cr), muscle mass‐independent cystatin C (eGFR_Cys), and the combination of creatinine and cystatin C (eGFR_Cr‐Cys) and predicted probabilities of discordant classification given age, sex, and CER index.Methods: We included 8076 adults enrolled in the PREVEND study. Discordant classification was defined as not having eGFR_Cr <60 mL/min per 1.73 m² when eGFR_Cys was <60 mL/min/1.73 m². Baseline effects of age and sex on CER index were quantified with linear models using generalized least squares. Baseline effects of CER index on eGFR were quantified with quantile regression and logistic regression. Effects of annual changes in CER index on trajectories of eGFR were quantified with linear mixed‐effects models. Missing observations in covariates were multiply imputed.Results: Mean (SD) CER index was 8.0 (1.7) and 6.1 (1.3) mmol/24 h per meter in male and female participants, respectively (P_difference < 0.001). In male participants, baseline CER index increased until 45 years of age followed by a gradual decrease, whereas a gradual decrease across the entire range of age was observed in female participants. For a 70‐year‐old male participant with low muscle mass (CER index of 2 mmol/24 h per meter), predicted baseline eGFR_Cr and eGFR_Cys disagreed by 24.7 mL/min/1.73 m² (and 30.1 mL/min/1.73 m² when creatinine was not corrected for race). Percentages (95% CI) of discordant classification in male and female participants aged 60 years and older with low muscle mass were 18.5% (14.8–22.1%) and 15.2% (11.4–18.5%), respectively. For a 70‐year‐old male participant who lost muscle during follow‐up, eGFR_Cr and eGFR_Cys disagreed by 1.5, 5.0, 8.5, and 12.0 mL/min/1.73 m² (and 6.7, 10.7, 13.5, and 15.9 mL/min/1.73 m² when creatinine was not corrected for race) at baseline, 5 years, 10 years, and 15 years of follow‐up, respectively.Conclusions: Low muscle mass may cause considerable overestimation of single measurements of eGFR_Cr. Muscle wasting may cause spurious overestimation of repeatedly measured eGFR_Cr. Implementing muscle mass‐independent markers for estimating renal function, like cystatin C as superior alternative to creatinine, is crucial to accurately assess renal function in settings of low muscle mass or muscle wasting. This would also eliminate the negative consequences of current race‐based approaches.