This is the first study to assess the risk of co-endemic Plasmodium vivax and Plasmodium falciparum transmission in the Peruvian Amazon using boosted regression tree (BRT) models based on social and environmental predictors derived from satellite imagery and data. Yearly cross-validated BRT models were created to discriminate high-risk (annual parasite index API > 10 cases/1000 people) and very-high-risk for malaria (API > 50 cases/1000 people) in 2766 georeferenced villages of Loreto department, between 2010–2017 as other parts in the article (graphs, tables, and texts). Predictors were cumulative annual rainfall, forest coverage, annual forest loss, annual mean land surface temperature, normalized difference vegetation index (NDVI), normalized difference water index (NDWI), shortest distance to rivers, time to populated villages, and population density. BRT models built with predictor data of a given year efficiently discriminated the malaria risk for that year in villages (area under the ROC curve (AUC) > 0.80), and most models also effectively predicted malaria risk in the following year. Cumulative rainfall, population density and time to populated villages were consistently the top three predictors for both P. vivax and P. falciparum incidence. Maps created using the BRT models characterize the spatial distribution of the malaria incidence in Loreto and should contribute to malaria-related decision making in the area.

Background: Visceral leishmaniasis (VL) is an endemic in Southern Europe. However, details regarding disease burden, clinical presentations, laboratory markers, management and outcome in children are scarce. Methods: Medical records of children (<14 years) admitted with VL to 10 pediatric units in Andalusia (2004–2019) were retrospectively reviewed. VL diagnosis was based on clinical presentation, serology, microscopy and molecular methods. Diagnosis of secondary hemophagocytic lymphohistiocytosis (sHLH) was established using the hemophagocytic lymphohistiocytosis-2004 criteria. Results: A total of 127 patients were identified. Median age was 14.5 months; the main clinical presentations were fever and splenomegaly (95.3% each). Cytopenias were the most common laboratory abnormalities. Diagnostics as well as treatment regimens varied over time and the participating centers. Liposomal amphotericin B was prescribed in 97.6%; relapses as well as adverse events were rarely observed (3.1% each). Thirty-seven patients, diagnosed with sHLH required longer hospital admission (P = 0.001), an increased number of platelet (P < 0.006) and red blood cell (P = 0.0001) transfusions and pediatric intensive care unit admission (P = 0.007). Monocytopenia (P = 0.011) and high C-reactive protein levels (P = 0.031), variables not included in the hemophagocytic lymphohistiocytosis-2004 criteria, were associated with sHLH. One patient deceased in the context of the Leishmania infection. Conclusions: We report data on the largest pediatric VL cohort from Europe, commonly associated with sHLH. Raised C-reactive protein levels and monocytopenia appear to be associated with sHLH. The latter may help to identify these patients and to guide decisions regarding need of additional supportive clinical care and immunomodulatory therapies. The observed high rate of heterogeneity in terms of diagnosis and management warrants the establishment of appropriate guidelines.