Artesunate, the recommended drug for severe malaria, rapidly clears the malaria parasite from infected patients but frequently induces anemia—called post-artesunate delayed hemolysis (PADH)—for which a simple predictive test is urgently needed. The underlying event in PADH is the expulsion of artesunate-exposed parasites from their host erythrocytes by pitting. We show that the histidine-rich protein 2 (HRP2) of the malaria parasite Plasmodium falciparum persists in the circulation of artesunate-treated malaria patients in Bangladesh and in French travelers who became infected with malaria in Africa. HRP2 persisted in whole blood (not plasma) of artesunate-treated patients with malaria at higher levels compared to quinine-treated patients. Using an optimized membrane permeabilization method, HRP2 was observed by immunofluorescence, Western blotting, and electron microscopy to persist in once-infected red blood cells from artesunate-treated malaria patients. HRP2 was deposited at the membrane of once-infected red blood cells in a pattern similar to that for ring erythrocyte surface antigen (RESA), a parasite invasion marker. On the basis of these observations, we developed a semiquantitative titration method using a widely available HRP2-based rapid diagnostic dipstick test. Positivity on this test using a 1:500 dilution of whole blood from artesunate-treated patients with malaria collected shortly after parasite clearance predicted subsequent PADH with 89% sensitivity and 73% specificity. These results suggest that adapting an existing HRP2-based rapid diagnostic dipstick test may enable prediction of PADH several days before it occurs in artesunate-treated patients with malaria.

An outbreak of Pneumocystis jirovecii pneumonia (PCP) occurred among heart transplant recipients (HTR) at the outpatient clinic of a university hospital, from March to September 2015. Clinical, therapeutic, biological, and molecular data were analyzed to determine its origin and control the outbreak. Clinical and biological data regarding all HTR followed in the outpatient clinic were collected. PCP diagnosis was based on microscopy and real-time polymerase chain reaction (PCR). Investigations were performed by building a transmission map, completed by genotyping Pneumocystis isolates and by a control of chemoprophylaxis observance. Asymptomatic exposed patients were screened for colonization using real-time PCR. Among 124 HTR, 7 PCP cases were confirmed. Screening identified 3 additional patients colonized by P. jirovecii. All patients were cured, and no further cases were identified after trimethoprim-sulfamethoxazole prophylaxis was introduced in the entire cohort. Genotyping demonstrated the same strain in all PCP cases and colonized patients. All cases were linked with possible transmission chains from 2 possible index patients. Interhuman transmission was significantly associated with more frequent visits in the outpatient clinic. Six cases were receiving atovaquone as a prophylaxis. The occurrence of PCP was significantly associated with atovaquone prophylaxis. This is the first outbreak with detailed molecular analysis in HTR so far. Genotyping and transmission chain confirmed interhuman transmission in all colonized/infected PCP cases. Outpatient clinic layout and high encounters probably caused this PCP cluster, which was controlled after systematic trimethoprim-sulfamethoxazole prophylaxis in exposed patients.

Biological sciences, drug discovery and medicine rely heavily on cell phenotype perturbation and microscope observation. However, most cellular phenotypic changes are subtle and thus hidden from us by natural cell variability: two cells in the same condition already look different. In this study, we show that conditional generative models can be used to transform an image of cells from any one condition to another, thus canceling cell variability. We visually and quantitatively validate that the principle of synthetic cell perturbation works on discernible cases. We then illustrate its effectiveness in displaying otherwise invisible cell phenotypes triggered by blood cells under parasite infection, or by the presence of a disease-causing pathological mutation in differentiated neurons derived from iPSCs, or by low concentration drug treatments. The proposed approach, easy to use and robust, opens the door to more accessible discovery of biological and disease biomarkers.

Plasmodium falciparum is responsible of severe malaria, including cerebral malaria (CM). During its intra-erythrocytic maturation, parasite-derived proteins are expressed, exported and presented at the infected erythrocyte membrane. To identify new CM-specific parasite membrane proteins, we conducted a mass spectrometry-based proteomic study and compared the protein expression profiles between 9 CM and 10 uncomplicated malaria (UM) samples. Among the 1097 Plasmodium proteins identified, we focused on the 499 membrane-associated and hypothetical proteins for comparative analysis. Filter-based feature selection methods combined with supervised data analysis identified a subset of 29 proteins distinguishing CM and UM samples with high classification accuracy. A hierarchical clustering analysis of these 29 proteins based on the similarity of their expression profiles revealed two clusters of 15 and 14 proteins, respectively under- and over-expressed in CM. Among the over-expressed proteins, the MESA protein is expressed at the erythrocyte membrane, involved in proteins trafficking and in the export of variant surface antigens (VSAs), but without antigenic function. Antigen 332 protein is exported at the erythrocyte, also involved in protein trafficking and in VSAs export and exposed to the immune system. Our proteomics data demonstrate an association of selected proteins in the pathophysiology of CM.

We report a case of a 54-year-old Moroccan woman living in France diagnosed with eosinophilic meningitis caused by Angiostrongylus cantonensis. Diagnosis was based on clinical symptoms and confirmed by testing of serum and cerebrospinal fluid samples. Physicians should consider the risk for A. cantonensis infection outside of endemic areas.