Detection and quantification of Plasmodium falciparum in human blood by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: a proof of concept study.

BACKGROUND: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) has revolutionized identification of bacteria and is becoming available in an increasing number of laboratories in malaria-endemic countries. The purpose of this proof-of-concept study was to explore the potential of MALDI-TOF as a diagnostic tool for direct detection and quantification of Plasmodium falciparum in human blood. METHODS: Three different P. falciparum strains (3D7, HB3 and IT4) were cultured and synchronized following standard protocols. Ring-stages were diluted in fresh blood group 0 blood drawn in EDTA from healthy subjects to mimic clinical samples. Samples were treated with saponin and washed in PBS to concentrate protein material. Samples were analysed using a Microflex LT MALDI-TOF and resulting mass spectra were compared using FlexAnalysis software. RESULTS: More than 10 peaks specific for P. falciparum were identified. The identified peaks were consistent among the three genetically unrelated strains. Identification was possible in clinically relevant concentrations of 0.1% infected red blood cells, and a close relationship between peak intensity and the percentage of infected red blood cells was seen. CONCLUSION: The findings indicate that the method has the potential to detect and quantify P. falciparum at clinically relevant infection intensities and provides proof-of-concept for MALDI-TOF-based diagnosis of human malaria. Further research is needed to include other Plasmodium spp., wildtype parasite isolates and to increase sensitivity. MALDI-TOF may be a useful tool for mass-screening purposes and for diagnosis of malaria in settings where it is readily available.

Exploring training needs of newly graduated medical doctors to inform the undergraduate simulation-based curriculum: a national Delphi consensus study.

PURPOSE: Mastering technical procedures is a key component in succeeding as a newly graduated medical doctor and is of critical importance to ensure patient safety. The efficacy of simulation-based education has been demonstrated but medical schools have different requirements for undergraduate curricula. We aimed to identify and prioritize the technical procedures needed by newly graduated medical doctors. METHODS: We conducted a national needs assessment survey using the Delphi technique to gather consensus from key opinion leaders in the field. In the first round, a brainstorm was conducted to identify all potential technical procedures. In the second round, respondents rated the need for simulation-based training of each procedure using the Copenhagen Academy for Medical Education and Simulation Needs Assessment Formula (CAMES-NAF). The third round was a final elimination and prioritization of the procedures. RESULTS: In total, 107 experts from 21 specialties answered the first round: 123 unique technical procedures were suggested. Response rates were 58% and 64% in the second and the third round, respectively. In the third round, 104 procedures were eliminated based on the consensus criterion, and the remaining 19 procedures were included and prioritized. The top five procedures were: (i) insert peripheral intravenous catheter, (ii) put on personal protection equipment, (iii) perform basic airway maneuvers, (iv) perform basic life support, and (v) perform radial artery puncture. CONCLUSION: Based on the Delphi process a final list of 19 technical procedures reached expert consensus to be included in the undergraduate curriculum for simulation-based education.

The significance of spleen size in children with sickle cell anemia.

It is well established that splenic dysfunction occurs in early childhood in sickle cell anemia (SCA), although the determinants and consequences of splenic injury are not fully understood. In this study, we examined spleen size and splenic function in 100 children with SCA aged 0-16 years at King's College Hospital in London. Spleen size was assessed by abdominal ultrasound (US) and splenic function by pitted red blood cells (PIT counts). In our cohort, 5.6% of children aged 6-10 years and 19.4% of children aged 11-16 years had no visible spleen on US (autosplenectomy). Splenomegaly was common in all age groups, with 28% of children overall having larger spleens than the average for their age. Only one child had a PIT count suggesting preserved splenic function. We found no correlation between hemoglobin F levels and spleen size, nor was there any difference in spleen size between children treated with or without hydroxyurea. Although there was a trend toward increased spleen length in children with co-inherited α-thalassemia, this did not reach statistical significance. Finally, we found a strong association between erythrocyte deformability measured with oxygen gradient ektacytometry, spleen size, and PIT counts. In conclusion, our results do not agree with the general perception that most children with SCA undergo autosplenectomy within the first decade of life and indicate that loss of erythrocyte deformability contributes to loss of splenic filtration capacity in SCA, as well as phenotypical variations in spleen size.

Automating Pitted Red Blood Cell Counts Using Deep Neural Network Analysis: A New Method for Measuring Splenic Function in Sickle Cell Anaemia.

The spleen plays an important role in the body's defence against bacterial infections. Measuring splenic function is of interest in multiple conditions, including sickle cell anaemia (SCA), where spleen injury occurs early in life. Unfortunately, there is no direct and simple way of measuring splenic function, and it is rarely assessed in clinical or research settings. Manual counts of pitted red blood cells (RBCs) observed with differential interference contrast (DIC) microscopy is a well-validated surrogate biomarker of splenic function. The method, however, is both user-dependent and laborious. In this study, we propose a new automated workflow for counting pitted RBCs using deep neural network analysis. Secondly, we assess the durability of fixed RBCs for pitted RBC counts over time. We included samples from 48 children with SCA and 10 healthy controls. Cells were fixed in paraformaldehyde and examined using an oil-immersion objective, and microscopy images were recorded with a DIC setup. Manual pitted RBC counts were performed by examining a minimum of 500 RBCs for pits, expressing the proportion of pitted RBCs as a percentage (%PIT). Automated pitted RBC counts were generated by first segmenting DIC images using a Zeiss Intellesis deep learning model, recognising and segmenting cells and pits from background. Subsequently, segmented images were analysed using a small ImageJ macro language script. Selected samples were stored for 24 months, and manual pitted RBC counts performed at various time points. When comparing manual and automated pitted RBC counts, we found the two methods to yield comparable results. Although variability between the measurements increased with higher %PIT, this did not change the diagnosis of asplenia. Furthermore, we found no significant changes in %PIT after storing samples for up to 24 months and under varying temperatures and light exposures. We have shown that automated pitted RBC counts, produced using deep neural network analysis, are comparable to manual counts, and that fixed samples can be stored for long periods of time without affecting the %PIT. Automating pitted RBC counts makes the method less time consuming and results comparable across laboratories.

Oxygen gradient ektacytometry does not predict pain in children with sickle cell anaemia.

The loss of red blood cell (RBC) deformability in sickle cell anaemia (SCA) is considered the primary factor responsible for episodes of acute pain and downstream progressive organ dysfunction. Oxygen gradient ektacytometry (Oxygenscan) is a recently commercialised functional assay that aims to describe the deformability of RBCs in SCA at differing oxygen tensions. So far, the Oxygenscan has been evaluated only by a small number of research groups and the validity and clinical value of Oxygenscan-derived biomarkers have not yet been fully established. In this study we examined RBC deformability measured with the Oxygenscan in 91 children with SCA at King's College Hospital in London. We found a significant correlation between Oxygenscan-derived biomarkers and well-recognised modifiers of disease severity in SCA: haemoglobin F and co-inherited α-thalassaemia. We failed, however, to find any independent predictive value of the Oxygenscan in the clinical outcome measure of pain, as well as other important parameters such as hydroxycarbamide treatment. Although the Oxygenscan remains an intriguing tool for basic research, our results question whether it provides any additional information in predicting the clinical course in children with SCA, beyond measuring known markers of disease severity.

Pneumocystis jirovecii pneumonia in liver transplant recipients in an era of routine prophylaxis.

BACKGROUND: Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection in organ transplant recipients that may be prevented by antibiotic prophylaxis. We aimed to investigate the incidence rate (IR) of PCP and the related hospitalization and mortality rates in liver transplant recipients in an era of routine prophylaxis. METHODS: We included all adult liver transplant recipients transplanted at Rigshospitalet between January 1, 2011 and October 1, 2019. Microbiology data were obtained from the Danish Microbiology Database (MiBa), a national database containing all data from all Departments of Clinical Microbiology in Denmark receiving samples from both hospitals and general practices. According to local guidelines, PCP prophylaxis was initiated 1 week posttransplantation and discontinued after 6 months or sooner in patients experiencing side effects. RESULTS: We included 343 liver transplant recipients with 1153 person-years of follow-up (PYFU), of which 269 (78%) received PCP prophylaxis during the first 6 months posttransplantation. Seven (2%) recipients were diagnosed with PCP during follow-up. In the first 6 months posttransplantation and in 269 transplant recipients who received prophylaxis there were zero PCP events while the IR was 32 (95% confidence interval [CI] 2.9-148) per 1000 PYFU in 74 recipient who did not receive prophylaxis. During 7th to 12th month posttransplantation the IR was 20 (95% CI: 5.5-53) per 1000 PYFU. All seven (100%) recipients diagnosed with PCP were hospitalized, however none died. CONCLUSIONS: PCP was not detected in liver transplant recipients while on prophylaxis. Though, it worth mentioning that two out of the seven PCP patients received high-dose prednisolone before the PCP event. All liver transplant recipients with PCP were hospitalized, but none died. Randomized clinical trials to determine the optimal duration of prophylaxis are warranted.

Performance of a Histidine Rich Protein-2 Based (First Response) and a p-Lactate Dehydrogenase-based (Optimal) Rapid Diagnostic Test for Diagnosis of Malaria in Patients With Pediatric Sickle Cell Disease.

BACKGROUND: Rapid diagnostic tests (RDTs) have been extensively evaluated and play an important role in malaria diagnosis. However, the accuracy of RDTs for malaria diagnosis in patients with sickle cell disease (SCD) is unknown. METHODS: We compared the performance of a histidine rich protein 2 (HRP-2)-based RDT (First Response) and a lactate dehydrogenase (LDH)-based RDT (Optimal) with routine microscopy as reference standard in 445 children with SCD and an acute febrile illness in Accra, Ghana. RESULTS: The overall sensitivity, specificity, and positive and negative predictive values of the HRP-2-based RDTs were 100%, 95.7%, 73.8%, and 100%, respectively. Comparable values for the LDH-based RDTs were 91.7%, 99.5%, 95.7%, and 99.0%, respectively. A total of 423 results were true in both tests, 1 result was false in both tests, 16 results were false in the HRP-2 test only, and 5 were false in the LDH test only (McNemar test, P = .03). At follow-up, 73.7% (28/38), 52.6% (20/38), 48.6% (17/35), and 13.2% (5/38) of study participants were HRP-2 positive on days 14, 28, 35, and 42, respectively, compared with 0%, 2.6% (1/38), 2.9% (1/35), and 2.6% (1/38) for LDH. CONCLUSION: The HRP2-based RDT fulfilled World Health Organization criteria for malaria diagnosis in patients with SCD and may provide diagnostic evidence for treatment to begin in cases in which treatment would otherwise have begun presumptively based on symptoms, whereas LDH-based RDTs may be more suitable as a confirmatory test in low-parasitemic subgroups, such as patients with SCD.

Bloodstream Infections at Two Neonatal Intensive Care Units in Ghana: Multidrug Resistant Enterobacterales Undermine the Usefulness of Standard Antibiotic Regimes.

BACKGROUND: Bloodstream infections (BSIs) are a major cause of morbidity and mortality in hospitalized neonates. Data on antibiotic resistance in neonatal BSIs and their impact on clinical outcomes in Africa are limited. METHODS: We conducted a prospective cohort study at 2 tertiary level neonatal intensive care units (NICUs) in Ghana. All neonates admitted to the NICUs were included from October 2017 to September 2019. We monitored BSI rates and analyzed the effect of BSI and antibiotic resistance on mortality and duration of hospitalization. RESULTS: Of 5433 neonates included, 3514 had at least one blood culture performed and 355 had growth of a total of 368 pathogenic microorganisms. Overall incidence of BSI was 1.0 (0.9-1.1) per 100 person days. The predominant organisms were Klebsiella pneumoniae 49.7% (183/368) and Streptococcus spp. 10.6% (39/368). In addition, 512 coagulase negative Staphylococci were isolated but considered probable contaminants. Among K. pneumoniae, resistance to gentamicin and amikacin was 91.8% and 16.4%, respectively, while carbapenem resistance was 4.4%. All-cause mortality among enrolled neonates was 19.7% (1066/5416). The mortality rate was significantly higher in neonates with BSI compared with culture-negative neonates in univariate analysis (27.9%, n = 99/355 vs. 16.5%, n = 520/3148; hazard ratio 1.4, 95% confidence interval 1.07-1.70) but not in multivariate analysis. CONCLUSION: The diversity of etiologic agents and the high-risk of antibiotic resistance suggest that standard empirical treatment is unlikely to improve the outcome of BSIs in low and middle income. Such improvements will depend on access to reliable clinical microbiologic services.

High rates of multi-drug resistant gram-negative organisms associated with surgical site infections in a teaching hospital in Ghana.

BACKGROUND: There is limited data to guide the prevention and management of surgical site infections (SSI) in low- and middle-income countries. We prospectively studied aetiological agents associated with SSI and their corresponding antibiotic susceptibility patterns in a tertiary hospital in Ghana. METHODS: As part of a cohort study carried out at the surgical department of the Korle Bu Teaching Hospital (KBTH) from July 2017 to April 2019, wound swabs were collected from patients diagnosed with SSI. Isolates cultured from the wound swabs were identified by MALDI TOF and susceptibility testing was conducted according to EUCAST 2020 guidelines. Clinical data were monitored prospectively. RESULTS: Of 4577 patients, 438 developed an SSI and 352 microbial isolates were cultured. Isolates were predominantly Gram negative (286, 81%), a pattern seen for all kinds of surgery and all wound classes. The most common species included Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Acinetobacter baumannii. The majority of organisms were multi-drug resistant including 86% of E. coli, 52% of A. baumannii and 86% of K. pneumoniae; and 65% (17/26) of the cefotaxime-resistant K. pneumoniae were extended spectrum ß-lactamase producing. One of 139 E. coli, 15 of 49 P. aeruginosa, and 6 of 23 A. baumannii were meropenem resistant, but no clonal pattern was found. There was a 1% (5/428) prevalence of methicillin-resistant S. aureus. CONCLUSIONS: The predominance of Gram-negative organisms and the high level of multi-drug resistance indicate a need to re-evaluate antibiotic prophylaxis and treatment protocols in surgical practice in low- and middle-income countries.

Plasma Folate Levels in Acutely Ill and Steady State Pediatric Sickle Cell Disease Patients in Ghana.

BACKGROUND: Individuals with sickle cell disease (SCD) are susceptible to infective conditions that predispose them to hemolysis and anemia. Folic acid is recommended as a preventative measure against anemia in SCD patients; however, there is scarce literature on the implications of this practice. PATIENTS AND METHODS: Plasma concentrations of folate were measured in acutely ill pediatric SCD patients presenting with malaria or bacteremia and compared with those of SCD patients in steady state, or acutely ill non-SCD patients with confirmed malaria. RESULTS: The proportion of individuals with high (>45.3 nmol/L) folate concentrations was 29.5% (13/44), 18.2% (8/44), 33.3% (6/18), and 0% in the SCD-malaria, SCD steady state, SCD bacteremia, and the non-SCD malaria groups, respectively. The proportion of SCD patients with high folate levels did not vary significantly at steady state and during confirmed malaria (p = 0.216), and during acute bacteremia (p = 0.20). The median (interquartile range) plasma folate levels were 34.50 (24.40-52.00 nmol/L), 33.40 (15.83-60.85 nmol/L), 30.85 (24.68-39.65 nmol/L), and 13.30 (10.03-17.18 nmol/L), respectively, in the SCD malaria, SCD bacteremia, SCD steady state, and the non-SCD malaria sub-groups. The median folate levels of SCD steady state, SCD malaria, and SCD bacteremia sub-groups differed significantly (p < 0.0001) when compared with non-SCD patients, but the levels in the SCD bacteremia and malaria groups were not significantly different from the SCD steady state group. CONCLUSION: Elevated levels of plasma folate were found in a high proportion of pediatric SCD patients. The implications of such elevated folate levels in pediatric SCD patients are unknown but may suggest a need for review of current recommendations for prophylactic doses of folic acid in SCD patients.

In vitro selection for adhesion of Plasmodium falciparum-infected erythrocytes to ABO antigens does not affect PfEMP1 and RIFIN expression.

Plasmodium falciparum causes the most severe form of malaria in humans. The adhesion of the infected erythrocytes (IEs) to endothelial receptors (sequestration) and to uninfected erythrocytes (rosetting) are considered major elements in the pathogenesis of the disease. Both sequestration and rosetting appear to involve particular members of several IE variant surface antigens (VSAs) as ligands, interacting with multiple vascular host receptors, including the ABO blood group antigens. In this study, we subjected genetically distinct P. falciparum parasites to in vitro selection for increased IE adhesion to ABO antigens in the absence of potentially confounding receptors. The selection resulted in IEs that adhered stronger to pure ABO antigens, to erythrocytes, and to various human cell lines than their unselected counterparts. However, selection did not result in marked qualitative changes in transcript levels of the genes encoding the best-described VSA families, PfEMP1 and RIFIN. Rather, overall transcription of both gene families tended to decline following selection. Furthermore, selection-induced increases in the adhesion to ABO occurred in the absence of marked changes in immune IgG recognition of IE surface antigens, generally assumed to target mainly VSAs. Our study sheds new light on our understanding of the processes and molecules involved in IE sequestration and rosetting.

Oxacillinase-181 Carbapenemase-Producing Klebsiella pneumoniae in Neonatal Intensive Care Unit, Ghana, 2017-2019.

We sequenced 29 carbapenemase-producing Klebsiella pneumoniae isolates from a neonatal intensive care unit in Ghana. Twenty-eight isolates were sequence type 17 with blaOXA-181 and differed by 0-32 single-nucleotide polymorphisms. Improved surveillance and infection control are needed to characterize and curb the spread of multidrug-resistant organisms in sub-Saharan Africa.

High Carriage Rates of Multidrug-Resistant Gram-Negative Bacteria in Neonatal Intensive Care Units From Ghana.

BACKGROUND: Carriage of multidrug resistant (MDR) Gram-negative bacteria (GN) in hospitalized neonates may increase the risk of difficult-to-treat invasive infections at neonatal intensive care units (NICUs). Data on MDRGN carriage among hospitalized newborns in Africa are limited. METHODS: We conducted a cross-sectional study at the NICUs of 2 tertiary hospitals in Ghana. Swabs from the axilla, groin, perianal region, and the environment were cultured, GN were identified, and antibiotic susceptibility was tested. We obtained blood culture isolates from neonates with sepsis. Whole-genome sequencing was used to characterize carbapenemase-producing Klebsiella pneumoniae. Typing was done by multilocus sequence typing (MLST) and single nucleotide polymorphism (SNP) analysis. RESULTS: A total of 276 GN were isolated from 228 screened neonates. Pathogenic GN were cultured in 76.8% (175 of 228) of neonates. Klebsiella spp (41.7%; 115 of 276) and Escherichia coli (26.4%; 73 of 276) were the commonest organisms. Carriage rates of MDRGN and third-generation cephalosporin resistant organisms were 49.6% (113 of 228) and 46.1% (105 of 228), respectively. Among Klebsiella spp, 75.6% (87 of 115) phenotypically expressed extended-spectrum ß-lactamase activity, whereas 15.6% expressed carbapenemase and harbored bla- OXA-181 and bla- CTX-M-15. Overall, 7.0% (16 of 228) of neonates developed GN bloodstream infection. In 2 of 11 neonates, sequencing showed the same identity between carriage and the bloodstream isolate. Length of stay before specimen collection and antibiotic use were independently associated with carriage rates, which increased from 13% at admission to 42% by day 2 and reached a plateau at 91% by day 15. CONCLUSIONS: High carriage rates of MDRGN, including carbapenemase-producing enterobacterales may be an emerging problem in NICUs in Africa.

Critical evaluation of the appetite test for children with severe acute malnutrition.

OBJECTIVES: The appetite test is used to risk stratify for children with severe acute malnutrition (SAM) in inpatient or outpatient care. The test is recommended in guidelines despite lack of evidence. We evaluated its ability to identify children at risk of a poor treatment outcome. METHODS: We conducted an observational study of children diagnosed with SAM at three health facilities in Ethiopia. The appetite test was done independently, and the result did not affect decisions about hospitalisation and clinical care. Data were analysed using mixed linear and logistic regression models. RESULTS: Appetite was tested in 298 (89%) of 334 children enrolled; 56 (19%) passed. Children failing the appetite test had a 6.6% higher weight gain per day (95% CI: 2.6, 10.8) adjusted for type of treatment, oedema, duration of follow-up and age than children passing the test. We found medical complications in 179 (54%) children. Medical complications were associated with blood markers of metabolic disturbance. Children with medical complications tended to have lower weight gain than those without complications (3.5%, 95% CI: -0.25, 7.0). Neither the appetite test nor medical complications were correlated with bacteraemia or treatment failure. CONCLUSIONS: Our findings question the use of the appetite test to identify children who need inpatient care. An assessment of medical complications alone could be a useful risk indicator but needs to be evaluated in other settings.

OBJECTIF: Le test de l'appétit est utilisé pour stratifier les risques chez les enfants souffrant de malnutrition aiguë sévère (MAS) en soins hospitaliers ou ambulatoires. Le test est recommandé dans les directives malgré le manque d'évidence. Nous avons évalué sa capacité à identifier les enfants à risque de mauvais résultats de traitement. MÉTHODES: Nous avons mené une étude observationnelle chez des enfants diagnostiqués avec une MAS dans trois établissements de santé en Ethiopie. Le test de l'appétit a été effectué indépendamment et le résultat n'a pas affecté les décisions d'hospitalisation et de soins cliniques. Les données ont été analysées à l'aide de modèles de régression linéaire et logistique mixtes. RÉSULTATS: : L'appétit a été testé chez 298 (89%) des 334 enfants inscrits; 56 (19%) ont réussi le test. Les enfants qui échouaient au test de l'appétit avaient un gain de poids de 6,6% plus élevé par jour (IC95%: 2,6 à 10,8) ajusté pour le type de traitement, l'œdème, la durée du suivi et l'âge que les enfants réussissant le test. Nous avons trouvé des complications médicales chez 179 (54%) enfants. Des complications médicales ont été associées à des marqueurs sanguins de troubles métaboliques. Les enfants souffrant de complications médicales avaient tendance à avoir un gain de poids plus faible que ceux sans complications (3,5% ; IC95%: -0,25 à 7,0). Ni le test de l'appétit ni les complications médicales ne corrélaient avec une bactériémie ou à un échec du traitement CONCLUSION: Nos résultats remettent en question l'utilisation du test de l'appétit pour identifier les enfants qui ont besoin de soins hospitaliers. Une évaluation des complications médicales à elle seule pourrait être un indicateur de risque utile, mais doit être évaluée dans d'autres contextes MOTS-CLÉS: malnutrition aiguë sévère, appétit, gestionnaire de communauté, évaluation des risques, aliments thérapeutiques.

Prolonged and persistent diarrhoea is not restricted to children with acute malnutrition: an observational study in Ethiopia.

OBJECTIVES: To assess the prevalence of prolonged and persistent diarrhoea, to estimate their co-occurrence with acute malnutrition and association with demographic and clinical factors. METHODS: Case-control study where cases were children under 5 years of age with diarrhoea and controls were children without diarrhoea, frequency-matched weekly by age and district of residency. Controls for cases 0-11 months were recruited from vaccination rooms, and controls for cases 12-59 months were recruited by house visits using random locations in the catchment area of the study sites. Data were analysed by mixed model logistic regression. RESULTS: We enrolled 1134 cases and 946 controls. Among the cases, 967 (85%) had acute diarrhoea (AD), 129 (11%) had ProD and 36 (3.2%) had PD. More cases had acute malnutrition at enrolment (17% vs. 4%, P < 0.0001) and more were born prematurely (5.7% vs. 1.8%, P < 0.0001) than controls. About 75% of ProPD cases did not have acute malnutrition. Cases with AD and ProPD had different symptomatology, even beyond illness duration. CONCLUSIONS: ProPD is common among children presenting with diarrhoea and is not confined to children with acute malnutrition. There is an urgent need for studies assessing causes of ProPD with and without acute malnutrition to develop treatment guidelines for these conditions.

OBJECTIFS: Evaluer la prévalence des diarrhées prolongées et persistantes, estimer leur co-occurrence avec la malnutrition aiguë et leur association avec des facteurs démographiques et cliniques. MÉTHODES: Etude cas-témoins portant sur des enfants de moins de 5 ans souffrant de diarrhée et sur des témoins, des enfants sans diarrhée, appariées toutes les semaines, en fonction de l'âge et du district de résidence. Les témoins pour les cas de 0 à 11 mois ont été recrutés dans les salles de vaccination et les témoins pour les cas de 12 à 59 mois ont été recrutés au cours de visites à domicile en utilisant des endroits aléatoires dans la zone de recrutement des sites d'étude. Les données ont été analysées par la régression logistique de modèle mixte. RÉSULTATS: Nous avons inscrit 1134 cas et 946 témoins. Parmi les cas, 967 (85%) avaient une diarrhée aiguë (DA), 129 (11%) étaient atteints de diarrhées prolongée (ProD) et 36 (3,2%) de diarrhées persistante (DP). La malnutrition aiguë au moment de l'inscription était plus fréquente (17% contre 4%, P < 0,0001) et davantage étaient nés prématurément (5,7% contre 1,8%, P < 0,0001) par rapport aux témoins. 75% des cas de ProPD ne souffraient pas de malnutrition aiguë. Les cas de DA et de ProPD avaient une symptomatologie différente, même au-delà de la durée de la maladie. CONCLUSIONS: La ProPD est fréquente chez les enfants présentant une diarrhée et ne se limitait pas aux enfants souffrant de malnutrition aiguë. Il est urgent que des études évaluant les causes de ProPD avec et sans malnutrition aiguë développent des recommandations de traitement pour ces affections.

Population Pharmacokinetic Estimates Suggest Elevated Clearance and Distribution Volume of Desethylamodiaquine in Pediatric Patients with Sickle Cell Disease Treated with Artesunate-Amodiaquine.

BACKGROUND: There is limited information on the safety or efficacy of currently recommended antimalarial drugs in patients with sickle cell disease (SCD), a population predisposed to worse outcomes if affected by acute malaria. Artesunate-amodiaquine (ASAQ) is the first-line treatment for uncomplicated malaria (UM) in many malaria-endemic countries and is also used for treatment of UM in SCD patients. There is, however, no information to date, on the pharmacokinetics (PK) of amodiaquine or artesunate or the metabolites of these drugs in SCD patients. OBJECTIVES: This study sought to determine the PK of desethylamodiaquine (DEAQ), the main active metabolite of amodiaquine, among paediatric SCD patients with UM treated with artesunate-amodiaquine (ASAQ). METHODS: Plasma concentration-time data (median DEAQ levels) of SCD children (n = 16) was initially compared with those of concurrently recruited non-SCD paediatric patients with acute UM (n = 13). A population PK modelling approach was then used to analyze plasma DEAQ concentrations obtained between 64 and 169 hours after oral administration of ASAQ in paediatric SCD patients with acute UM (n = 16). To improve PK modeling, DEAQ concentration-time data (n = 21) from SCD was merged with DEAQ concentration-time data (n = 169) of a historical paediatric population treated with ASAQ (n = 103) from the same study setting. RESULTS: The median DEAQ concentrations on days 3 and 7 were comparatively lower in the SCD patients compared to the non-SCD patients. A two-compartment model best described the plasma DEAQ concentration-time data of the merged data (current SCD data and historical data). The estimated population clearance of DEAQ was higher in the SCD patients (67 L/h, 21% relative standard error (RSE) compared with the non-SCD population (15.5 L/h, 32% RSE). The central volume of distribution was larger in the SCD patients compared with the non-SCD patients (4400 L, 43% RSE vs. 368 L, 34% RSE). CONCLUSIONS: The data shows a tendency towards lower DEAQ concentration in SCD patients and the exploratory population PK estimates suggest altered DEAQ disposition in SCD patients with acute UM. These findings, which if confirmed, may reflect pathophysiological changes associated with SCD on DEAQ disposition, have implications for therapeutic response to amodiaquine in SCD patients. The limited number of recruited SCD patients and sparse sampling approach however, limits extrapolation of the data, and calls for further studies in a larger population.

Diagnostic accuracy of the 1,3-ß-D-glucan test for pneumocystis pneumonia in a tertiary university hospital in Denmark: A retrospective study.

1,3-ß-D-glucan (BG), a cell-wall component of most fungi including Pneumocystis (PC), is recommended by international guidelines for screening for pneumocystis pneumonia (PCP) in hematologic patients. We retrospectively validated the BG test in our tertiary university hospital. Forty-five patients (median age 53 years, 33% female) tested for PC by polymerase chain reaction (PCR) and/or immunoflourescence (IF)-microscopy with a stored blood sample within ±5 days of the PC test were tested by the Fungitell (cutoff <60 and >80 pg/ml). Cases had symptoms and radiology compatible with PCP and positive IF-microscopy (proven PCP, n = 8) or positive PCR (probable PCP, n = 10). Controls had no compatible symptoms/radiology and negative tests for PC on conventional testing (no PCP, n = 24), or positive PCR/IF-microscopy (colonized, n = 3). Median BG-levels were 1108 pg/ml (proven PCP), 612 pg/ml (probable PCP), 29 pg/ml (colonized), and 48 pg/ml (controls, P < 0.001). Compared to the PCP case/control classification, the BG test showed sensitivities of 83-89% and specificities of 64-74%, positive likelihood ratio (LR) of 3.2 and negative LR of 0.23 at recommended cutoff and moderate agreement between tests. Optimal cutoff was ≥73 pg/ml. In PCR-positive cases, the agreement between the BG test and IF-microscopy was 78-89% with fair/moderate agreement. Elevated BG levels were seen in controls with probable invasive fungal infections (n = 4), hemodialysis, bacterial infections and/or betalactams. To conclude, 11% of patients with PCP would be missed if the BG test had been used for diagnosing PCP. Specificity was moderate. Among PCR-positive patients, the BG test identified more cases than IF-microscopy. BG testing is potentially helpful but sensitivity is insufficient to exclude PCP.

Malaria causes long-term effects on markers of iron status in children: a critical assessment of existing clinical and epidemiological tools.

BACKGROUND: Most epidemiological studies on the interplay between iron deficiency and malaria risk classify individuals as iron-deficient or iron-replete based on inflammation-dependent iron markers and adjustment for inflammation by using C-reactive protein (CRP) or α-1-acid glycoprotein (AGP). The validity of this approach and the usefulness of fibroblast growth factor 23 (FGF23) as a proposed inflammation-independent iron marker were tested. METHODS: Conventional iron markers and FGF23 were measured in children with acute falciparum malaria and after 1, 2, 4, and 6 weeks. Children, who were transfused or received iron supplementation in the follow-up period, were excluded, and iron stores were considered to be stable throughout. Ferritin levels 6 weeks after admission were used as a reference for admission iron status and compared with iron markers at different time points. RESULTS: There were long-term perturbations in iron markers during convalescence from acute malaria. None of the tested iron parameters, including FGF23, were independent of inflammation. CRP and AGP normalized faster than ferritin after malaria episodes. CONCLUSION: Malaria may bias epidemiological studies based on inflammation-dependent iron markers. Better markers of iron status during and after inflammation are needed in order to test strategies for iron supplementation in populations at risk of malaria.

Increased Plasmodium chabaudi malaria mortality in mice with nutritional iron deficiency can be reduced by short-term adjunctive iron supplementation.

BACKGROUND: Iron deficiency is the most widespread nutrient deficiency and an important cause of developmental impairment in children. However, some studies have indicated that iron deficiency can also protect against malaria, which is a leading cause of childhood morbidity and mortality in large parts of the world. This has rendered interventions against iron deficiency in malaria-endemic areas controversial. METHODS: The effect of nutritional iron deficiency on the clinical outcome of Plasmodium chabaudi AS infection in A/J mice and the impact of intravenous iron supplementation with ferric carboxymaltose were studied before and after parasite infection. Plasma levels of the iron status markers hepcidin and fibroblast growth factor 23 were measured in animals surviving and succumbing to malaria, and accompanying tissue pathology in the liver and the spleen was assessed. RESULTS: Nutritional iron deficiency was associated with increased mortality from P. chabaudi malaria. This increased mortality could be partially offset by carefully timed, short-duration adjunctive iron supplementation. Moribund animals were characterized by low levels of hepcidin and high levels of fibroblast growth factor 23. All infected mice had extramedullary splenic haematopoiesis, and iron-supplemented mice had visually detectable intracellular iron stores. CONCLUSIONS: Blood transfusions are the only currently available means to correct severe anaemia in children with malaria. The potential of carefully timed, short-duration adjunctive iron supplementation as a safe alternative should be considered.