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Summary:. Clinical and pathological features in 23 children who developed acute renal failure from what was subsequently proven to be diethylene glycol poisoning are presented. Symptoms of cases included anuria, fever, diarrhoea and vomiting. Eighteen (78.3%) had hepatomegaly, 11 (47.8%) had evidence of respiratory dis tress and 7 (30.4%) had acidotic breathing. Seven (30.4%) of the children were dehydrated on physical examination. Alteration in the level of consciousness was observed in 13 (56.5%) children. The major biochemical abnormalities were acidosis and elevated blood urea nitrogen. Although serum bilirubin was normal in those in whom it was determined, the liver enzymes were elevated in the 2 patients in whom they were determined. Patients were treated as for acute renal failure of renal origin and four children had peritoneal dialysis. Twenty-two (95.6%) of the patients died and outcome was unknown in the remaining patient who was dis charged against medical advice. Autopsies in 7 patients revealed a characteristic nephrotoxic acute tubular necrosis and centrilo bular hepatic necrosis characterized by vacuolar and ballooning degeneration of the metabolically active renal tubular cells and hepatocytes.

Summary: In order to evaluate the usefulness of simple pre-laparotomy parameters in differentiat ing intrahepatic cholestasis (IHC) from extrahepatic cholestasis (EHC), 27 infants with cholestatic jaundice were studied prospectively. On initial evaluation, the following data was collected: birthweight, age at observation of jaundice, presence and consistency of hepatomegaly, splenomegaly, direct serum bilirubin, alkaline phosphatase, haematocrit, prothrombin time, per oxide haemolysis test and duodenal intubation and aspiration test. The sensitivity, specificity, negative and positive predictive values of each parameter were determined, while the definitive diagnosis was confirmed by exploratory laparotomy and intra-operative cholangiography in 12 cases of the clinical course of the disease. Patients with EHC reported to hospital late while the presence of acholic 'stools within 10 days of admission, hepatomegaly of >3 cm, peroxide haemolysis of >80 percent lysis and/or the presence or absence of bilious fluid on duodenal aspiration aided differential diagnosis of infantile cholestasis in the infants. The specificity of acholic stools, hepatomegaly and duodenal aspiration tests was 73.3 percent, 66.7 percent and 93.3 percent respectively, while the corresponding negative predictive values were 78.6 percent, 100 percent and 100 percent, respectively. These simple parameters in a set-up with limied diagnostic facilities, experience and expertise, should encourage immediate exploratory laparotomy, wedge liver biopsy and intraoperative cholangiography.

Summary: In order to determine the relative frequencies of the different causes of severe anaemia among patients with sickle cell anaemia (SCA), 104 con secutive patients with SCA presenting over an eight-month period with severe anaemia (PCV 15 percent) were studied at the children's emergency ward, University College Hospital, Ibadan. They accounted for 8.2 percent of all admissions and 24.2 percent of those who had severe anaemia. Among the patients with SCA, hyperhaemolytic, acute splenic sequestration and aplastic crises constituted 49,20 and 12.5 percent of the anaemic crises, respectively. Ten patients (9.6 percent) showed mixed features and could not be definitely classified. The frequency rate of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency was similar between patients with hyperhaemolytic and those with other forms of anaemic crisis, a finding which suggests that G 6-PD deficiency neither aggravates nor ameliorates haemolysis in SCA. The mortality in the series was 8.7 percent. Six of the patients who died had hyperhaemolysis while the other three had acute splenic sequestration crisis. Five of these deaths occurred despite emergency blood transfusion.

Summary: The three types of severe anaemic crises recognised in sickle-cell anaemia (SCA) are aplastic, acute splenic sequestration and hyperhaemolytic. However, among 104 consecutive SCA cases admitted to the Children Emergency Ward of the University College Hospital, Ibadan with severe anaemic crises recently, were ten (9.6 percent) children who had mixed features and did not fall neatly into any of the three recognised categories. The distributions of the sex and admission haematocrits in these ten children with mixed' anaemic crises were similar to those of the 94 others with easily classified (pure) anaemic crises. However, using statistical test appropriate for the small numbers involved, Salmonella bacteraemia was significantly more common (5/10) among the patients with ‘mixed' anaemic crises than in those (5/94) with pure crises (P=0.0006). The relative risk of Salmonella bacteraemia in ‘mixed' crises was 9.4 times that among those with pure crises (95%CI=3.28-26.98). Although none of the “mixed cases died, compared with a mortality of 9.6 percent among the 'pure cases, the difference was not significant (P=0.42). Bacteraemia appears to be associated with mixed' indeterminate) anaemic crises in SCA. This finding suggests that such patients would benefit from appropriate antibiotic therapy.

Over 200 million malaria cases globally lead to half-million deaths annually. The development of malaria prevalence prediction systems to support malaria care pathways has been hindered by lack of data, a tendency towards universal "monolithic" models (one-size-fits-all-regions) and a focus on long lead time predictions. Current systems do not provide short-term local predictions at an accuracy suitable for deployment in clinical practice. Here we show a data-driven approach that reliably produces one-month-ahead prevalence prediction within a densely populated all-year-round malaria metropolis of over 3.5 million inhabitants situated in Nigeria which has one of the largest global burdens of P. falciparum malaria. We estimate one-month-ahead prevalence in a unique 22-years prospective regional dataset of > 9 × 10 4 participants attending our healthcare services. Our system agrees with both magnitude and direction of the prediction on validation data achieving MAE ≤ 6 × 10 -2 , MSE ≤ 7 × 10 -3 , PCC (median 0.63, IQR 0.3) and with more than 80% of estimates within a (+ 0.1 to - 0.05) error-tolerance range which is clinically relevant for decision-support in our holoendemic setting. Our data-driven approach could facilitate healthcare systems to harness their own data to support local malaria care pathways.

Over 200 million malaria cases globally lead to half a million deaths annually. Accurate malaria diagnosis remains a challenge. Automated imaging processing approaches to analyze Thick Blood Films (TBF) could provide scalable solutions, for urban healthcare providers in the holoendemic malaria sub-Saharan region. Although several approaches have been attempted to identify malaria parasites in TBF, none have achieved negative and positive predictive performance suitable for clinical use in the west sub-Saharan region. While malaria parasite object detection remains an intermediary step in achieving automatic patient diagnosis, training state-of-the-art deep-learning object detectors requires the human-expert labor-intensive process of labeling a large dataset of digitized TBF. To overcome these challenges and to achieve a clinically usable system, we show a novel approach. It leverages routine clinical-microscopy labels from our quality-controlled malaria clinics, to train a Deep Malaria Convolutional Neural Network classifier (DeepMCNN) for automated malaria diagnosis. Our system also provides total Malaria Parasite (MP) and White Blood Cell (WBC) counts allowing parasitemia estimation in MP/μL, as recommended by the WHO. Prospective validation of the DeepMCNN achieves sensitivity/specificity of 0.92/0.90 against expert-level malaria diagnosis. Our approach PPV/NPV performance is of 0.92/0.90, which is clinically usable in our holoendemic settings in the densely populated metropolis of Ibadan. It is located within the most populous African country (Nigeria) and with one of the largest burdens of Plasmodium falciparum malaria. Our openly available method is of importance for strategies aimed to scale malaria diagnosis in urban regions where daily assessment of thousands of specimens is required., (© 2020 The Authors. American Journal of Hematology published by Wiley Periodicals, Inc.)

Background: Cerebral malaria (CM), is a life-threatening childhood malaria syndrome with high mortality. CM is associated with impaired consciousness and neurological damage. It is not fully understood, as yet, why some children develop CM. Presented here is an observation from longitudinal studies on CM in a paediatric cohort of children from a large, densely-populated and malaria holoendemic, sub-Saharan, West African metropolis., Methods: Plasma samples were collected from a cohort of children with CM, severe malarial anaemia (SMA), uncomplicated malaria (UM), non-malaria positive healthy community controls (CC), and coma and anemic patients without malaria, as disease controls (DC). Proteomic two-dimensional difference gel electrophoresis (2D-DIGE) and mass spectrometry were used in a discovery cohort to identify plasma proteins that might be discriminatory among these clinical groups. The circulatory levels of identified proteins of interest were quantified by ELISA in a prospective validation cohort., Results: The proteome analysis revealed differential abundance of circulatory complement-lysis inhibitor (CLI), also known as Clusterin (CLU). CLI circulatory level was low at hospital admission in all children presenting with CM and recovered to normal level during convalescence (p < 0.0001). At acute onset, circulatory level of CLI in the CM group significantly discriminates CM from the UM, SMA, DC and CC groups., Conclusions: The CLI circulatory level is low in all patients in the CM group at admission, but recovers through convalescence. The level of CLI at acute onset may be a specific discriminatory marker of CM. This work suggests that CLI may play a role in the pathophysiology of CM and may be useful in the diagnosis and follow-up of children presenting with CM.

Severe Malarial Anemia (SMA), a life-threatening childhood Plasmodium falciparum malaria syndrome requiring urgent blood transfusion, exhibits inflammatory and hemolytic pathology. Differentiating between hypo-haptoglobinemia due to hemolysis or that of genetic origin is key to understand SMA pathogenesis. We hypothesized that while malaria-induced hypo-haptoglobinemia should reverse at recovery, that of genetic etiology should not. We carried-out a case-control study of children living under hyper-endemic holoendemic malaria burden in the sub-Saharan metropolis of Ibadan, Nigeria. We show that hypo-haptoglobinemia is a risk factor for childhood SMA and not solely due to intravascular hemolysis from underlying schizogony. In children presenting with SMA, hypo-haptoglobinemia remains through convalescence to recovery suggesting a genetic cause. We identified a haptoglobin gene variant, rs12162087 (g.-1203G > A, frequency = 0.67), to be associated with plasma haptoglobin levels (p = 8.5 × 10 -6 ). The Homo-Var:(AA) is associated with high plasma haptoglobin while the reference Homo-Ref:(GG) is associated with hypo-haptoglobinemia (p = 2.3 × 10 -6 ). The variant is associated with SMA, with the most support for a risk effect for Homo-Ref genotype. Our insights on regulatory haptoglobin genotypes and hypo-haptoglobinemia suggest that haptoglobin screening could be part of risk-assessment algorithms to prevent rapid disease progression towards SMA in regions with no-access to urgent blood transfusion where SMA accounts for high childhood mortality rates.

Cerebral malaria (CM) is a severe complication of Plasmodium falciparum infection. This encephalopathy is characterized by coma and is thought to result from mechanical microvessel obstruction and an excessive activation of immune cells leading to pathological inflammation and blood-brain barrier alterations. IL-22 contributes to both chronic inflammatory and infectious diseases, and may have protective or pathogenic effects, depending on the tissue and disease state. We evaluated whether polymorphisms (n = 46) of IL22 and IL22RA2 were associated with CM in children from Nigeria and Mali. Two SNPs of IL22, rs1012356 (P = 0.016, OR = 2.12) and rs2227476 (P = 0.007, OR = 2.08) were independently associated with CM in a sample of 115 Nigerian children with CM and 160 controls. The association with rs2227476 (P = 0.01) was replicated in 240 nuclear families with one affected child from Mali. SNP rs2227473, in linkage disequilibrium with rs2227476, was also associated with CM in the combined cohort for these two populations, (P = 0.004, OR = 1.55). SNP rs2227473 is located within a putative binding site for the aryl hydrocarbon receptor, a master regulator of IL-22 production. Individuals carrying the aggravating T allele of rs2227473 produced significantly more IL-22 than those without this allele. Overall, these findings suggest that IL-22 is involved in the pathogenesis of CM., Competing Interests: The authors declare no competing financial interests.

Cerebral malaria (CM) is a neurological complication of infection with Plasmodium falciparum that is partly caused by cytokine-mediated inflammation. It is not known whether interleukin-17 (IL-17) cytokines, which regulate inflammation, control the development of CM. To evaluate the involvement of IL-17 cytokines in CM, we analyzed 46 common polymorphisms in IL17A, IL17F, and IL17RA (which encodes the common receptor chain of the members of the IL-17 family) in two independent African populations. A case-control study involving 115 Nigerian children with CM and 160 controls from the community (CC) showed that IL17F reference single nucleotide polymorphism (SNP) 6913472 (rs6913472) (P = 0.004; odds ratio [OR] = 3.12), IL17F rs4715291 (P = 0.004; OR = 2.82), IL17RA rs12159217 (P = 0.01; OR = 2.27), and IL17RA rs41396547 (P = 0.026; OR = 3.15) were independently associated with CM. A replication study was performed in 240 nuclear Malian family trios (two parents with one CM child). We replicated the association for 3 SNPs, IL17F rs6913472 (P = 0.03; OR = 1.39), IL17RA rs12159217 (P = 0.01; OR = 1.52), and IL17RA rs41396547 (P = 0.04; OR = 3.50). We also found that one additional SNP, IL17RA rs41433045, in linkage disequilibrium (LD) with rs41396547, was associated with CM in both Nigeria and Mali (P = 0.002; OR = 4.12 in the combined sample). We excluded the possibility that SNPs outside IL17F and IL17RA, in strong LD with the associated SNPs, could account for the observed associations. Furthermore, the results of a functional study indicated that the aggravating GA genotype of IL17F rs6913472 was associated with lower IL-17F concentrations. Our findings show for the first time that IL17F and IL17RA polymorphisms modulate susceptibility to CM and provide evidence that IL-17F protects against CM., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

Unlabelled: Severe malarial anemia (SMA) in semi-immune individuals eliminates both infected and uninfected erythrocytes and is a frequent fatal complication. It is proportional not to circulating parasitemia but total parasite mass (sequestered) in the organs. Thus, immune responses that clear parasites in organs may trigger changes leading to anemia. Here, we use an outbred-rat model where increasing parasite removal in the spleen escalated uninfected-erythrocyte removal. Splenic parasite clearance was associated with activated CD8(+) T cells, immunodepletion of which prevented parasite clearance. CD8(+) T cell repletion and concomitant reduction of the parasite load was associated with exacerbated (40 to 60%) hemoglobin loss and changes in properties of uninfected erythrocytes. Together, these data suggest that CD8(+) T cell-dependent parasite clearance causes erythrocyte removal in the spleen and thus anemia. In children infected with the human malaria parasite Plasmodium falciparum, elevation of parasite biomass (not the number of circulating parasites) increased the odds ratio for SMA by 3.5-fold (95% confidence intervals [CI95%], 1.8- to 7.5-fold). CD8(+) T cell expansion/activation independently increased the odds ratio by 2.4-fold (CI95%, 1.0- to 5.7-fold). Concomitant increases in both conferred a 7-fold (CI95%, 1.9- to 27.4-fold)-greater risk for SMA. Together, these data suggest that CD8(+)-dependent parasite clearance may predispose individuals to uninfected-erythrocyte loss and SMA, thus informing severe disease diagnosis and strategies for vaccine development., Importance: Malaria is a major global health problem. Severe malaria anemia (SMA) is a complex disease associated with partial immunity. Rapid hemoglobin reductions of 20 to 50% are commonly observed and must be rescued by transfusion (which can carry a risk of HIV acquisition). The causes and risk factors of SMA remain poorly understood. Recent studies suggest that SMA is linked to parasite biomass sequestered in organs. This led us to investigate whether immune mechanisms that clear parasites in organs trigger anemia. In rats, erythropoiesis is largely restricted to the bone marrow, and critical aspects of the spleen expected to be important in anemia are similar to those in humans. Therefore, using a rat model, we show that severe anemia is caused through CD8(+) T cell-dependent parasite clearance and erythrocyte removal in the spleen. CD8 activation may also be a new risk factor for SMA in African children., (Copyright © 2015 Safeukui et al.)

Systemic inflammation and sequestration of parasitized erythrocytes are central processes in the pathophysiology of severe Plasmodium falciparum childhood malaria. However, it is still not understood why some children are more at risks to develop malaria complications than others. To identify human proteins in plasma related to childhood malaria syndromes, multiplex antibody suspension bead arrays were employed. Out of the 1,015 proteins analyzed in plasma from more than 700 children, 41 differed between malaria infected children and community controls, whereas 13 discriminated uncomplicated malaria from severe malaria syndromes. Markers of oxidative stress were found related to severe malaria anemia while markers of endothelial activation, platelet adhesion and muscular damage were identified in relation to children with cerebral malaria. These findings suggest the presence of generalized vascular inflammation, vascular wall modulations, activation of endothelium and unbalanced glucose metabolism in severe malaria. The increased levels of specific muscle proteins in plasma implicate potential muscle damage and microvasculature lesions during the course of cerebral malaria.

Background & Objectives: Malaria and G6PD deficiency-related haemolyses are known causes of hospital admissions in Nigeria and pose great danger to child survival but data on interactions of these two pathologies are scarce. This study was carried out to determine the association between features of Plasmodium falciparum infection and G6PD status., Methods: G6PD and haemoglobin were typed by fluorescent spot test and electrophoresis respectively, in 1120 children with microscopically-proven falciparum malaria. Clinical features of malaria were compared between G6PD normal and deficient children., Results: There were 558 males and 562 females with median age of 35 months (range, 6 months-12 yr). In males, prevalence of G6PD-deficiency in patients with uncomplicated malaria (UM), severe malarial anaemia (SMA) and cerebral malaria (CM) was 23.4, 7 and 16.7%, respectively compared with 11.1, 7.3 and 4.4%, respectively among females. In both males and females, convulsion and rectal temperature above 38°C were less likely presentations among G6PD-deficient compared with G6PD-normal children (p <0.05). The proportions of children with pallor, convulsion and impaired consciousness were significantly lower among G6PD-deficient than normal males (p <0.05) but these features were not different between deficient and normal females (p >0.05)., Interpretation & Conclusion: Convulsions, pallor and elevated temperature were more frequent features of malaria in G6PD normal than deficient children. G6PD-deficient male children are protected against impaired consciousness. These differences may offer useful hints in malaria treatment and researches in endemic regions.

Aims and Objectives: To compare the outcome after a first clinical stroke, following treatment with and without hydroxyurea (HU)., Subjects and Methods: A retrospective review of a cohort of Nigerian children with SCD, who had suffered a first stroke, was carried out. Outcomes in the group of children who received and did not receive HU were compared., Results: Thirty two children presented with stroke and one died of haemorrhagic stroke at presentation. All the children had haemoglobin SS phenotype, and ischaemic stroke was the predominant form seen. Mean age at first clinical stroke was 7 years, 7 months (SD=2 years, 4 months). Thirteen children received HU while 18 declined HU therapy. Maximum dose of HU ranged from 20-25 mg/kg/ day. The secondary stroke incidence of 7/100 person years in the HU group was significantly lower than the 28/100 person years in the non-HU group (P=0.001, OR 3.808, 95% CI 1.556, 9.317). Children who did not receive HU were more likely to drop out of school and to have moderate-severe motor disabilities requiring caregiver assistance for daily living., Conclusion: In settings where facilities for chronic blood transfusion are not accessible or feasible, HU therapy should be considered for secondary stroke prevention in children with SCD.

Cerebral malaria (CM) and severe malarial anemia (SMA) are the most serious life-threatening clinical syndromes of Plasmodium falciparum infection in childhood. Therefore, it is important to understand the pathology underlying the development of CM and SMA as opposed to uncomplicated malaria (UM). Increased levels of hepcidin have been associated with UM, but its level and role in severe malarial disease remains to be investigated. Plasma and clinical data were obtained as part of a prospective case-control study of severe childhood malaria at the main tertiary hospital of the city of Ibadan, Nigeria. Here, we report that hepcidin levels are lower in children with SMA or CM than in those with milder outcome (UM). While different profiles of pro- and anti-inflammatory cytokines were observed between the malaria syndromes, circulatory hepcidin levels remained associated with the levels of its regulatory cytokine interleukin-6 and of the anti-inflammatory cytokine inerleukin-10, irrespective of iron status, anemic status, and general acute-phase response. We propose a role for hepcidin in anti-inflammatory processes in childhood malaria.

Biomarker discovery aims to find small subsets of relevant variables in 'omics data that correlate with the clinical syndromes of interest. Despite the fact that clinical phenotypes are usually characterized by a complex set of clinical parameters, current computational approaches assume univariate targets, e.g. diagnostic classes, against which associations are sought for. We propose an approach based on asymmetrical sparse canonical correlation analysis (SCCA) that finds multivariate correlations between the 'omics measurements and the complex clinical phenotypes. We correlated plasma proteomics data to multivariate overlapping complex clinical phenotypes from tuberculosis and malaria datasets. We discovered relevant 'omic biomarkers that have a high correlation to profiles of clinical measurements and are remarkably sparse, containing 1.5-3% of all 'omic variables. We show that using clinical view projections we obtain remarkable improvements in diagnostic class prediction, up to 11% in tuberculosis and up to 5% in malaria. Our approach finds proteomic-biomarkers that correlate with complex combinations of clinical-biomarkers. Using the clinical-biomarkers improves the accuracy of diagnostic class prediction while not requiring the measurement plasma proteomic profiles of each subject. Our approach makes it feasible to use omics' data to build accurate diagnostic algorithms that can be deployed to community health centres lacking the expensive 'omics measurement capabilities.

Background: Haemoglobinuria is one of the manifestations of severe malaria and results from severe intravascular haemolysis. Glucose-6-phosphate dehydrogenase (G6PD) deficiency has been implicated in its aetiology. Haemoglobinuria may be associated with severe anaemia and, less frequently, acute renal failure., Methods: A prospective case-control study was carried out to determine the incidence of haemoglobinuria as confirmed by dipstick urinalysis, microscopy and spectrophotometric measurement, among children with severe malaria. A total of 251 children presenting at the Children's Emergency Ward with severe malaria were recruited over a period of 21 months. The G6PD status and the outcomes of severe malaria in children with and without haemoglobinuria was studied with respect to renal failure, the recurrence of haemoglobinuria and blood pressure changes over a three-month follow-up period., Results: It was found that the incidence of haemoglobinuria among children with severe malaria is 19.1%. Children <5 years constituted 76.8% of all the study patients. Patients with haemoglobinuria had median age of 52.5 months, which was significantly higher than 35 months in patients without haemoglobinuria (p=0.001). Although, haemaglobinuria was commoner among boys (54.2%) than girls (45.8%), the difference was not statistically significant. There were no significant differences between children with and without haemoglobinuria regarding their nutritional status or parasite densities. Among the clinical features of the study patients, only jaundice was significantly associated with haemoglobinuria (p=0.0001). Renal failure occurred in three out of 48 children with haemoglobinuria and in none of the 203 without. There was not recurrence of haemoglobinuria in the follow-up period. At discharge, blood pressure was elevated in six children (one previously haemoglobinuric), but all returned to normal within the follow-up period., Conclusions: Haemoglobinuria was a prominent feature of severe malaria and it was significantly associated with jaundice at presentation. Haemoglobinuria was commoner in older children than younger children but not related to sex. G6PD deficiency was not an independent predictor of the occurrence or outcome of haemoglobinuria. Blood pressure was not affected by haemoglobinuria on admission nor during follow-up.

Transcranial Doppler (TCD) ultrasonography helps to identify children with sickle cell disease (SCD) who are at an increased risk of stroke,making primary stroke prevention a reality. A cross-sectional study of145 Nigerian children aged ≥3 years with SCD was carried out to describe the pattern of cerebral blood flow (CBF) abnormalities. The mean time-averaged mean velocity (TAMV) was 152 ±27.0 cm/sec and122 ±22.0 cm/sec in Hb SS and Hb S1C group, respectively. Abnormal velocities were recorded in six (4.7%) of the Hb SS patients and none of the Hb S1C while conditional risk (CR) velocities were recorded in 19.7% of Hb SS (low conditional 11.0%, high conditional 8.7%) and low conditional in 5.6% of Hb S1C cases. Cerebral flow velocities showed a negative correlation with age and hematocrit. Compared with African-American children, Nigerian children with Hb SS disease have a considerably higher prevalence of CR velocities.

Background: Cerebral malaria (CM) and severe malarial anemia (SMA) are the most serious life-threatening clinical syndromes of Plasmodium falciparum infection in childhood. Therefore it is important to understand the pathology underlying the development of CM and SMA, as opposed to uncomplicated malaria (UM). Different host responses to infection are likely to be reflected in plasma proteome-patterns that associate with clinical status and therefore provide indicators of the pathogenesis of these syndromes., Methods and Findings: Plasma and comprehensive clinical data for discovery and validation cohorts were obtained as part of a prospective case-control study of severe childhood malaria at the main tertiary hospital of the city of Ibadan, an urban and densely populated holoendemic malaria area in Nigeria. A total of 946 children participated in this study. Plasma was subjected to high-throughput proteomic profiling. Statistical pattern-recognition methods were used to find proteome-patterns that defined disease groups. Plasma proteome-patterns accurately distinguished children with CM and with SMA from those with UM, and from healthy or severely ill malaria-negative children., Conclusions: We report that an accurate definition of the major childhood malaria syndromes can be achieved using plasma proteome-patterns. Our proteomic data can be exploited to understand the pathogenesis of the different childhood severe malaria syndromes.

Introduction: Glucose-6-phosphate dehydrogenase (G6PD) deficiency (Gd-) contributes to morbidity and mortality in sub-Saharan Africa but recent data on the interaction between Gd- and malaria among children is scarce. We hypothesised that, being a haemolytic factor, Gd- makes severe malarial anaemia (SMA) more common and even more severe., Methodology: We selected 930 children aged 0.5-12 years attending a reference hospital with microscopically proven falciparum malaria. G6PD and haemoglobin were typed by the fluorescent spot test and electrophoresis, respectively. Molecular typing by PCR and restriction enzyme digestion was also performed on 15% of randomly selected samples. Haematocrit (PCV) values, haemoglobin type, blood group, presence of sickle cell trait (HbAS), and parasite counts were compared between G6PD-normal and deficient children., Results: Prevalence of Gd- was 16.4% and 8.1% among boys and girls with malaria, respectively. Mean PCV was 22.8% in deficient children compared with 21.0% in normal children (p = 0.041). In boys, 2.7% of Gd- had PCV ≤ 10%, as compared to 13.6% in Gd+ (p = 0.005). Similarly, 21.3% of Gd- had PCV ≤ 15% compared with 39.4% in Gd+ (p = 0.003). No such difference was found among girls. Overall, HbAS was typed in 7.6% and was more common in Gd- (13.0%) than in Gd+ (6.8%), but the difference was not statistically significant (p = 0.058). The mean parasite counts were significantly lower in Gd- (15477.5/µl) than in Gd+ (19784.4/µl; p = 0.013), and it was independent from HbAS., Conclusion: Gd- males but not females were significantly less likely to develop severe malarial anaemia.

Malaria merozoite surface protein 1 (MSP1) is cleaved in an essential step during erythrocyte invasion. The responses of children to natural malaria infection included antibodies that inhibit this cleavage and others that block the binding of these inhibitory antibodies. There was no correlation between the titer of the antibody to the 19-kDa fragment of MSP1 and its inhibitory activity. These findings have implications for the design of MSP1-based vaccines.

Plasmodium falciparum glucose 6-phosphate dehydrogenase (Pf Glc6PD), compared to other Glc6PDs has an additional 300 amino acids at the N-terminus. They are not related to Glc6PD but are similar to a family of proteins (devb) of unknown function, some of which are encoded next to Glc6PD in certain bacteria. The human devb homologue has recently been shown to have 6-phosphogluconolactonase (6PGL) activity. This suggests Pf Glc6PD may be a bifunctional enzyme, the evolution of which has involved the fusion of adjacent genes. Further functional analysis of Pf Glc6PD has been hampered because parts of the gene could not be cloned. We have isolated and sequenced the corresponding Plasmodium berghei gene and shown it encodes an enzyme (Pb Glc6PD) with the same structure as the P. falciparum enzyme. Pb Glc6PD is 950 amino acids long with significant sequence similarity in both the devb and Glc6PD domains with the P. falciparum enzyme. The P. berghei enzyme does not have an asparagine-rich segment between the N and C halves and it contains an insertion at the same point in the Glc6PD region as the P. falciparum enzyme but the insertion in the P. berghei is longer (110 versus 62 amino acids) and unrelated in sequence to the P. falciparum insertion. Though expression of this enzyme in bacteria produced largely insoluble protein, conditions were found where the full-length enzyme was produced in a soluble form which was purified via a histidine tag. We show that this enzyme has both Glc6PD and 6PGL activities. Thus the first two steps of the pentose phosphate pathway are catalysed by a single novel bifunctional enzyme in these parasites.

It is widely believed that malaria causes diarrhea. Yet, national and international diarrheal diseases control programs are silent about the overlap between these two major public health problems that coexist in most tropical countries. To test the hypothesis that malaria is associated with diarrhea and to define the role of malaria in morbidity due to diarrhea, 522 children 6-60 months of age presenting with acute diarrhea to the Children's Emergency Ward of the University College Hospital in Ibadan, Nigeria were routinely screened by means of thin and thick blood films for malaria parasitemia. Controls, without diarrhea, were studied in parallel. Detailed clinical features were recorded for every patient. Sixty-eight (13%) of the 522 diarrhea patients screened had malaria parasitemia. Among the controls (who had similar distributions of admission temperature, hemoglobin types, glucose-6-phosphate dehydrogenase deficiency, and prior treatment with antimalarial drugs), parasitemia was not significantly different, occurring in 56 (17.9%) of 313. In the dry season, however, a significantly higher prevalence of parasitemia was observed among the control group (15.5%) than in the diarrhea group (7.0%) (P = 0.004). Parasitemia was significantly more common in the dehydrated diarrhea patients than their well-hydrated counterparts (25% of 56 versus 11% of 466; P < 0.005). There were no significant differences in admission temperature, the presence of vomiting, or the home use of oral rehydration fluids between the dehydrated and the well-hydrated subsets of diarrhea patients. Consideration of parasite densities did not alter any of the foregoing relationships. These data contradict the widely held view that diarrhea is a symptom of malaria or that malaria causes diarrhea. They do, however, provide support for examining blood smears at least in dehydrated children with diarrhea in malaria-endemic areas and giving immediate antimalarial therapy to those who have malaria parasitemia.

To identify possible risk factors for persistent diarrhoea, 307 children with acute diarrhoea presenting at the University College Hospital, Ibadan, Nigeria over a 10-month period from July 1993 to April 1994 were followed up prospectively until the resolution of the illness. The children were aged 6-60 months. In 36 (11.7%) of them, diarrhoea became persistent (i.e. lasted more than 14 days). This hospital frequency of 11.7% of persistent diarrhoea is, as expected, higher than the figures from previous community-based studies of diarrhoea from Nigeria. The major factor associated with persistent diarrhoea was poor nutritional status. Mean z scores of weight-for-height and weight-for-age were significantly lower in the persistent diarrhoea group, while mean z scores of height-for-age were similar in the two groups. The frequencies of occurrence of undernutrition, marasmus and kwashiorkor were also higher in the persistent diarrhoea group. Therefore, in common with studies from other regions of the world, malnutrition is an important risk factor for persistent diarrhoea in this group of Nigerian children. The implication of these findings is that reduction in the prevalence of malnutrition may be associated with reduction in the proportion of acute diarrhoeal episodes that eventually progress to persistent diarrhoea.

Although both malaria and diarrhoea are major public health problems in developing countries, and separately each has been the subject of intense research, few studies have investigated the interaction between these two conditions. The interaction between diarrhoea and malaria among children aged 4 months to 12 years in two tertiary health-care facilities, University College Hospital, Ibadan, and Lagos University Teaching Hospital, Lagos, Nigeria was studied. In Ibadan, the prevalence of diarrhoea among the cerebral malaria patients on admission as 11.7% (7/60) compared to 9.3% (215/2312) among other admissions in 1990 (chi square = 0.16; p = 0.6913). Similarly, no significant difference in the prevalence of diarrhoea was found between the cerebral malaria patients (14.3%) and other patients (16.1%) seen in Lagos in 1992 (chi square = 0.06, p = 0.81). Thus, cerebral malaria does not seem to be associated with an increased or decreased prevalence of diarrhoea when compared with other conditions. The prevalence of malarial parasitaemia among the 554 diarrhoea patients studied in Ibadan during 1993-1994 was 13.6% compared with 17.9% among the 347 controls (chi square = 3.75, p = 0.053). However, of the children with diarrhoea, malarial parasitaemia was more common among the dehydrated patients (25.4%) than among the well-hydrated patients (11.6%) (chi square = 8.11, p = 0.004). These data suggest that diarrhoea is merely coincidental in severe malaria and conversely, malarial parasitaemia is similarly coincidental in children with acute diarrhoea, although it may be more frequent among dehydrated diarrhoea patients than well-hydrated ones.

A 9.5-kilobase plasmid of Yersinia pestis, the causative agent of plague, is required for high virulence when mice are inoculated with the bacterium by subcutaneous injection. Inactivation of the plasmid gene pla, which encodes a surface protease, increased the median lethal dose of the bacteria for mice by a millionfold. Moreover, cloned pla was sufficient to restore segregants lacking the entire pla-bearing plasmid to full virulence. Both pla+ strains injected subcutaneously and pla- mutants injected intravenously reached high titers in liver and spleen of infected mice, whereas pla- mutants injected subcutaneously failed to do so even though they establish a sustained local infection at the injection site. More inflammatory cells accumulated in lesions caused by the pla- mutants than in lesions produced by the pla+ parent. The Pla protease was shown to be a plasminogen activator with unusual kinetic properties. It can also cleave complement C3 at a specific site.