44 research outputs found
The clinical implications of thrombocytopenia in adults with severe falciparum malaria: a retrospective analysis
Background
Thrombocytopenia is a common finding in adults with severe falciparum malaria, but its clinical and prognostic utility is incompletely defined.
Methods
Clinical and laboratory data from 647 adults with severe falciparum malaria were analysed retrospectively to determine the relationship between a patient’s platelet count on admission to hospital and their subsequent clinical course.
Results
On admission, 614 patients (94.9%) were thrombocytopenic (platelet count <150 × 109/L) and 328 (50.7%) had a platelet count <50 × 109/L. The admission platelet count was inversely correlated with parasite biomass (estimated from plasma PfHRP2 concentrations, rs = −0.28, P = 0.003), the degree of microvascular sequestration (measured with orthogonal polarizing spectral imaging, rs = −0.31, P = 0.001) and disease severity (the number of World Health Organization severity criteria satisfied by the patient, rs = −0.21, P <0.001). Platelet counts were lower on admission in the patients who died (median: 30 (interquartile range 22 to 52) × 109/L versus 50 (34 to 78) × 109/L in survivors; P <0.001), but did not predict outcome independently from other established laboratory and clinical prognostic indices. The 39 patients (6%) with profound thrombocytopenia (platelet count <20 × 109/L) were more likely to die (odds ratio: 5.00, 95% confidence interval: 2.56 to 9.75) than patients with higher platelet counts, but these high-risk patients could be identified more rapidly with simple bedside clinical assessment. The admission platelet count did not reliably identify the 50 patients (7.7%) with major bleeding during the study.
Conclusions
Thrombocytopenia is a marker of disease severity in adults with falciparum malaria, but has limited utility in prognostication, triage and management
Provider and household costs of Plasmodium vivax malaria episodes: A multicountry comparative analysis of primary trial data
Objective: To determine household and health-care provider costs associated with Plasmodium vivax infection across a range of endemic settings.
Methods: We collected cost data alongside three multicentre clinical trials of P. vivax treatment in Afghanistan, Brazil, Colombia, Ethiopia, Indonesia, Philippines, Peru, Thailand and Viet Nam conducted between April 2014 to December 2017. We derived household costs from trial participant surveys administered at enrolment and again 2Â weeks later to determine the costs of treatment and transportation, and the number of days that patients and their household caregivers were unable to undertake their usual activities. We determined costs of routine care by health-care providers by micro-costing the resources used to diagnose and treat P. vivax at the study sites.
Findings: The mean total household costs ranged from 8.7 United States dollars (USÂ 254.7 (SD: 148.4) in Colombia. Across all countries, productivity losses were the largest household cost component, resulting in mean indirect costs ranging from USÂ 220.8 (SD: 158.40). The range of health-care provider costs for routine care was USÂ 0.9 to 13.5, consistently lower than the costs of the widely-used fluorescent spot test (US$Â 6.3 to 17.4).
Conclusion: An episode of P. vivax malaria results in high costs to households. The costs of diagnosing and treating P. vivax are important inputs for future cost-effectiveness analyses to ensure optimal allocation of resources for malaria elimination
Genomic epidemiology of artemisinin resistant malaria.
The current epidemic of artemisinin resistant Plasmodium falciparum in Southeast Asia is the result of a soft selective sweep involving at least 20 independent kelch13 mutations. In a large global survey, we find that kelch13 mutations which cause resistance in Southeast Asia are present at low frequency in Africa. We show that African kelch13 mutations have originated locally, and that kelch13 shows a normal variation pattern relative to other genes in Africa, whereas in Southeast Asia there is a great excess of non-synonymous mutations, many of which cause radical amino-acid changes. Thus, kelch13 is not currently undergoing strong selection in Africa, despite a deep reservoir of variations that could potentially allow resistance to emerge rapidly. The practical implications are that public health surveillance for artemisinin resistance should not rely on kelch13 data alone, and interventions to prevent resistance must account for local evolutionary conditions, shown by genomic epidemiology to differ greatly between geographical regions
Genomic epidemiology of artemisinin resistant malaria.
The current epidemic of artemisinin resistant Plasmodium falciparum in Southeast Asia is the result of a soft selective sweep involving at least 20 independent kelch13 mutations. In a large global survey, we find that kelch13 mutations which cause resistance in Southeast Asia are present at low frequency in Africa. We show that African kelch13 mutations have originated locally, and that kelch13 shows a normal variation pattern relative to other genes in Africa, whereas in Southeast Asia there is a great excess of non-synonymous mutations, many of which cause radical amino-acid changes. Thus, kelch13 is not currently undergoing strong selection in Africa, despite a deep reservoir of variations that could potentially allow resistance to emerge rapidly. The practical implications are that public health surveillance for artemisinin resistance should not rely on kelch13 data alone, and interventions to prevent resistance must account for local evolutionary conditions, shown by genomic epidemiology to differ greatly between geographical regions