Articles
Clinical presentation, biochemical, and haematological parameters and their association with outcome in patients with Ebola virus disease: an observational cohort study

https://doi.org/10.1016/S1473-3099(15)00144-9Get rights and content

Summary

Background

Clinical management of Ebola virus disease remains challenging. Routine laboratory analytics are often unavailable in the outbreak setting, and few data exist for the associated haematological and biochemical abnormalities. We aimed to assess laboratory and clinical data from patients with Ebola virus disease to better inform clinical management algorithms, improve understanding of key variables associated with outcome, and provide insight into the pathophysiology of Ebola virus disease.

Methods

We recruited all patients, alive on arrival, with confirmed Ebola virus disease who were admitted to the Kerry Town Ebola treatment centre in Sierra Leone. At admission, all patients had clinical presentation recorded and blood taken for Ebola confirmation using reverse-transcriptase-PCR (RT-PCR) and for haematological and biochemical analysis. We studied the association between these and clinical outcome. The primary outcome was discharge from the Ebola treatment centre.

Findings

150 patients were admitted to the treatment centre between Dec 8, 2014, and Jan 9, 2015. The mean age of patients was 26 years (SD 14·7). Case fatality rate was 37% (55/150). Most patients presented with stage 2 (gastrointestinal involvement, 72/118 [61%]) and stage 3 (severe or complicated, 12/118 [10%]) disease. Acute kidney injury was common (52/104 [50%]), as were abnormal serum potassium (32/97 [33%]), severe hepatitis (54/92 [59%]), and raised C-reactive protein (21/100 [21%]). Haematological abnormalities were common, including raised haematocrit (15/100 [15%]), thrombocytopenia (47/104 [45%]), and granulocytosis (44/104 [42%]). Severe acute kidney injury, low RT-PCR cycle threshold (<20 cycles), and severe hepatitis were independently associated with mortality.

Interpretation

Ebola virus disease is associated with a high prevalence of haematological and biochemical abnormalities, even in mild disease and in the absence of gastrointestinal symptoms. Clinical care that targets hypovolaemia, electrolyte disturbance, and acute kidney injury is likely to reduce historically high case fatality rates.

Funding

None.

Introduction

Ebola virus disease is caused by an RNA filovirus, and is characterised by a febrile illness (recorded in 87% of patients with Ebola virus disease), often progressing to diarrhoea (67%), vomiting (66%), and, sometimes, haemorrhage (18%).1 The current outbreak in west Africa is the largest up to now, with more than 27 500 cases (Aug 2, 2015).2 Clinical and public health management is challenging, especially in the worst hit countries of Sierra Leone, Liberia, and Guinea, because of severity of clinical presentation, infection control concerns, poor health-system infrastructure, and high population density.3, 4

There is currently no proven treatment for Ebola virus disease; therefore, management is supportive, including administration of oral and intravenous fluids and electrolytes, management of co-infections, and symptom control.3, 4, 5 Ebola virus disease causes marked biochemical abnormalities, which might be amenable to simple interventions, potentially reducing the high case fatality rate.4, 6, 7, 8, 9, 10, 11, 12 Because of the low-resource setting of outbreaks and risks associated with the collection and processing of laboratory samples, few data exist for these abnormalities, mostly from animal models, small cohorts, or case studies from resource-rich settings.6, 7, 8, 9, 11, 13

Kerry Town Ebola treatment centre, operated by Save the Children, opened on Nov 5, 2014, in Sierra Leone offering supportive care focused on fluid and electrolyte management, in accordance with WHO guidelines.3 This included haematology and biochemistry testing for all admissions from Dec 8, 2014. We aimed to report data for clinical presentation, laboratory abnormalities, and their association with mortality in patients admitted in 1 month. We hoped these data would improve understanding of key variables associated with outcome, inform clinical management algorithms, and provide insight into the pathophysiology of Ebola virus disease.

Section snippets

Study design

We undertook a cohort study of patients consecutively admitted to Kerry Town Ebola treatment centre between Dec 8, 2014, and Jan 9, 2015. During this period only patients with Ebola virus disease confirmed at other isolation or community care centres were admitted. We used a standard case definition as per WHO guidelines.2 All patients were included in the study except for those who were dead on arrival, or those who had no blood results within 24 h of admission. Primary outcome measure was

Results

During the study period, 150 patients were admitted with confirmed Ebola virus disease. Additionally, six patients who did not have Ebola virus disease were referred and four patients died in transit. Absent laboratory samples were the result of no sample being obtained on admission (n=8) and a laboratory isolator fault meaning no samples were processed between Dec 26 and Dec 29 (n=24). Of the 118 included patients, 104 had haematology parameters analysed and 114 had biochemistry analysed. In

Discussion

The natural history of Ebola virus disease is well characterised with a gastrointestinal stage leading to pronounced hypovolaemia, systemic hypoperfusion, and shock in patients who are inadequately fluid-resuscitated.4 The extent of multiorgan dysfunction syndrome, which commonly affects the renal, hepatic, neurological, and coagulation systems, varies from mild dysfunction to irreversible organ failure and death, but the pathogenesis of Ebola virus disease remains poorly understood. The

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