Meta-analysis of predictive symptoms for Ebola virus disease

Derivation and Internal Validation of a Mortality Prognostication Machine Learning Model in Ebola Virus Disease Based on Iterative Point-of-Care Biomarkers

Background

Although multiple prognostic models exist for Ebola virus disease mortality, few incorporate biomarkers, and none has used longitudinal point-of-care serum testing throughout Ebola treatment center care.

Methods

This retrospective study evaluated adult patients with Ebola virus disease during the 10th outbreak in the Democratic Republic of Congo. Ebola virus cycle threshold (Ct; based on reverse transcriptase polymerase chain reaction) and point-of-care serum biomarker values were collected throughout Ebola treatment center care. Four iterative machine learning models were created for prognosis of mortality. The base model used age and admission Ct as predictors. Ct and biomarkers from treatment days 1 and 2, days 3 and 4, and days 5 and 6 associated with mortality were iteratively added to the model to yield mortality risk estimates. Receiver operating characteristic curves for each iteration provided period-specific areas under curve with 95% CIs.

Results

Of 310 cases positive for Ebola virus disease, mortality occurred in 46.5%. Biomarkers predictive of mortality were elevated creatinine kinase, aspartate aminotransferase, blood urea nitrogen (BUN), alanine aminotransferase, and potassium; low albumin during days 1 and 2; elevated C-reactive protein, BUN, and potassium during days 3 and 4; and elevated C-reactive protein and BUN during days 5 and 6. The area under curve substantially improved with each iteration: base model, 0.74 (95% CI, .69-.80); days 1 and 2, 0.84 (95% CI, .73-.94); days 3 and 4, 0.94 (95% CI, .88-1.0); and days 5 and 6, 0.96 (95% CI, .90-1.0).

Conclusions

This is the first study to utilize iterative point-of-care biomarkers to derive dynamic prognostic mortality models. This novel approach demonstrates that utilizing biomarkers drastically improved prognostication up to 6 days into patient care.

Ebola virus disease: A review for the emergency medicine clinician

INTRODUCTION

Ebolavirus, the causative agent of Ebola virus disease (EVD) has been responsible for sporadic outbreaks mainly in sub-Saharan Africa since 1976. EVD is associated with high risk of transmission, especially to healthcare workers during patient care.

OBJECTIVE

The purpose of this review is to provide a concise review of EVD presentation, diagnosis, and management for emergency clinicians.

DISCUSSION

EVD is spread through direct contact, including blood, bodily fluids or contact with a contaminated object. Patients may present with non-specific symptoms such as fevers, myalgias, vomiting, or diarrhea that overlap with other viral illnesses, but rash, bruising, and bleeding may also occur. Laboratory analysis may reveal transaminitis, coagulopathy, and disseminated intravascular coagulation. The average clinical course is approximately 8-10 days with an average case fatality rate of 50%. The mainstay of treatment is supportive care, with two U.S. Food and Drug Administration-approved monoclonal antibody treatments (Ebanga and Inmazeb). Survivors of the disease may have a complicated recovery, marked by long-term symptoms.

CONCLUSION

EVD is a potentially deadly condition that can present with a wide range of signs and symptoms. Emergency clinicians must be aware of the presentation, evaluation, and management to optimize the care of these patients.

Serological Evidence of Filovirus Infection in Nonhuman Primates in Zambia

Ebolaviruses and marburgviruses are filoviruses that are known to cause severe hemorrhagic fever in humans and nonhuman primates (NHPs). While some bat species are suspected to be natural reservoirs of these filoviruses, wild NHPs often act as intermediate hosts for viral transmission to humans. Using an enzyme-linked immunosorbent assay, we screened two NHP species, wild baboons and vervet monkeys captured in Zambia, for their serum IgG antibodies specific to the envelope glycoproteins of filoviruses. From 243 samples tested, 39 NHPs (16%) were found to be seropositive either for ebolaviruses or marburgviruses with endpoint antibody titers ranging from 100 to 25,600. Interestingly, antibodies reactive to Reston virus, which is found only in Asia, were detected in both NHP species. There was a significant difference in the seropositivity for the marburgvirus antigen between the two NHP species, with baboons having a higher positive rate. These results suggest that wild NHPs in Zambia might be nonlethally exposed to these filoviruses, and this emphasizes the need for continuous monitoring of filovirus infection in wild animals to better understand the ecology of filoviruses and to assess potential risks of outbreaks in humans in previously nonendemic countries.