Roots, Not Parachutes: Research Collaborations Combat Outbreaks.

Recent infectious disease epidemics illustrate how health systems failures anywhere can create disease vulnerabilities everywhere. We must therefore prioritize investments in health care infrastructure in outbreak-prone regions of the world. We describe how "rooted" research collaborations can establish capacity for pathogen surveillance and facilitate rapid outbreak responses.

A Fc engineering approach to define functional humoral correlates of immunity against Ebola virus.

Protective Ebola virus (EBOV) antibodies have neutralizing activity and induction of antibody constant domain (Fc)-mediated innate immune effector functions. Efforts to enhance Fc effector functionality often focus on maximizing antibody-dependent cellular cytotoxicity, yet distinct combinations of functions could be critical for antibody-mediated protection. As neutralizing antibodies have been cloned from EBOV disease survivors, we sought to identify survivor Fc effector profiles to help guide Fc optimization strategies. Survivors developed a range of functional antibody responses, and we therefore applied a rapid, high-throughput Fc engineering platform to define the most protective profiles. We generated a library of Fc variants with identical antigen-binding fragments (Fabs) from an EBOV neutralizing antibody. Fc variants with antibody-mediated complement deposition and moderate natural killer (NK) cell activity demonstrated complete protective activity in a stringent in vivo mouse model. Our findings highlight the importance of specific effector functions in antibody-mediated protection, and the experimental platform presents a generalizable resource for identifying correlates of immunity to guide therapeutic antibody design.

Ebola Virus-Specific Neutralizing Antibody Persists at High Levels in Survivors 2 Years After Resolution of Disease in a Sierra Leonean Cohort.

Ebola virus (EBOV) infection results in Ebola virus disease (EVD), an often severe disease with a nonspecific presentation. Since its recognition, periodic outbreaks of EVD continue to occur in sub-Saharan Africa. The 2013-2016 West African EVD outbreak was the largest recorded, resulting in a substantial cohort of EVD survivors with persistent health complaints and variable immune responses. In this study, we characterize humoral immune responses in EVD survivors and their contacts in Eastern Sierra Leone. We found high levels of EBOV IgG in EVD survivors and lower yet substantial antibody levels in household contacts, suggesting subclinical transmission. Neutralizing antibody function was prevalent but variable in EVD survivors, raising questions about the durability of immune responses from natural infection with EBOV. Additionally, we found that certain discrete symptoms-ophthalmologic and auditory-are associated with EBOV IgG seropositivity, while an array of symptoms are associated with the presence of neutralizing antibody.

Lassa Fever Natural History and Clinical Management.

Lassa fever is caused by Lassa virus (LASV), an Old World Mammarenavirus that is carried by Mastomys natalensis and other rodents. It is endemic in Sierra Leone, Nigeria, and other countries in West Africa. The clinical presentation of LASV infection is heterogenous varying from an inapparent or mild illness to a fatal hemorrhagic fever. Exposure to LASV is usually through contact with rodent excreta. After an incubation period of 1-3 weeks, initial symptoms such as fever, headache, and fatigue develop that may progress to sore throat, retrosternal chest pain, conjunctival injection, vomiting, diarrhea, and abdominal pain. Severe illness, including hypotension, shock, and multiorgan failure, develops in a minority of patients. Patient demographics and case fatality rates are distinctly different in Sierra Leone and Nigeria. Laboratory diagnosis relies on the detection of LASV antigens or genomic RNA. LASV-specific immunoglobulin G and M assays can also contribute to clinical management. The mainstay of treatment for Lassa fever is supportive care. The nucleoside analog ribavirin is commonly used to treat acute Lassa fever but is considered useful only if treatment is begun early in the disease course. Drugs in development, including a monoclonal antibody cocktail, have the potential to impact the management of Lassa fever.

Ebola Virus Disease Sensitization: Community-Driven Efforts in Sierra Leone.

The 2014-2016 West Africa Ebola outbreak was the largest in history, resulting in approximately 11,000 deaths. Despite the outbreak's eventual end, national and international health sensitization and containment efforts were subject to criticism. This study investigates disease-related knowledge and beliefs, as well as trusted sources of health information among EVD-survivors and their family members, highlighting the importance of community-informed public health responses. Participants (n = 134) were adults who were either EVD-infected, affected families/caregivers, or community leaders. In-depth interviews and focus groups explored EVD-related experiences, including health effects, stigma, and community relationships. Using a grounded theory and thematic content analysis approach, transcripts were coded for evidence of health sensitization, as well as compliance with mitigation measures and trusted sources of information. Participants displayed a high level of knowledge around EVD and reported compliance with mandated and personal prevention measures. Levels of health sensitization and subsequent reintegration of survivors were reported to be largely the products of community-based efforts, rather than the top-down, national public health response. Primary sources of trusted information included EVD survivors acting as peer educators; local leaders; and EVD sensitization by community health workers. This study highlights the importance of a community-based response for increasing the effectiveness of public health campaigns. Participants expressed that relying on the experiences of trusted cultural insiders led to a deeper understanding of Ebola compared to top-down public health campaigns, and helped infected and affected community members reintegrate. Future public health efforts should incorporate community-based participatory approaches to address infectious disease outbreaks.

Post-Ebola Symptoms 7 Years After Infection: The Natural History of Long Ebola.

BACKGROUND: Lingering symptoms have been reported by survivors of Ebola virus disease (EVD). There are few data describing the persistence and severity of these symptoms over time. METHODS: Symptoms of headache, fatigue, joint pain, muscle pain, hearing loss, visual loss, numbness of hands or feet were longitudinally assessed among participants in the Liberian Ebola Survivors Cohort study. Generalized linear mixed effects models, adjusted for sex and age, were used to calculate the odds of reporting a symptom and it being rated as highly interfering with life. RESULTS: From June 2015 to June 2016, 326 survivors were enrolled a median of 389 days (range 51-614) from acute EVD. At baseline 75.2% reported at least 1 symptom; 85.8% were highly interfering with life. Over a median follow-up of 5.9 years, reporting of any symptom declined (odds ratio for each 90 days of follow-up = 0.96, 95% confidence interval [CI]: .95, .97; P < .0001) with all symptoms declining except for numbness of hands or feet. Rating of any symptom as highly interfering decreased over time. Among 311 with 5 years of follow-up, 52% (n = 161) reported a symptom and 29% (n = 47) of these as highly interfering with their lives. CONCLUSIONS: Major post-EVD symptoms are common early during convalescence and decline over time along with severity. However, even 5 years after acute infection, a majority continue to have symptoms and, for many, these continue to greatly impact their lives. These findings call for investigations to identify the mechanisms of post-EVD sequelae and therapeutic interventions to benefit the thousands of effected EVD survivors.

COVID-19 Symptoms by Variant Period in the North Carolina COVID-19 Community Research Partnership, North Carolina, USA.

In North Carolina, USA, the SARS-CoV-2 Omicron variant was associated with changing symptomology in daily surveys, including increasing rates of self-reported cough and sore throat and decreased rates of loss of taste and smell. Compared with the pre-Delta period, Delta and Omicron (pre-BA.4/BA.5) variant periods were associated with shorter symptom duration.

Antibiotic prescribing practices for acute respiratory illness in children less than 24 months of age in Kenema, Sierra Leone: is it time to move beyond algorithm driven decision making?

BACKGROUND: Lower respiratory tract infections are the leading cause of mortality in young children globally. In many resource-limited settings clinicians rely on guidelines such as IMCI or ETAT + that promote empiric antibiotic utilization for management of acute respiratory illness (ARI). Numerous evaluations of both guidelines have shown an overall positive response however, several challenges have also been reported, including the potential for over-prescribing of unnecessary antibiotics. The aims of this study were to describe the antibiotic prescribing practices for children less than 24 months of age with symptoms of ARI, that were admitted to Kenema Government Hospital (KGH) in the Eastern Province of Sierra Leone, and to identify the number of children empirically prescribed antibiotics who were admitted to hospital with ARI, as well as their clinical signs, symptoms, and outcomes. METHODS: We conducted a prospective study of children < 24 months of age admitted to the KGH pediatric ward with respiratory symptoms between October 1, 2020 and May 31, 2022. Study nurses collected data on demographic information, medical and medication history, and information on clinical course while hospitalized. RESULTS: A total of 777 children were enrolled. Prior to arrival at the hospital, 224 children (28.8%) reported taking an antibiotic for this illness without improvement. Only 15 (1.9%) children received a chest radiograph to aid in diagnosis and 100% of patients were placed on antibiotics during their hospital stay. CONCLUSIONS: Despite the lives saved, reliance on clinical decision-support tools such as IMCI and ETAT + for pediatric ARI, is resulting in the likely over-prescribing of antibiotics. Greater uptake of implementation research is needed to develop strategies and tools designed to optimize antibiotic use for ARI in LMIC settings. Additionally, much greater priority needs to be given to ensuring clinicians have the basic tools for clinical diagnosis, as well as greater investments in essential laboratory and radiographic diagnostics that help LMIC clinicians move beyond the sole reliance on algorithm based clinical decision making.

Virus genomes reveal factors that spread and sustained the Ebola epidemic.

The 2013-2016 West African epidemic caused by the Ebola virus was of unprecedented magnitude, duration and impact. Here we reconstruct the dispersal, proliferation and decline of Ebola virus throughout the region by analysing 1,610 Ebola virus genomes, which represent over 5% of the known cases. We test the association of geography, climate and demography with viral movement among administrative regions, inferring a classic 'gravity' model, with intense dispersal between larger and closer populations. Despite attenuation of international dispersal after border closures, cross-border transmission had already sown the seeds for an international epidemic, rendering these measures ineffective at curbing the epidemic. We address why the epidemic did not spread into neighbouring countries, showing that these countries were susceptible to substantial outbreaks but at lower risk of introductions. Finally, we reveal that this large epidemic was a heterogeneous and spatially dissociated collection of transmission clusters of varying size, duration and connectivity. These insights will help to inform interventions in future epidemics.

High crossreactivity of human T cell responses between Lassa virus lineages.

Lassa virus infects hundreds of thousands of people each year across rural West Africa, resulting in a high number of cases of Lassa fever (LF), a febrile disease associated with high morbidity and significant mortality. The lack of approved treatments or interventions underscores the need for an effective vaccine. At least four viral lineages circulate in defined regions throughout West Africa with substantial interlineage nucleotide and amino acid diversity. An effective vaccine should be designed to elicit Lassa virus specific humoral and cell mediated immunity across all lineages. Most current vaccine candidates use only lineage IV antigens encoded by Lassa viruses circulating around Sierra Leone, Liberia, and Guinea but not Nigeria where lineages I-III are found. As previous infection is known to protect against disease from subsequent exposure, we sought to determine whether LF survivors from Nigeria and Sierra Leone harbor memory T cells that respond to lineage IV antigens. Our results indicate a high degree of cross-reactivity of CD8+ T cells from Nigerian LF survivors to lineage IV antigens. In addition, we identified regions within the Lassa virus glycoprotein complex and nucleoprotein that contributed to these responses while T cell epitopes were not widely conserved across our study group. These data are important for current efforts to design effective and efficient vaccine candidates that can elicit protective immunity across all Lassa virus lineages.

The prevalence of Post-Ebola Syndrome hearing loss, Sierra Leone.

BACKGROUND: Globally, hearing loss is the second leading cause of disability, affecting approximately 18.7% of the world's population. However, the burden of hearing loss is unequally distributed, with the majority of affected individuals located in Asia or Sub-Saharan Africa. Following the 2014 West African Ebola Outbreak, disease survivors began to describe hearing loss as part of the constellation of symptoms known as Post-Ebola Syndrome. The goal of this study was to more fully characterize hearing loss among Ebola Virus Disease (EVD) survivors. METHODOLOGY AND PRINCIPAL FINDINGS: EVD survivors and their household contacts were recruited (n = 1,12) from Eastern Sierra Leone. Each individual completed a symptom questionnaire, physical exam, and a two-step audiometry process measuring both air and bone conduction thresholds. In comparison to contacts, EVD survivors were more likely to have complaints or abnormal findings affecting every organ system. A significantly greater percentage of EVD survivors were found to have hearing loss in comparison to contacts (23% vs. 9%, p < 0.001). Additionally, survivors were more likely to have bilateral hearing loss of a mixed etiology. Logistic regression revealed that the presence of any symptoms of middle or inner ear (p < 0.001), eye (p = 0.005), psychiatric (p = 0.019), and nervous system (p = 0.037) increased the odds of developing hearing loss. CONCLUSIONS AND SIGNIFICANCE: This study is the first to use an objective and standardized measurement to report hearing loss among EVD survivors in a clinically meaningful manner. In this study it was found that greater than 1/5th of EVD survivors develop hearing loss. The association between hearing impairment and symptoms affecting the eye and nervous system may indicate a similar mechanism of pathogenesis, which should be investigated further. Due to the quality of life and socioeconomic detriments associated with untreated hearing loss, a greater emphasis must be placed on understanding and mitigating hearing loss following survival to aid in economic recovery following infectious disease epidemics.

Post-Ebola Syndrome Presents With Multiple Overlapping Symptom Clusters: Evidence From an Ongoing Cohort Study in Eastern Sierra Leone.

BACKGROUND: Following the 2013-2016 West African Ebola outbreak, distinct, persistent health complaints were recognized in Ebola virus disease (EVD) survivors. Here we provide an in-depth characterization of post-Ebola syndrome >2.5 years after resolution of disease. Additionally, we report subphenotypes of post-Ebola syndrome with overlapping symptom clusters in survivors from Eastern Sierra Leone. METHODS: Participants in Eastern Sierra Leone were identified by the Sierra Leone Association of Ebola survivors. Survivors and their contacts were administered a questionnaire assessing self-reported symptoms and a physical examination. Comparisons between survivors and contacts were conducted using conditional logistic regression. Symptom groupings were identified using hierarchical clustering approaches. Simplified presentation of incredibly complex evaluations (SPICE), correlation analysis, logistic regression, and principal component analysis (PCA) were performed to explore the relationships between symptom clusters. RESULTS: Three hundred seventy-five EVD survivors and 1040 contacts were enrolled into the study. At enrollment, EVD survivors reported significantly more symptoms than their contacts in all categories (P < .001). Symptom clusters representing distinct organ systems were identified. Correlation and logistic regression analysis identified relationships between symptom clusters, including stronger relationships between clusters including musculoskeletal symptoms (r = 0.63, P < .001; and P < .001 for correlation and logistic regression, respectively). SPICE and PCA further highlighted subphenotypes with or without musculoskeletal symptoms. CONCLUSIONS: This study presents an in-depth characterization of post-Ebola syndrome in Sierra Leonean survivors >2.5 years after disease. The interrelationship between symptom clusters indicates that post-Ebola syndrome is a heterogeneous disease. The distinct musculoskeletal and non-musculoskeletal phenotypes identified likely require targeted therapies to optimize long-term treatment for EVD survivors.

Identification of Common CD8+ T Cell Epitopes from Lassa Fever Survivors in Nigeria and Sierra Leone.

Early and robust T cell responses have been associated with survival from Lassa fever (LF), but the Lassa virus-specific memory responses have not been well characterized. Regions within the virus surface glycoprotein (GPC) and nucleoprotein (NP) are the main targets of the Lassa virus-specific T cell responses, but, to date, only a few T cell epitopes within these proteins have been identified. We identified GPC and NP regions containing T cell epitopes and HLA haplotypes from LF survivors and used predictive HLA-binding algorithms to identify putative epitopes, which were then experimentally tested using autologous survivor samples. We identified 12 CD8-positive (CD8+) T cell epitopes, including epitopes common to both Nigerian and Sierra Leonean survivors. These data should be useful for the identification of dominant Lassa virus-specific T cell responses in Lassa fever survivors and vaccinated individuals as well as for designing vaccines that elicit cell-mediated immunity.IMPORTANCE The high morbidity and mortality associated with clinical cases of Lassa fever, together with the lack of licensed vaccines and limited and partially effective interventions, make Lassa virus (LASV) an important health concern in its regions of endemicity in West Africa. Previous infection with LASV protects from disease after subsequent exposure, providing a framework for designing vaccines to elicit similar protective immunity. Multiple major lineages of LASV circulate in West Africa, and therefore, ideal vaccine candidates should elicit immunity to all lineages. We therefore sought to identify common T cell epitopes between Lassa fever survivors from Sierra Leone and Nigeria, where distinct lineages circulate. We identified three such epitopes derived from highly conserved regions within LASV proteins. In this process, we also identified nine other T cell epitopes. These data should help in the design of an effective pan-LASV vaccine.

New-onset atrial arrhythmias associated with mortality in black and white patients hospitalized with COVID-19.

BACKGROUND: Specific details about cardiovascular complications, especially arrhythmias, related to the coronavirus disease of 2019 (COVID-19) are not well described. OBJECTIVE: We sought to evaluate the incidence and predictive factors of cardiovascular complications and new-onset arrhythmias in Black and White hospitalized COVID-19 patients and determine the impact of new-onset arrhythmia on outcomes. METHODS: We collected and analyzed baseline demographic and clinical data from COVID-19 patients hospitalized at the Tulane Medical Center in New Orleans, Louisiana, between March 1 and May 1, 2020. RESULTS: Among 310 hospitalized COVID-19 patients, the mean age was 61.4 ± 16.5 years, with 58,7% females, and 67% Black patients. Black patients were more likely to be younger, have diabetes and obesity. The incidence of cardiac complications was 20%, with 9% of patients having new-onset arrhythmia. There was no significant difference in cardiovascular outcomes between Black and White patients. A multivariate analysis determined age ≥60 years to be a predictor of new-onset arrhythmia (OR = 7.36, 95% CI [1.95;27.76], p = .003). D-dimer levels positively correlated with cardiac and new-onset arrhythmic event. New onset atrial arrhythmias predicted in-hospital mortality (OR = 2.99 95% CI [1.35;6.63], p = .007), a longer intensive care unit length of stay (mean of 6.14 days, 95% CI [2.51;9.77], p = .001) and mechanical ventilation duration(mean of 9.08 days, 95% CI [3.75;14.40], p = .001). CONCLUSION: Our results indicate that new onset atrial arrhythmias are commonly encountered in COVID-19 patients and can predict in-hospital mortality. Early elevation in D-dimer in COVID-19 patients is a significant predictor of new onset arrhythmias. Our finding suggest continuous rhythm monitoring should be adopted in this patient population during hospitalization to better risk stratify hospitalized patients and prompt earlier intervention.

Analysis of CD8+ T cell response during the 2013-2016 Ebola epidemic in West Africa.

The recent Ebola epidemic exemplified the importance of understanding and controlling emerging infections. Despite the importance of T cells in clearing virus during acute infection, little is known about Ebola-specific CD8+ T cell responses. We investigated immune responses of individuals infected with Ebola virus (EBOV) during the 2013-2016 West Africa epidemic in Sierra Leone, where the majority of the >28,000 EBOV disease (EVD) cases occurred. We examined T cell memory responses to seven of the eight Ebola proteins (GP, sGP, NP, VP24, VP30, VP35, and VP40) and associated HLA expression in survivors. Of the 30 subjects included in our analysis, CD8+ T cells from 26 survivors responded to at least one EBOV antigen. A minority, 10 of 26 responders (38%), made CD8+ T cell responses to the viral GP or sGP. In contrast, 25 of the 26 responders (96%) made response to viral NP, 77% to VP24 (20 of 26), 69% to VP40 (18 of 26), 42% (11 of 26) to VP35, with no response to VP30. Individuals making CD8+ T cells to EBOV VP24, VP35, and VP40 also made CD8+ T cells to NP, but rarely to GP. We identified 34 CD8+ T cell epitopes for Ebola. Our data indicate the immunodominance of the EBOV NP-specific T cell response and suggest that its inclusion in a vaccine along with the EBOV GP would best mimic survivor responses and help boost cell-mediated immunity during vaccination.

Survivors of Ebola Virus Disease Develop Polyfunctional Antibody Responses.

Monoclonal antibodies can mediate protection against Ebola virus (EBOV) infection through direct neutralization as well as through the recruitment of innate immune effector functions. However, the antibody functional response following survival of acute EBOV disease has not been well characterized. In this study, serum antibodies from Ebola virus disease (EVD) survivors from Sierra Leone were profiled to capture variation in overall subclass/isotype abundance, neutralizing activity, and innate immune effector functions. Antibodies from EVD survivors exhibited robust innate immune effector functions, mediated primarily by IgG1 and IgA1. In conclusion, development of functional antibodies follows survival of acute EVD.

Ebola-Specific CD8+ and CD4+ T-Cell Responses in Sierra Leonean Ebola Virus Survivors With or Without Post-Ebola Sequelae.

BACKGROUND: Ebola virus (EBOV) disease has killed thousands of West and Central Africans over the past several decades. Many who survive the acute disease later experience post-Ebola syndrome, a constellation of symptoms whose causative pathogenesis is unclear. METHODS: We investigated EBOV-specific CD8+ and CD4+ T-cell responses in 37 Sierra Leonean EBOV disease survivors with (n = 19) or without (n = 18) sequelae of arthralgia and ocular symptoms. Peripheral blood mononuclear cells were infected with recombinant vesicular stomatitis virus encoding EBOV antigens. We also studied the presence of EBOV-specific immunoglobulin G, antinuclear antibodies, anti-cyclic citrullinated peptide antibodies, rheumatoid factor, complement levels, and cytokine levels in these 2 groups. RESULTS: Survivors with sequelae had a significantly higher EBOV-specific CD8+ and CD4+ T-cell response. No differences in EBOV-specific immunoglobulin G, antinuclear antibody, or anti-cyclic citrullinated peptide antibody levels were found. Survivors with sequelae showed significantly higher rheumatoid factor levels. CONCLUSION: EBOV-specific CD8+ and CD4+ T-cell responses were significantly higher in Ebola survivors with post-Ebola syndrome. These findings suggest that pathogenesis may occur as an immune-mediated disease via virus-specific T-cell immune response or that persistent antigen exposure leads to increased and sustained T-cell responses.

Long-term Complications of Ebola Virus Disease: Prevalence and Predictors of Major Symptoms and the Role of Inflammation.

BACKGROUND: Cohort studies have reported a high prevalence of musculoskeletal, neurologic, auditory, and visual complications among Ebola virus disease (EVD) survivors. However, little is known about the host- and disease-related predictors of these symptoms and their etiological mechanisms. METHODS: The presence and patterns of 8 cardinal symptoms that are most commonly reported following EVD survival were assessed in the 326 EVD survivors who participated in the ongoing longitudinal Liberian EVD Survivor Study. At quarterly study visits, symptoms that developed since acute EVD were recorded and blood was collected for biomarkers of inflammation and immune activation. RESULTS: At baseline (mean 408 days from acute EVD), 75.5% of survivors reported at least 1 new cardinal symptom since surviving EVD, which in 85.8% was rated as highly interfering with life. Two or more incident symptoms were reported by 61.0% of survivors, with pairings of joint pain, headache, or fatigue the most frequent. Women were significantly more likely than men to report headache, while older age was significantly associated with musculoskeletal and visual symptoms. In analyses adjusted for multiple comparisons, no statistically significant association was found between any symptom and 26 markers of inflammation and immune activation. Symptom frequency remained largely unchanged during study follow-up. CONCLUSIONS: Post-EVD complications occur in a majority of survivors and remain present more than 4 years after acute infection. An association between markers of inflammation and immune activation and individual symptoms was not found, suggesting an alternative etiology for persistent post-EVD symptomatology.

Endotheliopathy and Platelet Dysfunction as Hallmarks of Fatal Lassa Fever.

Lassa fever (LF) causes multisystem disease and has a fatality rate <70%. Severe cases exhibit abnormal coagulation, endothelial barrier disruption, and dysfunctional platelet aggregation but the underlying mechanisms remain poorly understood. In Sierra Leone during 2015-2018, we assessed LF patients' day-of-admission plasma samples for levels of proteins necessary for coagulation, fibrinolysis, and platelet function. P-selectin, soluble endothelial protein C receptor, soluble thrombomodulin, plasminogen activator inhibitor 1, ADAMTS-13, von Willebrand factor, tissue factor, soluble intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 were more elevated in LF patients than in controls. Endothelial protein C receptor, thrombomodulin, intercellular adhesion molecule 1, plasminogen activator inhibitor 1, D-dimer, and hepatocyte growth factor were higher in fatal than nonfatal LF cases. Platelet disaggregation occurred only in samples from fatal LF cases. The impaired homeostasis and platelet dysfunction implicate alterations in the protein C pathway, which might contribute to the loss of endothelial barrier function in fatal infections.

Elevated L-threonine is a biomarker for Lassa fever and Ebola.

BACKGROUND: Lassa fever and Ebola are characterized by non-specific initial presentations that can progress to severe multisystem illnesses with high fatality rates. Samples from additional subjects are examined to extend and corroborate biomarkers with prognostic value for these diseases. METHODS: Liquid Chromatography Mass Spectrometry metabolomics was used to identify and confirm metabolites disrupted in the blood of Lassa fever and Ebola patients. Authenticated standards are used to confirm the identify of key metabolites. RESULTS: We confirm prior results by other investigators that the amino acid L-threonine is elevated during Ebola virus infection. L-Threonine is also elevated during Lassa virus infection. We also confirmed that platelet-activating factor (PAF) and molecules with PAF moiety are reduced in the blood of patients with fatal Lassa fever. Similar changes in PAF and PAF-like molecules were not observed in the blood of Ebola patients. CONCLUSIONS: Metabolomics may provide tools to identify pathways that are differentially affected during viral hemorrhagic fevers and guide development of diagnostics to monitor and predict outcome.