725. Complete Blood Count Values Vary in Degree of Change with Day of Fever in Children with Dengue Fever

Abstract Background Dengue fever (DF) is an acute viral disease which can lead to severe illness, including dengue hemorrhagic fever, marked by thrombocytopenia and hemolytic anemia, as well as end-organ damage. Despite the well-known presentation and prevalence, changes in hematologic markers across the DF course have not been well-described in children. We sought to investigate the association of clinical laboratory values over time with dengue disease progression and outcome in a pediatric population in the Dominican Republic. Methods Pediatric participants were enrolled at Hospital Infantil Dr. Robert Reid Cabral in Santo Domingo, Dominican Republic, in a prospective, observational case-based study. Laboratory values, including complete blood count (CBC) indices and dengue titer results, were collected over the course of hospital stay. Using linear mixed models, we assessed whether 13 different CBC values and time trajectories differed by dengue status, including age and sex as covariates. To account for multiple testing, p≤0.0033 was considered significant. Results A total of 575 children ages 0 to 211 months met inclusion criteria; 51.8% (n=298) were male, and the median (IQR) age was 59 (14-93) months. Eighty-two percent (n=472) of participants had DF. CBC values across days 1 to 10 of fever in those with and without DF are depicted in Figure 1. Those with DF showed levels dropping more quickly across days of fever for hematocrit and hemoglobin (p≤ 0.002), with a more rapid decline in those with severe DF (p < 0.0001). Those with DF had levels increasing more quickly for mean corpuscular hemoglobin concentration (MCHC), monocyte number, and white blood cell counts (p ≤ 0.003), with those with severe DF having a more rapid increase (p < 0.001). The direction of the change across time differed by DF status for mean corpuscular volume and red blood cell distribution width (RDW) (p ≤ 0.0003), with those with severe DF showing an increase in RDW across day of fever (p= 0.0004). Figure 1. CBC values across day of fever in dengue (blue) and non-dengue (purple) patients. The graph above depicts the following CBC values across day of fever in dengue (blue) and non-dengue (purple) patients: a) white blood cell (WBC) count, b) platelet count, c) monocyte number, d) hemoglobin, e) mean corpuscular hemoglobin concentration (MCHC), and f) mean corpuscular volume (MCV). Values with an asterisk (*) represent significant values (p < 0.0033). Conclusion The trajectory of CBC measures differs between those with and without DF, despite similar clinical presentations. These laboratory differences may facilitate a better understanding of the clinical course of DF and may aid in earlier identification of DF in resource-limited settings. Disclosures Elizabeth P. Schlaudecker, MD, MPH, Pfizer (Grant/Research Support)Sanofi Pasteur (Advisor or Review Panel member)

Background. Dengue fever (DF) is an acute viral disease which can lead to severe illness, including dengue hemorrhagic fever, marked by thrombocytopenia and hemolytic anemia, as well as end-organ damage. Despite the well-known presentation and prevalence, changes in hematologic markers across the DF course have not been well-described in children. We sought to investigate the association of clinical laboratory values over time with dengue disease progression and outcome in a pediatric population in the Dominican Republic.
Methods. Pediatric participants were enrolled at Hospital Infantil Dr. Robert Reid Cabral in Santo Domingo, Dominican Republic, in a prospective, observational case-based study. Laboratory values, including complete blood count (CBC) indices and dengue titer results, were collected over the course of hospital stay. Using linear mixed models, we assessed whether 13 different CBC values and time trajectories differed by dengue status, including age and sex as covariates. To account for multiple testing, p≤0.0033 was considered significant.
Results. A total of 575 children ages 0 to 211 months met inclusion criteria; 51.8% (n=298) were male, and the median (IQR) age was 59 (14-93) months. Eighty-two percent (n=472) of participants had DF. CBC values across days 1 to 10 of fever in those with and without DF are depicted in Figure 1. Those with DF showed levels dropping more quickly across days of fever for hematocrit and hemoglobin (p≤ 0.002), with a more rapid decline in those with severe DF (p < 0.0001). Those with DF had levels increasing more quickly for mean corpuscular hemoglobin concentration (MCHC), monocyte number, and white blood cell counts (p ≤ 0.003), with those with severe DF having a more rapid increase (p < 0.001). The direction of the change across time differed by DF status for mean corpuscular volume and red blood cell distribution width (RDW) (p ≤ 0.0003), with those with severe DF showing an increase in RDW across day of fever (p= 0.0004). Methods. AD personnel traveling for ≤ 6.5 months were prospectively enrolled between 2010-2019. Participants completed a post-travel survey regarding risk behaviors, illnesses and impact on daily activities. Trip purpose was categorized into DEP, EXR, TDY and syndromic definitions were used to identify cases of TD, ILI and FI based on symptoms. A multivariate logistic regression model with backward selection was used to determine the odds ratio associated with partial or complete incapacitation due to infections (a composite endpoint of either TD, ILI or FI).
Results. 1822 servicemembers were enrolled: 36.2% traveled on DEP, 36.2% for EXR and 27.7% for TDY (Table 1). 83.5% of personnel traveling for DEP were Special Operations and Marine units, and 82% of the EXR group participated in Pacific Pathways. Overall, 19% of US personnel experienced infections associated with partial or complete incapacitation (median duration of incapacitation-TD: 1 day; ILI: 4 days; FI: 3 days). DEP personnel had a longer travel duration and the highest rate of partial or complete incapacitation due to TD, ILI or FI (Figure 1 and 2). Risk factors associated with partial or complete incapacitation due to infections were non-adherence with malaria chemoprophylaxis (  Proportion of AD servicemembers that experienced TD, ILI or undifferentiated febrile illness during DEP, EXR, TDY (p<0.05 for the comparison of each illness between DEP, EXR and TDY). Figure 2.
Proportion of AD personnel with partial or complete incapacitation due to TD, ILI or FI during DEP, EXR or TDY (p < 0.05 for the comparison of each illness between DEP, EXR and TDY).
Conclusion. Infectious disease syndromes are common during overseas military travel. TD had the highest negative impact on military travel especially among DEP personnel. We identified several modifiable risk factors associated with incapacitating infections which can be used to inform preventive and treatment strategies.
Disclosures. All Authors: No reported disclosures