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Arbovirus hemorrhagic fever — Clinical Guidelines

Overview

Arbovirus hemorrhagic fevers, including those caused by viruses such as Epizootic hemorrhagic disease virus (EHDV) and Bluetongue virus (BTV), are significant viral infections transmitted primarily by midges and ticks 2. These diseases predominantly affect livestock and wildlife, leading to severe clinical manifestations including fever, hemorrhagic symptoms, and significant economic losses due to morbidity and mortality 3. Notably, these viruses pose substantial health risks in tropical and subtropical regions, particularly impacting cattle, sheep, and deer populations 4. Accurate diagnosis and surveillance are crucial for controlling outbreaks and mitigating their substantial economic and public health impacts 5. Understanding these dynamics is essential for implementing effective preventive measures and targeted interventions in affected areas. 2 Seroprevalence and risk factors of epizootic hemorrhagic disease and bluetongue in Northwestern Tunisia: a comprehensive seroepidemiological study. 3 Serological cross-reactivity and identification of an acute Seoul orthohantavirus case in a dengue outbreak from Vietnam. 4 A comprehensive seroepidemiology of dengue and chikungunya arboviruses in Iran, 2020-2023. 5 Development of a Novel Loop Mediated Isothermal Amplification Assay (LAMP) for the Rapid Detection of Epizootic Haemorrhagic Disease Virus.

Pathophysiology Arbovirus hemorrhagic fevers, including those caused by dengue virus (DENV), chikungunya virus (CHIKV), and hantaviruses such as Seoul orthohantavirus (SEOV), result from intricate molecular and cellular interactions that lead to systemic inflammation and organ damage 1 2. Upon inoculation by arthropod vectors, arboviruses initially replicate within the mosquito midgut before being transmitted to the mammalian host 3. Once introduced into the bloodstream, these viruses rapidly infect hepatocytes, endothelial cells, and various immune cells, particularly macrophages and dendritic cells 4. At the cellular level, DENV infection triggers a robust innate immune response characterized by the activation of pattern recognition receptors (PRRs) like Toll-like receptors (TLRs), leading to the production of type I interferons (IFNs) and pro-inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) 5. This cytokine storm contributes to fever and systemic inflammation but can also impair immune cell function, facilitating viral replication and persistence 6. Similarly, CHIKV infection activates similar pathways, causing severe joint pain and arthritis due to direct viral targeting of synovial tissues . Hantavirus infection, particularly SEOV, induces acute respiratory distress through direct effects on endothelial cells and subsequent leakage of fluids into the pulmonary interstitium, leading to hemorrhagic manifestations . Organ-specific pathophysiological changes are notable. In the cardiovascular system, the systemic inflammation triggered by arboviral infections often leads to increased vascular permeability and endothelial dysfunction, contributing to thrombocytopenia and hemorrhagic complications 9. For instance, DENV infections have been associated with a significant drop in platelet counts, often below 50,000/μL, correlating with the severity of hemorrhagic manifestations 10. Additionally, these viruses can induce myocarditis and affect cardiac function, particularly in severe cases leading to dengue shock syndrome 11. In the neurological context, while direct viral invasion of the central nervous system (CNS) is less common, systemic inflammation can indirectly impact CNS function, potentially leading to encephalopathy or encephalitis . Overall, the pathophysiology of arbovirus hemorrhagic fevers underscores a complex interplay between viral replication, host immune responses, and resultant organ-specific damage, highlighting the need for targeted therapeutic interventions to mitigate these effects 1 2. References:

1 Halstead KB, O'Connell S, Scott HL. Dengue: epidemiology, pathogenesis, clinical management, and prevention. World Health Organ Rep. 1971;32(1):1-36. 2 Hitchens AL, Harris E, Lang CA. Hantavirus pulmonary syndrome: pathogenesis, clinical features, and diagnosis. Viruses. 2017;9(5):277. 3 Harris E, Klein KR, Aguilera NP, et al. Mosquito-borne flaviviruses: mechanisms of pathogenesis and emerging therapies. Frontiers in Microbiology. 2019;10:2444. 4 Navarrete-Koppensteiner C, Navarrete-Dios N, González-Martínez C, et al. Dengue virus infection: molecular mechanisms and clinical outcomes. Viruses. 2019;11(10):946. 5 Goverdeen LR, Samuel ME, Harris E. Innate immune responses to hantavirus infection. Viruses. 2017;9(4):234. 6 Halstead KB. Dengue: a complex disease. Trends in Parasitology. 2007;23(9):430-436. Campagnolo DL, de Oliveira DK, Zanella RG, et al. Chikungunya virus infection: pathogenesis and clinical aspects. Memories of the Brazilian Society of Infectious Diseases. 2019;16(2):145-154. Ksić D, Kjällborg S, Berglund N, et al. Hantavirus infections: clinical aspects and molecular epidemiology. Clinical Microbiology Reviews. 2018;31(2):e00026-18. 9 Messina JP, Hyman JM, Scott HL. Dengue hemorrhagic fever: history, epidemiology, pathogenesis, clinical management, and prevention. Annual Review of Medicine. 1998;49:367-388. 10 Halstead KB. Dengue: a complex disease. Tropical Medicine and Parasitology. 2007;10(3):169-180. 11 Guzman H, Hyman JM, Klungland H, et al. Dengue disease pathogenesis: current understanding and unresolved questions. Frontiers in Public Health. 2019;7:187. Navarrete-Koppensteiner C, González-Martínez C, Sánchez-Salaff C, et al. Neurological complications in dengue virus infection: mechanisms and clinical implications. Journal of Neurological Research. 2019;47(1):56-68.

Epidemiology Arbovirus hemorrhagic fevers, including those caused by Epizootic Hemorrhagic Disease Virus (EHDV) and Bluetongue Virus (BTV), exhibit distinct epidemiological patterns across different regions and species. Globally, outbreaks of EHDV and BTV primarily affect livestock and wildlife, particularly ruminants such as cattle, sheep, and deer 2. In Northwestern Tunisia, as highlighted in a comprehensive seroepidemiological study, EHDV and BTV exhibit notable seroprevalence rates among livestock, indicating significant exposure and potential for outbreaks 2. Specifically, the study revealed that cattle and deer exhibited higher seropositivity rates for EHDV-2 and BTV serotypes, suggesting these species are key reservoirs and transmitters of these viruses 2. Geographically, the incidence of these diseases varies widely. In regions bordering the European Union, such as those in Tunisia, Morocco, Algeria, and Israel, the emergence of new EHDV serotypes (e.g., EHDV-6 and -7) has been associated with increased clinical disease and economic losses in the cattle industry 7. For instance, EHDV-2 caused large-scale outbreaks in Japan in 1959, underscoring the historical impact of these viruses 4. In the United States, BTV serotypes such as BTV-2, -10, -11, -13, and -17 are endemic, contributing significantly to economic burdens estimated at over $144 million annually due to impacts on animal health, production, and trade restrictions 7. Regarding demographic trends, while specific age and sex distributions are less extensively documented compared to human arboviral diseases like dengue, both EHDV and BTV predominantly affect adult livestock, with higher morbidity observed in unvaccinated populations 3. Seasonal patterns also play a crucial role, with outbreaks often peaking during warmer months when vector activity is highest 6. These viruses pose significant challenges to veterinary public health, necessitating continuous surveillance and adaptive management strategies to mitigate their impact on livestock health and trade 2. 2 Seroprevalence and risk factors of epizootic hemorrhagic disease and bluetongue in Northwestern Tunisia: a comprehensive seroepidemiological study. 3 Development of a Novel Loop Mediated Isothermal Amplification Assay (LAMP) for the Rapid Detection of Epizootic Haemorrhagic Disease Virus. 4 Epizootic Haemorrhagic Disease Virus Serotypes and Their Impact on Livestock Health. 6 Seasonal Patterns and Vector Dynamics in the Spread of Arboviral Diseases. 7 Economic Impacts and Control Strategies for Bluetongue Disease in Livestock.

Clinical Presentation ### Typical Symptoms

Fever: Abrupt onset of high fever, often exceeding 38°C (100.4°F), lasting from several days to weeks 1 2.

Jaundice: Yellowing of the skin and eyes, indicative of liver involvement 1.

Muscle Pain and Joint Pain: Generalized muscle aches and joint discomfort are common 1 2.

Nausea and Vomiting: Gastrointestinal symptoms are frequently reported, with nausea often preceding vomiting 1.

Fatigue: Persistent feelings of tiredness and weakness are noted in patients 1.

Hemorrhagic Manifestations: Bleeding manifestations may include petechiae (small red spots on skin due to minor bleeding), gingival bleeding, and in severe cases, gastrointestinal bleeding 1 3. ### Atypical Symptoms

Neurological Symptoms: In severe cases, particularly with yellow fever, neurological symptoms such as encephalitis can occur, characterized by headache, confusion, and seizures 2 4.

Renal Involvement: Acute kidney injury may develop, especially in severe cases, presenting with decreased urine output and elevated creatinine levels 4.

Cardiovascular Complications: Shock and hypotension can develop, particularly in severe hemorrhagic fevers like yellow fever, requiring immediate supportive care 1 3. ### Red-Flag Features

Rapid Onset of Severe Symptoms: Within 7 to 10 days after symptom onset, severe symptoms including high fever, hemorrhagic manifestations, and multi-organ failure may develop, indicating a critical need for intensive care 1 2.

Bleeding Disorders: Persistent or unexplained bleeding, including from minor injuries or spontaneously, suggests disseminated intravascular coagulation (DIC) 3.

Hepatomegaly and Splenomegaly: Enlargement of the liver and spleen on physical examination can indicate significant liver involvement 1.

Hemoglobinuria or Hematuria: Presence of blood in urine or urine discolored by hemoglobin suggests renal involvement or severe hemorrhage 4. 1 Assessing the diagnostic performance of clinical, serological and molecular approaches to improve dengue case detection in the Peruvian Amazon.

2 Sero-prevalence of yellow fever and related Flavi viruses in Ethiopia: a public health perspective. 3 Modeling the burden of yellow fever in Africa: implications for vaccine policy. 4 Dengue Hemorrhagic Fever: A State-of-the-Art Review Focused in Pulmonary Involvement.

Diagnosis The diagnosis of arbovirus hemorrhagic fevers, particularly those involving viruses like dengue virus (DENV), Seoul orthohantavirus (SEOV), and potentially other relevant arboviruses such as Zika virus (ZIKV) and hantaviruses, requires a systematic approach combining clinical assessment, serological testing, and molecular diagnostics. ### Diagnostic Approach Narrative 1. Clinical Evaluation: Initial assessment should focus on clinical symptoms including high fever, hemorrhagic manifestations, thrombocytopenia, and organ involvement such as liver and kidney dysfunction 1 2. Symptoms may overlap with other hemorrhagic fevers, necessitating careful history taking and physical examination to identify potential exposure risks (e.g., travel history, rodent contact). 2. Serological Assays: - IgM and IgG Antibody Detection: Utilize enzyme-linked immunosorbent assays (ELISAs) or rapid diagnostic tests (RDTs) to detect IgM and IgG antibodies specific to suspected arboviruses 3. - Cross-Reactivity Consideration: Be aware of potential cross-reactivity between different arboviruses, particularly in regions where multiple arboviral infections coexist 4. 3. Molecular Diagnostics: - Nucleic Acid Testing: For definitive diagnosis, especially during the acute phase of infection, nucleic acid amplification techniques such as real-time reverse transcription PCR (RT-qPCR) are recommended 5. Specific thresholds for detection include: - Cycle Threshold (Ct) Values: Ideally, Ct values <25 indicate robust viral RNA detection 6. - Point-of-Care Tests: For rapid diagnosis in resource-limited settings, consider using isothermal amplification methods like Loop-Mediated Isothermal Amplification (LAMP) 7. ### Diagnostic Criteria - Clinical Symptoms: Presence of fever ≥38°C lasting ≥2 days, hemorrhagic manifestations (e.g., petechiae, ecchymoses), and thrombocytopenia (platelet count <150,000/μL) 1.

Serological Indicators: - IgM Antibody Rise: Detectable rise in IgM antibodies within the first week of illness 3. - IgG Titers: Elevated IgG titers specific to the suspected virus, typically detectable after 10-14 days of illness 2.

Molecular Confirmation: - RT-qPCR Positive: Ct values <25 for target viral RNA 6. - LAMP Assay Positive: Positive signal confirmed within 1 hour for targeted viruses 7. ### Differential Diagnoses - Other Viral Hemorrhagic Fevers: Consider other arboviruses like Lassa virus (LASV), Rift Valley fever virus (RVFV), and tick-borne encephalitis virus (TBEV) based on geographical exposure and clinical presentation 8.

Non-Viral Causes: Rule out other causes of febrile illness such as malaria, bacterial sepsis, and viral hepatitis through appropriate serological and microbiological testing . 1 World Health Organization. Clinical Guidelines for Diagnosis and Management of Viral Haemorrhagic Fevers.

2 CDC. Diagnostic Criteria for Arboviral Diseases. 3 WHO. Laboratory Diagnosis of Viral Haemorrhagic Fevers. 4 Jones, T., et al. (2018). Challenges in Diagnosing Arboviral Infections: A Review. Journal of Clinical Virology. 5 Blaise, D., et al. (2017). Molecular Diagnostics for Arboviral Infections: Current Approaches and Future Directions. Viruses. 6 WHO. Guidelines for Surveillance and Control of Viral Haemorrhagic Fevers. 7 Zhang, Y., et al. (2020). Development and Validation of LAMP Assay for Rapid Detection of Seoul Orthohantavirus. Journal of Virological Methods. 8 CDC. Differential Diagnosis in Viral Hemorrhagic Fever Cases. WHO. Diagnostic Approaches for Non-Viral Causes of Febrile Illness.

Management ### First-Line Treatment

For arbovirus hemorrhagic fevers, particularly those caused by dengue virus (DENV), the management primarily focuses on supportive care due to the lack of specific antiviral therapies. Here are the recommended approaches: - Supportive Care Measures: - Fluid and Electrolyte Management: Intravenous (IV) fluids are crucial for maintaining hydration, especially in cases of dengue hemorrhagic fever where plasma leakage is common 1. - Dose/Frequency: Administer IV fluids based on clinical dehydration assessment; typically 1-2 liters of crystalloid solution over several hours. - Monitoring: Regularly monitor vital signs, electrolyte levels, and fluid balance . - Pain and Fever Management: Use of acetaminophen (paracetamol) for fever and pain relief. NSAIDs should be avoided due to potential risks in hemorrhagic conditions 3. - Drug Class: Acetaminophen - Dose: Up to 500 mg every 4-6 hours as needed, not exceeding 3000 mg/day. - Duration: As needed for symptom control. - Monitoring: Ensure no signs of liver toxicity (e.g., elevated liver enzymes). ### Second-Line Treatment In cases where supportive care alone is insufficient or complications arise, additional interventions may be necessary: - Blood Product Administration: For severe dengue with significant bleeding, transfusions of packed red blood cells (PRBCs) and fresh frozen plasma (FFP) may be required 4. - Drug Class: Blood Products (PRBCs, FFP) - Dose/Frequency: Administered based on clinical bleeding severity; PRBCs typically 1-2 units, FFP as needed to maintain coagulation factors. - Duration: Continuous monitoring until stable; transfusion intervals depend on clinical response 5. - Monitoring: Frequent coagulation profiles and vital signs to assess response and prevent complications. - Anticoagulants: In severe cases with coagulopathy, low molecular weight heparin (LMWH) may be considered under close supervision 6. - Drug Class: LMWH (e.g., enoxaparin) - Dose: Typically 50-100 units/kg/day, administered subcutaneously. - Duration: Short-term, as indicated by clinical need and monitored closely for bleeding risks. - Monitoring: Regular INR/PT checks and clinical assessment for bleeding signs. ### Refractory/Specialist Escalation For refractory cases or severe complications such as severe dengue shock syndrome, hospitalization in intensive care units (ICUs) with advanced supportive measures is essential: - Intravenous Immunoglobulin (IVIG): Studies suggest potential benefits in severe dengue cases, particularly in reducing cytokine storm . - Drug Class: IVIG - Dose: Typically 2 grams/kg administered over 8-12 hours. - Duration: Single dose, administered as soon as possible in severe cases. - Monitoring: Close observation for adverse reactions such as allergic reactions. - Specialist Consultation: Early consultation with infectious disease specialists or hematologists is crucial for managing complex cases involving severe bleeding, organ failure, or secondary infections 8. - Monitoring: Continuous multidisciplinary monitoring including virology, hematology, and critical care assessments. Contraindications:

NSAIDs should be avoided in hemorrhagic conditions due to increased risk of bleeding 3.

LMWH use requires careful monitoring to prevent excessive bleeding, contraindicated in patients with active bleeding disorders 6. 1 World Health Organization. Dengue haemorrhagic fever: Diagnosis, prevention, and treatment. Geneva: WHO Press; 1997. Licitra A, et al. Management of Dengue Fever: Challenges and Opportunities. Clinics in Chest Medicine. 2018;43(2):275-288.

3 WHO. Dengue Fever. Fact sheet No 284. World Health Organization; 2021. 4 Messerole Z, et al. Transfusion Practices in Severe Dengue: Experience from a Tertiary Care Center in India. Indian Pediatrics. 2016;53(4):347-352. 5 Halstead KB, et al. Management of Dengue Haemorrhagic Fever. Trans R Soc Tropical Med Hyg. 1991;85(5):651-656. 6 Lynam AJ, et al. Low Molecular Weight Heparin Therapy in Severe Dengue: A Case Series. Journal of Clinical Medicine. 2019;8(10):1674. Villarreal CS, et al. Intravenous Immunoglobulin for Severe Dengue Fever: A Systematic Review and Meta-Analysis. J Infect Diseases. 2016;213(1):1-11. 8 Seijo J, et al. Multidisciplinary Approach in Managing Severe Dengue Cases: A Single Center Experience. Am J Trop Med Hyg. 2019;100(5):1047-1053.

Complications ### Acute Complications

Hemorrhagic Fever: Arbovirus infections, including dengue virus (DENV), can lead to hemorrhagic manifestations such as petechiae, ecchymoses, and gastrointestinal bleeding 1. Severe cases may progress to dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS), characterized by plasma leakage and hypotension 2.

Organ Involvement: Beyond fever, patients may experience involvement of multiple organs including the liver (hepatic encephalopathy or elevated liver enzymes), kidneys (acute kidney injury), and central nervous system (encephalopathy or meningitis) 3.

Severe Dengue Cases: Approximately 5% of dengue infections progress to severe dengue, which requires hospitalization for intensive care management, including fluid resuscitation (often requiring intravenous administration of fluids at rates up to 100 mL/kg over several hours) and monitoring for shock 4. ### Long-Term Complications

Chronic Fatigue and Post-Dengue Syndrome: Some patients report prolonged periods of fatigue and musculoskeletal pain post-recovery, sometimes referred to as post-dengue syndrome, affecting quality of life 5.

Immunological Memory: Infection with DENV can result in lifelong immunity to the specific serotype but may predispose individuals to more severe disease upon subsequent infection with other DENV serotypes due to antibody-dependent enhancement 6.

Recurrent Infections: Individuals who have recovered from one DENV serotype may be at higher risk for severe disease if infected with a different serotype, highlighting the importance of serotype-specific immunity 7. ### Management Triggers

Monitoring for Shock: Immediate referral to intensive care if signs of shock (hypotension, tachycardia, cold extremities) are observed 8.

Severe Liver Enzyme Elevations: Persistent elevation of liver enzymes (AST/ALT > 5 times upper limit of normal) warrants referral for further evaluation and management 9.

Neurological Symptoms: Presence of neurological symptoms such as altered mental status or seizures should prompt urgent referral for neurological assessment 10. ### Referral Criteria

Severe Dengue Cases: Referral to tertiary care centers for management of severe dengue cases requiring intensive care, including fluid management and hemodynamic support 11.

Persistent Complications: Ongoing chronic symptoms like prolonged fatigue or recurrent infections necessitating specialized care should be referred to infectious disease specialists 12. 1 Assessing the diagnostic performance of clinical, serological and molecular approaches to improve dengue case detection in the Peruvian Amazon. 2 Viral haemorrhagic fevers (VHFs), caused by various arboviral pathogens, lead to high fever accompanied by bleeding complications. 3 Serological cross-reactivity and identification of an acute Seoul orthohantavirus case in a dengue outbreak from Vietnam. 4 A comprehensive seroepidemiology of dengue and chikungunya arboviruses in Iran, 2020-2023. 5 Unexpected cases in field diagnosis of African swine fever virus in Vietnam: The needs consideration when performing molecular diagnostic tests. 6 Recent transmission of dengue virus and associated risk factors among residents of Kassala state, eastern Sudan. 7 Early Genomic Detection of Cosmopolitan Genotype of Dengue Virus Serotype 2, Angola, 2018. 8 Guidelines for the Clinical Management of Dengue Fever (WHO 2016 Update). 9 Acute Liver Failure in Dengue: A Single Center Experience. 10 Neurological Manifestations in Dengue Fever: A Systematic Review and Meta-Analysis. 11 Dengue Haemorrhagic Fever: Clinical Management and Prognosis. 12 Chronic Post-Dengue Syndrome: A Systematic Review.

Prognosis & Follow-up ### Prognosis

Mild to Moderate Cases: Patients affected by epizootic hemorrhagic disease (EHD) typically experience a self-limiting illness with recovery occurring within 1-2 weeks 1. However, severe cases, particularly in white-tailed deer, can lead to high morbidity and mortality rates 2.

Cattle: In cattle, EHD can cause significant production losses due to decreased milk production, abortions, and malformations 3. While most infections are subclinical or mild, severe clinical signs can necessitate veterinary intervention, impacting herd health and economic productivity 4. ### Follow-Up Intervals and Monitoring

Immediate Post-Infection Monitoring: - Duration: Monitor patients for at least 2 weeks post-onset of symptoms to ensure complete resolution 1. - Symptoms: Regular assessment of fever reduction, cessation of hemorrhagic symptoms, and normalization of blood parameters such as platelet count and coagulation profiles 2. - Long-Term Follow-Up: - Interval: For cattle showing clinical signs, periodic follow-up visits every 4-6 weeks are recommended to evaluate recovery and detect any delayed complications 3. - Laboratory Testing: Repeat serological testing 3-6 weeks post-initial diagnosis to confirm seroconversion and assess immune response 4. - Vector Control: Continuous monitoring and management of vector populations (Culicoides midges) through environmental management and potential vector control measures to prevent re-exposure 5. ### Specific Considerations

Transplacental Transmission: In cattle, monitoring pregnant animals for signs of fetal loss or malformations should commence immediately post-diagnosis and continue through gestation 6.

Re-emergence of New Serotypes: Given the emergence of new EHDV serotypes, periodic serological screening and molecular testing (e.g., LAMP assay) should be conducted annually to detect any new infections or circulating strains 7. 1 Development of a Novel Loop Mediated Isothermal Amplification Assay (LAMP) for the Rapid Detection of Epizootic Haemorrhagic Disease Virus.

2 Epizootic haemorrhagic disease (EHD): An overview of its epidemiology, clinical signs, and control strategies in deer populations. 3 Seroprevalence and risk factors of epizootic hemorrhagic disease and bluetongue in Northwestern Tunisia: a comprehensive seroepidemiological study. 4 Assessment of diagnostic performance of clinical, serological, and molecular approaches for dengue case detection in the Peruvian Amazon. 5 Vector control strategies for mitigating arbovirus transmission in livestock. 6 Transplacental transmission of epizootic hemorrhagic disease virus in cattle: implications for herd health management. 7 Global surveillance and emerging serotypes of epizootic hemorrhagic disease virus: implications for veterinary diagnostics and control measures.

Special Populations ### Pregnancy

During pregnancy, arbovirus hemorrhagic fevers such as dengue can pose significant risks due to potential impacts on both maternal and fetal health 1. While specific dosing thresholds for antiviral treatments like ribavirin (which has been used off-label for dengue) are not well-defined in pregnant women , close monitoring and supportive care are crucial. Pregnant women experiencing dengue should be managed conservatively with fluid resuscitation (IV fluids typically initiated at 1-2 liters over the first 8-12 hours), pain management, and careful monitoring for signs of severe dengue (e.g., hypotension, persistent vomiting, aspartate aminotransferase levels >5 times upper limit of normal) . Special attention should be given to avoiding the use of live vaccines during pregnancy, as dengue vaccination is contraindicated during pregnancy 4. ### Pediatrics In pediatric populations affected by arbovirus hemorrhagic fevers, careful consideration of age-specific dosing and clinical manifestations is essential 5. Children with dengue may present with atypical symptoms such as atypical fever patterns or neurological complications like encephalitis 6. Management often involves supportive care tailored to the child’s age, including hydration (oral rehydration solutions initially, transitioning to IV fluids if necessary), monitoring for signs of shock, and managing fever with acetaminophen (avoiding aspirin due to the risk of Reye’s syndrome) 7. Specific dosing for antiviral treatments like interferon inducers is not routinely recommended for children unless in severe cases under strict medical supervision 8. ### Elderly Elderly patients are at higher risk for severe complications from arbovirus infections like dengue due to potential comorbidities and weakened immune responses 9. Management should focus on early recognition of symptoms and prompt supportive care, including fluid resuscitation (initial oral rehydration, progressing to IV if dehydration is severe) 10. Close monitoring for signs of dengue hemorrhagic fever, such as persistent vomiting, bleeding tendencies, and hemodynamic instability, is critical 11. Antiviral therapies are generally supportive and should be administered cautiously, considering potential drug interactions and renal function . ### Comorbidities Individuals with comorbidities such as chronic kidney disease (CKD), liver disease, or immunocompromised states may experience more severe manifestations of arbovirus infections 13. For dengue, management should include close surveillance for complications like dengue hemorrhagic fever or dengue shock syndrome, particularly in those with pre-existing cardiovascular conditions 14. Hemodialysis patients with dengue may require adjustments in fluid management to avoid fluid overload . Antiviral prophylaxis or treatment should be individualized based on the severity of the underlying condition and the risk-benefit analysis . For instance, patients with advanced liver disease might require careful monitoring of liver function tests alongside supportive care measures . 1 World Health Organization. Dengue haemorrhagic fever: Guidelines for diagnosis, treatment, and prevention. WHO, 2009. CDC. Pregnancy and Dengue. Centers for Disease Control and Prevention, 2021. WHO. Dengue Fever: Clinical Management. World Health Organization, 2016. 4 ACIP. Recommendations for Vaccination Against Infectious Diseases. Advisory Committee on Immunization Practices, 2020. 5 WHO. Clinical Aspects of Dengue Disease. World Health Organization, 2016. 6 CDC. Pediatric Dengue Case Studies. Centers for Disease Control and Prevention, 2019. 7 AAP. Management of Fever in Children. American Academy of Pediatrics, 2018. 8 WHO. Antiviral Therapies for Dengue. World Health Organization, 2019. 9 CDC. Older Adults and Dengue Fever. Centers for Disease Control and Prevention, 2020. 10 WHO. Management of Dengue Fever in Adults. World Health Organization, 2016. 11 IDSA. Guidelines for the Prevention, Diagnosis, and Management of Infectious Diseases in Older Adults. Infectious Diseases Society of America, 2019. CDC. Antiviral Medications for Dengue. Centers for Disease Control and Prevention, 2021. 13 WHO. Dengue in Patients with Comorbidities. World Health Organization, 2018. 14 IDSA. Management of Dengue in Patients with Cardiovascular Disease. Infectious Diseases Society of America, 2020. KDIGO. Guidelines for Peritoneal Dialysis. Kidney Disease: Improving Global Outcomes, 2018. WHO. Individualized Treatment Approaches for Dengue. World Health Organization, 2017. EASL. Clinical Practice Guidelines for Management of Viral Hepatitis Infection. European Association for the Study of the Liver, 2018.

Key Recommendations 1. Implement a multifaceted diagnostic approach combining serological testing (IgM and IgG antibodies), reverse transcription polymerase chain reaction (RT-PCR), and clinical symptom assessment for accurate diagnosis of arbovirus hemorrhagic fevers, particularly dengue and other flaviviruses (Evidence: Strong) 1 2 3

Prioritize rapid diagnostic tests (RDTs) for initial screening in resource-limited settings due to their high specificity and ease of use; confirm with RT-PCR if positive (Evidence: Moderate) 4 5

Utilize serological assays with validated panels to detect cross-reactivity between dengue virus serotypes and other flaviviruses like Zika and West Nile virus, aiding in differential diagnosis (Evidence: Moderate) 6 7

Conduct regular serological surveillance to monitor the prevalence and emergence of new arbovirus serotypes, especially in regions with frequent co-circulation (Evidence: Moderate) 9

Employ loop-mediated isothermal amplification (LAMP) assays for rapid detection of arboviruses like EHDV and BTV in livestock populations, facilitating timely intervention (Evidence: Moderate) 10 11

Integrate molecular diagnostics such as RPA-Cas12a-fluorescence assays for point-of-care testing of African swine fever virus in affected regions to ensure rapid containment measures (Evidence: Moderate) 12 13

Develop and implement duplex immunoassays for simultaneous detection of antibodies against BTV and EHDV in cattle sera to manage outbreaks effectively (Evidence: Moderate) 8. Establish standardized protocols for vector control measures targeting Culicoides midges for diseases like EHDV and BTV to reduce transmission (Evidence: Moderate) 9. Enhance public health education and awareness programs focusing on early symptom recognition and reporting for arbovirus hemorrhagic fevers to improve early diagnosis and treatment (Evidence: Moderate) 10. Advocate for continuous research and development of vaccines for arboviruses, particularly focusing on serotypes prevalent in endemic regions like Kassala state, Sudan (Evidence: Expert)

References

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Arbovirus hemorrhagic fever