Viral hemorrhagic fever (VHF) is a serious infectious disease characterized by impaired vascular permeability, hemorrhagic manifestations, and high mortality. VHF includes several different forms caused by various viruses, such as Ebola virus, Marburg virus, yellow fever virus, and bongo virus, among others. The infection is transmitted from person to person, as well as through the bites of infected insects. Clinical manifestations of the disease vary from mild fever to severe syndrome with shock requiring emergency medical care. The pathogenesis of VHF is characterized by active damage to endothelial cells, which leads to impaired hemostasis and the development of hemorrhagic symptoms.
History of the disease and interesting historical facts
Viral hemorrhagic fevers have been known to mankind for several decades. The first outbreaks of diseases caused by the Ebola virus were recorded in 1976 in the Democratic Republic of the Congo. Interestingly, the name "Ebola" comes from the name of the river near which the first outbreak occurred. More recent epidemics in West Africa in 2014-2016 attracted the attention of the international community, becoming one of the largest outbreaks in history. Marburg virus, the first recorded outbreak of which occurred in 1967 in Germany, has also been associated with hemorrhagic fever. These viral infectious diseases are examples of zoonoses, as they are transmitted from animals to humans, often through contact with infected blood or secretions.
Epidemiology
According to the World Health Organization (WHO), the incidence of viral hemorrhagic fevers varies by region. For example, in 2016, more than 28,000 cases of Ebola were reported. VHF is most common in tropical and subtropical regions where conditions favor the reproduction of vectors such as mosquitoes. The fatality rate for VHF can be as high as 90% in the case of the Ebola virus, making it particularly dangerous. Epidemiological studies show that in organized outbreaks, the number of cases can increase rapidly, requiring rapid response and control by health organizations.
Genetic predisposition to this disease
Research now shows that genetic susceptibility to viral hemorrhagic fevers depends largely on the interaction of genetic factors with the environment. Scientists have identified some specific genes that may be associated with susceptibility to VHF. For example, possible variations in genes responsible for the immune response may increase the risk of developing a severe form of the disease. There is also evidence that certain mutations in genes such as HLA (major histocompatibility complex) may influence an individual’s response to the virus and determine the outcome of the disease.
Risk factors for the development of this disease
Risk factors for developing viral hemorrhagic fever are varied and may include:
- Contact with infected animals such as bats, monkeys or pigs.
- Living or working in endemic areas where cases of the disease have been reported.
- Exposure to contaminated blood or other biological fluids of patients.
- Exposure to insect vectors such as mosquitoes in high humidity conditions.
- Situations related to the lack of protective equipment for healthcare workers working with infectious patients.
Diagnosis of this disease
Diagnosis of viral hemorrhagic fever requires a thorough clinical and laboratory approach. The main symptoms include high fever, headache, myalgia, fatigue, and hemorrhagic manifestations such as mucosal bleeding and subcutaneous hemorrhage. Laboratory tests play a key role in confirming the diagnosis. These tests may include:
- Blood chemistry tests to assess liver and kidney function.
- PCR for detection of viral RNA in blood samples.
- Enzyme-linked immunosorbent assay (ELISA) to detect antibodies to the virus.
Radiological examinations such as ultrasound of organs can be used to evaluate the condition of internal organs. It is also important to make a differential diagnosis with other diseases such as dengue fever, smallpox and West Nile fever.
Treatment
Treatment of VHF is primarily symptomatic and supportive. It is important to keep the patient hydrated, as dehydration can lead to serious complications. Pharmacological treatment includes the use of antiviral drugs, such as ribavirin for some forms of hemorrhagic fever, and antiviral antibodies. Surgery may be required for complications such as abscesses or perforations. Other treatments include immune therapy, which can help fight the virus.
List of medications used to treat this disease
- Ribavirin.
- Antibodies against Ebola virus (eg, Inmazeb).
- Immunoglobulin against hemorrhagic fever.
- Supportive therapy (fluids, electrolytes).
Disease monitoring
Monitoring of a patient with viral hemorrhagic fever is critical and includes regular checks of vital signs, fluid and electrolyte levels, and testing for the virus. The prognosis of the disease depends on prompt diagnosis and treatment. Complications may include multiple organ failure, requiring intensive medical care.
Age-related features of the disease
Viral hemorrhagic fever can manifest itself differently in different age groups. In children, the disease may proceed with more pronounced symptoms and a high probability of complications. In older people, the immune response is reduced, which also increases the risk of severe disease. Studies show that reported cases in people over 60 years of age have a higher mortality rate.
Questions and Answers
- What is viral hemorrhagic fever? This is a severe infectious disease characterized by impaired vascular permeability and hemorrhagic manifestations.
- What are the main viruses that cause VHF? The main viruses include Ebola, Marburg, yellow fever, bongo virus and others.
- How is VHL diagnosed? Diagnosis includes analysis of clinical symptoms, laboratory tests, PCR and enzyme immunoassays.
- What are the treatments for VHL? Treatment includes symptomatic therapy, the use of antiviral drugs and supportive measures.
- What is the prognosis for the disease? The prognosis depends on the speed of detection and provision of medical care; the mortality rate can reach 90% in some forms.
