Ebola hemorrhagic fever

Ebola Hemorrhagic Fever: A Severe and Deadly Disease

Ebola hemorrhagic fever, also known as Ebola virus disease (EVD), is a rare but severe and often fatal illness caused by the Ebola virus. It is characterized by high fever, unexplained bleeding, and a high mortality rate.

Symptoms of Ebola Hemorrhagic Fever

The symptoms of Ebola infection can be sudden and include:

• High fever
• Fatigue
• Muscle pain
• Headache
• Sore throat
• Vomiting
• Diarrhea
• Rash
• Internal and external bleeding

These symptoms can progress to more severe complications, including gastrointestinal symptoms, bleeding, shock, and multi-organ system failure.

Transmission of Ebola

Ebola virus disease is transmitted to people from wild animals, such as fruit bats, porcupines, and non-human primates. The virus then spreads in the human population through direct contact with the blood, secretions, organs, or other bodily fluids of infected people.

Mortality Rate

The mortality rate for Ebola hemorrhagic fever can range from 25% to 90%, with an average fatality rate of around 50%.

References:

• [1] Symptoms typically start anywhere between two days and three weeks after infection. (Source: Search result 3)
• [2] The first symptoms are usually fever, sore throat, muscle pain, and headaches. (Source: Search result 3)
• [3] Ebola virus disease is a severe, often fatal illness affecting humans and other primates. (Source: Search result 14)
• [4] The mortality rate for Ebola hemorrhagic fever can range from 25% to 90%. (Source: Search result 1)

Early symptoms of Ebola may appear 2 to 21 days after contact with the virus, with an average incubation period of 8 to 10 days [1]. The initial signs and symptoms are often referred to as "dry" symptoms, which can include:

• Fever
• Aches and pains in the muscles and joints
• Severe headache
• Weakness and fatigue
• Sore throat

As the disease progresses, it typically moves on to "wet" symptoms, which can include:

• Diarrhea
• Vomiting
• Unexplained bleeding (internal or external)

The time from infection to symptom onset is usually 2 to 21 days, with an average of 8 to 10 days [3]. In severe cases, Ebola can cause a range of symptoms, including marked fever, fatigue, dizziness, muscle aches, loss of strength, and exhaustion.

It's worth noting that the symptoms of Ebola can be sudden and severe, and can progress rapidly if left untreated. If you suspect exposure to Ebola or are experiencing any of these symptoms, it's essential to seek medical attention immediately.

References:

[1] Early symptoms of Ebola may appear 2 to 21 days after contact with the virus [4] [2] Initial signs and symptoms are nonspecific and may include elevated body temperature or subjective fever, chills, myalgia, and fatigue [2] [3] The time from infection to symptom onset is usually 2 to 21

Diagnosing Ebola Hemorrhagic Fever: A Review of Diagnostic Tests

Ebola hemorrhagic fever (EHF) is a severe and often fatal disease caused by the Ebola virus. Diagnosing EHF can be challenging due to its similar symptoms with other febrile illnesses. However, various diagnostic tests have been developed to aid in the early detection and confirmation of the disease.

Molecular Tests

Molecular tests have been the most frequently used tool in Ebola diagnosis in recent outbreaks [4][6]. These tests detect the genetic material of the virus and can be performed using various techniques such as:

• Real-Time Polymerase Chain Reaction (RT-PCR): This test is highly sensitive and specific, with a detection limit of 471 copies/mL for the Zaire strain of the Ebola virus [14].
• Antigen-capture enzyme-linked immunosorbent assay (ELISA): This test detects the presence of viral antigens in patient samples.
• Reverse transcription-PCR: This test detects the genetic material of the virus and can be used to confirm the diagnosis.

Serological Tests

Serological tests detect the presence of antibodies against the Ebola virus in patient serum. These tests include:

• Antibody-capture ELISA: This test detects the presence of IgG and IgM antibodies against the Ebola virus.
• Serum neutralization test: This test measures the ability of patient serum to neutralize the Ebola virus.

Clinical Evaluation

In addition to laboratory tests, clinical evaluation is also essential in diagnosing EHF. Healthcare providers should consider a range of symptoms, including:

• Fever
• Severe gastrointestinal symptoms
• Neurologic symptoms and hypovolemic shock
• Hemorrhagic manifestations (late-stage symptom)
• Uveitis (prominent symptom)

Travel and Contact History

A patient's travel and contact history from an Ebola-affected country can raise suspicion of EHF. This information should be considered in conjunction with laboratory test results.

In conclusion, diagnosing Ebola hemorrhagic fever requires a combination of laboratory tests and clinical evaluation. Molecular tests, such as RT-PCR, have been shown to be highly sensitive and specific for detecting the Ebola virus. Serological tests can also aid in diagnosis by detecting antibodies against the virus. Clinical evaluation is essential in identifying patients with EHF, particularly those with severe symptoms.

References:

[4] Molecular tests have been the most frequently used tool in Ebola diagnosis in recent outbreaks. [6] Real-Time Polymerase Chain Reaction (RT-PCR) has a detection limit of 471 copies/mL for the Zaire strain of the Ebola virus. [14] Antigen-capture enzyme-linked immunosorbent assay (ELISA) detects viral antigens in patient samples. [15] Clinical evaluation includes symptoms such as fever, severe gastrointestinal symptoms, neurologic symptoms and hypovolemic shock, hemorrhagic manifestations, and uveitis.

Current Treatments for Ebola Hemorrhagic Fever

There are currently two FDA-approved treatments available to treat Ebola disease (species orthoebolavirus zairense): Inmazeb and Ebanga [3]. These treatments are considered supportive care, which means they help manage the symptoms of the disease rather than curing it.

Monoclonal Antibody Treatments

Inmazeb and Ebanga are monoclonal antibody treatments that work by targeting specific proteins on the surface of the Ebola virus. This helps to neutralize the virus and prevent it from causing further damage in the body [8]. Monoclonal antibodies are given intravenously, which means they are administered directly into a vein.

Other Medications

In addition to Inmazeb and Ebanga, other medications such as ribavirin (Virazole) have been explored for use in treating Ebola hemorrhagic fever [5]. However, the efficacy of these treatments has not been established for all patients with Ebola disease.

Research Ongoing

Research is ongoing to develop new treatments for Ebola hemorrhagic fever. For example, Ansuvimab was developed by Ridgeback Biotherapeutics to treat EBOV infections in adults and pediatric patients [9]. However, more research is needed to fully understand the effectiveness of these treatments.

Key Points:

• Inmazeb and Ebanga are FDA-approved treatments for Ebola disease
• Monoclonal antibody treatments work by targeting specific proteins on the surface of the Ebola virus
• Other medications such as ribavirin have been explored for use in treating Ebola hemorrhagic fever
• Research is ongoing to develop new treatments for Ebola hemorrhagic fever

References:

[1] Context 3: Two FDA-approved treatments are currently available to treat Ebola disease (species orthoebolavirus zairense): Inmazeb and Ebanga. [2] Context 8: There are two monoclonal antibody treatments for Ebola virus disease, Inmazeb and Ebanga. [3] Context 3 [4] Context 5 [5] Context 9 [6] Context 1

The differential diagnosis for Ebola hemorrhagic fever (EHF) is broad and includes various conditions that can present with similar symptoms, making it challenging to diagnose early in the course of disease.

Conditions to Consider

• Acute surgical abdomen (as distinct from abdominal signs of EHF)
• Marburg hemorrhagic fever
• Lassa fever
• Crimean-Congo hemorrhagic fever
• Acute human immunodeficiency virus (HIV) infection
• Chikungunya virus
• Leptospirosis
• Malaria
• Malignancy
• Systemic lupus erythematosus

Key Points to Consider

• EHF is difficult to distinguish from other febrile illnesses, at least early in the course of disease [7].
• The differential diagnosis for African hemorrhagic fevers also includes yellow fever and Lassa fever, but these illnesses are not accompanied by hemorrhagic manifestations [9].
• Nonspecific symptoms such as fever, malaise, headache, and myalgias are common in EHF, making it difficult to diagnose early on [10].

Important Considerations

• Travel and contact history are crucial when considering the differential diagnosis in areas where Ebola is not endemic [15].
• Major bleeding is not found in most patients with EHF, and severe hemorrhage tends to be observed only in the late stages of disease [3][13].

The differential diagnosis for EHF requires a thorough understanding of the various conditions that can present with similar symptoms. Clinical suspicion of infection with prompt isolation is essential in areas where Ebola is endemic, especially in the context of a history of exposure.

References:

[1] 10 [3] 3 [7] 7 [9] 9 [13] 13 [15] 15