What Are the Symptoms of Ebola?

Ebola hemorrhagic fever (EBHF) is an acute hemorrhagic, animal-borne infectious disease caused by a filamentous virus infection. In 1976, Ebola hemorrhagic fever broke out in Sudan and Zaire, with a fatality rate of 50% to 90%. Because the disease originated in the Ebola river in northern Zaire and was severely endemic in the region, it was named Ebola virus. Its morphology and pathogenicity are similar to Marburg virus, but it is immunogenic The difference. ^[1]

Basic Information

nickname: Ebola virus disease
English name: Ebola hemorrhagic fever
Visiting department: Infectious Diseases
Common causes: Caused by Ebola virus (EBV)

Common symptoms: Fever, headache, sore throat, joint pain, and other symptoms of systemic poisoning, followed by severe vomiting and diarrhea
Contagious: Have
way for spreading: Spread through contact with the blood, body fluids, secretions, excreta, etc. of patients and sick animals

Causes of Ebola hemorrhagic fever

Caused by Ebola virus (EBV). Ebola virus belongs to the family Filaviridae and is an enveloped, non-segmented, negative-strand RNA virus. The family Filaviridae includes Marburg virus, cuevavirus and Ebola virus, of which Ebola virus has five different virus species. Zaire Ebola virus, Sudan Ebola virus, Bendibugio Ebola virus, Big forest Ebola virus, Reston Ebola virus. The Reston subtype only infects primates, and the others can infect humans. The deadliest is the Zaire subtype. The virus this time is a new Zaire Ebola virus subspecies.

Ebola is not easy to spread. The virus cannot be transmitted through water, air, or food, and people who have no symptoms will not. The only way to transmit the virus is through the patient's or deceased's body fluids and contaminated needles. Therefore, as long as the patients are identified and isolated from the testees, they can help control the epidemic.

Ebola hemorrhagic fever epidemiology

The Ebola outbreak occurred in Guinea in December 2013. The epidemic has spread to four countries, including Guinea, Liberia, Nigeria, and Sierra Leone. According to WHO's local time on August 11, currently 1,848 infected cases have been registered, including suspected and confirmed cases, of which 1,013 have died. This is the record for the worst Ebola outbreak to date.

Source of infection

Ebola virus is a zoonotic pathogen. Different species of fruit bats can carry the virus throughout central and southern Africa. Human-to-human transmission can cause outbreaks, which often begin with transmission from wild animal banks to humans. The genetics of the virus variants are almost the same, similar to the current outbreak in West Africa. According to the latest news, the initial infection of the outbreak was a 2-year-old boy who contracted Ebola virus through contact with bats.

2. Ways of transmission

Ebola cannot be transmitted by droplets, so it is not as contagious as measles or flu. People with measles or flu can spread the virus before symptoms appear, and people infected with Ebola virus are only contagious after they show symptoms.

Direct contact with infected people's secretions, such as saliva, is the basic route of transmission of Ebola virus. But Ebola cannot be transmitted by coughing or sneezing, and it cannot be transmitted by accidental contact. It is transmitted through the patient's secretions such as vomit, diarrhea or blood, and can also be transmitted through direct contact. It can also spread through direct contact with the patient's saliva, sweat, and tears.

3. Susceptible people

Because only those who have symptoms are contagious. The main infections are the medical staff who care for the patients, and family members who have close contact with the patients. Another way to get infected is with family members when dealing with dead bodies, as well as those who eat fruit bats, antelopes or other animals that may be infected with the virus.

Ebola hemorrhagic fever clinical manifestations

The incubation period for Ebola virus infection in humans is 2 to 21 days, and most patients are critically ill after 8 to 9 days of infection. Once infected, the patient develops symptoms within 1-2 days.

Clinical patients may develop symptoms of systemic poisoning such as high fever, headache, sore throat, and joint pain, followed by severe vomiting and diarrhea. Coagulation dysfunction and thrombocytopenia can occur within 24 to 48 hours, which can lead to bleeding in the nasal cavity or mouth, with bleeding skin blisters. Within 3 to 5 days, renal failure occurs, leading to multiple organ failure and diffuse intravascular coagulation, with significant fluid loss. ^[2]

Ebola hemorrhagic fever examination

Due to the lack of effective treatments, diagnosis is the key to responding to the Ebola virus. Detection experiments depend heavily on multiplex RT-PCR detection. Antigen tests can also be performed together as a confirmatory test. Antibody detection (such as IgM and IgG) is a secondary detection method.

The European Mobile Lab has played a huge role. The first mobile laboratory was dispatched to the Gakedou area in Guinea in March 2014. About 1100 tests have been carried out, of which more than 400 tests have been positive. A total of less than 2,000 confirmed or suspected cases of Ebola hemorrhagic fever have been found worldwide, and the Mobile Lab has made an important contribution to the diagnosis.

In August 2014, the EU will also set up a second mobile laboratory, which may be shipped to Sierra Leone.

This kind of "mobile laboratory" in the European Union has been designed to respond to emergencies. Its detection scope covers a variety of threatening viruses around the world. The Ebola epidemic has given it a practical opportunity to play a role. Continuously summarizing the characteristics of Ebola virus from actual combat and obtaining the latest data can help improve its diagnostic level. The "mobile" feature allows the laboratory to travel to many affected areas and improve the efficiency of patient detection.

Ebola hemorrhagic fever diagnosis

Ebola virus incubation period is 2 to 21 days, and how to detect it early is the key. Therefore, countries around the world are developing rapid detection methods. China is outstanding in this regard.

China already has the ability to develop diagnostic reagents for timely detection of Ebola virus. In terms of antibody technology, China has already had a very good ability to prepare multivariate antibodies in the early stage, including the antibody gene of Ebola virus, and it will not take too long to start the antibody production process.

China is well prepared for Ebola in terms of diagnostic reagents and antibody technology. China currently has about 9 subjects and 10 national-level research units engaged in Ebola virus research, including testing methods, diagnostic reagent development, vaccines, and drugs. This has provided very good technical support for China's response to the Ebola epidemic. Now many reagents have been developed, and many methods and diagnostic reagents' technical reserves are ready for application by our disease control departments.

Ebola hemorrhagic fever treatment

Status quo

No effective vaccine is currently available. Suspicious patients should be immediately quarantined when found, and sick monkeys should be hunted down if found. The dead patient was cremated immediately. ^[3]

The only treatments available are symptomatic support (intravenous infusion, blood and platelet transfusion).

Other methods include infusions to restore the plasma of healthy people infected with Ebola virus. The premise of this method is that life-saving neutralizing antibodies are contained in the plasma of the recovered patient. According to the latest reports during the outbreak, this experimental treatment is already in clinical use, although the efficacy of the treatment is unknown.

2. Progress of new drugs

Two U.S. patients infected with Ebola virus have been the first to receive experimental new drug treatment. They were originally in serious condition, but their condition began to improve after treatment with a drug called ZMapp. This has given the medical community hope to contain the Ebola virus. Although the ultimate efficacy remains to be seen, at least it shows that humans have hope of defeating this "killer" virus.

Before these two American patients started taking experimental drugs, no Ebola drug or vaccine had undergone in-depth clinical trials, let alone been certified and marketed by a medical regulatory agency.

From the public research data, at the global level, most of the relevant drugs have been tested initially in monkeys or some healthy people. Only two Ebola drugs and one vaccine are known to work well in monkeys. There are three companies developing these products, two in the United States and one in Canada, all of which have received funding from the U.S. Department of Health.