Ebola Virus (Hemorrhagic Fever)
Ebola Virus
Sample for Ebola Virus
- This can be diagnosed with patient blood, sputum, and tissue.
Epidemiology and History of the Ebola virus
- Ebola virus, formerly called Hemorrhagic fever.
- This disease spreads from wild animals (rodents).
- Also, this disease spreads from human to human.
- The fatality rate varies from 25% to 90%, and the average is around 50%.
- This disease outbreak is seen in remote villages of Central Africa near the tropical rainforest.
- The first outbreak was seen in 1976 in Sudan, Congo.
- The first case was identified along the Ebola River in Congo near the Sudan border.
- This was seen near the Ebola river in Congo, and it got its name from there.
- These cases have been reported from Senegal, Nigeria, Mali, Italy, Spain, the united states of America, and the United Kingdom.
- Ebola virus details were given on April 4th, 1995.
- A patient was reported in Kikwit city of Zare. He was a laboratory technician who developed a fever and severe headache.
- He has abdominal cramping pain, which settles later on. He has difficulty swallowing. Then he has blood in the stool, and later on, blood from the nose and mouth starts.
- Within 2 weeks, his other workers developed similar signs and symptoms.
- Fever = 94%, diarrhea = 80%, weakness = 74%, dysphagia = 41%, hiccups = 15%, and bleeding from the mucous membranes of GITract, vagina, and skin = 38%.
- By June, there were 296 cases.
- Samples were sent to CDC, and samples were subjected to PCR and immunoabsorbent assay; the report was positive for the Ebola virus.
- Filo, in filoviridae, means filament in Latin and describes the filamentous shape of the RNA viruses Ebola and Marburg, which is part of the filovirus family.
Transmission of the Ebola virus
- The host is bats (Pteropodidae family).
- This virus spreads through close contact with an infected animal’s blood, secretions, and body fluids, such as chimpanzees, gorillas, monkeys, and fruit bats.
- Ebola virus then spreads through human-to-human transmission via:
- Direct contact (through broken skin or mucous membranes).
- Through the blood, secretions, organs, or other body fluids of infected people and with surfaces and materials (e.g., bedding, clothing) contaminated with these fluids.
- Humans and monkeys are infected during outbreaks of this disease, but the reservoir source is unknown.
- Health-care workers have frequently been infected while treating patients with suspected or confirmed Ebola virus infection.
- This has occurred through close contact with patients when not strictly practiced infection control precautions.
- People remain infectious as long as their blood and body fluids contain the virus, including semen and breast milk.
- Men who have recovered from the disease can still transmit the virus through their semen for up to 7 weeks after recovery from illness.
- So the main source of the spread is direct contact with body fluids.
- Direct contact with blood, urine, stool, vomitus, or semen from the active disease patients, alive or dead, is the most important transmission source.
- This occurs through the skin or mucous membrane contact with virus-infected body fluid.
- The reuse of unsterile needles was the main source of spread in the Kikwit, Zaire patients.
The Types of Ebola Viruses
- Filo means filaments in Latin, and it describes the filamentous shape of the RNA Ebola and Marburg virus belonging to the filovirus group.
- Ebola is a single-stranded RNA.
- The virus family Filoviridae includes 3 genera:
- Cuevavirus.
- Marburg virus,
- Ebola virus.
Species of Ebola virus:
These are identified as follows:
- Zaire Ebola virus.
- Bundibugyo Ebola virus.
- Sudan Ebola virus.
- Reston Ebola virus.
- Taï Forest ebolavirus.
- The first 3, Bundibugyo ebolavirus, Zaire ebolavirus, and Sudan ebolavirus, have large African outbreaks.
- In another reference, three clinically active viruses are Zaire, Sudan, and Tai forest.
- The virus causing the 2014 West African outbreak belongs to the Zaire species.
- The first 3, Bundibugyo ebolavirus, Zaire ebolavirus, and Sudan ebolavirus, have large African outbreaks.
Signs and Symptoms of the Ebola virus
- The incubation period is 2 to 21 days before symptoms appear.
- The average time for S/S to appear is 8 to 10 days.
- 95% will have a sign and symptoms during the first 14 days.
- Humans are not infectious until they develop symptoms.
- There is a sudden onset of:
- Fever.
- There is malaise, fatigue, myalgia, and arthralgia.
- Muscle pain, headache, and sore throat.
- After 3 to 5 days:
- This is followed by vomiting and diarrhea.
- Rash.
- There are symptoms of impaired kidney and liver function.
- In some cases, internal and external bleeding (e.g., oozing from the gums, blood in the stools).
- Nausea and vomiting worsen, cannot tolerate oral intake.
- Diarrhea becomes a large volume, and patients may lose 5 or more liters of fluid per day.
- The disease progresses, and the patient may develop neurological symptoms.
- Encephalitis is accompanied by confusion, agitation, and occasional seizures.
- The patient may go into shock.
- Hemorrhagic manifestations are seen in only 1 to 5% of the cases.
- A complication of the Ebola virus:
- There is a hypovolemic shock.
- There may be a multiorgan failure.
- Fever.
Diagnosis of Ebola virus
Laboratory findings include:
- Blood sample:
- Low white blood cell and platelet counts.
- Abnormal Liver function tests.
- Increased serum creatinine level.
- ELISA (antibody-capture enzyme-linked immunosorbent assay).
- IgM antibodies appear after 10 days of the infection.
- After 2 weeks, IgG antibodies appear.
- Serum neutralization test.
- Antigen-capture detection tests.
- PCR – RT (Reverse transcriptase-polymerase chain reaction assay) can diagnose in the first three days of illness
- Repeat this test if negative and the patient still has signs and symptoms.
- Electron microscopy.
- Virus isolation by cell culture.
Prevention of the Ebola virus
- There is no available vaccine.
- There are vaccines under trial.
- If you travel to or are in an area affected by an Ebola outbreak, make sure to do the following.
- Practice careful hygiene. Avoid contact with blood and body fluids.
- After you return, monitor your health for 21 days and seek medical care immediately if you develop signs and symptoms of an Ebola virus infection.
- Avoid hospitals where Ebola patients are being treated.
- Avoid contact with bats and nonhuman primates or blood, fluids, and raw meat prepared from these animals.
- Avoid funeral or burial rituals that require handling the body of someone who has died from Ebola.
- Do not handle items that may come into contact with an infected person’s blood or body fluids.
Treatment of the Ebola virus
- This is mainly supportive.
- Rehydrate the patient, and that may reduce mortality.
- Antiviral drugs may be tried.
- People sometimes give antimalarial and broad-spectrum antibiotics.
Questions and answers:
Question 1: What are the species of the Ebola viruses?
Question 2: What is the blood picture in the Ebola virus?