Ebola Virus (Haemorrhagic Fever)

Sample

• This can be diagnosed with patient blood, sputum, and tissue.

Epidemiology

1. Ebola virus formerly called Hemorrhagic fever.
2. This disease spread from a wild animal (rodents).
3. Also, this disease spread from human to human.
4. The fatality rate varies from 25% to 90% and the average is around 50%.
5. This disease outbreak is seen in remote villages of Central Africa, near the tropical rainforest.
6. The first outbreak was seen in 1976 and was seen in Sudan, Congo.
   1. The first case was identified along the Ebola River, in Congo near the Sudan border.
7. In Congo, this was seen near the river named as Ebola river and it got the name from there.
8. These cases have been reported from Senegal, Nigeria, Mali, Italy, Spain, the united states of America, and the United Kingdom.

Transmission 

1. The host is bats (Pteropodidae family).
2. This virus spread through close contact with blood, secretions, body fluids of an infected animal such as chimpanzees, gorillas, monkeys, and fruit bats.
3. Ebola virus then spreads through human-to-human transmission via:
   1. Direct contact (through broken skin or mucous membranes).
   2. 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.

4. 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 infection control precautions are not strictly practiced.
5. People remain infectious as long as their blood and body fluids, including semen and breast milk, contain the virus.
   • Men who have recovered from the disease can still transmit the virus through their semen for up to 7 weeks after recovery from illness.

The Types of Viruses

1. Ebola is a single-stranded RNA.
2. The virus family Filoviridae includes 3 genera:
   1. Cuevavirus.
   2. Marburg virus,
   3. Ebola virus.

Species of Ebola virus that have been identified:

1. Zaire Ebola virus.
2. Bundibugyo Ebola virus.
3. Sudan Ebola virus.
4. Reston Ebola virus.
5. Taï Forest ebolavirus.
   1. The first 3, Bundibugyo ebolavirus, Zaire ebolavirus, and Sudan ebolavirus have been associated with large outbreaks in Africa.
      1. In another reference three, clinically active viruses are Zaire, Sudan, and Tai forest.
   2. The virus causing the 2014 West African outbreak belongs to the Zaire species.

Sign and Symptoms

1. The incubation period is 2 to 21 days before symptoms appear.
2. The average time for S/S to appear is 8 to 10 days.
   1. 95% will have a sign and symptoms during the first 14 days.
3. Humans are not infectious until they develop symptoms.
4. There is a sudden onset of:
   1. Fever.
      1. There is malaise, fatigue, myalgia, and arthralgia.
   2. Muscle pain, headache, and sore throat.
   3. After 3 to 5 days:
      1. This is followed by vomiting, diarrhea.
      2. Rash.
      3. There are symptoms of impaired kidney and liver function.
      4. In some cases, both internal and external bleeding (e.g. oozing from the gums, blood in the stools).
   4. Nausea and vomiting worsen, cannot tolerate oral intake.
      1. Diarrhea becomes a large volume and patients may lose 5 or more liters of the fluid per day.
   5. The disease progresses and the patient may develop neurological symptoms.
      1. Encephalitis is accompanied by confusion, agitation, and occasional seizers.
   6. The patient may go into shock.
   7. Hemorrhagic manifestations are seen in only 1 to 5% of the cases.
   8. A complication of the Ebola virus:
      1. There is a hypovolemic shock.
      2. There may be a multiorgan failure.

Diagnosis

Laboratory findings include:

1. Blood sample:
   1. Low white blood cell and platelet counts.
   2. Abnormal Liver function tests.
   3. Increased serum creatinine level.
2. ELISA (antibody-capture enzyme-linked immunosorbent assay).
   1. IgM antibodies appear after 10 days of the infection.
   2. After 2 weeks IgG antibodies appear.
   3. Serum neutralization test.
3. Antigen-capture detection tests.
4. PCR – RT (Reverse transcriptase-polymerase chain reaction assay), can diagnose in the first three days of illness
   1. If negative and, the patient has still signs and symptoms then repeat this test.
5. Electron microscopy
6. Virus isolation by cell culture.

Prevention

1. There is no available vaccine.
   1. There are vaccines under trial.
2. If you travel to or are in an area affected by an Ebola outbreak, make sure to do the following.
   1. Practice careful hygiene. Avoid contact with blood and body fluids.
   2. After you return, monitor your health for 21 days and seek medical care immediately if you develop signs and symptoms of Ebola virus infection.
   3. Avoid hospitals where Ebola patients are being treated.
   4. Avoid contact with bats and nonhuman primates or blood, fluids, and raw meat prepared from these animals.
   5. Avoid funeral or burial rituals that require handling the body of someone who has died from Ebola.
   6. Do not handle items that may have come into contact with an infected person’s blood or body fluids.

Treatment

1. This is mainly supportive.
2. Rehydrate the patient and that may reduce the mortality.
3. Antiviral drugs may be tried.
4. People sometimes give antimalarial and broad-spectrum antibiotics.

 

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