EBOLA VIRUS

 

EBOLA VIRUS

WHAT IS EBOLA VIRUS?

        Ebola virus is animal borne deadly virus and mostly spreads from bats, which transmit the virus to other animal and human. Ebola is a rare virus that causes severe inflammation and tissue damage throughout the body. It is known as a hemorrhagic fever virus. Ebola virus belongs to the filoviridae family. The name is derived from the Latin word “filum” meaning thread. Filoviridea viruses are negative stranded RNA viruses. They are most common to infect humans and primates, causing highly fatal hemorrhagic fever.   

SPECIES OF EBOLA VIRUS:

     The genus Ebola virus currently is classified into five species:

1.    Sudan Ebola virus

2.    Zaire Ebola virus

3.    Bundi bugyo Ebola virus

4.    Tai forest (Ivory coast) Ebola virus

5.    Reston Ebola virus

         The first three subtypes have been associated with large EVD outbreaks in Africa. The Reston subtype is found in the western pacific and its highly pathogenic in nonhuman primates, it is not known to cause illness. In addition to Ebola virus, one other member of the filovirus family, known as Marburg virus (named after the city in Germany in which it was first discovered), that also causes hemorrhagic fever. 

ORIGIN OF EBOLA VIRUS

        In 1976, Dr. Peter Piot first detected the disease in Zaire and Sudan, Africa (presently the Democratic Republic of Congo). The name “Ebola” was termed as the disease was noticed near the Ebola River in Congo. In 1994, first case of Ebola Hemorrhagic fever (EHF) occurred in Western Africa in the Tai Forest Reserve in Côte d’Ivoire (Ivory Coast). An ecologist was infected by performing a necropsy on a dead chimpanzee. The outbreak of Ebola disease in West Africa from 2014 to 2016, involving Zaire Ebola virus was the largest outbreak disease in history.

CAUSES OF EBOLA VIRUS:

       Fruit bats of pteropodidae family, such as Hypsignathus monstrous, Epomops franqueti and myonycteris torquataserve are the natural hosts of the EBOV in Africa. Non hemon primates develop the infection by eating the partly eaten fruits and transmit the infection to human. Infected bats can transmit the virus to monkeys and apes, so humans can be infected while killing or butchering these animals. Humans and animals become infected through contact with infected bats or fruit contaminated by infected bat droppings. The vast majority of people contract the virus through direct exposure to the body fluids of an infected person.

STRUCTURE OF EBOLA:

•  Genome 19kb long.
•  Diameter 80mm; length 960nm to 120nm.
• Four viral proteins; polymerase (L), nucleoprotein, and proteins VP35  and VP30.
•  Spikes formed by GP/GP2 complexes (envelope glycoprotein).
•  VP24 (membrane protein) associated with envelope.

HOW DOES THE VIRUS SPREAD?

         Ebola virus transmission primarily takes places through close bodily contact with the infected patients like

·       Through blood of an infected person

·       Body fluids like breast milk, stool, saliva, semen, sweat, urine or vomit.

·       Objects like needle or syringe that is contaminated with the virus.

·       Animals such as bats and primates that are infected with the virus.

·       Clothing from alive, infected or deceased individuals.

·       Unsafe of traditional burial practices plays a pivotal role in disease transmission.

·       Transmission through air is not possible.

MECHANISM OF ACTION:

Ø Every tissue is affected, except bones and muscles.

Ø The virus creates blood clots.

Ø Clot goes towards internal organs (lungs and eyeball).

Ø It prevents transport of oxygen to the tissues (affinity with collagen).

SYMPTOMS OF EBOLA DISEASE:

         Symptoms begin 8 to 10 days after a person gets infected with the virus.

EARLY SYMPTOMS    

·       Fever                                                          

·       Muscle pain                                       

·       Head ache                                                  

·       Weakness

MID SYMPTOMS

·       Nausea

·       Diarrhoea

·       Stomach pain

·       Bruising or Bleeding

·       Bloody nose, bloodspot eyes or blood in urine or diarrhoea

LATER STAGES OF ILLNESS:

·       Organ failure

·       Inflammation of the brain

·       Seizures

·       Lack of blood flow in the body (shock)

·       Death

DIAGNOSIS:

Ø Diagnosing Ebola can be difficult at first since early symptoms, such as fever, are nonspecific to Ebola infection.

Ø Samples from the patients are collected and tested to confirm the infection by:

1.    Antibody-capture enzyme-linked immunosorbent assay (ELISA).

2.    Antigen-capture detection tests.

3.    Serum neutralization test.

4.    Reverse transcriptase polymerase chain reaction (RT-PCR) assay.

5.    Electron microscopy.

6.    Virus isolation by cell culture.

EFFECTS IN THE HUMAN ORGAN

             The Ebola virus has the ability to affect most systems throughout the body

Cardiovascular system:

·       Coagulopathy (increased fibrin-degradation products, reduced clotting factor, and thrombocytopenia).

·       Sespsis

·       Tachycardia

Endocrine system:

·       Adrenal failure (impairs secretion of hormones, resulting hypotension, hypovolemia, and renal sodium loss)

·       Pancreatitis

Gastrointestinal system:

·       GI hemorrhage (lower and upper)

·       Haematemesis

·       Malena

Hepatic system:

·       Hepatitis

·       Hepatocellular lesions

·       Hepatocellular necrosis

·       Hepatomegaly

·       Liver damage

Immune system:

·       Lymphadenopathy

·       Systemic inflammatory response

Neurological system:

·       Aggression

·       Confusion

·       Hiccups

·       Metabolic encephalopathy

·       Neurotropism

·       Seizure

Ocular system:

·       Conjunctival infection

·       Uveitis

Renal system:

·       Acute kidney injury

·       Renal dysfunction

PRECAUTION:       

Ø  Above the age of 18 years can be vaccinated. Vaccine ERVEBO can protect from getting infected by one strain of Ebola virus. But it is not suitable for all strains of Ebola virus.

Ø Avoid travelling to virus exposed areas.

Ø Avoid direct or indirect contact with infected person.

TREATMENT:                                                          

v Currently two treatments approved by WHO in adults and children. The drug INMAZEB, is a combination of three monoclonal antibodies. The second drug EBANGA, is a single monoclonal antibody (abbreviated as mAbs). These antibodies are proteins produced in lab that act like natural antibodies to stop a virus from replicating after it has infected person. These mAbs bind to a portion of the Ebola virus’s surface called the glycoprotein, which prevents the virus from entering a person’s cell.

v Fluids given through a vein (IV) to help keep your body hydrated

v Dialysis to help clear waste from the blood.

v Vasopressor drugs to help raise blood pressure that is too low.

v Take medicine to relieve from fever, diarrhoea, nausea and pain.

v Supplemental oxygen or assisted ventilation to keep enough oxygen in the body.

v Medication to help the blood clot. 

EBOLA VIRUS RECOVERY:

           After recovering from Ebola, person may have body aches and weakness for weeks or months. Ebola can last in semen for at least three months from recovery. Women should not breastfeed until consulting with their doctor. A person who has recovered from Ebola may be immune for 10 years or longer.

CONCLUSION

          Ebola virus is a lethal pathogen that has caused significant morbidity and mortality since its discovery in 1976. While prevention and management of the disease remains a challenge, the 2014 outbreak led to new discoveries in therapeutics and vaccine, which offer a glimmer of hope for better future management of the disease. Understanding the clinical aspects, immediate diagnosis and suitable treatment are major steps toward the prevention of death and transmission of the virus to the other people.