Ebola Virus Disease or Ebola Haemorrhagic Fever is fast making its presence felt along the length and breadth of African continent as its recorded and verified spread which started from Guinea has engulfed Liberia, Sierra Leone and Nigeria. The disease spread is seen in majorly in the remote villages near tropical rainforests. It is the deadliest outbreak of the disease which has claimed 1145 lives out of 2127 total cases reported so far. There is no known cure for the fever and thus almost 90% of the patients lose their life.
Ebola first surfaced in 2 successive outbreaks in Sudan and in Democratic Republic of Congo in 1976. It also derives its name from the Ebola River which flows close to the village in DRC where it first showed up.
Ebola Virus is a member of family Filoviridae. The family has three members:
- Genus Ebolavirus
- Genus Marburgvirus
- Genus Cuevavirus
Genus Ebolavirus is further classified into 5 viral species. They are:
- Bundibugyo ebolavirus (BDBV)
- Zaire ebolavirus (EBOV)
- Reston ebolavirus(RESTV)
- Sudan ebolavirus(SUDV)
- Tai Forest ebolavirus(TAFV)
The most deadly species to make a mark this year are BDBV, EBOV and SUDV. The genome is nearly 19 kbps long and carry specific sequences. These are generally very coiled and highly filamentous particles.
The virus has shown easy spread in humans. It transmits through close contact with blood, secretions, organs and other body fluids. In other animals, bats are reported to be likely the largest reservoir of ebola. The African infection possibly spread from the workers handling infected chimpanzees, gorillas, fruit bats etc. in the rainforests. Men who have recovered from infection have potential to spread it for 7 weeks through their semen. The most vulnerable people are the health care workers who are treating people already infected with the disease. There are proven results of such transmissions in Africa. Experts however, rule out possibilities of a widespread occurrence as it is only spread via direct contact.
There is a lag of 2- 20 days observed between contracting the infection and manifestation of symptoms. Early signs have been equated to dengue, malaria or other tropical fevers. EVD typically causes an acute viral illness which begins with an abrupt fever, fatigue, muscle pain, headache and sore throat. Further progress is marked by vomiting, diarrhea, rash, impaired kidney and liver functions. This often leads to a worsened bleeding phase which is spelt by internal and subcutaneous bleeding. The WBC count drops considerably and liver enzymes shoot in number. People are seen to carry infection for about 2-3 months after they have recovered from the disease.
Diagnosis and Treatment
The diagnosis takes time as the early manifestations of infection are similar to other viral infections. So, the scientists start by ruling out possibilities of any other infection before boiling down to Ebola. It thus takes an extensive laboratory process to diagnose Ebola. Tests which are done for the same are:
- Antigen detection tests
- Serum neutralization tests
- RT-PCR assay
- Electron Microscopy
There is no defined cure available for the same. Even though many vaccines are being put to test. New drug therapies are constantly evaluated and tested. Patients who are badly ill need very intensive acre due to frequent dehydration.