Ebola: The deadly virus strikes again!
Ebola virus causes acute hemorrhagic fever leading to up to 90% lethality.
The Ebolaviruses known to
have five subtypes: Ebola virus (Formerly known as Zaire virus), Sudan
virus, Reston virus (non human), Tai Forest virus and Bundibugyo
Of the five identified
ebolavirus subtypes, four are capable of human-to-human transmission.
implicates "Fruit bats" as reservoir hosts for ebolaviruses.
Increasingly frequent outbreaks and the placement of
Ebola virus in the
category A list of potential biothreat agents have boosted interest in
Marburg Virus Disease.
Ebola Virus Disease
has a high mortality.
of new technologies (Example: reverse genetics systems) and
extensive studies on Ebola haemorrhagic fever in animal models
have substantially expanded the knowledge on the pathogenic mechanisms
that underlie this disease.
Two major factors
in Ebola virus pathogenesis are the impairment of the immune response and
The deadly disease which
has killed hundreds across West Africa (Guinea, Liberia and Sierra
Leone) has now been reported in Lagos - Nigeria. (July 2014)
39 new cases and 21
deaths have been reported in Guinea between May and June 2014. In
Sierra Leone 13 new cases have been reported during this same period.
In Liberia 11 cases have been suspected and are being followed up.
History of past outbreaks:
Ebola virus infection was
first recognized during a human outbreak in 1976 with almost
simultaneous outbreaks in both the Sudan and Zaire (now the Democratic
Republic of the Congo). It was named after a
river in the Democratic Republic of the Congo.
After an outbreak
in 1979 in the Sudan, Ebola appeared relatively quiescent until it
appeared among macaque monkeys imported from the Philippines and
housed at a primate facility in Reston, Virginia.
In late 1994, a
single case in a researcher who performed a necropsy on an ill
chimpanzee led to the identification of a new subtype, Ebola-Ivory
Africa, outbreaks of Ebola virus infection occurred from 1994 to 1997.
Another appearance was
in 2000-2001 with an Ebola outbreak in Uganda that resulted in 425
cases with 224 deaths by January 2001. In this
outbreak, events and conditions associated with acquired disease were
: funeral attendance for those who died with Ebola hemorrhagic fever, intrafamilial contact, and nosocomial
infections. Schools were closed
and a ban against funerals was enacted. In November, 2001, an
Ebola outbreak again occurred in Gabon. and in the Democratic Republic
of the Congo, and multiple outbreaks occurred in 2000-2004 in Gabon,
the Congo, Sudan, and Uganda.
Outbreaks continued in
the Congo in 2005. At the same time, it
was noted that Ebola outbreaks occurred in large mammals, mainly
chimpanzees, duikers (a type of antelope), and gorillas, and that
human outbreaks tended to follow those observed in animals. Airborne transmission
of the Ebola Zaire strain to monkeys by aerosol have been demonstrated.
The is necrosis of
the hepatocytes, fatty change and presence of large
intracytoplasmic eosinophilic inclusion bodies.
There is necrosis of
adrenal cortical cells
Lymphnodes are enlarged. Necrosis of lymphoid follicles and
medulla. There is infection of macrophages and dendritic cells
causing depletion of host immune response.
Necrosis of the red pulp.
The ebolaviruses appear to spread rapidly by close and prolonged contact with an infected person or by
inoculation from contaminated syringes and needles.
Infected patients should be strictly isolated to prevent spread of
Marburg Virus Disease
Further update on Ebola virus infection:
As long there is one
case of Ebola virus disease anywhere in the world and people are
allowed to travel, every country in the world remains at risk -
Nigeria's health minister, Onyebuchi Chukwu. September 8th 2014
The Nigeria's health minister was
absolutely right when he said those wise words.
Thomas Eric Duncan was tested
positive for the deadly Ebola virus in USA. According to official
report he travelled from Liberia to USA with no symptoms of
In USA he started showing symptoms
of Ebola and was admitted to Texas Health Presbyterian Hospital.
He died after 2 weeks.
Dallas hospital nurse Nina Pham
who took care of Thomas Eric Duncan was tested positive for Ebola.
According to report her neck was exposed while taking care of the
patient. She was shifted from Texas Health Presbyterian Hospital
to National Institutes of Health's state-of-the-art facility in
Bethesda, Maryland. She is stable and doing well.
The second nurse Amber Vinson was
infected with Ebola at the Texas Health Presbyterian Hospital in
Dallas while treating Thomas Eric Duncan, was shifted to Emory
University Hospital in Atlanta for further treatment in a
specialized isolation unit.
New cases of Ebola in West Africa
could reach 10,000 per week by December.
October 17th 2014