1. Assignment
On
Submitted By:
Gaulib Haidar
NSU ID: 1510898630
Department: BBA
Course: PBH
Section: 47
Submission date: 23-02-2015
one
Submitted To:
Dr. Tanzila Rafique
BDS, FCPS, MPH
Department of Public Health
North South University (NSU)
Bashundhara, Dhaka 1229
Bangladesh
2. 1
TABLE OF CONTENTS
What is Ebola? ...................................................... 2
Background of EbolaVirus.................................... 2
What causes Ebola? .............................................. 2
Transmission......................................................... 3
Timeline ................................................................ 5
Signs and symptoms ............................................. 8
Diagnosis............................................................... 8
Prevention ............................................................. 9
Treatment and Cure............................................. 11
Conclusion .......................................................... 11
Bibliography...................................................... 11
3. 2
WHAT IS EBOLA?
Ebola, is a disease of humans and other primates caused by ebolaviruses.
It is also known as:
Ebola virus disease or EVD
Ebola hemorrhagic fever or EHF
BACKGROUND OF EBOLAVIRUS
Ebolavirus comes from the virus family Filoviridae which includes 3 genera: Cuevavirus, Marburgvirus,
and Ebolavirus. 5 species of the Ebloavirus have been identified:
1. Zaire or simply Ebola virus (EBOV)
2. Bundibugyo (BDBV)
3. Sudan (SUDV)
4. Reston
5. Taï Forest (TAFV)
The first 3, Bundibugyo ebolavirus, Zaire
ebolavirus, and Sudan ebolavirus have been
associated with large outbreaks in Africa. The virus causing the 2014 West African outbreak belongs
to the Zaire species.
WHAT CAUSES EBOLA?
EVD in humans is caused by four of five viruses of the genus Ebolavirus. The four are:
Bundibugyo virus (BDBV)
Sudan virus (SUDV)
Taï Forest virus (TAFV)
and one simply called Ebola virus (EBOV, formerly Zaire Ebola virus)
EBOV species or Zaire Ebola Virus, is the most dangerous of the known EVD-causing viruses, and is
responsible for the largest number of outbreaks. The fifth virus, Reston virus (RESTV), is not thought
to cause disease in humans, but has caused disease in other primates.
The virus is transmitted to people from wild animals and spreads in the human population through
human-to-human transmission.
Electron micrograph of an Ebola virus virion
4. 3
TRANSMISSION
Ebola virus is transmitted into human in two ways:
1. Animal-to-human
2. Human-to-human
Animal-to-human:
It is thought that fruit bats of the Pteropodidae family are natural Ebola virus hosts. Ebola is introduced
into the human population through close contact with the blood, secretions, organs or other bodily
fluids of infected animals such as chimpanzees, gorillas, fruit bats, monkeys, forest antelope and
porcupines found ill or dead or in the rainforest.
However, the virus can be easily transferred to humans from an infected animal like pig through its
fluids and flesh.
Human-to-human:
Between humans, Ebola disease spreads only by direct contact with the blood or body fluids of a
person who has developed symptoms of the disease. Body fluids that may contain Ebola viruses
include:
Saliva
Mucus
Vomit
Feces
Sweat
Tears
Breast milk
Urine
Semen.
The WHO states that only people who are very sick are able to spread Ebola disease in saliva, and
whole virus has not been reported to be transmitted through sweat. Most people spread the virus
through blood, feces and vomit.
Entry points for the virus include:
Nose
Mouth
Eyes
Open wounds
Cuts
Abrasions
5. 4
Some common ways of transmission of Ebola virus from human-to-human are mentioned below:
Ebola may be spread through large droplets; however, this is believed to occur only when a
person is very sick. This can happen if a person is splashed with droplets.
Contact with surfaces or objects contaminated by the virus, particularly needles and syringes,
may also transmit the infection.
The virus is able to survive on objects for a few hours in a dried state, and can survive for a
few days within body fluids.
The Ebola virus may be able to persist for up to 8 weeks in the semen after recovery, which
could lead to infections via sexual intercourse.
Ebola may also occur in the breast milk of women after recovery, and it is not known when it
is safe to breastfeed again.
Burial ceremonies in which mourners have direct contact with the body of the deceased
person can also play a role in the transmission of Ebola.
Health-care workers have frequently been infected while treating patients with suspected or
confirmed EVD. This has occurred through close contact with patients when infection control
precautions are not strictly practiced.
However, some misconceptions about transmission of the virus into humans are:
Spread of the disease through the air between primates, including humans, has not been
documented in either laboratory or natural conditions.
Spread of EBOV by water, or food other than bushmeat, has not been observed.
No spread by mosquitos or other insects has been reported.
6. 5
TIMELINE
In 1976, the disease was first identified in two simultaneous outbreaks:
One in Nzara, South Sudan (then part of Sudan) and
The other in a village named Yambuku of Zaire (now Democratic Republic of Congo) near the
“Ebola River” from which the disease takes its name.
In 1995, the second major outbreak occurred in Zaire (now the Democratic Republic of the Congo,
affecting 315 and killing 254.
In 2000, Uganda had an outbreak affecting 425 and killing 224; in this case the Sudan virus was
found to be the Ebola species responsible for the outbreak.
In 2003, there was an outbreak in the Republic of the Congo that affected 143 and killed 128, a
death rate of 90 percent, the highest death rate of a genus Ebolavirus outbreak to date.
In 2004, a Russian scientist died from Ebola after sticking herself with an infected needle.
In 2007,
Between April and August, a fever epidemic which took place in a four-village region of the
Democratic Republic of the Congo was confirmed in September to have cases of Ebola. Many
of the dead were people who attended the recent funeral of a local village chief. The 2007
outbreak eventually affected 264 individuals and resulted in the deaths of 187.
Later on 30 November 2007, the Uganda Ministry of Health confirmed an outbreak of Ebola
in the Bundibugyo District in Western Uganda. After confirmation of samples tested by the
United States National Reference Laboratories and the Centers for Disease Control, the
World Health Organization confirmed the presence of a new species of genus Ebolavirus,
which was tentatively named Bundibugyo. The WHO reported 149 cases of this new strain
and 37 of those led to deaths
In 2012,
The WHO confirmed two small outbreaks in Uganda.
The first outbreak affected 7 people and resulted in the death of 4.
The second affected 24, resulting in the death of 17.
The Sudan variant was responsible for both outbreaks.
On 17 August, the Ministry of Health of the Democratic Republic of the Congo reported an
outbreak of the Ebola-Bundibugyo variant in the eastern region. Other than its discovery in
2007, this was the only time that this variant has been identified as responsible for an
outbreak. The WHO revealed that the virus had sickened 57 people and claimed 29 lives. The
probable cause of the outbreak was tainted bush meat hunted by local villagers around the
towns of Isiro and Viadana.
7. 6
In 2014,
On March, the World Health Organization (WHO) reported a major Ebola outbreak in Guinea,
a western African nation. Researchers traced the outbreak to a two-year old child who died
December 2013. The disease then rapidly spread to the neighboring countries of Liberia and
Sierra Leone. It is the largest Ebola outbreak ever documented, and the first recorded in the
region. In a 26 September statement, the WHO said, "The Ebola epidemic ravaging parts of
West Africa is the most severe acute public health emergency seen in modern times. Never
before in recorded history has a biosafety level four pathogen infected so many people so
quickly, over such a broad geographical area, for so long." As of 18 February 2015, 23,406
suspected cases and 9,467 deaths had been reported; however, the WHO has said that these
numbers may be underestimated.
As of 15 October 2014, there have been 17 cases of Ebola treated outside of Africa, four of
whom have died.
On 19 September, Eric Duncan flew from his native Liberia to Texas; 5 days later he
began showing symptoms and visited a hospital, but was sent home. His condition
worsened and he returned to the hospital on 28 September, where he died on 8
October. Health officials confirmed a diagnosis of Ebola on 30 September—the first
case in the United States.
In early October, Teresa Romero, a 44-year-old Spanish nurse, contracted Ebola after
caring for a priest who had been repatriated from West Africa. This was the first
transmission of the virus to occur outside of Africa. On 20 October, it was announced
that Teresa Romero had tested negative for the Ebola virus, suggesting that she may
have recovered from Ebola infection.
On 12 October, the CDC confirmed that a nurse in Texas who had treated Duncan
was found to be positive for the Ebola virus, the first known case of the disease to be
contracted in the United States.
On 15 October, a second Texas health-care worker who had treated Duncan was
confirmed to have the virus. Both of these people have since recovered.
On 23 October, a doctor who returned to the United States from Guinea after
working with Doctors Without Borders, tested positive for Ebola. His case is
unrelated to the Texas cases. The person has recovered and was discharged from
Bellevue Hospital Center on November 11
On 29 December, the first case was confirmed in the United Kingdom. Pauline
Cafferkey, a British nurse who had just returned to Glasgow from Sierra Leone was
diagnosed with Ebola at Glasgow's Gartnavel General Hospital. After initial treatment
in Glasgow, she was transferred by air to RAF Northolt, then to the specialist high-
level isolation unit at the Royal Free Hospital in London for longer-term treatment.
9. 8
SIGNS AND SYMPTOMS
The incubation period, that is, the time interval from infection with the virus to onset of symptoms is
2 to 21 days, usually between 4 to 10 days. Humans are not infectious until they develop symptoms.
First symptoms are:
Sudden onset of fever fatigue, higher than 38.3 °C (100.9 °F)
Muscle pain
Headache
Sore throat
This is often followed by:
Vomiting
Diarrhea
Abdominal Pain
Next the following may occur:
Shortness of breath
Chest pain
Swelling
In about half of the cases, the skin
may develop a maculopapular rash, a
flat red area covered with small
bumps, 5 to 7 days after symptoms begin
Symptoms of impaired kidney and liver function
In some cases, both internal and external bleeding (e.g. oozing from the gums, blood in the
stools), typically begins five to seven days after the first symptoms
In some cases, bleeding into the whites of the eyes
DIAGNOSIS
It can be difficult to distinguish EVD from other infectious diseases such as malaria, typhoid fever and
meningitis. Confirmation that symptoms are caused by Ebola virus infection are made using the
following investigations:
Antibody-capture Enzyme-Linked Immunosorbent Assay (ELISA)
Antigen-Capture Detection Tests
Serum Neutralization Test
Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) Assay
Electron Microscopy
Virus isolation by cell culture
Samples from patients are an extreme biohazard risk; laboratory testing on non-inactivated samples
should be conducted under maximum biological containment conditions.
10. 9
PREVENTION
Good outbreak control relies on:
Applying a package of interventions
Namely case management
Surveillance and contact tracing
A good laboratory service
Safe burials
Social mobilization
Community engagement by raising awareness of risk factors for Ebola infection and protective
measures that individuals can take is an effective way to reduce human transmission
Risk reduction messaging should focus on several factors:
Reducing the risk of wildlife-to-human transmission:
Prohibiting contact with infected fruit bats or monkeys/apes and the consumption of
their raw meat.
Handling animals with gloves and other appropriate protective clothing.
Thoroughly cooking animal products (blood and meat) before consumption.
Reducing the risk of human-to-human transmission:
Prohibiting direct or close contact with people with Ebola symptoms, particularly with
their bodily fluids.
Wearing gloves and appropriate personal protective equipment when taking care of
ill patients at home.
Regular hand washing after visiting patients in hospital, as well as after taking care of
patients at home.
Outbreak containment measures:
Prompt and safe burial of the dead
Identifying people who may have been in contact with someone infected with Ebola
Monitoring the health of contacts for 21 days
Separating the healthy from the sick to prevent further spread
11. 10
Maintaining good hygiene and a clean environment
Controlling infection in health-care settings:
Health-care workers should always take standard precautions when caring for patients, regardless of
their presumed diagnosis. These include:
Basic hand hygiene
Respiratory hygiene
Use of personal protective equipment (to block splashes or other contact with infected
materials)
Safe injection practices
Safe burial practices.
Health-care workers caring for patients with suspected or confirmed Ebola virus should apply extra
infection control measures to prevent contact with the patient’s blood and body fluids and
contaminated surfaces or materials such as clothing and bedding. When in close contact (within 1
meter) of patients with EBV, health-care workers should wear:
Face protection: a face shield or a medical mask and goggles
A clean, non-sterile long-sleeved gown
Gloves (sterile gloves for some procedures)
Laboratory workers are also at risk. Samples taken from humans and animals for investigation of Ebola
infection should be handled by trained staff and processed in suitably equipped laboratories.
12. 11
TREATMENT AND CURE
It is a matter of great sorrow and threat that there is no FDA-approved vaccine or medicine (e.g.,
antiviral drug) available for Ebola. However, a range of potential treatments including blood products,
immune therapies and drug therapies are currently being evaluated with 2 potential vaccines
undergoing human safety testing.
Symptoms of Ebola and complications are treated as they appear. The following basic interventions,
when used early, can significantly improve the chances of survival:
Providing intravenous fluids (IV) and balancing electrolytes (body salts).
Maintaining oxygen status and blood pressure.
Treating other infections if they occur.
Recovery from Ebola depends on good supportive care and the patient’s immune response. People
who recover from Ebola infection develop antibodies that last for at least 10 years, possibly longer. It
is not known if people who recover are immune for life or if they can become infected with a different
species of Ebola. Some people who have recovered from Ebola have developed long-term
complications, such as joint and vision problems.
CONCLUSION
WHO aims to prevent Ebola outbreaks by maintaining surveillance for Ebola virus disease and
supporting at-risk countries to developed preparedness plans. When an outbreak is detected WHO
responds by supporting surveillance, community engagement, case management, laboratory services,
contact tracing, infection control, logistical support and training and assistance with safe burial
practices.
The objective of this document is to describe preparedness, prevention, and control measures that
have been implemented successfully during previous epidemics. Ebola virus disease constitute a major
public health issue in Sub-Saharan Africa as well as the whole world if not dealt with within time. With
no licensed cure to Ebola, it can ransack and utter destruction to the whole human race. So the time
has come when all the nations of the world come together to resolve this burning public health issue
before it becomes a global disaster and threatens our existence.
BIBLIOGRAPHY
Ebola virus disease. (n.d.). Retrieved from Wikipedia, the free encyclopedia:
http://en.wikipedia.org/wiki/Ebola_virus_disease
Ebola virus disease. (2014, September). Retrieved from World Health Organization: WHO:
http://www.who.int/mediacentre/factsheets/fs103/en/
List of Ebola outbreaks. (n.d.). Retrieved from Wikipedia, the free encyclopedia:
http://en.wikipedia.org/wiki/List_of_Ebola_outbreaks
