Ebola virus and Dengue FeverBy:Rozita Yousefian

IN THE NAME OF GOD

HISTORYFilovirus epidemics have originated from Africa and apparently from a single source in the Philippines.

• 1976: First recognized when two unrelated epidemics occurred in northern Zaire and southern Sudan, with subsequent outbreaks in Sudan, Zaire, Ivory Coast, Gabon, Uganda, DRC, and South Africa

• 1989-1991: Another Ebola subtype in Reston, Virginia, among dying cynomolgus monkeys,o1992 in Italyo1996 in the US .

• Classified among the highest priority for bioterrorism agents.

What is ebula?

Ebola HF is a severe, often-fatal disease in humans and nonhuman primates

The virus is one of two members of a family of RNA viruses called the Filoviridae

There are five identified subtypes of Ebola virus. Four of the five have caused disease in humans: Ebola-Zaire, Ebola-Sudan, Ebola-Ivory Coast and Ebola-Bundibugyo. The fifth, Ebola-Reston, has caused disease in nonhuman primates, but not in humans.

Disease Agent Characteristics:

Family: Filoviridae; Genus: Ebolavirus

Virion morphology and size: Enveloped, helical, cross-striated nucleocapsid, filamentous or pleomorphic virions that are flexible

with extensive branching80 nm in diameter and 970-1200 nm in length

Nucleic acid: Linear, negative-sense, single-strandedRNA, ~18,900 kb in length

Physicochemical properties: Stable at room temperature and can resist desiccation; inactivated at 60°C for30 minutes; infectivity greatly reduced or destroyed by UV light and gamma irradiation, lipid solvents

The crystal structure of ebolavirus GP The three GP1 subunits(colored blue and green), mediate attachment to new host cells, and are tethered together by the three GP2subunits (white). GP2 forms the proteinmachinery which drives fusion of the viralmembrane with the host cell. The humanantibody KZ52 (yellow) binds an epitope atthe base of the GP chalice where it bridgesGP1 to GP2.

Ebola Virus Replication

Infection, spread and target cell destruction by Ebola virus

How is it spread?

researchers have hypothesized that the first patient becomes infected through contact with an infected animal.

direct contact with the blood and/or secretions of an infected person

contact with objects, such as needles, that have been contaminated with infected secretions.

Symptoms and Signs

The incubation period for Ebola HF ranges from 2 to 21 days

The onset of illness is abrupt and is characterized by;Fever headache muscle aches sore throat

Weekness followed by diarrhea, vomiting, and stomach pain.

After 5 days rash, red eyes, hiccups and internal and external bleeding may be seen in some patients.

Laboratory diagnosed of ebula

Virus culture antigen detection IgG and IgM antibody serology and electron

microscopy ELISA and PCR

treatment

There is no standard treatment for Ebola HF.

Patients receive supportive therapy. This consists of balancing the patient’s fluids and electrolytes, maintaining their oxygen status and blood pressure, and treating them for any complicating infections.

Vaccine

DNA vaccine VLP-based ebola virus VSV-based ebola virus DNA prime boost adenovirus vaccine

prevention

wearing of protective clothing, such as masks, gloves and goggles

isolation of Ebola HF patients from contact with unprotected persons.

Using properly disinfected equipment and educating health care

worker.

If a patient with Ebola HF dies, it is important that direct contact with the body of the dead person be prevented.

What is

mosquito-borne disease and viral illness caused by infection with 1 of 4 types of the dengue virus.

When a person recovers from dengue infection they develop a long-term (not always lifetime) immunity to that type, but not

the other 3 types. If the person is infected again with a different virus type, they

may develop the more severe form of the illness known as DHF.

World Distribution of Dengue 2008

Dengue Risk Areas No Known Dengue Risk

Pacific ocean

Atlantic Ocean

Indian Ocean

How is it spread?

by the bite of an infected dengue mosquito (usually the Aedes aegypti species).

There is no spread from human to human

Symptomes of dung fever

Sympotomes of DHF

It commonly seen in children under 15 years but can also occur in adults.

It begins with the same symptoms as dengue fever but is followed by rapid deterioration, bleeding and cardiovascular collapse 2-5 days later.

The duration of DHF depends on the severity of the illness

and response to treatment. It can be fatal.

Laboratory diagnostic

RT-PCR serologic diagnosis by testing for IgM antibodies to

dengue with an IgM antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA).

……..

Treatment?

There is no specific treatment or vaccine.

Aspirin and non-steroidal anti-inflammatory drugs should not be used as they can affect blood clotting

DHF require hospitalization with intensive monitoring and treatment.

How to avoid getting dengue fever

1) Improve environmental monitoring

2) Support better health surveillance

3) Improve mosquito control

4) Reduce global warming pollution to decrease the extent and severity of warming

5) Provide information for travelers visiting high-risk dengue areas

RefrencesJason S. Richardson.et all,Recent advances in ebola virus vaccine development,Human vaccines6:6 439-449,2010

 

Ebola Hemorrhagic Fever Information Packet , Division of High-Consequence Pathogens and Pathology National Center for Emerging Zoonotic Infectious

Diseases Centers for Disease Control and Prevention U.S. Department of Health and Human Services,1-12 2009

 

Apendix 2, TRANSFUSION,49-2009

 

Kim Knowlton,et all, Mosquito-Borne Dengue Fever

Threat Spreading in the Americas, Natural Resources Defense Council,2009

 

Dengue fever,center of Disease Control,2010