EBOLA VIRUS DISEASE

Rifat Mannan,MDResident, Dept. of Pathology

Mt.Sinai St.-Luke’s Roosevelt Hospital Center,New York

What is Ebola?• EBOLA VIRUS DISEASE [previously called Ebola

Hemorrhagic Fever]is a fatal viral hemorrhagic fever , caused by Ebola virus.

• The first Ebolavirus species was discovered in 1976 in the Democratic Republic of the Congo near the Ebola River.

• Since then, outbreaks have appeared sporadically.

2014 EVD OUTBREAK

2014 EVD OUTBREAK

US patients• On 31 July 2014, CDC issued a travel advisory for

Guinea, Liberia and Sierra Leone, warning against non-essential travel.

• American aid worker Kent Brantly, infected with the Ebola virus, was flown to the US at the beginning of August and treated at Emory University Hospital, near the headquarters of the CDC. He had become infected while working in a Monrovia treatment center as medical director for the aid group Samaritan’s Purse.

• Nancy Writebol, one of Brantly's missionary coworkers, became infected at the same time and was flown to the same hospital

EBOLA VIRUS

The virus belongs to Filoviridae family.

There are five identified subspecies :• Bundibugyo ebolavirus (BDBV)• Zaire ebolavirus (EBOV): current outbreak• Sudan ebolavirus (SUDV)• Taï Forest ebolavirus (TAFV)• Reston ebolavirus (RESTV): not in humans

VIRUS STRUCTURE

• Ebolavirions contain linear nonsegmented, single-strand, RNA genomes of negative polarity

• Like all filoviruses, ebolavirions are filamentous particles that may appear in the shape of a shepherd's crook or in the shape of a "U" or a "6", and they may be coiled, toroid, or branched.

• Median particle length ranges from 974 to 1,086 nm; 80 nm in width.

Clinical presentation

• Symptoms may appear anywhere from 2 to 21

days after exposure to ebolavirus [8-10 days is MC]

Typical symptoms

• Fever• Headache• Joint and muscle aches• Weakness• Diarrhea• Vomiting• Stomach pain• Lack of appetite

How is Ebola transmitted?

• Fruit bats of the Pteropodidae family are considered to be the natural host of the Ebola virus.

Transmission to humans

• The virus is transmitted to people from wild animals.

• Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals.

• In Africa, infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest.

Transmission among humans

• through direct contact with the blood or bodily fluids of an infected symptomatic person

• though exposure to objects (such as needles) that have been contaminated with infected secretions.

• The viruses often spread through families and friends because they come in close contact with infectious secretions when caring for ill persons.

• During outbreaks of Ebola HF, the disease can spread quickly within health care settings (such as a clinic or hospital).

• Exposure to virus can occur in health care settings where hospital staff are not wearing appropriate protective equipment, such as masks, gowns, and gloves.

• Proper cleaning and disposal of instruments, such as needles and syringes, is also important.

• If instruments are not disposable, they must be sterilized before being used again. Without adequate sterilization of the instruments, virus transmission can continue and amplify an outbreak.

Transmission in Health care settings

Can Ebola be transmitted through the air?

• No. Ebola is not a respiratory disease; not transmitted through the air.

Can we get Ebola from contaminated food or water?

• No. Ebola is not a food-borne illness.

Can we get Ebola from a person who is infected but doesn’t have any symptoms?

• No. Individuals who are not symptomatic are not contagious. In order for the virus to be transmitted, an individual would have to have direct contact with an individual who is experiencing symptoms.

Diagnosis

• Diagnosing EVD in an individual who has been infected for only a few days is difficult, because the early symptoms are non specific.

• However, if a person has the early symptoms of Ebola HF and there is reason to believe that Ebola HF should be considered, the patient should be isolated and public health professionals notified. Samples from the patient can then be collected and tested to confirm infection.

LABORATORY DIAGNOSIS

Treatment

Supportive therapy :• balancing the patient’s fluids and electrolytes• maintaining their oxygen status and blood

pressure• treating them for any complicating infections

Prevention

• The prevention of EVD presents many challenges. • Still unknown how exactly people are infected , there

are few established primary prevention measures.• When cases of the disease do appear, there is

increased risk of transmission within health care settings.

• Therefore, health care workers must be able to recognize a case of EVD and be ready to employ practical viral hemorrhagic fever isolation precautions or barrier nursing techniques. They should also have the capability to request diagnostic tests or prepare samples for shipping and testing elsewhere.

What is CDC doing in the U.S.?

• On the remote possibility that an ill passenger enters the U.S., CDC has protocols in place to protect against further spread of disease.

• These include notification to CDC of ill passengers on a plane before arrival, investigation of ill travelers, and, if necessary, isolation.

• CDC has also provided guidance to airlines for managing ill passengers and crew and for disinfecting aircraft.

• CDC has issued a Health Alert Notice reminding U.S. healthcare workers of the importance of taking steps to prevent the spread of this virus, how to test and isolate suspected patients and how they can protect themselves from infection

http://www.bt.cdc.gov/han/han00364.asp

Patient Evaluation Recommendations to Healthcare Providers

• Early recognition is critical for infection control. Healthcare providers should be alert for and evaluate any patients suspected of having EVD.

Case Definition for EVDSuspected Case• Illness in a person who has both consistent symptoms and risk factors as follows: 1) Clinical criteria : fever > 38.6 degrees C / 101.5 degrees F, and additional symptoms such as severe

headache, muscle pain, vomiting, diarrhea, abdominal pain, or unexplained hemorrhage;

AND 2) Epidemiologic risk factors within the past 3 weeks before the onset of symptoms, - contact with blood or other body fluids of a patient known to have or suspected

to have EVD; - residence in—or travel to—an area where EVD transmission is active; - direct handling of bats, rodents, or primates from disease-endemic areas. • Malaria diagnostics should also be a part of initial testing.

Case Definition for EVD

Confirmed Case• A suspected case with laboratory-confirmed

diagnostic evidence of ebolavirus infection.

CDC recommends testing for all persons with onset of fever within 21 days of having a high-risk exposure.Any of the following:• percutaneous / mucous membrane exposure/ direct skin

contact with body fluids of a person with a confirmed or suspected case of EVD without appropriate personal protective equipment (PPE)

• laboratory processing of body fluids of suspected or confirmed EVD cases without appropriate PPE or standard biosafety precautions

• participation in funeral rites or other direct exposure to human remains in the geographic area where the outbreak is occurring without appropriate PPE.

Patient Evaluation Recommendations to Healthcare Providers

Recommended Infection Control Measures

• Patient placement: Patients should be placed in a single patient room (containing a private bathroom) with the door closed.

Healthcare provider protection:

• Healthcare providers should wear: gloves, gown (fluid resistant or impermeable), shoe covers, eye protection (goggles or face shield), and a facemask.

• Additional PPE might be required in certain situations (e.g., copious amounts of blood, other body fluids, vomit, or feces present in the environment), including but not limited to double gloving, disposable shoe covers, and leg coverings.

Aerosol-generating procedures:

• Avoid aerosol-generating procedures. If performing these procedures, PPE should include respiratory protection (N95 filtering facepiece respirator or higher) and the procedure should be performed in an airborne isolation room.

Environmental infection control• Diligent environmental cleaning and disinfection and safe handling

of potentially contaminated materials is paramount.• Appropriate disinfectants : 10% sodium hypochlorite (bleach)

solution, or hospital-grade quaternary ammonium or phenolic products.

• Healthcare providers performing environmental cleaning and disinfection should wear recommended PPE and consider use of additional barriers (e.g., shoe and leg coverings) if needed.

• Face protection (face shield or facemask with goggles) should be worn when performing tasks such as liquid waste disposal that can generate splashes.

• Follow standard procedures, per hospital policy and manufacturers’ instructions, for cleaning and/or disinfection of environmental surfaces, equipment, textiles, laundry, food utensils and dishware.

Recommendations to Public Health Officials

• If public health officials have a patient that is suspected of having EVD or has potentially been exposed and intends to travel, please contact CDC’s Emergency Operations Center 1 (770) 488-7100.

What is being done to prevent ill passengers in West Africa from getting on a plane?

• CDC is assisting with active screening and education efforts on the ground in West Africa to prevent sick travelers from getting on planes.

• In addition, airports in Liberia, Sierra Leone and Guinea are screening all outbound passengers for Ebola symptoms, including fever,.

• Passengers are required to respond to a healthcare questionnaire.

• CDC is also surging support in the region by deploying 50 additional workers to help build capacity on the ground.

CDC’s Travel Alert Level 3 ?

• On July 31, the CDC elevated their warning to U.S. citizens encouraging them to defer unnecessary travel to Guinea, Liberia, and Sierra Leone over concerns that travelers may not have access to health care facilities and personnel should they need them in country.

Thank you.