Outbreak of Ebola Virus (2014)

Dr. Anton VurdaftZambia

On August 8, 2014 the WHO declared the Ebola outbreak raging in West Africa a global public health emergency of international proportions

(7)

Intro: Current Outbreak

What is Ebola Virus?

• RNA Virus of Filoviruses family• One of the viruses causing hemorrhagic fever

syndrome• Virus with extremely high mortality rates (up

to 90%)• Virus is highly contagious (fast spread)• The exact source of Ebola virus is still unknown

(2)

What is Ebola Virus?

• 5 types of Ebola virus: Sudan, Zaire, Tai Forest (formerly Ivory Coast or Côte d’Ivoire), Reston ebolavirus, Bundibugyo ebolavirus

• Of this 5 types, only 3 are truly African, and are natural killers – Sudan, Zaire and Bundibugyo Ebola Viruses.

• The last one gave an outbreak only twice (2007-2008 in Uganda, 2012 in DRC).

(2,3)

What is Ebola Virus?

• So, Zaire and Sudan Ebola Viruses are the major killers.

• Sudan virus killed in total 405 people (53% of all infected).– This includes every outbreak from 1976 to 2011.– Epidemics did not exceed 5 months.

(2)

What is Ebola Virus?

• Zaire virus killed in total 1141 (76,6% of all infected) – Including every outbreak from 1976 to December

2012 (36 years)– Epidemics did not exceed 6 months period– Epidemics did not involve several countries at one

time

(2)

Intro: Current Outbreak

• Current Epidemic is caused by virus 97% identical to Zaire Ebola Virus

• It has already spread to 4 countries (Guinea, Sierra Leone, Liberia, Nigeria).

• It has survived for NINE months already (starting from December 2013, in Guinea)

• It has already killed 1013 people (as for 13.08.2014)

(2, 6)

Intro: Current Outbreak

• So, basically, THE VIRUS HAS DOUBLED ITS TOTAL NUMBER OF VICTIMS IN ONLY 9 MONTHS.36 years (1141 deaths) 9 months (1013 deaths)*

* as for 13.08.2014 (2, 6)

Intro: Current Outbreak

Total numbers of current epidemic:• Suspected and Confirmed Case Count:

1848• Suspected Case Deaths: 1013 (373 –

Guinea, 323 – Liberia, 315 – Sierra Leone, 2 – Nigeria)• Laboratory Confirmed Cases: 1176

(6)

Intro: History of Outbreaks (Zaire Ebola Virus)

(2)

Year Location Reported Cases, No.

Deaths, No. (%)

1976 Zaire 318 280 (88)1977 Zaire 1 1 (100)1994 Gabon 52 31 (60)1995 DRC 315 250 (81)Jan 1996 to Apr 1996 Gabon 37 21 (57)Jul 1996 to Jan 1997 Gabon 60 45 (74)

Intro: History of Outbreaks (Zaire Ebola Virus)

(2)

1996 South Africa (acquired in Gabon)

1 1 (100)

Oct 2001 to Mar 2002 Gabon 65 53 (82)

Oct 2001 to Mar 2002 DRC 59 44 (75)

Dec 2002 to Apr 2003 DRC 143 128 (89)

Nov 2003 to Dec 2004 DRC 35 29 (83)

2007 DRC 264 187 (71)Dec 2008 to Feb 2009 DRC 32 15 (47)

July 2012 Uganda 24 17 (71)Nov 2012 DRC 77 36 (46)Dec 2012 Uganda 7 4 (57)Total 1490 1141 (76.6)

Transmission: Hosts

• Likely hosts, reservoirs: fruit bats (identified in 1996 by S.African specialists, who went to DRC to test the virus on plants and animals; bats were the only who survived virus replication)

• Feces and blood of infected fruit bats contained high load of viable Ebola virus (2)

Transmission: Fruit Bats

Transmission: Habitat of Fruit Bats

Transmission: Hosts

• Dogs have been shown to have asymptomatic Ebola virus infection (probably by contact with feces of products unknown hosts).

• In the areas of Ebola outbreak, infection of the dogs reaches 31,8% (asymptomatic). (2)

Transmission: Hosts

• Primates are known to transmit Reston virus (even in USA)

Transmission: Ways

• Infection occurs through the direct contact with body fluids (saliva, blood, semen); infected tissues; mucous membranes including conjunctiva, pharyngeal and gastrointestinal surface

• IS NOT AIRBORNE. (2)

Transmission: Ways

• In 1995 the virus transmission mode was tested on rhesus-monkeys. Virus spread in form of aerosol directly to the bronchi caused severe infection with death in 5-7 days. (2)

Transmission: Ways

• One study reported the observations of 24 close contacts of symptomatic patients actively infected with Ebola. Eleven of the 24 contacts developed evidence of asymptomatic infection associated with viral replication. (2)

• Lab workers are at greater risk (2)

Transmission

• Clinical infection is associated with rapid and extensive replication of virus in ALL the tissues. All body tissues and fluids are highly infectious.

(2)

Transmission: Risks• Adults (in 1995, children accounted only for 8,6% of infected)• Consumption of “bush meat” (primate carcasses)• No sex predilection• Workers of the LAB• Animal care workers• Health care workers• The persons, working abroad at affected countries (i.e.

mines), coming back home to Zambia• Any other visitors of affected countries

(2)

Transmission: Bush Meat

Bushmeat - from animals such as bats, antelopes, porcupines and monkeys - is a prized delicacy in much of West Africa but can also be a source of Ebola (10)

Transmission: Contagiousness

• Recovered person is infective for another 7 weeks (up to 61 days)

(2)

Incubation period

• Incubation period is 3-8 days in primary infections, though can be up to 21 day

• Patient is only contagious, when has symptoms

(2)

Symptoms: Clinical Criteria

• Clinical criteria for the Ebola Virus disease includes fever of greater than 38.6 degrees Celsius, and additional symptoms such as severe headache, muscle pain, vomiting, diarrhea, abdominal pain, or unexplained hemorrhage

• Malaria should be excluded first(9)

Symptoms

Onset symptoms:• Severe headache (50-74%)• Arthralgias, myalgias (50-79%)• Fever +/- chills (95%)• Anorexia (45%)• Asthenia (85-95%)

(2)

Symptoms

EARLY:• Fever• Pharyngitis• Maculopapular rash of the trunk (~ day 5 of

infection)• Bilateral conjunctival injection• Abdominal pain, nausea, diarrhea• Hiccups

(2)

Symptoms

LATER:• Expressionless facies• Bleeding from intravenous puncture sites• Bleeding from mucous membranes (50%)• Bleeding anywhere in GI tract• Myocarditis, pulmonary edema

(2)

Symptoms

TERMINAL SYMPTOMS:• Tachypnea (unfavourable sign, none survivours had

tachypnea)• Hypotension• Anuria• Obtundation• Coma• Normothermia• Shock

(2)

Symptoms of survivors

Survivors had some late symptoms:

Myalgias, Asymmetric and migratory arthralgias, Headache, Fatigue, Bulimia, Amenorrhea, Hearing loss, Tinnitus, Unilateral orchitis, Suppurative parotitis

(2)

Symptoms of survivors

• OCULAR INVOLVEMENT:– Ocular pain– Photophobia– Tearing– Decreased visual acuityIn short – this was a uveitis. Tx was usual, successful.

(2)

Differential Diagnosis

• Acute surgical abdomen• Malaria• Thyphoid• Other hemorrhagic viral fevers

(2)

Differential Diagnosis

• Cases, when Ebola confused with malaria are well documented.

• Every fever patient should be treated as an Ebola suspect

(10)

Diagnostics

• FBC (early signs – thrombocytopenia, leukopenia, pronounced lymphopenia)

• Elevated neutrophils, ALT, AST (after several days)

• Bilirubin normal or slightly elevated

(2)

Diagnostics• Terminal symptoms:• Blood urea nitrogen, serum creatinine increase, metabolic

acidosis• Serology (ELISA) + PCR + tissue culture (Zambia has

Laboratory capacity to test and confirm for Ebola at University of Zambia School of Veterinary Medicine, according to MoH statement. But, according to CDC, no attempt should be made to culture the virus, except when culture can be performed in a maximum-containment biosafety level 4 laboratory with laboratory personnel wearing positive-pressure suits equipped with high-efficiency particulate air filters and an umbilical-fed air supply)(2, 5)

Diagnostics

Histological findings:

Focal necrosis in the liver, spleen, lymph nodes, kidney, lung, and gonads

(2)

Treatment• There is no effective specific treatment or registered vaccine

currently (2)• Though experimental vaccines have been sent to the involved

countries by Canada• General medical support is needed (replacement of

coagulation factors and heparin for DIC control)• Strict care of all contact with fluids (saliva, blood, urine, stool)• Surgical intervention is usually made mistakenly due to

abdominal pains(2)

Treatment

• Supportive medical treatment:– Intravascular volume regaining– Electrolytes– Nutrition– Comfort careAre of a help for a sick person.

(2)

Treatment

• During the 1995 outbreak in Kikwit, DRC, human convalescent plasma was used to treat 8 patients with proven Ebola disease, and only 1 patient died. Subsequent studies could not demonstrate survival benefit conferred by convalescent plasma products. The survival of these patients suggests that passive immunity may be of benefit in some patients. (2)

Treatment

• Anti-Ebola immunoglobulins have been shown effective in treating the infection in some studies. No commercially available option yet.

(2)

Vaccines

• WHO (12 August, 2014) considered it to be ethical to offer unproven interventions with unknown efficacy and safety as potential treatment or prevention in the ongoing Ebola outbreak

(7)

Prophylactics

• Barrier isolation • Barrier protection – double gloves, – fluid-impermeable gowns, – face shields with eye protection, – coverings for legs and shoes.

(2)

Prophylactics

• Education of communities at risk• Education of Health Care Workers • CDC advised not to visit Sierra Leone, Guinea,

Liberia, and be especially careful with contacts in Nigeria (avoid direct blood / mucous contacts) (2)

• The involved countries of West Africa close the borders between each other (Guinea closed the borders with Sierra Leone and Liberia)(2)

Prophylactics: In The Hospital

• Admission of the patient in the situation, when hospital lacks isolation facilities; use of contaminated medical equipment AMPLIFIES the infection and causes rapid spread of nosocomial infection. (2)

• Disinfect fluids, secretions and clothes of sick patient with sodium hypochlorite 0,5%

Prophylactics: In The Hospital

• Patients should be placed in a single-patient room (containing a private bathroom) with the door closed. Medical equipment should be dedicated to the individual patient, and facilities should maintain a log of all persons entering the patient's room. Visitors should be avoided or limited.(8)

Prophylactics: In The Hospital

• For the medical staff – use of protective equipment while treating Ebola suspects.

Prophylactics: In The Hospital

Prophylactics: In The Hospital

Cleaning and/or disinfection of environmental surfaces, equipment, textiles, laundry, food utensils and dishware

(9)

Prophylactics: In The Mortuary

• Alteration in burial rituals should be implemented to avoid rapid spread

• Family members and persons involved in burials – are at risk.

• Prompt burial should be performed with as little of contact as possible(2)

Burial, Liberia

Burial, Liberia

Strict precautions must be observed when burying those who have died of Ebola, Guine (10)

Prognosis

• The overall prognosis for patients with Ebola virus infection is poor. However, those who survive for 2 weeks often make a slow recovery.

• In those patients who do recover, recovery often requires months, and delays may be expected before full resumption of normal activities. Weight gain and return of strength are slow. Ebola virus continues to be present for many weeks after resolution of the clinical illness. (2)

Prognosis

• Those die, who fail to develop humoral immunity (do not have antibodies)

• Survivors have developed enough of antibodies

• Survivors develop some late complications (as mentioned earlier) (2)

Memos distribution

• Memo distribution:• Doctors, nurses, clinical officers• Workers of the wards, the laboratory, the mortuary• Bus station, NAPSA, Market, Shoprite, Town• Radio, TV• Game parks workers (especially those ones who

work with primates)• Churches (bush meat cooking)

Memos distribution

People in Guinea are poorly informed about the virus (10)

MoH Statement• According to the statement of Zambian MoH:- Personal Protective equipment (PPE’s) for use by Health personnel has

been procured.- The National Epidemic preparedness committee has put Ebola top of its

agenda and has reactivated the provincial and district rapid response teams

- Information Education and Communication (IEC) materials have been developed and awaiting printing to educate the general public and care providers on the dangers of Ebola and how to prevent it.

- Ensure 24 hour surveillance at all busy Points of Entry in the country with specific and dedicated health care providers assigned to man them

(5)

In conclusion

• According to CDC Director Dr. Tom Frieden, "We do know how to stop Ebola. It's old-fashioned, plain and simple public health: Find the patients, make sure they get treated, find their contacts, track them, educate people, do infection control at the hospitals...do them really well and Ebola goes away.“ (8)

References:• 1 PMID: 24750692• 2 http://www.medscape.com/viewarticle/829577• 3 http://www.who.int/mediacentre/factsheets/fs103/• 4 http://emedicine.medscape.com/article/216288-overview• 5 PRESS STATEMENT ON THE THREAT OF THE EBOLA OUTBREAK

IN WEST AFRICA (MoH Zambia)• 6 http://www.cdc.gov/vhf/ebola/outbreaks/guinea/index.html• 7 http://www.medscape.com/viewarticle/829797• 8 http://www.medscape.com/viewarticle/829611_2• 9 http://emergency.cdc.gov/han/han00364.asp• 10 http://www.bbc.com/news/world-africa-26835233