The National Institute for Health Research Health Protection Research Unit in Emergency Preparedness and Response at UEA
Ebola virus disease Paul R Hunter & Samir Dervisevic The Norwich Medical School & Norfolk & Norwich NHS Trust
VIRUS CLASSIFICATION • Family Filoviridae • 3 genera: Marburg (1967), Ebola (1976), Cuevavirus (Spain 2002) • Order Mononegavirales • Enveloped, single-strand, negative-sense RNA • 5 known species: Sudan, Zaire, Tai Forest, Bundibugyo, Reston
Photo credit: http.//www.CDC.gov/media/dpk/2014/images/ebolaoutbreak/img8.jpg
CLINICAL PRESENTATION • Incubation period is 2-21 days (usually 5 – 10 days) • Abrupt onset of fever (>38ºC) • Feeling tired, muscle pain, sore throat, swollen lymph glands • Combination of nausea and vomiting, abdominal pain, diarrhoea, jaundice • Chest pain, shortness of breath, cough • Headache, confusion, coma • Maculopapular rash around day 5 is typical • In second week patient either defervesces and improves markedly or dies in shock with multi-organ dysfunction and disseminated intravasular coagulation
http://www.md-health.com/Ebola-VirusDisease-Pictures.html
TREATMENT AND PROPHYLAXIS • Mainstay of treatment is supportive care – Fluid & electrolyte balance
• No proven antiviral therapy • Zmapp (3 monoclonal antibodies against GP) – – – – –
Grown in tobacco plant Prevents virus attachment and further infection Shown to be effective in non-human primates Given after exposure to 7 people (2 died) Out of stock
• Several vaccines under development and in trial
EPIDEMIOLOGY
Photo credit: http://www.cdc.gov/vhf/ebola/resources/virus-ecology.html
Reported cases as at 8th October Country
Total Cases
Lab confirmed cases
Total deaths
Guinea Liberia Sierra Leone
1350 4076 2950
1097 943 2593
778 2316 930
Nigeria
20
19
8
Senegal Spain
1 1
1 1
0 0
United States
2 8400
2 4656
1 4033
TOTAL
CDC
ECDC
TRANSMISSION
Detection of Ebola by PCR in body fluids Sample type Phase Saliva Skin Urine Vomit
Samples tested
Positive
Acute
8
12
Convalescent
0
4
Acute
1
9
Convalescent
0
3
Acute
0
7
Convalescent
0
4
Acute
0
1
Convalescent
0
1
0
1
0
1
Sputum Acute Convalescent Bausch et al. 2007 J Inf Dis
Sample type Phase Breast milk Acute
Samples tested
Positive 0
1
Convalescent
0
1
Stool
Acute
2
4
Sweat
Acute
0
1
Tears Nasal blood Body louse
Acute
1
1
Acute
1
1
Convalescent
0
1
Semen Convalescent
1
2
Intra household/family transmission • Of 173 household contacts of a case • 28 (16%) developed infection • All 28 had direct physical contact with index case • None of 78 household contacts who did not have direct physical contact became sick Dowell et al. Transmission of Ebola Hemorrhagic Fever: A Study of Risk Factors in Family Members, Kikwit, Democratic Republic of the Congo, 1995. J Inf Dis 1999;179(Suppl 1):S87–91
Risks of household transmission of Ebola hemorrhagic fever (EHF) among 173 household contacts of 27 EHF patients, after adjusting for direct physical contact during illness and contact with the patient's body fluids.
Dowell S F et al. J Infect Dis. 1999;179:S87-S91 © 1999 by the Infectious Diseases Society of America
Univariate analysis of risk factors for Ebola hemorrhagic fever related to patient care among 83 contacts, Gulu, Uganda, 2000 Risk factors Cared for patient No Cared only during patient’s early stage Cared until the patient’s death at hospital the hospital Cared until the patient’s death at home
No. cases (%) 2 (5.0) 6 (30.0) 6 (42.9) 6 (66.7)
Crude PPR a (95%CI)
p value
1 6.00 (1.33 to 27.10) 8.57 (1.95 to 37.66) 13.33
