Post on 29-Jul-2020
transcript
Coronavirus Disease 2019 (COVID-19)
General Introduction
Outline
● Welcome ● Nomenclature● Epidemiology● Microbiology – where does this come from?● Clinical presentation and outcomes● Transmission● Prevention ● Drugs and vaccines
ACKNOWLEDGEMENT
The information contained within this presentation has been curated by Dr Tim Tucker & Dr Nandi Siegfried (SEAD) through the following sources NICD, DOH……
HIGHER HEALTH appreciates the expertise and guidance of SEAD Consulting for their specialist public health input and support
HOW TO STAY INFORMED:
THIS SITUATION IS RAPIDLY EVOLVING
PLEASE CHECK FOR UPDATES ON THE NICD AND NDOH WEBSITES (www.nicd.ac.za and www.ndoh.gov.za)
Nomenclature:
Virus vs disease
Virus vs Disease
● VirusSARS-CoV-2
● DiseaseCoronaVirus Disease-2019 (COVID-19)
SARS in 2003
• A new coronavirus transmitted from (probably) bats
• SARS (severe acute respiratory syndrome) outbreak
• Guangdong province of southern China
• 8000 infections in >20 countries
• 8% mortality
• Contained and not more infections in humans
MERS in 2012
• Middle East respiratory syndrome (MERS)
• A new coronavirus transmitted from camels
• +- 200 cased with 34% mortality
Other coronavirus transmissions to humans
Epidemiology
31 December 2019
• World Health Organization (WHO) China country office reported a cluster of pneumonia cases in Wuhan, Hubei Province of China
7 January 2020
• Chinese identify virus as novel coronavirus
30 January 2020
• WHO declares a “Public Health Emergency of International Concern (PHEIC)
11 March 2020
• Pandemic
• “An epidemic occurring worldwide, or over a very wide area crossing international boundaries
Chinese and WHO declarations - timeline
Initially person-to-person transmission not
apparent
Majority of cases epidemiologically linked to a
seafood, poultry and live wildlife market in China
R0 factor >1
• Influenza = 1.3
• COVID-19 = 2 to 2.5
What makes a new epidemic? 2 factors
1: Animal to human spread
Introduction – global spread
Chinese localized outbreak
emerging into Public Health
Emergency of International
Concern
Role of asymptomatic and
minimally symptomatic cases
COVID-19: Situation update
WHO: 02 April
Globally
• Approx. 1 million confirmed
• Approx. 50,000 deaths (828)
African Region
• Emerging epidemic
“Doubling time”
Approximately 3 days
• Coronaviruses are enveloped, RNA viruses.
• Covered with protein spikes
- Looks like ‘crown’ – hence the name ‘coronavirus.’
• Many coronaviruses in humans and animals
• In humans
- Responsible for the common cold
- Usually cause self-limited upper respiratory tract infections.
Microbiology
Chinese authorities reported on 7 January 2020 that the causative pathogen was identified as a novel coronavirus
• SARS CoV2
SARS CoV2 related to bat coronaviruses
• Genetic (RNA) sequence >96% identical to Rhinolophus bat coronavirus
• Only 79% identical in genetic to original SARS
SARS CoV2 most likely went from bats to humans
• Maybe with an intermediary animal – Malaysian pangolin
Current coronavirus transmission
Clinical Presentation
COVID-19
Incubation period
• 1-12 days
• Median 5.5 days
Influenza-like symptoms
• Most common presenting symptom has been fever
• ~90%, but only present in 44% on admission
• Other common symptoms include
cough (68%), fatigue (38%), sputum production (34%), shortness of breath (19%), myalgia or arthralgia (15%), sore throat (14%), headache (13.6%) and chills (12%)
• Gastrointestinal symptoms such as nausea or vomiting (5%) and diarrhoea (3.8%) appear to be uncommon.
• Loss of taste and/or smell
Chest X-ray and CT scan
• Abnormalities are visible on chest X-ray in ~60% of COVID-19 patients,
• In ~85% of patients’ chest CT scans.
• Both are more common with severe disease (77% and 95% respectively).
COVID-19: Clinical presentation and outcome
Severity
• Persons with underlying co-morbid illness especially pulmonary disease, and the elderly are more at risk.
• Very few children under 15 years of age
COVID-19: Clinical presentation and outcome
81%
15%
4%
Mild
Severe /hospitalized
ICU
• Vast majority of cases
Full recovery
May take several weeks, particularly in severe cases.
• Minority
Progression to acute respiratory distress syndrome (ARDS)
Multiple organ failure
Sometimes death.
• If ventilation needed
Very poor outcome
COVID-19: Clinical presentation and outcome
Very different figures from around the world
• Possibly <1%, but up to >5% (Italy)
• Do not yet know how many are without symptoms
Risk factors
• Chinese Journal of Epidemiology – 72,000 cases
• Persons with underlying co-morbid illness especially pulmonary disease, hypertension, diabetes and cancer
• HIV and TB comorbidities - unknown
• Striking age-related mortality
Zero dead under age of 9 years
Of those who are symptomatic!
COVID-19: Clinical presentation and outcome
Age Mortality
10-39 0,2%
40-49 0,4%
50-59 1,3%
60-69 3,6%
70-79 8%
>80 14,8%
Transmission & Prevention
Respiratory transmission
• Droplets
Person infected coughs, exhales, release droplets of infected fluid
Larger droplets fall on nearby surfaces and objects
People infected when touch contaminated surface then touch their eyes, nose or mouth
Can survive for hours on surfaces
People infected by breathing in droplets if standing with 1m of infected person
• Aerosols
Possible evidence to support smaller droplet sizes that remain
airborne
COVID-19 transmission: How does it spread?
Testing
Two testing concepts
• Testing for the virus : Infected now
• Testing for antibodies to the virus: Previously infected
COVID-19: Testing
Prevention
• Wash hands
Ordinary soap and water
Alcohol hand wash - At least 60%
• Cough into elbow – not on hand
If using a tissue, then wash hands immediately
• Do not touch mouth, eyes and nose
• Wash surfaces regularly
• Limit social contact
• Work from home
• National lockdown
• Social distancing
• PPE
COVID-19: Prevention
What is social distancing?
• Interpersonal space
• Stay at home
• Regional or national shutdown
What is “flattening the curve?
Benefits of “flattening the curve”
COVID-19: Prevention
www.washingtonpost.com
Treatment & Vaccines
Drugs
• Nothing yet demonstrated to work
Ramdesivir
• Anecdotal evidence for chloroquine
• “Solidarity trial” in many countries
Randomized trial
Vaccines
• Many groups working on this
• Unclear when they will be shown to work
• Then massive process to manufacture enough for the world
Drugs and vaccines for COVID-19
Thank You