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