coronavirus Flashcards
What is the coronavirus genome?
ss positive sense RNA. It is enveloped and has external spike slycoproteins
How does coronavirus replicate and transcribe?
It has its own virally encoded RNA dependent and RNA polymerases. Follows the same process as HIV.
Replication and assembly in cytosol, buds into ER and golgi, exits cells by exocytosis (secretion).
How does coronavirus enter a cell?
The external spike protein binds to ACE 2 (angiotensin converting enzyme 2) on the host cell membrane. TMPRSS2 (transmembrane protease serine 2) is a cellular protease that will cleave the spike protein and reveals the fusion domain on the spike protein, causing the virion to fuse with the cell membrane and the nucleocapsid will enter the cell.
What are the ‘novel’ coronaviruses?
They are all beta coronaviruses:
SARS-CoV (2003 first reported human case)
MERS-CoV (2012 first reported human case)
SARS-CoV-2 (2019 first reported human case)
SARS = Severe Acute Respiratory Syndrome
MERS = Middle East Respiratory Syndrome
Brief history of SARS:
- November 2002, Southern China, Guangdong
- Spread to a hotel February 2003 by a Chinese physician who died after 10 days.
- 8 hotel guests carried the virus to other countries
- 8439 infected, 812 died of progressive respiratory failure.
How was SARS spread? (zoology)
Reservoir - Horseshoe bats
Intermediate host - Civets (rodent)
Humans
What are the symptoms of SARS?
initial fever for a few days; non-productive cough and shortness of breath.
Possibility of developing pneumonia - fatal in 10% cases.
Brief history of MERS-CoV:
- first case Jeddah, Saudia Arabia 2012
- fatality rate = 37%
- camels -> humans
- limited spread as it requires long close contact
- can cause pneumonia and GI problems
What is the virus and disease associated with coronavirus the new pandemic?
Virus = severe acute respiratory syndrome coronavirus (SARS-CoV-2)
Disease = coronavirus disease (COVID-19)
What was the WHO response to the COVID-19 pandemic?
- 4 Jan 2020 WHO publishes first disease outbreak on new virus
- 30th Jan declared a public health emergency
- 11th Feb gets official name covid 19
- 11 March pandemic declared
How is COVID-19 transmitted?
Fomites - surfaces
Droplets - around 5 micrometres in diameter
Aerosols
What are the main symptoms of COVID-19?
- high temperature
- new, continuous cough
- loss or change in sense of smell and taste
What are symptoms of delta coronavirus?
- headache
- runny nose
- sore throat
- possibly skin rashes
What is the timeline for being infected with coronavirus?
Exposure to virus
Asymptomatic for 6-7 days
Infectious period starts 4 days in and can last 8-10 days
Illness lasts 10 days or longer after asymptomatic period.
Complications of COVID-19?
- silent hypoxia (low pO2 levels)
- ARDS (acute respiratory distress syndrome) which causes shortness of breath, lung failure, pulmanory scarring and tough recovery
- sepsis
- secondary infections
