View source for COVID-19: Epidemiology and pathophysiology

== Virology ==
*[[Coronaviruses]] are common human pathogens
**Cause the common cold
**In epidemics, cause up to one-third of community-acquired upper respiratory tract infections in adults; and may cause diarrhea in infants and children
*[[SARS-CoV-2]] is a novel coronavirus (a new strain not previously identified in humans)
**Likely primary source = bats
**It is a betacoronavirus in the same subgenus as the severe acute respiratory syndrome (SARS) virus. Middle East respiratory syndrome (MERS) virus is another, more distantly related, betacoronavirus. Like the SARS coronavirus, SARS-CoV-2 uses angiotensin-converting enzyme 2 [ACE2] for cell entry
*Surface survival time of [[SARS-CoV-2]]: 
**stainless steel: persists for 3 hours (or longer)
**underscores the importance of environmental cleaning / disinfection
***cleaning gets rid of the proteins that would interfere with a disinfectants effectiveness
**Note: studied in a simulated lab environment. Lab virions not covered in protein and mucus and other things that would mimic real life and that could prolong survival

== Pathophysiology ==
*[[Acute respiratory distress syndrome|ARDS]] - Possibly due to direct alveolar damage by the virus AND inflammatory reaction. <ref>Xu Z, Shi L, Wang Y et al. Pathological findings of COVID-19 associated with acute respiratory distress syndrome. The Lancet Respiratory Medicine. 2020;8(4):420-422. doi:10.1016/s2213-2600(20)30076-x</ref>
*[[Cytokine release syndrome|Cytokine Storm]]

==Pathophysiology==
*[[Acute respiratory distress syndrome|ARDS]] - Possibly due to direct alveolar damage by the virus AND inflammatory reaction. <ref>Xu Z, Shi L, Wang Y et al. Pathological findings of COVID-19 associated with acute respiratory distress syndrome. The Lancet Respiratory Medicine. 2020;8(4):420-422. doi:10.1016/s2213-2600(20)30076-x</ref>
*[[Cytokine release syndrome|Cytokine Storm]] 


== Risk Factors==
*Older age
*Underlying conditions (lung disease, Renal Failure, Malignancy, heart disease, [[diabetes]])


NOT Risk Factors
*Children: milder disease
*Pregnant patients: see [[COVID-19 in pregnancy]]

==Transmission==
[[File:Ro example.png|thumb|Ro Example]]
* [[COVID-19]]: R0 = 2.2 - 4.2
** Where R0 = expected number of secondary cases produced by a single typical infection in a susceptible population (basic reproductive rate)
** R0 for seasonal flu ~ 1.3
** R0 for pandemic flu ~ 1.5-1.8
* Incubation: 5 days (median); range of 2-14 days
* Serial interval duration = 7.5 days 
** Serial interval refers to the time from illness onset in successive cases in a transmission chain

*Surface survival time of [[SARS-CoV-2]]: 
**stainless steel: persists for 3 hours (or longer)
**underscores the importance of environmental cleaning / disinfection
***cleaning gets rid of the proteins that would interfere with a disinfectants effectiveness
**Note: studied in a simulated lab environment. Lab virions not covered in protein and mucus and other things that would mimic real life and that could prolong survival

==Incubation Period==


==Infectious Period==

==See Also==
{{COVID see also}}

==References==

[[Category:COVID-19]]