Thread by @Vaccinologist

[Pls RT] #COVID19 virus #SARSCoV2, #SARSCoV, #MERS - all #coronaviruses: are they closely related? Excellent @CMIJournal review by @oergonul1 & #InfectiousDisease experts from @INMISpallanzani @UninaIT @KU_Medicine @OmaniMOH @ESCMID #IDTwitter #MedTwitter clinicalmicrobiologyandinfection.com/article/S1198-…

Although related to the Severe Acute Respiratory Syndrome (#SARSCoV) & the Middle East Respiratory Syndrome (#MERS), #COVID19 virus #SARSCoV2 shows some peculiar pathogenetic, epidemiological & clinical features which have not been completely understood to date.

#SARSCoV2 is more phylogenetically related to #SARSCoV than to #MERS. Only minor differences have been found in the #genome sequences of SARS-CoV-2 comparing with SARS-CoV. SARS-CoV-2 affinity for angiotensin converting enzyme 2 (#ACE2) receptor is higher than in SARS-CoV.

#COVID19 #SARSCoV2 fatality rate (so far!) is lower than that found in #SARSCoV and #MERS. SARS-CoV-2 #RNA has been detected in the stools of infected patients, similar to SARS-CoV and MERS-CoV. Thus far, 1.2% of COVID-19 cases are asymptomatic.

#COVID19 not very different from #SARS & #MERS with regards to demographic characteristics, lab & radiological findings. Complications in COVID-19 are as frequent as in SARS, but less frequent than in MERS.

Viral loads in #COVID19 patients higher at the time of symptoms onset & progressively decrease during the clinical course of the disease.

https://twitter.com/Vaccinologist/status/1246146754313158657

Remaining questions: 1) role of amino acid substitutions on the #SARSCoV2 receptor binding domain in terms of pathogenesis 2) Does the higher affinity of SARS-CoV-2 than #SARSCoV for angiotensin converting enzyme 2 (#ACE2) receptor have implications in respiratory complications?

More questions: 3) fecal-oral transmission possible for #COVID19? 4) role of asymptomatic COVID-19 cases in the epidemiology of the disease? 5) what is the ACTUAL COVID-19 #SARSCoV2 basic reproductive number (R0)? US CDC latest: R0 5.7 (95% CI 3.8–8.9)

https://twitter.com/Vaccinologist/status/1247869169162428416

Still more questions: 6) Are differences in viral kinetics in respiratory tract responsible for the different spreading potential of #COVID19 #SARS #MERS? 7) What is the minimal infective dose / lowest # of viral particles that cause an infection in 50% of individuals? #IDtwitter