Hey guys,
I thought the following might be of interest and maybe answer a few questions:
Swine Flu (H1N1)
H1N1 (in humans) is spread from human to human by contact/proximity. (It is occasionally spread from swine to human and vise versa, but these cross-species mutations are relatively mild in comparison to the human-to-human type.)
H1N1 1918 pandemic
450,000,000-600,000,000 estimated infected worldwide
50,000,000-100,000,000 dead (6%-10% mortality rate)
H1N1 2009 pandemic
43,000,000-89,000,000 estimated infected worldwide (1st year only)
2,000 dead (1st year only) (2.2%-4.6% mortality rate)
H1N1 2015 epidemic
10,000 reported infected (India only)
775 dead reported (India only) (7.8% mortality rate)
West Nile virus
West Nile is spread from infected animals or infected humans to humans via mosquito bite. No mosquito, no spread. (There may have been a few cases in where it was transmitted via blood transfusion.)
Zika virus
Zika virus is spread from infected humans to humans via mosquito bite. No mosquito, no spread. (There may have been a few cases in where it was transmitted via blood transfusion.)
SARS-CoV (Coronavirus)
Transmission (in humans) occurs from human to human by contact/proximity.
SARS-CoV February-July 2003 epidemic (pandemic?)
Transmission occurs from human to human, usually in the second week of infection. The majority of cases occurred in a health care environment due to poor sterile/isolation procedures.
8,000+ reported infected, primarily in China, but spread to 25+ countries)
780 dead reported
The overall mortality rate of ~10% was above 50% for those of age 60+.
Please note that warm weather does not appear to significantly effect the transmission of SARS-CoV. Other than exposure to elevated levels of UV light, here is no evidence, to date, of any warm climate reducing effect.*
MERS-CoV (Coronavirus)
Transmission (in humans) occurs from human to human by contact/proximity.
First known case occurred in Jordan in 2012. The outbreak has been confined in the Middle East for the most part, primarily to the Arabian Peninsula, though South Korea had an outbreak in 2015.
MERS-CoV is an equal opportunity virus, patients have ranged in age from younger than 1 to 99 years old, and most MERS-CoV patients develop severe respiratory illness with symptoms of fever, cough and shortness of breath, regardless of age. However, MERS-CoV (like SARS-CoV and COVID-19) is most likely to hit the elderly the hardest, with the large majority of deaths occurring in the 65 and older age group.
The overall mortality rate of MERS-CoV is extreme, substantially higher than that of SARS-CoV or COVID-19, at between 30% and 40%. For an as yet unknown reason, MERS-CoV does not transmit as readily as SARS-CoV and COVID-19.
During the South Korea outbreak, there were 38 deaths out of 186 confirmed cases, a mortality rate of 20%.
There have only been 2 confirmed cases in the US, with 0 US deaths.
The WHO and US CDC, along the equivalent agencies of other countries, are closely monitoring the situation in the Middle East.
Please note that warm weather does not appear to significantly effect the transmission of MERS-CoV. Other than exposure to elevated levels of UV light, here is no evidence, to date, of any warm climate reducing effect.*
COVID-19 (Coronavirus)
Transmission (in humans) occurs from human to human by contact/proximity.
Data from China shows that each COVID-19 patient seems to infect around 2 to 2.5 additional people. The average flu patient spreads the flu virus to about 1.3 others. The same data set from China shows that 20% of COVID-19 cases are serious enough to get sent to the hospital. That's about 10x times more often than flu. This is in line with US CDC findings that the hospitalization rate for the flu is 1%-2% depending on type.
As of 29 February 2020 there were 15 (22?) confirmed COVID-19 cases in the US, with 1 resulting death (in Seattle WA).
As of 15 March 2020, out of 4,226 confirmed COVID-19 cases in the US, there were 44 resulting deaths, for a mortality rate of just over 1%. 80% of US deaths related to COVID-19 were in the age group of 65+, with 34% of deaths older than 85. There had been no US COVID-19 related deaths (as of March 16) of anyone under 19 years of age.
As of 21 March 2020, out of 26,867 confirmed COVID-19 cases in the US, there were 348 resulting deaths, for a mortality rate of just under 1.3%.
The mortality rate for the seasonal flu that comes around each year is .1%, or in other words, the US mortality rate for COVID-19 is 10x-13x that of the seasonal flu, so far.
Please note that warm weather does not appear to reduce the transmission of COVID-19. Other than exposure to elevated levels of UV light, here is no evidence, to date, of any warm climate reducing effect.*
For anyone who thinks that the current behavior/actions of the WHO, US CDC, and the equivalent agencies of other countries are under- or over-estimating the potential danger of COVID-19:
SARS | Guidance in Absence of SARS-CoV Transmission Worldwide | CDC
Although the above link is to a document produced by the US CDC, the modern equivalent agencies in most other nations with capable healthcare systems, as well as the WHO, have very similar documents.
It is also telling in that - though the US has an agency (the CDC) specifically for such things, and possesses a massive modern healthcare system - even with this document from late-2003 indicating how seriously the CDC took a potential later SARS-CoV outbreak - the US was still seriously unprepared for the current COVID-19 outbreak. In this case, as far as I can tell, politics had little to do with the US experience. There was, however, a serious initial willingness to ignore the potential problems by the current government.
*A general rule is that temperatures of 60°C/140°F for 60 minutes or more are required to destroy most viruses. Except for direct exposure to sunlight on some surfaces (such as sand in the desert for one example) these temperatures do not generally occur under humans living conditions.