People don't really understand exponential growth or probabilities. If you were sick with a respiratory virus in Jan 2020, it was almost certainly cold, flu, or RSV. If you were sick with a respiratory virus in Jan 2021, it was almost certainly either a cold or COVID. COVID was doubling roughly every 5 days from a zoonosis in late October 2019, so by Jan 2020 we'd expect about 2^12 = 4096 cases worldwide = 1 in a million odds. But it spreads more readily than flu and RSV, so the countermeasures we put in place to stop COVID basically completed halted flu/RSV transmission over 2020.
Streptococcus pneumoniae is actually the #1 cause of pneumonia. Streptococcus agalactiae also commonly causes pneumonia in infants.
Can you provide any citation or reference on this claim? 5 days sounds about right to me, but I'm not yet aware of any literature supporting that number so I would be grateful to learn more.
I agree with your general point regarding the statistical improbability.
However it's important to be aware that multiple recent studies have documented serological evidence suggesting that SARS-CoV-2 was circulating in the United States earlier than previously recognized - as early as 13–16 December 2019 [1][2]. For reference that is over a month before the first officially confirmed case in Washington state (15-19 January 2020) [3]. Furthermore, reports have identified a hospitalized patient with confirmed SARS-CoV-2 infection in Wuhan with symptom onset as early as 1 December 2019 [1].
So when people say they had COVID in early 2020, consider that it may not be as unlikely as we originally thought. Hindsight and future research may reveal a need to further adjust the timeline.
> These findings indicate that SARS-CoV-2–reactive antibodies were detected in 106 specimens, a small percentage of blood donations from California, Oregon, and Washington, as early as 13–16 December 2019. The presence of these serum antibodies indicate that isolated SARS-CoV-2 infections may have occurred in the western portion of the United States earlier than previously recognized [1]
[1] Serologic Testing of US Blood Donations to Identify Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)–Reactive Antibodies: December 2019–January 2020 https://academic.oup.com/cid/article/72/12/e1004/6012472
[2] Identification of the first COVID-19 infections in the US using a retrospective analysis https://assets.researchsquare.com/files/rs-707353/v1/baa84b8...
[3] https://www.cdc.gov/media/releases/2020/p0121-novel-coronavi...
My 1 year old daughter came down with a bizarre rash on New Years Eve in 2019. We took her to a pediatric urgent care where they diagnosed her with a viral rash (not uncommon, anyone with kids is probably familiar). Some Tylenol did the trick and she was fine.
Two days later we followed up with her doctor, who did a full exam and did not identify anything in particular. The next day, she was acting lethargic and had a slight fever. Nothing we hadn't dealt with before. That night though, things took a turn for the worst. She began vomiting heavily and had a febrile seizure which prompted us to call 911 and they transported her to the ER.
There, her temperature was 103 and they immediately administered medication. A chest x-ray showed she had developed pneumonia in one of her lungs.
The next day when we were finally discharged from the hospital, I realized I too had developed a terrible fever which soon turned into a cough. My daughter had rapidly improved after treatment for the pneumonia, while I was suffering from a terrible cough. Laying in bed, I became delusional with a high fever, sweating through everything I wore, and went to the ER twice over the span of 4 days with shortness of breath. My sense of smell and taste was gone. I had a residual cough for about 2 weeks after.
You're probably thinking, wow, you and your daughter had COVID-19 in January of 2020. And you'd most likely be wrong. We both had RSV, confirmed through rapid testing. I was tested later in 2020 for the COVID-19 antibodies, and nothing popped up.
Take that into account when people say they had COVID in early 2020.