The incidence of myocarditis and pericarditis in unvaccinated Covid patients

Put simply, not every single patient in the study was appropriately tested for myocarditis and/or pericarditis. The statistics provided by this retrospective cohort study depend on the outcome of patients traversing the healthcare system of the population in question. These statistics are really telling you the outcome of multiple probabilistic events (listed below). Once you think through each of these events, it quickly becomes apparent that all of the biases lead these conditions to be dramatically undercounted.

1. Patient sought healthcare 2. Patient reported symptoms doctor could identify as potential myocarditis and or pericarditis 3. Doctor recognized symptoms 4. Doctor ordered appropriate diagnostic testing 5. Radiologist recognized the condition.

Let's look at each of these.

1. Given this was a retrospective study, we know that (1) happened 100% of the time. No problem here.

2 and 3. A patient with myocarditis may have one or more of the symptoms below. Some of these symptoms, such as swelling in the lower extremities, are likely a dead give away. However, most are extremely common in COVID.

- Signs of a viral infection, such as body aches, joint pain, fever, headaches, vomiting, diarrhea or a sore throat. - Rapid or abnormal heart rhythms (arrhythmias). - Chest pain. - Shortness of breath, both at rest and during physical activity. - Swelling of your lower extremities (legs, ankles and feet). - Fatigue.

I would wager that most patients who demonstrated one or more of these symptoms indicative for potential myocarditis/pericarditis were not actually tested for the disease. To get tested, a patient lacking extreme myocarditis would likely have to push and push hard to get the doctor to test. This *heavily* biases the results toward under counting.

4. Diagnosing COVID-caused myocarditis and pericarditis is hard. The typical standard of care, at least in the US, is an echocardiogram. This diagnostic ultrasound can indeed pick up some forms of the disease but multiple papers have shown that COVID-caused myocarditis and pericarditis can be invisible on an echocardiogram. The definitive scan is a specialized MRI machine capable of a particular scan sequence. This machine is hard to find even in major health centers (there are three of them total in the Washington DC area). The cost of an MRI is at least an order of magnitude more than an echocardiogram. The echo takes about 15 minutes whereas the cardiac MRI is about 90 minutes. Thus, it is highly unlikely that the doctors in question ordered the appropriate test that can actually detect the disease in question. This further biases the findings in the same direction.

Finally, the study looks at patients from March 2020 and January 2021. The fact that COVID myocarditis and pericarditis can typically only be resolved on a specialized cardiac MRI was not common knowledge for most of the study period.

Thus, the conclusions from this study are DRAMATICALLY underestimated.

> Vaccination was most strongly associated with an elevated risk of myocarditis (risk ratio, 3.24; 95% confidence interval [CI], 1.55 to 12.44; risk difference, 2.7 events per 100,000 persons; 95% CI, 1.0 to 4.6)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9025013/

Giving the risk difference in terms of events per 100,000 people is useful. It's also trickier to interpret because the length of the follow-up period is important: if the vaccine changes the rate of events, then a study that observes patients for two years after vaccination will have (roughly) double the number of events of a study that follows patients for one year after vaccination. That's why people like relative risks in this setting.

Here is but one such paper - https://link.springer.com/article/10.1007/s11695-022-06338-9

> Gastric specimens from 26 (32.5%) patients and 4 (100%) cholecystectomy [gallbladder removal] specimens showed positive cytoplasmic staining for the anti-SARS-CoV-2 nucleocapsid protein in surface mucosal epithelial cells.

> The median time between initial COVID-19 infection and surgery was 274 and 380 days in the positive and negative staining groups, respectively (p = 0.371). It's not clear whether these had any long lasting symptoms since infection.

> The inclusion criteria were a history of COVID-19 with one or more gastrointestinal symptoms [during the acute phase] and a negative PCR test result at the time of bariatric surgery.

There are literally dozens of these.

The problem is that most people don't get tissues resected from inside their body when their alive and most such tissues are not tested for the virus.

With regards to the general question of persistent corona viruses, just look at FIP in cats for another such example.

The only confirmed cases of SARS-CoV-2 infections in humans lasting beyond a few weeks have been in immunocompromised patients. Their immune systems were able to somewhat suppress the virus, but not clear the infection. (There is a hypothesis that such patients were the sources for some of the variants because the extended infections gave the virus more time to evolve but that can't be conclusively proven.)

Neither of your linked articles do any such thing. They demonstrate and conclude correlation alone, and - again - correlation != causation.

The first article you linked only assesses myocarditis diagnoses after vaccination (since that's how VAERS data works), i.e. it makes zero attempt to eliminate the possibility of myocarditis having been present before having even received the vaccine and then subsequently detected later. Again: athletes (including those of the youth variety) are already at disproportionately higher risk for myocarditis, with or without the vaccine.

The second article you linked (or rather, the actual study, rather than an editorialized summary thereof) is a meta-analysis of other studies, and itself documents some pretty glaring caveats - namely, inability to control for post-vaccination infection, missing data on first v. second dose, and lack of access to the text of some of the analyzed papers. The analyzed papers all seem to have the same problem as the first one you linked: they take myocarditis diagnoses and work backwards to whether or not the patient was vaccinated, and therefore make no effort to determine whether myocarditis preceded or succeeded vaccination in the affected individuals.

A more compelling test would be to check for myocarditis, then administer the vaccine, then check for myocarditis again (and repeat for subsequent doses). That still wouldn't prove causality, but it would at least actually establish (or fail to establish) that elevated myocarditis risk actually follows vaccination rather than already existing and only being detected after vaccination.

If you're going to accuse me of "nonsense bordering on medical misinformation", you are encouraged to refrain from doing the same.