宇野






私は、胃のｐHが3以下の人では新型コロナウイルスが重篤化しにくいという仮説をたてています。

逆に、胃のｐHが3以上であれば、感染しやすく、重篤化しやすいということです。


新型コロナは、ｐH3以下の消毒液では、不活化されます。

人間の体でも同じということです。







そのため、鼻腔、唾液、肺でウイルスが検出されやすいのです。



そして、胃のｐHを上昇させるPPIを服用している人では、感染しやすいことが報告されました。


さらに、小児では5歳未満の小児が、成人と比して、

10から100倍のウイルス量を有していることが報告されました。

Heald-Sargent T, Muller WJ, Zheng X, et al. Age-related differences in nasopharyngeal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) levels in patients with mild to moderate Coronavirus Disease 2019 (COVID-19). JAMA Pediatr. Published online July 30, 2020. doi:10.1001/jamapediatrics.2020.3651

胃のｐHが成人並みに安定するのは、3から7歳です。

それより前は、胃のｐHが高いために、胃でウイルスが不活化されず、

新型コロナウイルスによる消化器感染を容易に生じます。

一般的に、常識として、胃でのｐH上昇は、全ての肺炎のリスクを高めます。

つまり、

高齢者だけではなく、乳幼児の糞便管理が重要となります。


これに関して、JAMA Periatr.にレターを書いたのですが、

リジェクトされたので、ここで公開します。

Dear Editors,

I wish to submit an article under the category Letter to the editor for publication in The JAMA Pediatrics, titled "Why do young children have high amounts of SARS-CoV-2 viral RNA?”.

 

I am not a pediatrician, but a gastroenterologist. However, I suggested for the first time that high gastric pH promotes infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Uno Y. Why does SARS-CoV-2 invade the gastrointestinal epithelium? Gastroenterology. doi: 10.1053/j.gastro.2020.04.006 (2020).

 

And recently, the incidence of symptomatic COVID-19 was reported to be 2-4 times higher in PPI users. The reason why COVID-19 becomes severe in infants and the elderly can be explained by the fact that SARS-CoV-2 does not inactivate at pH 3 and above.

I believe this letter contains important information for pediatrics. This manuscript is likely to be of interest to many readers and should be given priority in competition with other articles. This manuscript has not been published or presented elsewhere in part or in entirety and is not under consideration by another journal.

 

Thank you very much for your consideration.

Sincerely,

 

Yoshiharu Uno, MD, PhD

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Why do young children have high amounts of SARS-CoV-2 viral RNA?

 

Author Names: Yoshiharu Uno, MD, PhD

Author Affiliation: Office Uno Column

 

Key words: COVID-19, SARS-CoV-2, Children, Gastric pH

Running title: COVID-19 in children

 

Word count: 399

References: 5

 

Abbreviations:

SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2
ACE2: Angiotensin-converting enzyme 2

PPI: Proton pump inhibitor 

I read with interest the article by Heald-Sargent et al. that compared the amount of viral nucleic acids among different age groups of patients with COVID-19.¹ They found that children aged <5 had the highest amounts of SARS-CoV-2 viral nucleic acids in their nasopharyngeal swab samples, i.e., approximately 10–100 times more abundant than in adults. This result is consistent with that of a previous epidemiological study on COVID-19 that showed that the risk of developing severe and critical illness was significantly higher in patients aged <5 years than in those aged ≥6 years.² In infants with a thumb-sucking habit, the virus may be more likely to be transmitted via saliva, although it still cannot explain the high viral load and severity. However, this can be explained by the “gastric pH” that can alter the viral load in children and elderly patients.³ Angiotensin-converting enzyme 2 (ACE2) is the main host cell receptor for SARS-CoV-2 and plays a crucial role in the entry of the virus into the cell to cause the final infection. ACE2 is abundantly found in the epithelial cells of the digestive tract. Since SARS-CoV-2 is inactivated when the pH is <2, the virus is also theoretically inactivated in the stomach if the secreted gastric acid is sufficient.  However, even the viruses that can be inactivated at pH 1–2 may not be inactivated if the gastric pH increases due to atrophic gastritis or proton pump inhibitor (PPI) intake. The COVID-19 infection rate of the population taking PPIs has been reported to be 2–4 times higher than that of individuals without PPI.⁴ In children, intragastric pH during fasting is 3–4 in neonates, 1.5–3 in infants, 1–3 in preschool children, and 1–2 in school children; the postprandial increases in intragastric pH last approximately 3 h in young children.⁵ Theoretically, children aged <5 years are less likely to inactivate SARS-CoV-2 in the stomach, and are therefore, more likely to have the virus propagated in the digestive tract. Norovirus is also not inactivated even at low pH; therefore, it propagates in the digestive tract and causes fecal–oral infection. Even in SARS-CoV-2 infection, young children are likely to have fecal–oral infection and require the same infection control measures as for norovirus. In addition, viral diffusion due to reflux into the oral cavity should be considered in the gastroesophageal sphincters of vulnerable infants.

 

References

1)     Heald-Sargent T, Muller WJ, Zheng X, et al. Age-related differences in nasopharyngeal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) levels in patients with mild to moderate Coronavirus Disease 2019 (COVID-19). JAMA Pediatr. Published online July 30, 2020. doi:10.1001/jamapediatrics.2020.3651

2)     Dong Y, Mo X, Hu Y, et al. Epidemiological characteristics of 2143 pediatric patients with 2019 coronavirus disease in China. Pediatrics. 2020, e20200702; doi: 10.1542/peds.2020-0702

3)     Uno Y. Why does SARS-CoV-2 invade the gastrointestinal epithelium? Gastroenterology. doi: 10.1053/j.gastro.2020.04.006 (2020).(in press)

4)     Almario CV, Chey WD, Spiegel BMR. Increased risk of COVID-19 among users of proton pump inhibitors. Am J Gastroenterol. 2020. (in press)

https://journals.lww.com/ajg/Documents/AJG-20-1811_R1(PUBLISH%20AS%20WEBPART).pdf

5)     Nagita A, Amemoto K, Yoden A, et al. Diurnal variation in intragastric pH in children with and without peptic ulcers. Pediatric Research. 1996;40, 528–532.

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