3.4 Related factors of severe pneumonia in pediatric inpatients
by multivariate analysis
Binary logistic regression analysis was used to examine risk factors of
severe pneumonia among all the children. Table 4 showed
that longer hospital stay (OR =
1.521, P = 0.000), milk allergy (OR = 6.552, P = 0.033)
and Ca insufficiency (OR = 12.048, P = 0.019) were high-risk
factors for severe pneumonia in the pediatric inpatients, after
adjusting for other factors.
Discussion
We found that between March-August 2020, the number of children
hospitalized with pneumonia at Xinhua Hospital was decreased by 74%
compared with the same period of 2019. Recent studies have witnessed a
significant reduction in the numbers of pediatric admissions in 2020 in
many other countries, including France, the United States and
Morocco20, 21. This was due to the recommendations
imposed at the beginning of the pandemic to avoid access to hospital,
except in cases of real need, and also to the public fear of SARS‐CoV‐2
infection in the hospital 22. Additionly, the change
in lifestyle during the COVID-19 pandemic might also have reduced the
onset of respiratory viral diseases by preventing much person-to-person
disease transmission23, 24. In other words, this
reduction could be considered as an unexpected positive consequence of
the NPIs taken during the COVID-19
pandemic, which may have led to a decrease in morbidity and healthcare
costs of the infectious diseases25.
For pathogens, our results showed
that viral, Mp and mixed infection rate was reduced
respectively in 2020 in children
with pneumonia, which was similar to Pengcheng
Liu
et al’s, Ying Zhang et al’s and Huang QS et al’s reports, possibly
because of the use of stringent NPIs such as lockdown and border
closures in 202025-27. However, in our study, the
detection of coxsackie virus increased compared with 2019. The result is
in line with the study of Andrew Po-Liang Chen et al’s in
Taiwan28. Since coxsackie virus is a non-enveloped
virus, it might be inherently less susceptible to inactivation by
ethanol-containing disinfectant29. This viral property
might hamper the preventive effectiveness using routine hand
disinfectants. Furthermore, Leung et al’s randomized control trial
suggests that face mask is more effective in filtering out enveloped
viruses than non-enveloped viruses30. Consequently,
chloride- and hydrogen peroxide-based products should be added for
comprehensive infection control. In addition, it is important that
coxsackie virus should continue to be monitored diligently in children
during the COVID-19 pandemic. And the diseases caused by coxsackie virus
should be taken seriously such as hand-foot-mouth disease (HFMD) or
herpangina.
Change in lifestyle could trigger the change of people’s susceptibility
to various allergens16. Our study showed that the
positive rates of allergens, including house-dust mite, shrimp and crab
in 2020 were significantly higher than those in 2019 in children with
pneumonia. The increasing positive rate of house dust mite during the
COVID-19 pandemic might be because people stayed at home for a long time
with poor ventilation. Shanghai has a humid subtropical monsoon climate.
The lack of ventilation led to long-term high relative humidity and lack
of sunshine in the house, which were more conducive to the accumulation
and reproduction of dust mites in carpets, pillows, and
mattresses31, 32. Moreover, house dust mite allergen,Der p1, exerts several key activities on the airway
mucosa33. Such molecules have been shown to
favor oxidative stress of the
respiratory mucosa and, thus, to exacerbate inflammatory conditions such
as asthma or allergic rhinitis34. Regarding shrimp and
crab allergens, the reason would be that people’s eating habits had been
changed during the pandemic and it also might be related to the
co-sensitization with the increasing positive rate of house dust
mite35. Therefore,
during home isolation, our room
should be fully ventilated, and the sheets and blankets should be washed
frequently.
Our study found that hospitalized patients with pneumonia in children
presented the lower levels of vitamin B2, B6, C and 25(OH)D in 2020 than
those in 2019. The possible reason would be that the COVID-19 lockdown
has affected the dietary habits and nutritional patterns. It has been
reported that the dietary patterns of Chinese people during the COVID-19
lockdown changed, showing a decrease in the frequency of intake of fresh
vegetables and fruit, rice, poultry, meat, and soybean
products36. However, certain nutrients such as vitamin
A, vitaminB2, vitamin B6, vitamin B12, vitamin D, vitamin C, and the
minerals Ca and Zn, are important for proper immune
function37. Deficiencies and a suboptimal nutritional
status of these micronutrients could potentially favor the spread of
diseases by reducing resistance to infection and
reinfection17. For example, the vitamin D receptor is
expressed in almost all types of cells of the immune system and the
correct immune system function will depend on the correct
bioavailability of vitamin D from these cells38. For
vitamin C, it also has roles in several aspects of immunity, including
supporting leucocytes migration to sites of infection, phagocytosis and
bacterial killing, natural killer cell activity and antibody
production39. To date, despite the existence of
several vaccines in motion to deal with the SARS-CoV-2, the global
population must learn to live for a longer time with the virus among
us17. Therefore,
we should keep a healthy and
balanced diet in our daily life to strengthen our natural defense
system.
There were some limitations in this retrospective study. First, our
report was a single-center study, and we only enrolled pneumonia
inpatients in our clinical center between March-August 2020 when all
students studied online at home and stringent public health measures
were adopted during the COVID-19 pandemic. From September 2020, students
went back to school. As the control, pneumonia inpatients in the same
period of 2019 were recruited prior to the COVID-19 pandemic. Our
results were based on a small number of pneumonia cases, and thus they
should be interpreted with caution and confirmed in future studies.
Second, the identification of the pathogens responsible for pneumonia
remains challenging, particularly when mixed infections occur. A
proportion of children in this study had no proven causal pathogen. The
low detection rate of bacteria and viruses in our study may be due to
the fact that some inpatients received antibiotic therapy in outpatient
department. The use of next-generation sequencing for pathogen detection
could be a useful additional method. Third, only five main allergens
were analyzed in this study. Finally, the effects of micronutrient
supplementation was not taken into account due to lack of information in
this aspect.
Conclusions
The data in this study suggest that
number of children hospitalized with
pneumonia and incidence of common pathogen infections were both reduced,
and that allergy and micronutrient status in children were also changed
after the outbreak of the COVID-19 pandemic and adoption of stringent
public health measures.
ACKNOWLEDGEMENTS
We thank all of the study participants and their parents.