Admission patterns among children with non-Covid gastro-intestinal infections before and
during the Covid-19 pandemic

1. Purpose To compare incidence of and clinical characteristics of children admitted with
gastro-intestinal infections during the Covid-19 pandemic relative to prepandemic
seasons.

This will improve understanding of the indirect effects of the Covid-19 pandemic

HYPOTESES

1. During the winter-spring months after the lock-down in 2020 fewer children were
admitted with gastro-intestinal infections, relative to the winter-spring months of
the pre-pandemic years, while more children were admitted during the winter-spring
season of 2021 relative to pre-pandemic years.

2. Children admitted during the winter-spring season of 2021 were more severely ill,
and older than children admitted during the prepandemic seasons.

2. BACKGROUND During the COVID-19 pandemic, admission patterns for infections other than
Covid-19 have changed dramatically among children worldwide. [1][2]

During the first lockdown of 2020 a dramatic decline in children admitted with infections
other than Covid-19 was reported worldwide. [1] Initially, concerns was expressed that
this decline could be due to fear of seeking health care, or other barriers to access
health care. For example, children with newly diagnosed diabetes in Germany were reported
to present with ketoacidosis more frequently than before the pandemic. [3] [4] However,
the main reason is likely to be reduced social contact limiting the spread of many other
infections.

Later, reports of delayed epidemics - for example, the expected annual epidemic of
respiratory syncytial virus did not occur in the winter of 2021, only to occur later and
unexpectedly in the summer. This was first reported in Australia, and later in the
Northern hemisphere, including Denmark [5][6].

Particularly admissions due to respiratory infections and later invasive streptococcal
infections have been well documented.

Annual epidemics of viral gastrointestinal infections are known to occur in children in
the winter and spring months, most caused by rotavirus infections. In the spring of 2021
many Danish paediatricians experienced an unusual surge of children admitted with
gastroenteritis, and the general impressioin was that children werre older and more
severely dehydrated than during previous seasons.

However, it has not yet been assessed whether gastroenteritis rates were indeed higher in
2021 during the pandemic, compared to the previous years, and whether the admitted
children differed from children admitted before the pandemic.

Accordingly, this is what is planned to investigate with the current project.

Hopefully, the project may improve understanding of how well-known and regular epidemics
are affected indirectly by the emergence of new diseases - and by the public health
measures applied to prevent its spread. This may potentially inform management of future
pandemics to reduce the harms, directly as well as indirectly.

3. METHODS Study design

Retrospective review of patient files among children admitted with gastrointestinal
infections in the paediatric department of Slagelse Hospital, during the spring-winter
months (january to june) of three periods:

- pre-pandemic: january - june of 2017, 2018 and 2019 as well as january and february
of 2020

- early pandemic: march-june 2020

- late pandemic: january - june of 2021

Participants:

Children aged from >1 months to <5 years with symptoms of gastroenteritis admitted to the
paediatric department in Slagelse Hospital

Patient files will be identified in the electronic health record (EPIC) by a search of
diagnoses such as "gastroenteritis", "rotavirus", "vomiting", "diarrhea", "dehydration".
Each patient file will be evaluated by a doctor, and the child will be included if it is
confirmed that the child was admitted with symptoms of gastrointestinal infection.

Data From the identified patient files anonymized data will be retrieved on age, gender,
preexisting disease, past history, family type, breastfeeding, nutritional status,
estimated degree of dehydration, as well as symptoms and clinical findings on admission,
treatment given, duration of admission as well as microbiology and biochemical data.

Handling of data Data will be handles according to GDPR regulations. Anonymized data will
be entered into a secured database (RedCAP) and analysed using the statistical package
Stata.

5. Funding The Slagelse hospitals research fund has funded three months of salary for a
junior doctor and a medical student to type data and conduct the study

6. Ethical issues and authorisation: The project has been registered on the research
directory of Region Zealand (Regions Sjællands Interne Forskningsfortegnelse, no.
REG-087-2021.)

The committee of research ethics of Region Zealand has stated that the study does not
need reaserch ethical approval according to Danish Law, as it only involves retrieval of
data from hospital files.

Regions Zealand has approved that anonymized data is collected from patient files without
consent from the parents (Ref nr: R-21041034)

7. PUBLICATION OF RESULTS The results of the project (whether positive, negative or
inconclusive) will be submitted for publication to a peer reviewed scientific journal.