Differential impact of the COVID-19 pandemic on laboratory reporting of norovirus and Campylobacter in England: A modelling approach. PLoS One [Internet]. 2021;16(8)


HPRU-EZI Authors - Roberto Vivancos


The COVID-19 pandemic has impacted surveillance activities for multiple pathogens. Since
March 2020, there was a decline in the number of reports of norovirus and Campylobacter
recorded by England’s national laboratory surveillance system. The aim is to estimate and
compare the impact of the COVID-19 pandemic on norovirus and Campylobacter surveillance data in England.

We utilised two quasi-experimental approaches based on a generalised linear model for
sequential count data. The first approach estimates overall impact and the second approach
focuses on the impact of specific elements of the pandemic response (COVID-19 diagnostic
testing and control measures). The following time series (27, 2015–43, 2020) were used:
weekly laboratory-confirmed norovirus and Campylobacter reports, air temperature, conducted Sars-CoV-2 tests and Index of COVID-19 control measures stringency.

The period of Sars-CoV-2 emergence and subsequent sustained transmission was associated with persistent reductions in norovirus laboratory reports (p = 0.001), whereas the
reductions were more pronounced during pandemic emergence and later recovered for
Campylobacter (p = 0.075). The total estimated reduction was 47% - 79% for norovirus (12–
43, 2020). The total reduction varied by time for Campylobacter, e.g. 19% - 33% in April, 1%
- 7% in August.

Laboratory reporting of norovirus was more adversely impacted than Campylobacter by the
COVID-19 pandemic. This may be partially explained by a comparatively stronger effect of
behavioural interventions on norovirus transmission and a relatively greater reduction in norovirus testing capacity. Our study underlines the differential impact a pandemic may have
on surveillance of gastrointestinal infectious diseases.


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