123 patients were included and their median age was 3.5 years.
Difficulty breathing, seizures before or during admission and congenital
cardiac defect significantly (p<0.05 ) increased the
likelihood of ITU admission. The likelihood of oxygen requirement was
significantly increased by difficulty breathing on presentation, cardiac
defect, genetic co-morbidity and male gender. Admission length was
significantly increased by cardiac defect and Oncological/Haematological
co-morbidity. Table 1 shows the regression models.
Table :Table showing the regression model summaries illustrating the
clinical parameters which affected the three outcome variables in our
sample.
Eighty-seven patients were tested for respiratory viruses, 33% of which
had at least 1 isolated. Rhinovirus was the most commonly detected virus
at 14.94% followed by Adenovirus at 12.64%. On univariate analysis,
viral isolation significantly increased the likelihood of ITU admission
and the length of admission. However, addition of any other variables to
the univariate models resulted in virology becoming non-significant,
implying much of the association was due to confounders like
co-morbidity. Similarly, individual viruses including COVID-19 did not
impact outcomes apart from adenovirus, which occurred in only 10 cases
but was significantly associated with ITU admission.
Our study identified several predictors of morbidity in our cohort of
severe paediatric ILI patients. Specifically, given that cardiac defects
significantly worsened all outcome measures, efforts must be made to
continue to deliver the surgical care necessary for these patients. Many
surgical units suspended or postponed a high number of non-urgent
operations during the pandemic. Our study implies that further research
into balancing the risks and benefits of such measures in particular
groups, such as children with cardiac defects, may be justified.
While univariate analysis showed that positive virology increased
admission length and the likelihood of PICU admission, taking into
account any other severity predictors resulted in this association
becoming non-significant. This suggests that any association in our
sample was heavily modified by co-morbidities. Several similar studies
to ours have also concluded that viral isolation is of little value.(3)
However, our study was conducted outside peak respiratory virus season
and our sample’s viral positivity rate was low (33%) compared to
studies which found that viral isolation impacted disease severity.(5)
It is therefore possible that virology becomes an important predictor of
severity in high-prevalence environments. Regardless, virology tests are
uncomfortable for patients and take up clinical and laboratory time, so
research into their impact on a patient’s treatment in low-prevalence
environments is necessary.
Our study is subject to some limitations. One will note the large
confidence intervals around some of the ORs and coefficients in the
study. All models were evaluated for collinearity, specification error
and goodness-of-fit. None of these tests identified any problems with
the model, implying that the large odds ratios were due to sample size.
Therefore we have identified clinical parameters which affect viral
respiratory illness outcome in our sample as well as effect direction,
but we cannot precisely estimate effect size.
In conclusion, this study identified several groups of children which
exhibit disproportionately severe ILI. As the social distancing measures
present during the study period are lifted it is likely that there will
be a rise in infective presentations. These groups should therefore be
given special consideration by public health policy makers. Positive
virology in general had little predictive value, therefore research into
the necessity of these tests is required.
- Fleming DM, Taylor RJ, Haguinet F, et al. Influenza-attributable
burden in United Kingdom primary care. Epidemiol Infect .
2016;144(3):537-47.
- Tregoning JS, Schwarze J. Respiratory viral infections in infants:
causes, clinical symptoms, virology, and immunology. Clin
Microbiol Rev . 2010;23(1):74-98.
- Mistry RD, Fischer JB, Prasad PA, et al. Severe Complications in
Influenza-like Illnesses. Pediatrics . 2014;134(3):e684-e90.
- Dalziel SR, Thompson JMD, Macias CG, et al. Predictors of severe H1N1
infection in children presenting within Pediatric Emergency Research
Networks (PERN): retrospective case-control study. BMJ .
2013;347:f4836.
- Shi T, McLean K, Campbell H, Nair H. Aetiological role of common
respiratory viruses in acute lower respiratory infections in children
under five years: A systematic review and meta-analysis. J Glob
Health . 2015;5(1):010408.