A5V4d

Viral co-infection
Management by the paediatric specialist
their outcome. These investigations need to be both sensitive and specific so that
most serious bacterial infections are identified and so that antibiotics are not given
to children who don't need them. The inflammatory markers C-reactive protein and
procalcitonin have shown varying performance characteristics for identifying
bacterial infection in a variety of populations. If either or both were found to be
sensitive and specific for identifying serious bacterial infection in children with fever
without apparent source, there would be evidence for their more widespread use.
The cost effectiveness of this approach would need to be calculated.
Only a minority of young children with fever have bacterial infections. The rest are presumed to have
viral infections, although these are rarely confirmed and mostly do not need treatment. If it were
possible to identify those children with definite viral infections, this might help identify those at low risk
of serious illness. However, if bacterial infection co-existed with viral infection then differentiating
between serious and non-serious illness would not be helped by identifying those with viral infection.
Review question
What is the incidence of co-existing bacterial infection in a child presenting with fever in which a virus
(e.g. influenza or RSV) is detected (with a rapid test)?
Narrative evidence
Three EL 3 retrospective studies 181–183 which investigated co-existing bacterial infection in children
with respiratory syncytial virus (RSV) infection were found. One retrospective cohort 181 investigated
the prevalence of co-existing SBI in 178 children less than 8 weeks old with proven RSV infection and
fever. Those children with RSV were over five times more likely to have an increased work of
breathing compared with those who were RSV negative (RR 5.1, 95% confidence interval [CI] 2.9 to
8.9). The other two retrospective cross-sectional studies investigated children with influenza virus 182
and RSV respiratory tract infection. 183 The odds of any SBI were 72% less in children who tested
positive for influenza than in those who did not (odds ratio [OR] 0.28, 95% CI 0.16 to 0.48). 182 Febrile
RSV-positive infants had a lower rate of bacteraemia compared with febrile RSV-negative infants
(1.1% versus 2.3%). Similarly, none of the febrile children with RSV respiratory tract infection tested
had positive cerebrospinal cultures, but urinary tract infection was found in 14% of those less than
3 months old and 8.4% of those over 3 months old. 183
Evidence summary
The incidence of SBI is lower in feverish children with proven RSV or influenza infections compared
with those in whom viral investigations are negative. However, SBI, especially UTI and influenza/RSV,
infections can co-exist.
GDG translation
Since children with proven viral infection still have a risk of SBI (although this was reduced compared
with children without proven viral infection), the GDG felt that they should be assessed for serious
illness in the same way as other children. Those with no features of serious illness should have urine
tested, while those with features of serious illness should be assessed by a paediatric specialist.
Given that rapid detection of viral illness (such as influenza or RSV infection) does not exclude a coexisting
SBI, the GDG recognised that the use of these tests is not an efficient use of scarce
healthcare resources.
Recommendations
Number Recommendation
Viral co-infection
59 Febrile children with proven respiratory syncytial virus or influenza infection should
be assessed for features of serious illness. Consideration should be given to urine
175