Anyone else's child had a virus with fever lasting over five days?

[Worryingmom]

Has anybody else's DC caught a horrible virus where the fever lasted longer than 5 days?

My 4 year old is now on day 7, have been to see the GP twice. Is now on 3rd day of antibiotics for possible tonsilitis, but not convinced. back to GP this morning as no improvement, good check over, chest and ears clear, urine clear, throat a little red and inflamed.

adviaed continue antibiotics, calpol and ibuprofen.

When he has calpol it brings his temp down and he's his usual self, but what on earth could cause this? I've never known just a virus take him out for long and if it is tonsilitis I'd like to think the antibiotics would be kicking in by now!

Someone in the UK parenting forum on Another Website caught something like this from their child and had it confirmed as adenovirus by PCR in hospital.

One of mine has done that before, as the days went on the fever took longer to spike after calpol and didnt go quite as high though.
If hes drinking ok and not completely washed out id be less worried too.
Keep an eye for sepsis or meningitis symptoms like always with a fever, but chances are its just a nasty virus.

How long did it last?

DD had a temp for 9 days with Covid. As did I. It hasn’t gone away.

Children don't usually succumb to covid as much as adults in my experience but I guess it could absolutely be this and also different strains etc.

My daughter gets exactly like this with tonsillitis. It’s one of the only illnesses that makes her really poorly and unable to carry on as normal.
Viral tonsillitis just a red throat and bacterial tonsillitis white spots and needs antibiotics

my DD is 4 and currently has adenovirus, she’s on day 8 of fever. She’s been quite cold-y with a really sore throat, and her tummy has been off as well

My youngest had a temperature for 10 days when they had Covid.

Thanks all. I have wondered if it is that adenovirus or covid.
He's completely himself until he gets a fever and then crashes again. Everytime it looks like hes turning a corner and getting better he gets a fever again. It feels never ending.

My 16 month old has had spiking temperatures for nearly 3 weeks.

She’s been to the doctors 3 times and on the second visit they gave her antibiotics for a nasty cough which he thought was a possible chest infection. The antibiotics cleared up the cough but she’s still having on-off spiking temperatures. Usually once or twice a day but brought down by Calpol or ibuprofen. Otherwise she’s a bit grumpy but fine and eating/drinking normally. 3rd visit to the doctor, he just said that viruses really can last that long to clear and we just have to let nature take its course. He said it’s fine to medicate with Calpol/nurofen until it clears.

At her age though it’s tricky to know if she’s just picking up a new thing one after another, she’s in her first 6 months of nursery and hasn’t been 100% well since she started!

COVID you could certainly rule out with a rapid test from Boots, but there's actually rather more adenovirus, paraflu (causes croup) and metapneumovirus (like RSV, can cause bronchiolitis) around right now then flu or COVID. https://www.gov.uk/government/statistics/national-flu-and-covid-19-surveillance-reports-2025-to-2026-season/national-flu-and-covid-19-surveillance-report-26-march-2026-week-13
Figure 8a shows that only a small proportion of coughs and colds are COVID this week, 8b shows hMPV, paraflu and AdV. Plus the good old common cold but that shouldn't really make a healthy child ill for so long.

In littles, adeno is currently between 1 in 10 and 1 in five colds/coughs right now https://assets.publishing.service.gov.uk/media/69c3f3d8cdfd19de13d0f5e6/weekly-flu-and-COVID-19-surveillance-graphs-week-13-2026.pdf - page 21 shows what age groups and catching which virus.