The UK nurse diagnosed with ebola reportedly told officials on arrival at Heathrow she felt unwell but was allowed to continue her journey home.
Pauline Cafferkey was diagnosed the following day and is now being treated at hospital in London.
UK procedures for screening healthcare workers returning from Ebola-affected areas are to be reviewed as a result.
Another passenger on Pauline Cafferkey's flight to London via Casablanca described the screening procedures as 'chaotic'.
Dr Derek Gatherer from Lancaster University says alarm bells should have rung - even if the nurse's temperature didn't appear high.
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Dr Derek Gatherer from Lancaster University says the risk from returning health workers is actually quite low.
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OUT: ...observation."
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