Nurse Pauline Cafferkey is fighting for her life having contracted Ebola haemorrhagic fever. Others have questioned the organisation and resources which faced her and her colleagues when she returned from Sierra Leone.
I want to challenge the clinical strategic decision-making which followed her arrival at Heathrow’s Terminal 4.
She successfully underwent routine temperature screening on arrival. Later, while waiting to return to Scotland, she reported that she felt her temperature was rising.
She was reassessed six times in about half an hour. All readings were reported to be within the “normal range”. As a consequence, she was advised to continue her journey to Scotland, with an “all clear”.
Historically, the thermometer has been a great asset in medicine. However, even the most sophisticated models remain relatively blunt instruments with which to reflect the subtleties and vagaries of biological parameters.
Moreover, these “normal ranges” referred to in medicine do not represent discrete, mutually exclusive categories; they are sections of dimensions or continua. Thus, to make a crucial clinical decision requires the careful consideration of a number of factors.
First, we have to consider all the “scientific” data available to us. Second, we must listen to what the patient tells us. Third, we need to think through the consequences of a diagnostic error.
Those of us who are required to make diagnoses are fully familiar with the perennial question: “Is it better to diagnose patients as ill when they later prove not to be, or is it better to give patients the ‘all-clear’ when they later prove to be ill?”
The first error we call a “false positive” and the second is a “false negative”. Obviously, the seriousness of each type of error varies.
In the case of the Ebola virus, we know that it is highly lethal; our resources to combat it are very limited, and early identification is crucial.
The other factors which should have been highly influential in this lady’s case are that the victim had been deployed to a very “high risk” region of exposure to the virus; she had been conducting clinical duties known to be of “high risk”, and she is an experienced and highly competent clinical nurse.
By adhering to her professional protocol, and reporting that she felt unwell, she was by implication confirming that she would accept the consequences of being identified as a “case”, even if the final outcome was that she proved to be a “false positive”. In such a serious situation, faced with competing information from thermometers and the self report from such a patient, I would have thought that any competent clinician would have backed the patient’s self report. Many of us have sensed that we were about to “go down with something” long before any biological measure confirmed this outcome.
It is to be hoped that Mrs Cafferkey, her family, her colleagues and her friends do not have to suffer much more for this opportunity to revise our strategic decision-making.
(Emeritus Prof) David A Alexander FRSM