Fever in a returning traveller
P.F. is a 38-year-old who returned from a visit to her relatives in India four weeks ago. Soon after her return she was admitted to hospital by a partner at the practice with a febrile illness, in view of the risk of malaria, but was discharged 24 hours later with a diagnosis of probable viral illness. Today she tells you that overnight she suddenly felt shivery and started shaking. She feels a bit better today and is no longer feverish. Dr Richard Stokell discusses.
Why is this a problem case?
This case poses difficulties on several levels. The most obvious may be a knowledge gap. You may remember details of blood films and presenting features, but how reliable are the tests and how clear are you about the different types of malaria?
Our next problem is to apply that knowledge to our patient. She seems too well to admit but can she be managed without referral? How do you feel about this level of uncertainty? Finally, if you have decided that admission is not necessary, how do you convey this to the patient in a reassuring way?
What other important pointers should be elicited?
We need details of where the patient has been and when. We also need to know about possible exposure to malaria and use of prophylaxis during and after her trip. Examination should look for a focus of infection to explain the possible fever and also assess the severity of her illness.
What are the possible diagnoses to consider?
These can be divided into tropical and non-tropical causes. Non-tropical causes remain more likely and include viral infection, UTI and respiratory infection. Malaria is by far the commonest tropical cause but enteric fevers, hepatitis, diarrhoeal illnesses and tuberculosis can also occur. Malaria is most likely to occur within three months of exposure. About 10 per cent of travellers report fever during travel or within one month after1 but only a small percentage will turn out to have malaria.
How is malaria diagnosed and how reliable is this?
Malaria usually presents with fever, sweating, rigors, malaise and myalgia. Fever can be intermittent and can occur cyclically every two to three days. Gastrointestinal upsets commonly occur and with falciparum malaria, rapid deterioration with altered conciousness, convulsions, oliguria, respiratory failure and secondary infection may occur.
Diagnosis is usually made by examination of peripheral blood films, thick film to look for the presence of the parasites and thin to decide which strain is present. The parasite may not appear in the films and it may be necessary to repeat the test several times to get a positive result.
What are our management options?
If you didn't know all the above details, one call to your local microbiologist would probably be enough to find it all out. Have a very detailed history at your fingertips as a cross-examination about your patient is likely.
This still leaves us with a decision. The patient is now afebrile and seems too well to admit. How do you feel about a small risk that she has malaria? Uncertainty can be reduced by taking a good history and examining her properly for clinical signs of significant infection. Close follow-up also provides an opportunity to observe the evolution of her illness. Review after 48 hours and tell her to phone earlier if necessary.
How can this be presented to the patient?
Thinking aloud is often the best way of involving the patient and reassuring them about your approach. In this case I might say: 'It seems unlikely you have malaria because you have been tested and my examination of you today is normal. I wonder if we should watch things for a day or two and get more tests if you become feverish again?'
She may ask what might happen if it was malaria – would waiting be harmful? – before accepting or rejecting your suggestion. Allowing her to decide but offering early contact if she is worried is a reasonable course of action.
Richard Stokell is a GP in Merseyside
1 Schlagenhauf et al. Behavioral aspects of travellers and their use of malaria treatment,
British Association for Accident and Emergency Medicine www.baem.org.uk/malaria.htm