Symptoms in travellers returning from abroad
Symptoms in travellers returning from abroad
• Department of Health. Health Information for Overseas Travel. 2nd edition. London: The Stationery Office; 2001.
Available from PO Box 29, St Crispins, Duke St, Norwich NR3 1GN, and authorised bookshops and from www.tso.co.uk.
The full text is available on the professionals' homepage at www.nathnac.org.
The history must include:
• the dates and places visited
• visits to rural areas
• contact with animals
• swimming in inland waters
• sexual contact with local people
• what immunisations were given, what prophylaxis was taken and for how long.
Remember that the patients may be contacts of travellers, and not the travellers themselves.
One study of returned travellers found that a history of exposure was of little value in the prediction of parasitic disease.
• Humar A, Keystone J. Evaluating fever in travellers returning from tropical countries. BMJ 1996; 312: 953–956.
• Looke DFM, Robson JMB. Infections in the returned traveller. MJA 2002; 177: 212–219.
• FBC with request for thick and thin films for malaria
• Culture blood and stool
• Arbovirus serology if suspected
Consider a cause unrelated to travel, such as respiratory or urinary infection.
The commonest cause is travel-associated diarrhoea, at least in children. If diarrhoea is present, proceed as for diarrhoea (below).
Consider the diseases below.
• There are about 2,000 cases of malaria imported into the UK each year, and failure to diagnose malaria is regularly referred to in medical defence associations' reports. Falciparum accounts for over half of UK cases and can kill within 24 hours. Conversely, the first presentation of falciparum may be up to 12 months after exposure. Vivax may cause illness as late as 18 months after return.
• Fever in a traveller from tropical Africa should be assumed to be due to malaria until proven otherwise. Malaria can be contracted by patients in an aircraft on the runway in an endemic area. Malaria does exist even in countries for which prophylaxis is not recommended, for instance the North African coast.
• If the first blood film is negative, the patient may still have malaria. Continue to send blood films over 72 hours unless the fever abates or another diagnosis is reached.
The patient may present with fever, without jaundice. There are about 1,000 cases a year in returning travellers to the UK, 20 per cent of them hepatitis B.
Typhoid and paratyphoid fever
These account for 400 cases a year in the UK. They should be suspected in anyone with fever within three weeks of returning from an area where typhoid is endemic (such as the Indian subcontinent), when malaria has been excluded. Paratyphoid B is most commonly acquired in the Mediterranean area, including Spain.
The fever may be associated with headache, myalgia and cough. About 25 per cent of cases have watery diarrhoea as a prodrome. About one-third of cases in the UK are contracted in foreign hotels. Men over 50 are especially at risk. There will probably be no chest signs, but the chest X-ray will be abnormal.
The diagnosis can be confirmed by sputum culture, urine antigen tests or three serum samples for antibodies, three to six weeks apart.
Tuberculosis may be acquired abroad. Suspect it readily in immigrants from areas of high risk.
Lassa fever and other viral haemorrhagic fevers
Suspect this in anyone with persistent fever who has been in an endemic area within the last three weeks.
• Lassa fever: West Africa from Senegal to Nigeria
• Ebola fever: Zaire and Sudan
• Marburg fever: Uganda
• Crimean/Congo haemorrhagic fever: East and West Africa, Central Asia and the former USSR.
Arrange for an immediate home visit by the consultant in communicable disease control or the consultant in infectious diseases. Do not admit the patient directly to a general hospital. If the patient is admitted to a high security infectious disease unit, the ambulance service will do so as a category III removal.
The fever may be associated with abdominal pain, cough, urticaria and eosinophilia. Assume that all rivers, lakes and fresh water in the tropics and subtropics are colonised with snails infected with schistosomiasis.
Amoebic liver abscess
Suspect this in anyone who has visited the tropics or subtropics within the last year. The majority of cases have pain in the right hypochondrium but some have no focal signs.
• Dengue is common between latitudes 35°N and 35°S. It has been found to be the cause of fever in 8 per cent of travellers returning with fever. Classic dengue can be recognised with the abrupt onset of fever, headache, vomiting, muscle and joint pains and rash. It does not occur more than three weeks after return. Diagnosis is by serology.
• Leptospirosis is worldwide and caught from inland water.
• Brucellosis is caught from drinking unpasteurised dairy products.
• Rickettsial infections are tick borne. They are common in the Mediterranean. Serology is usually negative in the acute phase and antibiotic treatment (for instance, doxycycline) is justified if the typical rash is present, especially if there is an eschar.
• Visceral leishmaniasis is also found in the Mediterranean; 10 cases a year occur in the UK.
• Meningococcal infection may be imported from Africa, the Arabian peninsula, North India or Nepal.
• Relapsing fever accounts for 10 cases a year in the UK.
• Send fresh stool for microscopy for ova, cysts and parasites, and for culture, specifying the places visited. If the stool contains blood and mucus it is especially important that it should reach the lab fresh, for microscopy for amoebae.
• Warn the patient that if a pathogen is isolated they will be contacted by the local environmental health department.
• Mild symptoms: treat with codeine phosphate, loperamide or diphenoxylate as needed.
• Moderate to severe symptoms: treat with ciprofloxacin 500mg bd for five days without waiting for the stool result. This has been shown to speed recovery in travellers' diarrhoea but at the possible price of prolonged excretion of the bacteria in the stool and development of resistance. Children and pregnant women may be given trimethoprim 200mg bd for five days.
• Diarrhoea suggestive of giardiasis: treat with metronidazole 2g daily for three days or tinidazole 2g as a single dose, even if stool microscopy is negative. Giardiasis is suggested by a long incubation period (two weeks or longer), by watery stool with a lot of flatus and no fever. Symptoms respond promptly to the above antibiotics, providing a more reliable test than stool examination.
• Diarrhoea continuing for more than two weeks: send two further stool samples for microscopy and culture, as well as blood for FBC and films for eosinophilia and parasites, U&Es and LFTs. Discuss with the laboratory the need for serology for parasites and testing for Clostridium difficile toxin. Refer to a gastroenterologist or specialist in infectious diseases if the cause is still not clear.
Falciparum malaria commonly presents with diarrhoea as well as fever. In a traveller with these symptoms from an endemic area, exclude this before treating the patient for gastroenteritis.
Gastroenteritis may trigger an exacerbation of inflammatory bowel disease or lead to lactose intolerance, which may then continue as prolonged diarrhoea.
• Send blood for LFTs and hepatitis serology; viral hepatitis is the most common cause.
• Send blood for thick and thin films for malaria if the patient has returned from sub-Saharan Africa and is febrile.
• Remember that leptospirosis, typhoid, dengue, relapsing fever and yellow fever can present as jaundice.
• Send a throat swab for diphtheria.
• Remember that Lassa fever may present with pharyngitis and fever.
Sexually transmitted diseases
• Screen all returning travellers who admit to casual, unprotected sexual contact abroad for STD (including HIV).
• Consider chancroid, lymphogranuloma venereum and granuloma inguinale in returning travellers with genital ulcers or inguinal lymphadenopathy. Genital herpes and syphilis are, however, far more common.
In a large study, eosinophilia was found in 5 per cent of travellers returning from the tropics; a definite diagnosis was made in a third of them. However, when the eosinophilia exceeded 15 per cent of the total white count, a positive diagnosis was found in two-thirds. Conversely, over half in whom helminthic infestation was found did not have eosinophilia.
Only a third of all those with eosinophilia were asymptomatic; the others suffered mainly from fatigue, diarrhoea and skin lesions. Helminth infestations were most common (for example strongyloidiasis, filariasis, hookworm, schistosomiasis, cutaneous larva migrans and ascariasis), followed by protozoal infection (amoebiasis, malaria, blastocystis and giardiasis).
• Send three stools for ova, cysts and parasites.
• Discuss with the laboratory the feasibility of serological tests for schistosomiasis, filariasis, strongyloidiasis, toxocariasis and angiostrongyliasis.
• Once the stools have been sent discuss with the patients the use of broad-spectrum antihelminthic, such as mebendazole.
This is an extract from Practical General Practice 5e, ISBN 07506 8867X, Elsevier Ltd, April 2006, price £47.99. To order your copy please go to www.elsevierhealth.com or phone Elsevier customer services on 01865 474000.
Practical General Practice 5e is compiled by Alex Khot, a GP in East Sussex, and Andrew Polmear, a retired GP and former senior research fellow at the University of Sussex
For travel information and personalised patient reports, see www.pulse-i. co.uk/travel clinic