PG133-138 3/10/05 4:35 PM Page 133 THE TRAVELLER WITH FEVER THE RETURNING TRAVELLER WITH FEVER As numbers of visitors returning from exotic destinations in less developed parts of the world increase, the challenges to the physician grow. Travellers face a number of health risks during their journeys. The majority of incidents are related to trauma or to underly- ing co-morbid disease, most commonly cardiovascular dis- ease. Infectious diseases however are a significant problem and range from the potentially life-threatening, such as malaria, to those that are more mundane, such as travellers’ diarrhoea. This article will focus on the traveller who returns with a suspected infectious disease and will discuss a diag- nostic approach, before describing important syndromes and their common causes. HISTORY LUCILLE BLUMBERG JOHN FREAN Pyrexial illness is a presentation of most travel-associated MB BCh, MMed (Microbiol), MB BCh, MMed (Path), infectious diseases, but many common infections such as DTM&H, DOH, DCH DTM&H, MSc (Med Parasitol) influenza and pneumonia also occur in the tropics or may be Specialist Microbiologist Specialist Microbiologist acquired en route to and from exotic regions. Patients may National Institute for National Institute for also have chronic or recurrent medical problems that are Communicable Diseases and Communicable Diseases and unrelated to their tropical exposure. In approaching a pyrexi- University of the University of the al patient, therefore, a general medical history should elicit Witwatersrand Witwatersrand Johannesburg Johannesburg the presence of underlying conditions, particularly those John Frean qualified at the associated with increased risk of infections such as diabetes, Lucille Blumberg is currently University of the malignancy, HIV infection, splenectomy, and pregnancy. head of the Epidemiology and Witwatersrand in 1980, and Outbreak Unit, and medical Specific questions about the current illness are listed below. currently holds a senior posi- consultant to the Viral The travel history, both recent and past, is of vital impor- tion in the National Institute Haemorrhagic Fever Unit. Dr for Communicable Diseases of tance. Duration of illness in relation to known incubation Blumberg has a background the National Health periods helps to include or eliminate certain infections. in clinical infectious diseases. Laboratory Service and the Areas visited and the nature of the travel may suggest likely Her special interest is in trav- University of the el-related infectious diseases, exposures, e.g. business travel in city hotels has a different Witwatersrand. His main in particular the prevention risk profile compared with river-rafting adventures. interests are parasitic and and management of malaria. zoonotic diseases. History — important questions • Symptoms and sequence of symptoms • Travel departure and return dates • Purpose of travel (elicit specific details): business, leisure, missionary, military, expatriate • Onset of illness in relation to travel • Countries visited, including stopovers, and specific areas within the country • Season and climate • Type of travel: e.g. overland, air, sea, backpacking • Type of accommodation: e.g. camping, hotel • Pre-travel immunisations: what and when • Prophylaxis, including chemoprophylaxis, e.g. malaria: type and compliance with drugs March 2005 Vol.23 No.3 CME 133 PG133-138 3/10/05 4:35 PM Page 134 THE TRAVELLER WITH FEVER • Exposures: see Table I Table I. Specific exposures and associated infections • Past illness: general plus specific ill- nesses such as hepatitis A Type of exposure Associated infections • Co-morbid disease, medication • Immunosuppression: specific illness- Bites es or drug-induced, previous Mosquito Malaria, dengue, yellow fever, encephalitis, splenectomy filariasis • Specific symptoms: fever (onset of Tick Borreliosis (Lyme disease, relapsing fever), fever, fever pattern), headache, rig- rickettsioses (tick bite fever, typhus, Rocky ors, photophobia, conjunctivitis, Mountain spotted fever); Congo-Crimean haemor- arthritis, arthralgia, myalgia, pres- rhagic fever, Q fever, tularaemia, encephalitis, ence of rash or skin lesions (see ehrlichiosis below), lymphadenopathy, gastro- intestinal symptoms (diarrhoea, Fly African trypanosomiasis, onchocerciasis, leishma- presence of blood, vomiting), jaun- niasis, bartonellosis, myiasis, loiasis dice, and haematuria. Flea Plague, tungiasis, murine typhus PHYSICAL EXAMINATION Triatomine bugs American trypanosomiasis (Chagas’ disease) A thorough physical examination is Mammal Rabies, rat-bite fever, tularaemia, anthrax, Q fever, essential, and together with the histo- cellulitis ry, will direct the choice of further radiological and laboratory investiga- Ingestion tions (Table II). A full blood count and Water (untreated) Hepatitis A/E, cholera, Norwalk/caliciviruses, examination of blood smears is a Salmonella, Shigella, Giardia, poliomyelitis, nearly obligatory basic investigation. Cryptosporidium, Cyclospora, dracunculiasis The physician should focus initially on those infections that carry the greatest Dairy (unpasteurised) Brucella, tuberculosis, Listeria morbidity and mortality, those that are Enteric bacteria (Salmonella, Shigella, E. coli, treatable and those that pose a public C. jejuni, etc.) health risk. Raw or undercooked food Helminths (Ascaris, Trichinella, Taenia – including UNDIFFERENTIATED FEVER (meat, fish, vegetables) cysticercosis, whipworm, Capillaria, Angiostrongylus), protozoa (amoebiasis, toxoplas- Diagnosis and management of malaria mosis) in travellers is urgent, and should be considered in anyone returning from a Freshwater skin Leptospirosis, schistosomiasis, Acanthamoeba, or malaria transmission area with symp- contact Naegleria toms of a flu-like illness, fever, rigors, Sand/dirt/mud skin Hookworm, cutaneous larva migrans, headache and/or myalgia, irrespec- contact visceral larva migrans, leptospirosis tive of the season or whether chemo- prophylaxis was taken. The risk of Sexual contact HIV, hepatitis B/C, syphilis, gonorrhoea, contracting malaria is highest in Africa Chlamydia, herpes, papillomavirus and Oceania, followed by Asia and Latin America. Most large cities in by inappropriate chemoprophylaxis or resistant Plasmodium falciparum is a South and Central America and poor compliance, and clinical illness problem globally. Artemisinin combi- Southeast Asia are malaria-free but may be delayed in patients with non- nation therapy is considered highly this is not true of Africa (apart from falciparum malaria. A blood smear or effective, with quinine and doxycycline South Africa, the Kenyan capital rapid antigen detection test is usually as an alternative for malaria acquired Nairobi, Gaborone in Botswana, sufficient to confirm the diagnosis, but in Africa. Chloroquine and primaquine Windhoek in Namibia and Harare in a negative test does not exclude are effective for most strains of Zimbabwe). Plasmodium falciparum is malaria and repeat tests may be nec- Plasmodium vivax with the exception of the commonest species in Africa and essary. Thrombocytopenia is frequent, some resistance in Oceania and overall the most serious, frequently even in uncomplicated cases. Choice Papua New Guinea. progressing rapidly to complicated dis- of treatment depends on severity of ease. Most travellers with malaria disease and the likely drug resistance Typhoid fever characteristically pres- present 7 - 21 days after exposure but pattern of the parasite. Chloroquine- ents insidiously with fever, headache, incubation periods may be prolonged 134 CME March 2005 Vol.23 No.3 PG133-138 3/10/05 4:35 PM Page 135 THE TRAVELLER WITH FEVER East African trypanosomiasis is gener- Table II. Differential diagnosis of physical findings for some ally an acute, often fulminating condi- febrile diseases tion with a substantial mortality. Physical finding Differential diagnosis Transmission to tourists has occurred recently in game reserves in Tanzania, Lymphadenopathy Plague, HIV, rickettsioses, brucellosis, leishmania- Malawi and Kenya. The vectors are sis, dengue, lymphogranuloma venereum, Lassa tsetse flies, which are aggressive and fever deliver an unmistakably painful bite, Hepatomegaly Malaria, leishmaniasis, amoebic liver abscess, often through clothing. At the site of typhoid, hepatitis, leptospirosis the bite a trypanosomal chancre may form a few days afterwards. Systemic Splenomegaly Malaria, leishmaniasis, trypanosomiasis, typhoid, disease is an acute febrile illness, not brucellosis, typhus, dengue unlike malaria. Disease may be rapid- ly complicated by myocarditis, coagu- Jaundice Hepatitis, malaria, leptospirosis, relapsing fevers, lation disorder including disseminated cholelithiasis, pancreatitis intravascular coagulation (DIC), and Petechiae/ecchymosis Meningococcaemia, yellow fever, dengue, rick- central nervous system invasion. ettsioses, viral haemorrhagic fevers Trypanosomes in the blood may be scanty and easily missed unless the Wheezing Löffler’s syndrome, Katayama fever, tropical pul- laboratory is warned of their possible monary eosinophilia presence. Specific treatment in the form of suramin or melarsoprol (in the Table III. Skin lesions associated with infections case of CNS invasion) is mandatory but is toxic and must be given under Skin lesion Differential diagnosis expert supervision. Maculopapular Arboviruses, acute HIV, rickettsia, syphilis, typhus, FEVER AND RASH bartonellosis, typhoid, rubeola, rubella, scarlet fever, cercarial dermatitis, scabies, arthropod