Travellers' fever & malaria



Fever in Travellers

  • About 50% of due to tropical disease
  • The remainder are due to cosmopolitan illnesses
  • The most urgent infections present as febrile illnesses

Travel History

  • When did the patient travel?
  • Short incubation < 10 days - dengue, malaria, Legionella, cholera, dysentery
  • Intermediate 7 - 28 days - Hep A, malaria, typhoid, typhus, amoebic dysentery, TBE, VHF
  • Long > 4 weeks - brucellosis, Hep A,B,C,E, Leishmaniasis, malaria, schistosomiasis, rabies
  • Weeks - years - HIV, rabies, TB, amoeba
  • Duration of travel
  • Countries visited
  • Type of travel (expatriates, health workers, backpackers, business travellers)
  • Insect bites sustained (tsetse, ticks, fleas) anti-malarials taken
  • Animal contact
  • Swimming in fresh water lakes

Immunisation history

  • DTP, polio, Hib, meningitis C
  • Hepatitis A/B
  • Yellow fever
  • Pneumococcal, Meningococcal AC, Hib
  • Jap B encephalitis, rabies
  • TBE (Cholera)
  • Anti-malarials taken?

Past Medical History

  • Previous and underlying illnesses - IHD, renal/respiratory disease
  • Illnesses that may affect immunity
    • Pregnancy, DM, malignancy, immunodeficiency, splenectomy, blood disorders (thalassaemia, sickle cell)

Possible localizing symptoms/signs

  • Sore throat - streptococcal, diphtheria
  • Cough - bronchitis, pneumonia
  • Joint pain - pyogenic arthritis
  • Loin pain and dysuria - pyelonephritis
  • Headache/neck stiffness - meningitis
  • Pelvic pain - PID
  • Bloody diarrhoea - dysentery
  • Skin inflammation - cellulitis, erysipelas

Associated signs/symptoms

  • Headache
  • Malaria, typhus
  • Myalgia
  • Dengue, haemorrhagic fevers
  • Photophobia
  • Rabies, leptospirosis, dengue
  • Skin lesions

Type of Fever

  • Persistent low - parasitic, chronic bacterial
  • Sustained high - typhoid, typhus, plague
  • Subnormal temp. - protozoan infections, G-ve bacteraemia, overwhelming viral infections

Physical examination

  • Must be thorough
  • Temperature, pulse, RR, BP
  • Jaundice, LNs, rashes, meningism, skin lesions, organomegaly
  • If VHF suspected protect yourself!

Types of skin rash

  • Papular/maculopapular - spotted fevers, dengue (morbilliform)
  • Petechiae/haemorrhagic - usually septicaemia (meningococcal), viral haemorrhagic fevers, dengue (haemorrhagic)
  • Scrub typhus
  • Rocky Mountain Tick Fever

Localised skin lesions

  • Eschars - anthrax, typhus (look for LN)
  • Chancre - trypanosomiasis
  • Buboes - plague

Causes of Jaundice

  • Hepatitis A
  • Malaria
  • Visceral Leishmaniasis
  • Viral infections - CMV, EBV
  • Typhoid, leptospirosis
  • No localizing features
    • Septicaemia
    • Leptospirosis (often jaundice)
    • Tick and louse-borne fevers

Malaria

Important - please see specific page for management of possible malaria.


Other Important Causes of Fever

  • Bacterial Infections
  • Pneumonia
  • UTI
  • Streptococcal throat
  • Typhoid
  • Legionella
  • Leptospirosis

Enteric Fever

  • Salmonella typhi or paratyphi
  • Presents with fever, malaise, headache, cough
  • After a week ill with splenomegaly and rose spot rash (50%) often paradoxically slow pulse
  • WBC usually low, normal platelets
  • If delay in treatment complications - bowel perforation, haemorrhage
  • Untreated mortality approx 15 %
  • Vaccine only 70% efficacy

Legionnaire's Disease

  • More on legionnaire's
  • Causes 4-10 deaths in UK travellers/year
  • Often presents non specifically - 'flu' or 'chest infection', has not responded to Amoxicillin
  • Often confused with hyponatraemia
  • Often from common destinations - Spain, Turkey
  • CXR most useful. If consolidation - macrolid

Tuberculosis

  • May present acutely with fever, cough, night sweats, weight loss
  • Abdominal, renal TB may be very difficult to diagnose
  • WBC usually normal

Viral Infections

  • Dengue and other arbovirus infections
  • Hepatitis
  • VHF

Dengue Fever

  • Fever, headache, retro-orbital pain, severe myalgia, morbilliform rash
  • WBC normal or low, thrombocytopaenia
  • Haemorrhagic form is uncommon in travellers
  • Dengue fever - haemorrhagic

Hepatitis

  • Often present as fever
  • Fever usually settles when jaundice develops (unlike malaria)
  • Normal white cells and platelets
  • ↑ AST

Viral Haemorrhagic Fevers

  • YF, dengue, rift valley fever - mosquitoes
  • Crimean-Congo, Omsk, Kyasanur - ticks
  • Hantaan, Korean, Lassa - rodent excreta
  • Marburg, Ebola - unknown (body fluids)
  • Possibility must be considered in febrile travellers
  • Incubation 3 - 21 days

Chronic fevers

Need investigations?

  • FBC and differential often give useful guide

Possible causes:

  • Schistosomiasis
  • Leishmaniasis, liver flukes, toxocariasis
  • Trypanosomiasis
  • TB (commonest cause of PUO)
  • Plague

Rickettsial and Protozoal Infections

  • Tick Typhus
  • Louse borne infection
  • Amoebic abscess

Summary

  • Feverish travellers may have potentially fatal illnesses
  • Take a thorough travel history
  • Check out the VHF page and or use the VHF Triage form (more on VF)
  • Always consider malaria and take 3 thick films
  • Give broad spectrum antibiotics if life-threatening infections - meningitis
  • Consult early with ID specialists


Content by Dr Íomhar O' Sullivan. Last review Dr ÍOS 18/02/24.