Fever in a returned traveller

1. Fever in a returned traveller OuliXie Intern

2. Fever in a returned traveller • 30 year old man presents with fever 38.5C associated with abdominal pain • Returned 2 months ago from a 3 week trip to India • Multiple exposures and no travel prophylaxis • Associated with 2 days of loose bowels but now BNO for 2 days • Some nausea but no vomiting • PHx: Nil • Meds: Nil

3. Examination • Haemodynamically stable, T 38.5C • Diaphoretic, unwell looking • Fluid depleted • Dual heart sounds, no murmur • Chest clear to auscultation • Tender RIF on palpation, but abdomen soft

4. DDx? • Malaria • Bacterial enteritis • Inflammatory bowel disease • Appendicitis!

5. An approach • History • Travel/exposure history • Examination • Common causes of fever • Causes not to miss • Investigations • Treatment

6. History • Time course is essential • Including progression of illness • Incubation period can help distinguish illnesses • Dengue unlikely after 2 weeks • Associated features • Rash, headache, GI symptoms, myalgia/arthralgia etc.

7. Exposure history • T • O • A • D • S – travel – specific places and dates rural/urban – occupation – activities – detailed list of activities animals, fresh water, food etc. – drugs – including IVDU – sex

8. Causes • Travel specific • Malaria • Dengue • Bacterial enteritis • More prevalent in area of travel • Influenza • Respiratory illnesses • General causes of fever • Appendicitis etc.

9. The big 3 • Malaria • Typhoid • Dengue

10. Malaria • Caused by mosquito-borne protozoan • Plasmodium falciparum • Plasmodium ovale • Plasmodium vivax • Plasmodium malariae • Plasmodium knowlesi • Carried by dawn/dusk biting Anopheles mosquito • Multiple stages in life cycle

11. Malaria life cycle http://www.cdc.gov/malaria/about/biology/

12. Characteristic features • Falciparum malaria can be fulminant and cause death • Ovale and vivaxhave dormant liver stages and may reactivate • Malariae may have low levels of parasetaemia and recrudesce weeks after infection • Characteristically described as cyclical fevers

13. Falciparum malaria • The most common cause of symptomatic malaria • Risk of complicated malaria • Systemic symptoms or high level of parasetaemia >5% • Incubation 12-14 days • Associated with high levels of chloroquine resistance

14. Complicated malaria • Systemic symptoms or high parasetaemia • Altered conscious state +/- seizures • ARDS • Circulatory collapse • Metabolic acidosis • Renal failure or haemaglobinuria • Haptic failure • Coagulopathy +/- DIC • Severe anaemia • Hypoglycaemia http://courses.washington.edu/med620/mechanicalventilation/case3answers.html

15. Clinical features • Hx • High cyclical fevers • May have non-specific associated features including: • Headache, cough, nausea/vomiting, diarrhoea, abdo pain, myalgias/arthralgias • Examination • Splenomegaly • Jaundice

16. Diagnosis • Thick and thin films • Operator dependent • Serial films required • Rapid diagnostic tests • ICT used at RMH (immunochromatographic test) • Used to detect malaria antigens • Can distinguish between Falciparum and non-falciparum malaria • Sensitivity and specificities ~95%

17. Treatment • Artesunate is the preference for treatment of falciparum malaria • 3 day course of artemether-lumefantrine • IV form available for severe falciparum malaria • Always given in combination to prevent resistance • Non-faciparum malaria can be treated with chloroquine if sensitive • Note primaquine required for liver stage of vivax and ovale

18. Dengue • 4 serotypes • Carried by day-biting mosquito Aedesaegypti • Usually not lethal • Risk of dengue haemorrhagic fever • Infection with 1 serotype results in super-antigen response • Circulatory collapse and haemorrhage/coagulopathy

19. Dengue clinical features • History • Fever, arthalgias, myalgias and severe headache (often retro-orbital) • “Breakbone fever” • Maculopapular rash • Examination • Non-specific • May find some lymphadenopathy, rash, hepatomegaly http://en.wikipedia.org/wiki/Dengue_fever

20. Diagnosis and treatment • Basic bloods • Classically shows a thrombocytopaenia and leukopaenia • Diagnosis • Dengue serology • Dengue PCR/ELISA • Treatment • Supportive

21. Enteric fever • Typhoid/paratyphoid fever • Caused Salmonella enterica serotype Typhi or serotype paratyphi • Faecal-oral spread • Typhoid Mary • Can be associated with chronic carriage • Colonisation of biliary system • Incubation 5-21 days

22. Clinical features • Hx • Classic progression described • Rising fever in first week • Abdo pain in second week with appearance of rash • Septic shock in third week • May describe constipation or diarrhoea • Exam • Characteristic rose spot rash • Abdo pain, hepatosplenomegaly http://www.zipheal.com/typhoid/typhoid-fever-symptoms/3761

23. Investigations • Basic investigations • May demonstrate a leukocytosis or leukopaenia • Abnormal LFTs even in hepatitic pattern • Diagnosis • Blood culture (+ve in 40-80%) • May also be cultured in stool or urine • Serology minimal value

24. Treatment • Supportive treatment • Antibiotic therapy • Azithromycin or ceftriaxone • Ciprofloxacin useful if susceptible • Beware resistance against fluoroquinolones in South/South-East Asia

25. Summary • Take a careful history • Remember that fever in returned traveler does not have to be a travel related illness! • Remember the big 3 – malaria, dengue and enteric fever • Time course can often be the key

26. References • Uptodate • Yung, Allen P (2005). Infectious diseases : a clinical approach (2nd ed). IP Communications, East Hawthorn, Vic • Kumar P and Clark M (Eds) (2009) Kumar and Clark’s Clinical Medicine (7th edition). Edinburgh: Saunders Elsevier.