Fever in a returned traveller

Ouli XieIntern

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

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

DDx?

• Malaria• Bacterial enteritis• Inflammatory bowel disease

• Appendicitis!

An approach

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

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.

Exposure history

– travel – specific places and dates rural/urban

– occupation– activities – detailed list of activities animals, fresh water, food etc.– drugs – including IVDU– sex

• T

• O• A

• D• S

Causes

• Travel specific– Malaria– Dengue– Bacterial enteritis

• More prevalent in area of travel– Influenza– Respiratory illnesses

• General causes of fever– Appendicitis etc.

The big 3

• Malaria

• Typhoid

• Dengue

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

Malaria life cycle

http://www.cdc.gov/malaria/about/biology/

Characteristic features

• Falciparum malaria can be fulminant and cause death

• Ovale and vivax have dormant liver stages and may reactivate

• Malariae may have low levels of parasetaemia and recrudesce weeks after infection

• Characteristically described as cyclical fevers

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

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

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

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%

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

Dengue

• 4 serotypes• Carried by day-biting mosquito Aedes aegypti• Usually not lethal• Risk of dengue haemorrhagic fever– Infection with 1 serotype results in super-antigen

response– Circulatory collapse and

haemorrhage/coagulopathy

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

Diagnosis and treatment

• Basic bloods– Classically shows a thrombocytopaenia and

leukopaenia• Diagnosis– Dengue serology– Dengue PCR/ELISA

• Treatment– Supportive

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

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

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

Treatment

• Supportive treatment• Antibiotic therapy– Azithromycin or ceftriaxone– Ciprofloxacin useful if susceptible– Beware resistance against fluoroquinolones in

South/South-East Asia

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

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.