Fever in Returning Traveller

Question 1

What is Malaria?

Answer 1

Protozoal infection (Plasmodium spp.) spread by female Anopheles mosquito (bites at
night, attracted by heat + CO2)

Question 2

What is the incubation period of malaria?

Answer 2

Usually 7-30 days (10-15)

However, dormant staes of vivax can reactivate after months

Question 3

What are the different species of malaria and how do they differ in their clinical presentation?

Answer 3

Overall there are 5 different types of plasmodium species causing malaria, clinically different in presentation and fever spikes

1. Falciparum: most severe form, dominant in africa (75% of global cases, associated with mortality)
2. Vivax: 2nd most common; mainly outside sub-saharan africa and overall less severe

Question 4

What is the general clinical presentation of an malaria infection?

Answer 4

Unlocalised fever
* can be cyclical
* sweating and flu-like symptoms

More specific (can be present in more severe cases)
* Blood: Thrombocytopenia and haemolytic anaemia (anaemia + organ failure usually cause for mortality)
* GI: N&V, diarhooea, abdominal pain, hepatomegaly + jaundice
* CNS impariement: hallucinations, confusion, coma

Question 5

What investigations should be done in suspected malaria infection?

Answer 5

1. Spot test: antigen detection (less sensitive than:)
2. Blood film: thin and thick (gold standart)–> shows intra-e

Question 6

What is the approach to treatment of an Malaria infection?

Answer 6

1. Acute Treatment

For Falciparum Malaria
Depending on Parasithemia (best prognostic factor for falciprum severity)

• Mild: ACT (Artemisinin combination therapies)
• Severe >5% paracythaemia, any organ failure : IV Artesunate

For Non-Falciparum

• chloriquine

2. Prevention of recurrence

• parasites (hypnozoites) go and sleep in liver –> if treatment not continues could reactivate after weeks - months

Question 7

What is Dengue Fever?

How is it transmitted?

Answer 7

Infectious disease caused by infection witth Dengue virus (Flavivirus)

Transmission via Aedes aegypti moskito

Question 8

What is the clinical presentaition of a primary dengue infection?

Answer 8

Usually mild (but can be severe) for 1-2 weeks

• High fever
• severe, retro.orbital headache
• myalgia/arthralgia
• N&V
• Rash “sunburn” even on non-exposed areas)

Question 9

What is the incubation period of dengue ?

Answer 9

Short: 2-7 days

Question 10

How can a dengue infection be diagnosed?

Answer 10

Usually initially Blood/urine PCR

Later on

• serology (but only 5-7 days after fever)

Question 11

Explain the pathophysiology of Dengue haemorrhagic fever

Answer 11

There are 4 sub-types of dengue viruses. Infection with one virus grants life-time protection to this sub-type, but not to others

If infection with different sub-type: antibody-mediated intracellular entry of dengue virus –> much more severe disease

Question 12

What are your top differentials in a returning traveller with a fever and thrombocytopenia ?

Answer 12

Mainly
1. Malaria
2. Dengue

NOT: typhoid

Question 13

What is the epidemiology of typoid fever?

Answer 13

Most risk: indian sub-continent

Question 14

What is typhoid fever?

How is it transmitted?

Answer 14

Infectious disease with salmonella typhi (Gram -ve rod, with flagella)

Transmitted fecal-oral human to human contact

Question 15

What is the clincal presentation of Typhoid fever?

Answer 15

• Gradual onset of high-prolonged fever
• Headache
• rose-spots (rare)
• constipation
• dry cough

Usually if untreated in 3 phases, 1 week each
1. Fever with bradycardia +/- epistaxis
2. Extreme fatigue,
3. Complications: intestinal haemorrage/ perforation

Question 16

What is the management of salmonella typhi infection?

Answer 16

• Oral rehydration
• Cetriaxone IV – >then oral azithromycin/ ciprofloxacin

Pre-antibiotic mortality 10-20%