Week 6 - Fever in a Traveller

Question 1

List 7 differential diagnosis?

Answer 1

1. Malaria
2. Acute viral hepatitis (A or E)
3. Arboviral infections - Dengue fever, yellow fever
4. Typhoid or paratyphoid fever
5. Acute mononucleosis (EBV or CMV infection)
6. Leptospirosis
7. Acute HIV seroconversion illness.

Question 2

What questions are important in a history from a returned traveller?

Answer 2

Question 3

What should you ask about her pre-travel health precautions?

Answer 3

1. Vaccination history (including time of vaccination before travel as most vaccinations have a 2-3 week period before peak seroconversion occurs)
2. Any pre-existing medical conditions - e.g. chronic hepatitis B or C, autoimmune liver disease

Question 4

What 5 initial investigations are required?

Answer 4

Question 5

Initial thick and thin films are negative. How often should these be repeated? If a positive film is returned, what complications should she be monitored for and what would be the treatment?

Answer 5

Question 6

TGA Guidelines on Standard treatment for uncomplicated malaria?

Answer 6

• Do not use atovaquone+proguanil to treat malaria if it was used for prophylaxis.
• Monitor parasite count daily until negative.
• Perform full blood count and malaria microscopy at 7 and 28 days after completion of therapy, to assess for recrudescence of malaria parasites.

Question 7

What is malaria? 5 species?
How is the severity of malaria assessed?

Answer 7

Malaria is caused by Plasmodium parasites that are transmitted to humans through the bites of infected mosquitoes. Of the five Plasmodium species that infect humans (P. falciparum, P. vivax, P. knowlesi, P. malariae and P. ovale), P. falciparum and P. knowlesi are the most pathogenic and P. falciparum is the most resistant to standard antimalarials. P. knowlesi is increasingly a cause of malaria in parts of Southeast Asia; it has a similar appearance on microscopy to P. falciparum (ring stages) or P. malariae (mature stages).

Question 8

Standard treatment for severe malaria?

Answer 8

Seek expert advice for patients with severe P. falciparum malaria acquired in the Greater Mekong Subregion (Thailand, Vietnam, Cambodia, Laos and Myanmar), where the prevalence of artemisinin resistance is increasing. Combination therapy with intravenous artesunate plus intravenous quinine is now recommended for these patients. Do not delay therapy if only one of the two intravenous drugs is immediately available—start treatment with one drug and request urgent shipment of the other.