Infection 15 - Travel Related Infections + Malaria

Question 1

What 4 things are important to consider when assessing a patient with a potential travel related infection?

Answer 1

1) Where have they been
2) When did the symptoms begin
3) What are the symptoms/signs
4) How did they acquire it/what activities

Question 2

What are the 5 main species of the plasmodium parasite (causative agent of malaria)?
What is the vector for the parasite?

Answer 2

1) Falciparum
2) Vivax
3) Ovale
4) Malariae
5) Knowlesii

• Female anopheles mosquito

Question 3

What is the incubation period for malaria?

What are the symptoms of malaria?

Answer 3

• Minimum 6 days (falciparum 4 weeks, vivale/ovale upto 1 year)
• Fever, chills, headache, confusion, jaundice (due to haemolytic anaemia) haemoglobinuria, low BP, high HR, oxygen low (don’t confuse with sepsis)

Question 4

How does the parasite cause problems?

Answer 4

• Parasites enter the liver, then are shed into the blood causing breakdown of RBC’s, hence the jaundice.

Question 5

How is malaria diagnosed + treated?

Answer 5

Diagnosis = 3 x flood films, FBC’s, head CT scans + CXR

Treatment - falciparum = quinine + doxycycline. Others.= chloroquine.

Question 6

How is enteric fever (typhoid/paratyphoid) transmitted?
What are the causative agents?
What are its virulence factors?

Answer 6

• Faecal-oral route from contaminated food/water
• Salmonella typhi or salmonella paratyphi (aerobic gram negative bacillus)
• Low infectious dose, survives gastric acid, fimbriae adhere to epithelium over lymphoid tissue, reside within macrophages.

Question 7

What are the signs and symptoms of enteric fever?

What are the potential complications?

Answer 7

• Systemic disease - fever, headache, abdominal discomfort, dry cough + bradycardia
• Intestinal haemorrhage + perforation. 10% mortality if untreated.

Question 8

How is diagnosis of enteric fever made?

What is the treatment?

Answer 8

• Blood culture

- IV ceftriaxone (cephalosporin) or azithromycin (macrolide) for 7-14 days