Travel Related Infections: Clincal Questions

Question 1

Why would you look at someone’s eosinophil levels in a full blood count? What does it indicate?

Answer 1

A parasitic infection

Question 2

If you believe someone to have malaria what sort of things would you be looking for when ordering a full blood count and why?

Answer 2

• eosinophilia (indicative of a parasitic infection)
• low Hb (anaemic because the malaria is destroying rbcs)
• platelets

Question 3

Which groups of people are most likely to develop sever malaria?

Answer 3

This who are immunocompromised ie pregnant women, children, elderly, HIV patients, cancer patients (having chemo), those who are asplenic etc

Question 4

Why, when treating someone with primaquine (for malaria), would you perform a G6PD screen?

Answer 4

You need to make sure they don’t have a deficiency because if they do in the presence of Primaquine the patient may experience haemolysis

Question 5

Name a condition that is associated with fresh water contact?

Answer 5

Acute schistosomiasis

Question 6

What is the treatment for acute schistosomiasis?

Answer 6

Praziquantel

Question 7

When a specimen is sent to the microbiology lab, what type of investigations can it be subjected to?

Answer 7

1. Microscopy
2. Culture
3. Antigen detection
4. Antibody detection
5. Molecular techniques eg PCR

Question 8

What causes legionnaires’ disease?

Answer 8

Legionella pneumophilia serogroup 1

Question 9

What is legionnaires disease?

Answer 9

A form of atypical pneumonia

Question 10

What type of bacteria is legionella pneumophilia?

Answer 10

Gram negative rods

Parasite- aerobic

Question 11

How is legionnaires’ disease usually spread?

Answer 11

Aerosol spread- inhalation

*Human to human transmission does not occur

Question 12

Legionella pneumophilia uses a feature of the innate immunity to aid its replication. What is this?

Answer 12

The bacteria are phagocytosed by macrophages but prevent the phagosome fusing with a lysosome so evades destruction. Instead it uses the macrophages as a site to replicate and spread.

Question 13

What do you use to treat legionnaires disease?

Answer 13

Quinolone class antibiotics eg levofloxacin

Question 14

Does someone with legionnaires disease need to be treated in a side room?

Answer 14

No, because there is no case to case spread so there is no need for isolation

Question 15

What type of micro-organism is influenza A?

Answer 15

Virus spherical, enveloped RNA

Question 16

How is influenza A transmitted?

Answer 16

Spread via respiratory droplets

There patient would need to be isolated

Question 17

Influenza A can be subtypes depending on the antigen associated with its outer viral proteins. What are the names of these outer viral proteins?

Answer 17

Haemagglutinin (H)

Neuraminidase (N)

*they are designated by the unique combination of H and N antigens they possess eg H1N1

Question 18

What is antigenic shift in relation to influenza A?

Answer 18

This is a process where one cell is infected with two different subtypes of the influenza virus. Reassortment of the viral RNA from both subtypes leads to the creation of new subtypes of the virus