Q Fever Case Study: Tom

You are working as a GP in Dubbo, NSW (city about 300km northwest of Sydney). Tom is a 29-year-old male who lives by himself outside of Dubbo. He presents to you in January feeling very unwell with a fever and cough. He has had no recent travel. He reports no gastrointestinal or UTI symptoms.

Q: What other signs and symptoms would you ask Tom about?

A: chills, profuse sweats, severe headache (especially behind the eyes), photophobia, weakness, anorexia, myalgia and arthralgia, abdominal pain, weight loss, nausea, and fatigue. Tom also reports having a headache, sweats, chills, myalgia and fatigue. He hasn’t been able to work since the fever started 3 days ago.

Q: What are the more common possible causes of Tom’s illness?

A: Influenza (albeit unlikely in January without overseas travel), Ross River or Barmah Forest fever (less likely in Dubbo), psittacosis, other community acquired pneumonias, EBV or HIV.

Q: What would you look for on objective examination?

A:

  • high fever
  • hepatosplenomegaly, jaundice, cholecystitis
  • tachycardia
  • meningeal signs
  • pneumonia signs
  • pericardial rub
  • cardiac murmur

On objective examination Tom has a fever of 38.5°C. You can palpate his liver and spleen 1 cm below the costal margin, his heart rate is 100. He has no skin rashes or lymphadenopathy. There are a few crackles in left lower lung.

Q: What tests would you order at this stage?

A: FBC, EUC, LFTs, blood cultures, CRP, urinalysis, CXR, serology for chlamydiosis, mycoplasma and EBV.

Q: Outline the specific questions you could ask Tom to determine his risk of Q fever?

A: You want to find out about Tom’s contact with animals or animal products (especially cattle, sheep and goats) in the past 6 weeks. This contact could occur while at work or outside of work.

Tom is a sheep shearer and has been shearing sheep in the 6 weeks before his symptoms started. He has mainly stayed in the western region and hasn’t travelled to parts of the state with floods, nor has he gone pig hunting. He reports no risk\ factors for HIV.

Q: Before you consider Q fever as a diagnosis what would you ask Tom?

A: Have you ever had Q fever before or been vaccinated for Q fever?

If Tom has been vaccinated or has had Q fever in the past he is likely to be immune. Tom has not heard of Q fever before and is pretty sure he has never been vaccinated.

Q: Do you think Tom could have Q fever? Why or why not?

A: Yes. Based on Tom’s symptoms and work as a shearer in the incubation period you suspect Q fever.

Q: What treatment would you recommend?

A: You know early treatment is beneficial. Tom is not on any other medications and has no history of adverse reactions to doxycycline or tetracyclines so you start him on doxycycline (100mg po bd) and test for Q fever. You tell him it is important to complete the antibiotic course even if he is feeling better.

Given it is less than a week since his symptom onset you request a Q fever PCR as well as baseline serology (request Phase I and Phase II IgG and IgM serology and titres) in addition to tests for Psittacosis, Mycoplasma pneumonia, EBV and chlamydiosis. You also request liver function tests as they usually show raised transaminases if it’s acute Q fever.

Q: When would you ask Tom to come back for another appointment?

A: In 1 week, whether he is better or not, sooner if he is getting worse. In a week, if he is better, you can organise repeat serology for one week’s time.

Tom cancels his appointment because he is feeling better now and needs to be back at work. His Q fever PCR test was negative. He tested negative for psittacosis, Mycoplasma pneumonia and EBV.

Q: Does Tom need to come back if he is well?

A: It is important that Tom returns as he needs to have convalescent serology 2 – 3 weeks after first collection to confirm his diagnosis. If Q fever is confirmed on serology he will need to be monitored as acute Q fever can progress to chronic Q fever. He should be assessed for his chronic Q fever risk.

Reproduced by permission, NSW Health © 2019