Case Study: Infectious Disease Diagnosis for a Patient with Fever and Other Symptoms

Patient Presentation and Symptoms

Akua is a 29-year old lady form Botswana who arrived in the UK two months ago. She presents at the Teddington Memorial Hospital Walk-In Centre complaining of fever. The fever started 14 days ago, accompanied by muscle pain and nausea. On initial questioning, it becomes apparent that her fever is episodic and is always associated with shaking and sweating. She also looks pale and has lost some weight in the last month. She has not been in contact with anyone with fever and has never had TB. She denies any recent history of diarrhoea, but claims that she once saw something in her stool, which she thought was odd. She occasionally takes OTC analgesics when she has a headache and has no known allergies. She is referred to the Emergency Department for further investigations.

A physical examination at the Emergency Department revealed the following:

• Pale mucous membrane

• BP: 100/65

• Pulse: 120 b/m, regular

• No skin lesions (petechiae or chancres)

• Temp: 39^Oc

• Palpable liver and spleen and lymphadenopathy

She has no localising cardiovascular, respiratory or gastrointestinal symptoms.

Akua is referred to the Communicable Disease Unit for further tests based on suspicion of an infection. The results were as follows:

Blood:

• Hb: 90 g/L

• MCV: 72 fl

• WBC: 6.5 x 10⁹(mostly polymorphonuclear leukocytes)
• Platelets: 95 x 10⁹

• ESR: 85 mm/h

• Urea: 9.0mmol/L

• Creatinine: 82 mmol/L
• Glucose: 3.2 mmol/L

Liver function test:

• Albumin: 30 g/L

• AST: 110 U/L
• ALP: 75 U/L
• Bilirubin (unconjugated): 32 g/L

The chest X-ray does not indicate lung pathology.

Blood film & culture and stool examination results confirm the presence of an infectious agent.

She was treated for her infection and anaemia and she felt better by day four. Her fever also subsided, however her temperature didn’t get back to normal.

Four weeks post treatment she is still not feeling quite herself and presents to the clinic again. She has continuing low-grade fever, night sweats, malaise and lymphadenopathy. Considering her symptoms, the health advisor discusses testing for HIV infection. She is tested for HIV and the following day she is told that a second blood sample is needed for testing. Both samples were reported as positive for HIV-antibody. A test for other sexually transmitted infections (chlamydia DNA, syphilis serology and gonorrhoea culture) was negative. A further blood sample was taken for the measurements of CD4 count and HIV viral load. The results were as follows:

• CD4⁺count: 155 cells/mm³

• Viral load: 255352 copies/ml

The health advisor spends some time with Akua discussing transmission of HIV and its effect on the immune system. They also discuss the importance of barrier contraception and post exposure prophylaxis, as well as, the current anti-retroviral therapy. Her last sexual intercourse, which was without using any barrier contraception, was a week before her trip to UK.

Akua was offered anti-retroviral combination therapy ‘HAART’ and PCP prophylaxis with Cotrimoxazole.

You are required to write a report based on the patient’s presentation, clinical findings and test results in relation to the relevant infectious disease.

Within your report, make sure you include the following:

• Make a diagnosis for the patient’s initial infectious disease (i.e. prior to HIV diagnosis) based on the signs and symptoms, as well as, physical examination and blood test findings.

• Explain the patient’s symptoms and signs in relation to your proposed diagnosis and explain the abnormalities in tests and investigation results.
  
  
• What treatment regimen was she most likely put on for her initial diagnosis of an infection?

• Describe the structure and life cycle of the infectious agents in question and explain how these may be related to the clinical presentation and the current treatment approaches.

• Outline the modes of transmission and the immune responses against the pathogens in question.
  
  
• Explain the clinical effects of HIV infection and why they occur from an immunological perspective.
  
  
• Explain the significance of viral load and CD4 count in relation to HIV infection status and prognosis. How does the viral load result influence management?

• How are AIDS and HIV infection distinguished and the rationale behind the current treatment options, both prophylactic and responsive?

• Recognise evasion of immune responses by HIV.

• The common opportunistic infections associated with HIV/AIDS and how they are prevented/ treated.

• How should our patient be monitored and managed? What support and counselling services are available for HIV sufferers?