An elderly woman with a fever

1. An elderly woman with a fever Case Presentatoin Dr M Haghighi

2. A woman in her seventies presented to the emergency department because of a febrile illness of one week's duration. She reported daily fevers up to 104°F (40°C), rigors and sweats.

3. She also reported a dry cough, without shortness of breath, sinus congestion, headache, abdominal pain, nausea, vomiting, diarrhea, dysuria or urinary frequency.

4. Past Medical History • She had hypertension and left bundle branch block, a previous history of invasive melanoma (status post excision in four years before) and, many years before, Lyme disease. She had never had a blood transfusion.

5. Medications • She took verapamil daily.

6. Allergies • She had no allergies.

7. Social History • She was retired, and had previously worked in an office.

8. Epidemiological History • She lived in Tehran. She had traveled extensively, including to Africa, Europe and South America. Her most recent international trips were eight months earlier to South Africa where she visited Kruger National Park and participated in game drives and walking safaris and one year earlier to Kenya.

9. She did not take anti-malarial prophylaxis. She did not report any recent sick contacts or insect bites.

10. Physical Examination • The patient appeared diaphoretic, but was not in any acute distress. The temperature was 104.7°F (40.4°C ), blood pressure 122/69 mm Hg, pulse 68 beats per minute, respirations 18 breaths per minute and oxygen saturation by pulse oximetry 94% while breathing room air.

11. There were fine crackles in the bases of both lungs, and the examination was otherwise normal.

12. Studies • The level of hemoglobin was 12.0g/dl, white blood count 4,400 cells per cubic millimeter (61% neutrophils, 32% lymphocytes, and 6% monocytes) and platelet count 52,000 per cubic millimeter (reference range 150,000-450,000).

13. The level of aspartate aminotransferase was 193 U/L (reference range 8-37 U/L) and alanine aminotransferase was 157 U/L (reference range 8-35 U/L). Results of other routine laboratory tests and urinalysis were normal.

14. A chest radiograph revealed small bilateral pleural effusions

16. Cultures of the blood and urine were sterile.

17. Thick and thin peripheral blood smears are shown, The intraerythrocytic parasites were thought to represent Plasmodium falciparumwith 1.11% parasitemia.

18. Peripheral smear, Wright-Giemsa stain

19. Peripheral smear, Wright-Giemsastain

20. Peripheral smear, Wright-Giemsa stain, x1250 magnification

21. Atovaquone and proguanil hydrochloride (in combination, 4 tabs orally, daily) were administered.

22. On the evening of the first day, fevers persisted and the level of parasitemia was 0.83%. • On the second day, the maximum temperature was 104.2°F (40.1°C). The platelet count was 62,000 per cubic millimeter and the level of parasitemia 0.74%.

23. Malaria PCR was negative.

24. What is the diagnosis?

26. Thick and thin peripheral blood smears revealed intraerythrocytic ring forms including multiple vacuolated forms (Figures 2 through 4). No schizonts or gametocytes were visualized. Because of the persistent fevers, the peripheral smears were reviewed and additional testing performed. • Malaria PCR was negative. Babesia PCR was positive for Babesiamicroti; BabesiamicrotiIgG and IgM were elevated at greater than 1:1024 (reference range less than 1:64) and greater than 1:320 (reference range less than 1:20), respectively.

27. Final Diagnosis • Babesiosis caused by Babesia microti.