AN ELDERLY WOMAN WITH A FEVER

Case Presentatoin

Dr M Haghighi

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.

S

he also reported a dry cough, without

shortness of breath, sinus congestion,

headache, abdominal pain, nausea,

vomiting, diarrhea, dysuria or urinary

frequency.

PAST MEDICAL HISTORY

S

he 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.

MEDICATIONS

S

he took verapamil daily.

ALLERGIES

S

he had no allergies.

SOCIAL HISTORY

S

he was retired, and had previously

worked in an office.

EPIDEMIOLOGICAL HISTORY

S

he 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.

S

he did not take anti-malarial

prophylaxis. She did not report any

recent sick contacts or insect bites.

PHYSICAL EXAMINATION

T

he 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.

T

here were fine crackles in the bases of

both lungs, and the examination was

otherwise normal.

STUDIES

T

he 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).

T

he 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.

A

chest radiograph revealed small

bilateral pleural effusions

C

ultures of the blood and urine were

sterile.

T

hick and thin peripheral blood smears are

shown, The intraerythrocytic parasites

were thought to represent Plasmodium

falciparum with 1.11% parasitemia.

PERIPHERAL SMEAR, WRIGHT-GIEMSA STAIN

PERIPHERAL SMEAR, WRIGHT-GIEMSA STAIN

PERIPHERAL SMEAR, WRIGHT-GIEMSA STAIN, X1250 MAGNIFICATION

A

tovaquone and proguanil hydrochloride

(in combination, 4 tabs orally, daily)

were administered.

O

n the evening of the first day, fevers persisted and

the level of parasitemia was 0.83%.

O

n 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%.

M

alaria PCR was negative.

WHAT IS THE DIAGNOSIS?

T

hick 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.

M

alaria PCR was negative. Babesia PCR was positive for Babesia microti ;

Babesia microti IgG 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.

FINAL DIAGNOSIS

B

abesiosis caused by Babesia

microti.