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An Interesting Case of Pancytopenia

Course Authors

Robert G. Lerner, M.D.

In the past three years, Dr. Lerner has served as a consultant for RPR, and has served on the Speakers' Bureau for Pharmacia & Upjohn.

Estimated course time: 1 hour(s).

Albert Einstein College of Medicine – Montefiore Medical Center designates this enduring material activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

In support of improving patient care, this activity has been planned and implemented by Albert Einstein College of Medicine-Montefiore Medical Center and InterMDnet. Albert Einstein College of Medicine – Montefiore Medical Center is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team.

 
Learning Objectives

Upon completion of this Cyberounds®, you should be able to:

  • Discuss the multiple infections sometimes caused by tick bites

  • Discuss the infectious causes of pancytopenia as well as infectious complications of pancytopenia

  • Discuss the treatment for babesiosis and be aware of its prevalence in the northeastern United States, particularly in the summer.

 

Case History

In August of a recent year, an 81-year-old man was admitted by our ER with a history of dizziness and night sweats, together with decreased appetite and weakness over one week duration. Except for hypertension requiring treatment for many years, the patient had been in good health. The patient had been treated by his private physician but his fever did not respond to broad-spectrum antibiotics.

Upon admission, it was noted that the patient, a resident of Miami, Florida, had been living in the Hamptons on Long Island from May to August in the period preceding hospitalization. It was in early July, in fact, while in the Hamptons, that he first noted a feverish feeling with fatigue and sweats. The symptoms progressed -- though the patient had occasional asymptomatic days -- so much so that by late August the patient had developed profound weakness and could hardly stand. The patient denied any tick bites, rash, diarrhea, cough or rigors. He denied animal contact, ill contacts at home, prior infections, unpasteurized dairy products or travel out of the U.S. He had a negative skin test for TB in the past when he worked as a police officer.

Physical Exam

On physical exam, he was orthostatic with a BP 130/60 while sitting, dropping to 90/60 while standing. Temp. 100.2, pulse 78, respiration 20. Head, eyes, ears, nose and throat were unremarkable. Neck was supple and there was no enlargement of lymph nodes or thyroid. Chest was clear; heart had regular rhythm without murmur; abdomen was soft, not tender, and revealed no enlarged organs. The extremities were normal, as were deep tendon reflexes. Stool was brown and negative for occult blood. The skin over the right popliteal area revealed a faint semicircular red ring, about 16 cm in diameter. The ring was difficult to distinguish and there was questionable completion of this circle superiorly.

Procedures and Lab

The ECG done at time of admission showed a rate of 86, with normal sinus rhythm. The chest x-ray showed no infiltrates or congestion. The admission lab tests were notable for a BUN of 38, creatinine 1.6, and Na 127. The initial blood count revealed white count of 4.7, Hgb 10.6, Hct 31 and platelets 44,000. During his first days in the hospital, the white count fell to 3,400, with a differential of 69% segmented forms, 12% lymphocytes, 14% monocytes, 1 basophil, 1 atypical lymphocyte, 2 metamyelocytes and 1 myelocyte. The platelet count fell to 33,000. The reticulocyte count was 1.1%. Red cells were essentially normal in appearance with some slight targeting. The urinalysis revealed 2+ protein, 2+ blood and 10-25 white cells. The prothrombin time was 15.5 sec and a PTT was 26.7 sec. Urine culture revealed <10,000 organisms, blood cultures were repeatedly negative for bacteria and fungi.

Acid fast culture of both blood and bone marrow were negative. A direct Coombs test was negative. An ultrasound exam of the abdomen revealed mild hepatosplenomegaly. Bone marrow exam revealed essentially normal bone marrow.

Treatment and Clinical Course

The patient was initially treated with Unasyn® and ciprofloxacin without improvement. The patient was then seen by an Infectious Disease consultant who actually detected the rash in the right popliteal area. The ID physician, therefore, strongly suspected that the rash was erythema migrans, secondary to infection with Borrelia burgdorferi and a possible co-infection with human granulocytic ehrlichiosis or babesiosis, all of which are transmitted by the same Ixodes tick.

Accordingly, multiple exams of the buffy coat were made for ehrlichia but all were negative. Smears for parasites were then carried out and babesia organisms were seen. Lyme disease antibody tests were positive for both IgG and IgM antibodies. Antibody tests for human babesiosis were also positive for both IgG and IgM antibodies.

When the diagnosis of babesiosis was established, the patient was started on clindamycin 600 mg IV every 8 hours and quinine 650 mg orally every 8 hours. The patient was also given doxycycline 100 mg every 12 hours for his Lyme disease. The patient improved significantly and became afebrile within a few days. His Hgb and Hct rose and the platelet count returned to normal.

Discussion

The Ixodes tick is the vector for Borrelia burgdorferi, which causes Lyme Borreliosis as well as Babesia microti, which causes babesiosis, and ehrlichia species, which cause human granulocytic ehrlichiosis. Krause et al(1) reported that 10% of patients with Lyme disease in southern New England are coinfected with babesiosis in sites where both diseases are zoonotic. In a recent article from New York Medical College, Varde, Beckley and Schwartz(2) reported on the results of analysis of 100 adult ticks collected in an endemic area of NJ. Fifty-five ticks were infected with at least one of the three pathogens, 43 with Borrelia burgdorferi, five with Babesia microti and 17 with the human granulocytic ehrlichiosis agent. Ten of the ticks were co-infected with two of the pathogens.

Human babesiosis is a parasitic disease very much like malaria. The etiologic agent Babesia microti is carried by the same tick that is the primary vector of Borrelia burgdorferi, which causes Lyme Disease. It is believed that most babesia infections in humans remain asymptomatic. However, elderly or immunocompromised individuals may have clinically obvious, serious or even fatal infections. The most severe (and often fatal) cases occur in individuals who have had their spleen removed.

Finding the intracellular parasite within the red cells on a blood smear can make the diagnosis. The organism exists in tetrads, giving the appearance of a Maltese cross.

Figure 1 shows a blood smear from a more heavily infested individual seen at our hospital. There is a "Maltese cross" in the center of the picture. Very frequently the organism closely resembles the Plasmodium organisms seen in malaria.

Figure 1.

Figure 1

An antibody test using an indirect immunofluorescent technique is now available to aid in the diagnosis. The currently recommended treatment is the administration of quinine combined with clindamycin.

A Word of Warning

With the summer months upon us, the CDC has posted the article by Varde et al of NYMC about the prevalence of multiply infected ticks in New Jersey on their web site. This article warns that Hunterdon County, NJ residents are at considerable risk for infection by a tick-borne pathogen after a deer tick bite. The Tick Research Laboratory at the University of Rhode Island maintains a web site with additional information on tick-borne disease.

Babesiosis has been reported in spring, summer and fall, not only in the coastal areas of northeastern United States but also in Wisconsin, California, Georgia and some European countries. The New York State Department of Health Communicable Disease Fact Sheets has especially noted that Nantucket Island, off the Massachusetts shore, and Long Island, New York, are hot spots for babesiosis.


Footnotes

1Krause PJ, Telford SR 3rd, Spielman A, Sikand V, Ryan R, Christianson D, Burke G, Brassard P, Pollack R, Peck J, Pershing DH; JAMA 1996 Jun 5 275(21):1657-60.
2Varde S, Beckley J, Schwartz I; Prevalence of tick-borne pathogens in Ixodes scapularis in a rural New Jersey county. Emerg Infect Dis (United States), Jan-Mar 1998, 4(1) p97-9.