1: Ann Intern Med. 1996 Apr 1;124(7):643-50.    Related Articles, Links

Comment in:
Ann Intern Med. 1997 Jan 15;126(2):172.

A fatal case of babesiosis in Missouri: identification of another piroplasm
that infects humans.

Herwaldt B, Persing DH, Precigout EA, Goff WL, Mathiesen DA, Taylor PW,
Eberhard ML, Gorenflot AF.

Centers for Disease Control and Prevention, Atlanta, Georgia, USA.

OBJECTIVE: To characterize the etiologic agents (MO1) of the first reported
case of babesiosis acquired in Missouri. DESIGN: Case report, serologic
testing, animal inoculations, and molecular studies. SETTING: Southeastern
Missouri. PATIENT: A 73-year-old man who had had a splenectomy and had a
fatal case of babesiosis. MEASUREMENTS: Serum specimens from the patient
were assayed by indirect immunofluorescent antibody testing and
immunoprecipitation for reactivity with antigens from various Babesia
species. Whole blood obtained from the patient before treatment was
inoculated into hamsters and jirds and into calves and bighorn sheep that
had had splenectomy and were immunosuppressed with dexamethasone.
Piroplasm-specific nuclear small-subunit ribosomal DNA was recovered from
the patient's blood by using broad-range amplification with the polymerase
chain reaction; a 144 base-pair region of the amplification product was
sequenced; and phylogenetic analysis was done to compare MO1 with various
Babesia species. RESULTS: Indirect immunofluorescent antibody testing showed
that the patient's serum had strong reactivity with Babesia divergens, which
causes babesiosis in cattle and humans in Europe, but that it had minimal
reactivity with B. microti and WA1, which are the piroplasms previously
known to cause zoonotic babesiosis in the United States.
Immunoprecipitations showed that MO1 is more closely related to B. divergens
than to B. canis (a canine parasite). None of the experimentally inoculated
animals became demonstrably parasitemic. Phylogenetic analyses, after DNA
sequencing, showed that MO1 is most closely related to B. divergens (100%
similarity). CONCLUSIONS: Although MO1 is probably distinct from B.
divergens, the two share morphologic, antigenic, and genetic
characteristics; MO1 probably represents a Babesia species not previously
recognized to have infected humans. Medical personnel should be aware that
patients in the United States can have life-threatening babesiosis even
though they are seronegative to B. microti and WA1 antigen.

Publication Types:
Case Reports

PMID: 8607592 [PubMed - indexed for MEDLINE]