Persistent and relapsing babesiosis in immunocompromised patients.
BACKGROUND
Human babesiosis is a tickborne malaria-like illness that generally resolves without complication after administration of atovaquone and azithromycin or clindamycin and quinine. Although patients experiencing babesiosis that is unresponsive to standard antimicrobial therapy have been described, the pathogenesis, clinical course, and optimal treatment regimen of such cases remain uncertain.


METHODS
We compared the immunologic status, clinical course, and treatment of 14 case patients who experienced morbidity or death after persistence of Babesia microti infection, despite repeated courses of antibabesial treatment, with those of 46 control subjects whose infection resolved after a single course of standard therapy. This retrospective case-control study was performed in southern New England, New York, and Wisconsin.


RESULTS
All case patients were immunosuppressed at the time of acute babesiosis, compared with <10% of the control subjects. Most case patients experienced B cell lymphoma and were asplenic or had received rituximab before babesial illness. The case patients were more likely than control subjects to experience complications, and 3 died. Resolution of persistent infection occurred in 11 patients after 2-10 courses of therapy, including administration of a final antimicrobial regimen for at least 2 weeks after babesia were no longer seen on blood smear.


CONCLUSIONS
Immunocompromised people who are infected by B. microti are at risk of persistent relapsing illness. Such patients generally require antibabesial treatment for >or=6 weeks to achieve cure, including 2 weeks after parasites are no longer detected on blood smear.
Krause
Peter J
PJ
Division of Infectious Diseases, Connecticut Children's Medical Center, and Department of Pediatrics, University of Connecticut School of Medicine, Farmington, Connecticut 06106, USA. PKrause@ccmckids.org
Gewurz
Benjamin E
BE
Hill
David
D
Marty
Francisco M
FM
Vannier
Edouard
E
Foppa
Ivo M
IM
Furman
Richard R
RR
Neuhaus
Ellen
E
Skowron
Gail
G
Gupta
Shaili
S
McCalla
Carlo
C
Pesanti
Edward L
EL
Young
Mary
M
Heiman
Donald
D
Hsue
Gunther
G
Gelfand
Jeffrey A
JA
Wormser
Gary P
GP
Dickason
John
J
Bia
Frank J
FJ
Hartman
Barry
B
Telford
Sam R
SR
Christianson
Diane
D
Dardick
Kenneth
K
Coleman
Morton
M
Girotto
Jennifer E
JE
Spielman
Andrew
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000981:Antiprotozoal Agents / Q000627:therapeutic use; D001404:Babesiosis / Q000188:drug therapy / Q000276:immunology* / Q000469:parasitology; D016022:Case-Control Studies; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D015047:Zoonoses / Q000469:parasitology
D000981:Antiprotozoal Agents