New England Souvenirs
This paper has been presented at the 12th CISTM, May 8 to 12, 2011, in Boston, MA, USA.
Professor Martin P. Grobusch, MD, Infectious Diseases, Center for Tropical Medicine & Travel Medicine, Division of Internal Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, PO Box 22660, 1100 DD Amsterdam, The Netherlands. E-mail: firstname.lastname@example.org
A 54-year-old woman presented with 2 weeks of fever after a trip to the Northeastern United States. Except for an erythematous skin lesion on her right shoulder, no physical abnormality was detected. We diagnosed concomitant borreliosis and babesiosis. Both infections were possibly acquired by one bite from Ixodes scapularis.
Clinical Case Report
A 54-year-old woman presented in July 2009 with a 2-week history of chills and fever up to 40°C. Because of her job as event manager, she had visited Egypt, Costa Rica, and South Africa over the past years. In February and March 2009, she had traveled to Indonesia (Bali, Sulawesi, and Papua) taking atovaquone–proguanil as malaria chemoprophylaxis. On a recent trip to the United States in June, she had visited Boston, the Niagara Falls area, and Cape Cod where she went hiking with a friend.
We saw a moderately ill, febrile woman, neither anemic nor jaundiced. Except for an erythematous skin lesion of 5 cm diameter on her right shoulder, no physical abnormalities were detected.
Initial laboratory tests yielded an ESR of 52 mm/h, hemoglobin 7.4 mmol/L, WBC 5.3 × 109/L with atypical lymphocytes, platelets 135 × 109/L, and CRP 146 mg/L. Liver enzymes were elevated (ASAT 118 U/L, ALAT 183 U/L, ALP 314 U/L, GGT 165 U/L, and LDH 516 U/L). Serum bilirubin and creatinine were within the normal range. All other tests including chest radiograph, urinalysis, ECG, and Coombs test were normal.
Because of recent visits to tropical areas malaria was suspected. Scanty parasites were observed by quantitative buffy coat fluorescence microscopy, Giemsa-stained thick and thin blood smears, morphologically resembling Babesia spp., but malaria could initially not be excluded. Treatment with chloroquine was started prior to polymerase chain reaction (PCR) confirmation. The next day, after our patient had another overnight fever episode, the initial skin lesion had developed into a classic erythema migrans, with additional lesions appearing on her back and extremities. A repeated thin blood smear demonstrated Babesia spp. A multiplex real-time PCR for malaria proved positive using a generic probe, but species-specific probes remained negative.1 Sequence analysis of the PCR amplicon showed identity to 18S rDNA sequences of Babesia microti, suggesting cross-reaction with the plasmodial primer/probe set. The diagnosis was confirmed by amplification and sequence analysis of a 238 nucleotide sequence of the same target using Babesia-specific primers.2
A biopsy of the skin lesion was taken for Borrelia culture and PCR, and a serum sample for serological tests. The biopsy was positive for Borrelia burgdorferi by culture and PCR. Serological tests proved positive for Babesia and Borrelia, and negative for Ehrlichia. Treatment was initiated with atovaquone and azithromycin, thus covering both agents. Blood films and PCR for babesiosis turned negative on day 13. Our patient was symptom free at her final checkup 6 weeks after initial presentation.
Both infections were possibly acquired by one bite from Ixodes scapularis. Both Borrelia and Babesia as well as the agent of human granulocytic ehrlichiosis are transmitted by ticks (Ixodes spp.), have overlapping distribution areas, and are regularly found concomitantly in vector ticks, animal reservoirs, and in human seroprevalence studies in the United States and Europe.3–5 However, finding borreliosis and babesiosis concomitantly in acutely ill patients is only infrequently described in literature.3 Without the history of having visited a malaria-endemic area the babesiosis in our patient could have gone undetected, given the high cure rate in immunocompetent individuals. In the United States, there are fewer babesiosis cases reported than Lyme disease cases, as human babesiosis coincides only in certain Lyme disease foci; furthermore, for these diseases there is no obligatory notification. Signs and symptoms of babesiosis may be unspecific, ranging from severe disease to resembling a viral illness.5–8 The recommended therapy for babesiosis is a 7- to 10-day course of clindamycin (600 mg every 6 h) and quinine (650 mg every 8 h). Azithromycin (500–600 mg on d 1 and 250–600 mg on subsequent days) and atovaquone (750 mg every 12 h) were found to be equally effective. The latter combination is associated with fewer adverse effects and in our patient covered both infections.9 Whereas our patient recovered uneventfully, one US group reported from a retrospective analysis of 14 cases that coinfected individuals may be more symptomatic and have longer disease duration than monoinfected patients.3,5,8
The authors thank Suzanne Jurriaans and Anneke Oei for laboratory assistance.
Declaration of Interests
The authors state that they have no conflicts of interest to declare.
Authors' Contributions Statement
M. v. V., J. W., and M. H. contributed to patient care. T. v. G., M. K., N. V., L. S., and A. B. contributed to the diagnostic procedures. M. v. V. and M. P. G. drafted this article. All authors contributed to the final version of this article and approved of it submission. M. P. G. as corresponding author had full access to all data and holds final responsibility for the decision to submit for publication.