A previously healthy 47-years-old male developed abruptly malaise, high fever (40 C) and chills only 3 days after walking and sleeping in the countryside of the island of Bornholm (Denmark) during summer season. He also reported profuse night sweats, a small left infraclavicular non-painful cutaneous lesion. The patient did not report outdoor activities in the month before and did not recall any tick bite. Three days later the fever vanished and he was first observed in a hospital in Berlin. He was prescribed with amoxicillin/clavulanate 875mg/125mg twice-a-day for 7 days.
On the 15th day of disease, he was observed in Portugal because of ongoing malaise. During the observation he did not complain of respiratory symptoms nor headache.
He presented a non-pruritic macular erythematous rash of the trunk, a non-painful left infraclavicular cutaneous lesion covered with a black crust suggestive of a skin eschar and multiple small painless, non-adherent cervical, and axillar lymphadenopathies (Figures 1, 2).
Routine laboratory tests evidenced minor unspecific inflammatory abnormalities: white blood count (WBC; leucocytes 12.060 x 106/L, polymorphonuclear predominancy), platelet count 307000 x 106/L, C-reactive protein 28.4 mg/L. Liver functions tests, blood urea nitrogen, creatinine and electrolyte levels, were within normal range. Human immunodeficiency virus infection tested negative.
Soft tissue ultrasound revealed several lymphadenopathies of the left axillary region, most within dimensions of 1.0-1.5cm (of the largest axis) and two larger (1.8 and 2.3cm) with tendency to suppuration.
Considering an exanthematic fever and an inoculation-like lesion, a Rickettsial infection or Lyme borreliosis were suspected. Blood samples were collected and the patient initiated empirically doxycycline 100 mg bid (twice a day). Later on both detections for antibodies to Rickettsia sp. and Borrelia burgdorferi s.l were negative. Careful revision of zoonosis with prominent lymphadenopathies in Denmark was carried out and an infection with Francisella tularensis was suspected.
Serum specimen was shown to be positive for F. tularensis specific antibodies, which was demonstrated by an agglutination test with a titer of 160, followed by enzyme-linked immunosorbent assay (ELISA) classic Francisella tularensis (Virion/Serion GmbH Institute, Wurzburg, Germany) IgM (titer: 114.53 U/ml (cut-off 15 U/ml), and IgG (titer: > 300 U/ml (cut off 15 U/ml).
As the patient showed no improvement after 4 days with doxicycline he started intramuscular streptomycin 1 g every 12 h in an outpatient basis for 10 days without complications.
The inoculation-like lesion resolved, but the lymphadenopathies remained mostly unchanged. Despite this, the patient left Portugal for working reasons.
Three weeks later the left cervical lymphadenopathy increased in size and the axillary evolved into a suppurative lymphadenitis. He was called back and an excision of the left cervical lymph node was performed.
The excisional biopsy of the lymph node was cultured on chocolate agar media (bioMerieux) at 37 C in a 5% CO2- enriched atmosphere of. After 3 days, some suspicious colonies of Francisella grow. This observation was confirmed by a real-time multitarget TaqMan PCR, using tul4 and ISFtu2 assays and fopA gene with positives further tested using real-time TaqMan PCR assays which differentiate between F. tularensis subsp. tularensis (type A) and F. tularensis subsp. holarctica (type B). For additional characterization, a phylogenetically informative region of lpnA (231 bp) was amplified by conventional PCR as previous described.
Amplicons obtained by lpnA PCR were purified and sequenced with the ABI BigDye Terminator Cycle Sequencing Ready Reaction Kit (Applied Biosystems, Inc., Foster City, CA, USA). The lpnA sequences for F. tularensis subsp. holarctica (PoHuF2) was assigned with the GenBank accession number: MH068785.
On the other hand, histopathology showed cell necrosis and no evidence of tumor cells nor Mycobacterium tuberculosis bacilli was found. An ulceroglandular form of tularemia was unequivocally diagnosed.
In the absence of response to the first line antibiotic therapy with aminoglycosides, he was treated with ciprofloxacin 500 mg twice-a-day for 60 days and performed percutaneous drainage of the bigger axillar lymph nodes with clinical improvement.