Fever from the shadows: Borrelia duttonii in a migrant in Italy

Abstract

In a striking diagnostic breakthrough, a Senegalese man arrived at SS. Annunziata Hospital in Chieti gripped by relentless high fever, throbbing headache, vomiting, right hypochondrium tenderness, lower limb myalgias, generalized lymphadenopathy, conjunctival injection, and photophobia—signaling a systemic infection with neurologic red flags. Labs showed thrombocytopenia, elevated CRP, procalcitonin, and indirect hyperbilirubinemia; lumbar puncture was negative. The game-changer came during peak fever: an extraordinarily rare visual spectacle on peripheral blood smear—motile spirochetes "dancing" under the microscope, a near-mythical "smoking gun" for Borrelia species, far less common than for Plasmodium. Real-time PCR confirmed Borrelia duttonii, the culprit of soft tick-borne relapsing fever This case highlights that in this world we must always be ready to make unusual diagnoses.

Case

A 46-year-old Senegalese migrant arrived at Madrid airport with a high fever (39°C), a throbbing headache, and vomiting. He was given antipyretics, and after his condition improved, he continued to Italy. However, his symptoms persisted, forcing him to visit the emergency room at the SS. Annunziata Hospital in Chieti four days later. Physical exam revealed right hypochondrium tenderness, cervical and lumbosacral spine pain, lower limb myalgias, generalized lymphadenopathy, conjunctival injection, and photophobia—raising red flags for systemic infection with possible neurologic involvement. Labs showed thrombocytopenia, elevated C-reactive protein (CRP) and procalcitonin (PCT), plus indirect hyperbilirubinemia. A lumbar puncture, prompted by neurologic concerns, was negative. To rule out malaria, peripheral blood smear was examined during peak fever—and there they were: motile spirochetes dancing under the microscope (see Figures). Real-time PCR confirmed Borrelia duttonii, providing species-level identification with superior specificity, especially crucial in migrants from endemic areas [1]. This visual "smoking gun" is exceptionally rare for Borrelia, unlike Plasmodium, where smears shine [2]. Empiric therapy kicked off with doxycycline and ceftriaxone. Within 48 h, fever broke, and clinical-laboratory parameters improved steadily—no Jarisch-Herxheimer reaction noted. Early intervention sealed a favorable prognosis. (Fig.1)

Fig. 1.

Borrelia duttoni, is a spirochete transmitted by soft-body ticks (primarily Ornithodoros spp.), causing soft tick born relapsing fever (STBRF). The initial illness typically lasts approximately 3 days; untreated, spirochetemia recurs every 7–10 days as the parasite's antigenic variation dodges immunity. Blood smears have low sensitivity outside fever peaks, underscoring PCR's role in imported cases [3]. Tetracyclines are first-line; cephalosporins suit severe cases. In our hyper-connected world, this Chieti case spotlights "tropical" threats at Europe's doorstep. Train your eye for spirochetes in febrile travelers—microscopy can still deliver breakthroughs. (Fig.2)

Fig. 2.

Funding source

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Author agreement

We confirm that this work is original, we have all seen and approved the final version. This has not been previously published elsewhere, and is not under consideration by another journal or book. We will also not submit the material to another journal until the completion of the editorial decision process at ID Cases. We have no conflicts of interest to disclose. We approve the manuscript and have contributed significantly to the work.

Informed consent

Written informed consent was obtained from the subject for publication of this case report and the accompanying images.

CRediT authorship contribution statement

Alessandra Gambi: Data curation. Jacopo Vecchiet: Supervision. Francesca Chiappini: Data curation. Katia Falasca: Visualization, Writing – review & editing. UCCIFERRI Claudio: Conceptualization, Supervision, Writing – original draft, Writing – review & editing, Validation.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.