Epidemiology of Tick-Borne Relapsing Fever in Endemic Area, Spain.

Tick-borne relapsing fever (TBRF) is caused by spirochetes of Borrelia bacteria. We collected data on all TBRF cases in a TBRF-endemic area in southwest Spain during 1994-2016. We analyzed data from 98 patients in whom TBRF was diagnosed by light microscopy and analyzed the relationship between climatic data and TBRF incidence. Most cases occurred a rural environment during summer and autumn. We describe demographic, epidemiologic, clinical, and analytical characteristics, treatment, and occurrence of Jarisch-Herxheimer reaction. Most patients had fever and headache, and laboratory test results included elevated C-reactive protein, thrombocytopenia, and neutrophilia. No patients died, but 10.1% had Jarisch-Herxheimer reaction. B. hispanica was the infecting species in 12 cases with PCR results. Clinicians often do not suspect TBRF because clinical signs and symptoms vary; therefore, it is likely underdiagnosed, even in disease-endemic areas.

First Cases of Natural Infections with Borrelia hispanica in Two Dogs and a Cat from Europe.

Canine cases of relapsing fever (RF) borreliosis have been described in Israel and the USA, where two RF species, Borrelia turicatae and Borrelia hermsii, can cause similar clinical signs to the Borrelia persica in dogs and cats reported from Israel, including fever, lethargy, anorexia, thrombocytopenia, and spirochetemia. In this report, we describe the first clinical cases of two dogs and a cat from Spain (Cordoba, Valencia, and Seville) caused by the RF species Borrelia hispanica. Spirochetes were present in the blood smears of all three animals, and clinical signs included lethargy, pale mucosa, anorexia, cachexia, or mild abdominal respiration. Laboratory findings, like thrombocytopenia in both dogs, may have been caused by co-infecting pathogens (i.e., Babesia vogeli, confirmed in one dog). Anemia was noticed in one of the dogs and in the cat. Borrelia hispanica was confirmed as an infecting agent by molecular analysis of the 16S rRNA locus. Molecular analysis of housekeeping genes and phylogenetic analyses, as well as successful in vitro culture of the feline isolate confirmed the causative agent as B. hispanica.

A 13-year old girl with pancytopenia at the presentation of a Borrelia hispanica infection: a case report and review of the literature.

BACKGROUND: It is not uncommon that a child with a febrile illness of unknown etiology is admitted to the hospital. When the complete blood count reveals a pancytopenia, the diagnostic process can be a real challenge. CASE PRESENTATION: A 13-year girl of Arab-Berber descent presented with abdominal pain and fever after a holiday in northwestern Morocco. A complete blood count revealed a pancytopenia and blood smear test results revealed spirochetes. Borrelia hispanica was identified by sequencing the 16S ribosomal ribonucleic acid gene. Our patient was treated with tetracyclines and during this treatment we saw full clinical and hematological recovery. CONCLUSIONS: Borrelia hispanica is a known cause of tick-borne relapsing fever and is transmitted to humans through the bite of soft ticks of the genus Ornithodoros (Alectorobius). Although the link between tick-borne relapsing fever and thrombocytopenia has been documented, there are only a few case reports of tick-borne relapsing fever presenting with pancytopenia. To the best of our knowledge, there is no previous report of Borrelia hispanica presenting with pancytopenia.

Borrelia crocidurae in Ornithodoros ticks from northwestern Morocco: a range extension in relation to climatic change?

Tick-borne relapsing fever (TBRF) is caused by Borrelia spirochetes transmitted to humans by Argasid soft ticks of the genus Ornithodoros. We investigated the presence of Ornithodoros ticks in rodent burrows in nine sites of the Gharb region of northwestern Morocco where we recently documented a high incidence of TBRF in humans. We assessed the Borrelia infection rate by nested PCR and sequencing. All sites investigated were colonized by ticks of the Ornithodoros marocanus complex and a high proportion of burrows (38.4%) were found to be infested. Borrelia infections were observed in 6.8% of the ticks tested. Two Borrelia species were identified by sequencing: B. hispanica and B. crocidurae. The discovery in northwestern Morocco of Ornithodoros ticks infected by B. crocidurae represents a 350 km range extension of this Sahelo-Saharan spirochete in North Africa. The spread of B. crocidurae may be related to the increasing aridity of northwestern Morocco in relation to climate change.