Reversible hearing impairment: delayed complication of murine typhus or adverse reaction to azithromycin?

Delayed and reversible hearing loss occurred in a 55-year-old male patient with murine typhus infection. The patient had the initial symptoms of headache, fever and chills, followed by the occurrence of bilateral hearing loss on day 9 from fever onset. Murine typhus was diagnosed with a high IgM titre by indirect immunofluorescence assay. After treatment with azithromycin and prednisolone, the fever and other symptoms subsided gradually and bilateral hearing loss improved 3 weeks later. Though an adverse reaction to azithromycin could not be ruled out, delayed onset of hearing loss was more likely a complication of murine typhus, mainly because the hearing loss did not occur during the azithromycin usage period. Although hearing loss due to murine typhus is rare, clinicians should be alert to the existence of such a delayed complication.