Seek and Find! PCR analyses of skin infections in West-European travelers returning from abroad with an eschar.

BACKGROUND: Skin infections are among the leading causes of diseases in travelers. Diagnosing pathogens could be difficult.

METHOD: We applied molecular assays for the diagnostic of a large collection of skin biopsies and swabs from travelers with suspected skin infections. All samples were tested by qPCR for Coxiella burnetti, Bartonella sp., Rickettsia sp., Borrelia sp., Ehrlichia sp., Tropheryma whipplei, Francisella tularensis, Mycobacteria sp., Staphylococcus aureus, Streptococcus pyogenes, Leishmania spp., Ortho poxvirus and Para poxvirus and then screened for the presence of bacteria by PCR amplification and sequencing, targeting the 16S rRNA gene.

RESULTS: From January 2009 to January 2017, 100 international travelers presenting with a suspected skin infection were enrolled. We detected 51 patients with an identified pathogen on skin samples. Travelers presenting with eschars were more likely to have a positive PCR sample (n = 44/76, 57.9%) compared to other patients (n = 7/24, 29.2%). Spotted fever group Rickettsia (n = 28) was the most frequently detected pathogens (19 R. africae, 6 R. conorii, 3 R. mongolitimonae); S. aureus were detected in 11 patients; S. pyogenes in 3; Leishmania sp.; M. leprae and B. henselae in 1 patient, respectively.

CONCLUSION: By targeting the most commonly encountered causative agents of travel-related skin infections, our strategy provides a sensitive and rapid diagnostic method.