Monkeypox in Bulgaria: Significance of Various Clinical Samples, Clinical Manifestation, and Molecular Detection.

Background/Objectives : Monkeypox (mpox) is currently the most common orthopoxvirus (OPXV) zoonotic disease, and, since 2022, there has been atypical person-to-person transmission observed in non-endemic countries. The present study aimed to investigate the frequency of monkeypox virus (MPXV) and OPXV DNA detection in recommended and alternative clinical materials taken during the acute and convalescent phases of infection in Bulgarian patients. Methods : The study included laboratory investigation by real time PCR of 181 clinical samples from 42 Bulgarian patients with possible mpox infections. Results : MPXV DNA was detected in 23/181 (12.71%), and OPXV DNA in 20/181 (11.05%) clinical samples. There were six mpox-confirmed patients aged 23 to 44. At the highest frequency, MPXV and OPXV DNA were detected in samples of vesicular contents (6/6) and nasal/oropharyngeal secretions (5/6 and 4/6) during the first three days from the appearance of clinical symptoms. We demonstrated MPXV and OPXV DNA in alternative samples (urine, feces, ejaculate, and saliva), and in follow-up patient samples, taken two weeks after mpox confirmation in the convalescent phase (vesicular contentsand urine). Conclusions : Our findings suggested that MPXV may be detected in a larger set of clinical materials, including alternatives, where the virus can persist for more than two weeks.