Longitudinal Analysis of Mpox Virus DNA Detectability From Multiple Specimen Types During Acute Illness: A Cohort Study

Darrell H S Tan; Oscar Pico Espinosa; John Matelski; Shreya S Khera; Attia Qamar; Reva Persaud; Jacklyn R Hurst; Angel Ly; Jessica Lam; Maedeh Naghibosadat; Natasha Christie; Maan Hasso; Kevin Gough; Linda R Taggart; Charlie Tan; Mario Ostrowski; Huiting Ma; Scott D Gray-Owen; Robert Kozak; Sharmistha Mishra

doi:10.1093/ofid/ofae073

Longitudinal Analysis of Mpox Virus DNA Detectability From Multiple Specimen Types During Acute Illness: A Cohort Study

Open Forum Infect Dis. 2024 Feb 7;11(2):ofae073. doi: 10.1093/ofid/ofae073. eCollection 2024 Feb.

Authors

Darrell H S Tan^{1

2

3

4

5}, Oscar Pico Espinosa², John Matelski¹, Shreya S Khera², Attia Qamar⁶, Reva Persaud², Jacklyn R Hurst⁷, Angel Ly⁸, Jessica Lam⁸, Maedeh Naghibosadat⁷, Natasha Christie⁸, Maan Hasso⁹, Kevin Gough^{1

3}, Linda R Taggart^{1

3}, Charlie Tan^{1

3}, Mario Ostrowski^{1

3}, Huiting Ma², Scott D Gray-Owen^{8

10}, Robert Kozak^{7

11}, Sharmistha Mishra^{1

2

3

4

5

12}

Affiliations

¹ Division of Infectious Diseases, St. Michael's Hospital, Toronto, Ontario, Canada.
² MAP Centre for Urban Health Solutions, St. Michael's Hospital, Toronto, Ontario, Canada.
³ Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
⁴ Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
⁵ Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, Toronto, Ontario, Canada.
⁶ Scarborough Health Network, Scarborough, Ontario, Canada.
⁷ Biological Sciences, Sunnybrook Research Institute, Sunnybrook Hospital, Toronto, Ontario, Canada.
⁸ Toronto High Containment Facility, Temerty Medicine, University of Toronto, Toronto, Ontario, Canada.
⁹ Public Health Ontario Laboratory, Toronto, Ontario, Canada.
¹⁰ Department of Molecular Genetics, Temerty Medicine, University of Toronto, Toronto, Ontario, Canada.
¹¹ Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
¹² ICES, Toronto, Ontario, Canada.

Abstract

Background: Longitudinal data on the detectability of monkeypox virus (MPXV) genetic material in different specimen types are scarce.

Methods: We describe MPXV-specific polymerase chain reaction (PCR) results from adults with confirmed mpox infection from Toronto, Canada, including a cohort undergoing weekly collection of specimens from multiple anatomic sites until 1 week after skin lesions had fully healed. We quantified the time from symptom onset to resolution of detectable viral DNA (computed tomography [Ct] ≥ 35) by modeling exponential decay in Ct value as a function of illness day for each site, censoring at the time of tecovirimat initiation.

Results: Among 64 men who have sex with men, the median (interquartile range [IQR]) age was 39 (32.75-45.25) years, and 49% had HIV. Twenty received tecovirimat. Viral DNA was detectable (Ct < 35) at baseline in 74% of genital/buttock/perianal skin swabs, 56% of other skin swabs, 44% of rectal swabs, 37% of throat swabs, 27% of urine, 26% of nasopharyngeal swabs, and 8% of semen samples. The median time to resolution of detectable DNA (IQR) was longest for genital/buttock/perianal skin and other skin swabs at 30.0 (23.0-47.9) and 22.4 (16.6-29.4) days, respectively, and shortest for nasopharyngeal swabs and semen at 0 (0-12.1) and 0 (0-0) days, respectively. We did not observe an effect of tecovirimat on the rate of decay in viral DNA detectability in any specimen type (all P > .05).

Conclusions: MPXV DNA detectability varies by specimen type and persists for over 3-4 weeks in skin specimens. The rate of decay did not differ by tecovirimat use in this nonrandomized study.

Keywords: monkeypox; mpox; orthopoxvirus; polymerase chain reaction; prospective cohort study; tecovirimat.