Monkeypox: another test for PCR

Abstract

Monkeypox was declared a public health emergency of international concern by the World Health Organization (WHO) on 23 July 2022. Between 1 January and 23 July 2022, 16,016 laboratory confirmed cases of monkeypox and five deaths were reported to WHO from 75 countries on all continents. Public health authorities are proactively identifying cases and tracing their contacts to contain its spread. As with COVID-19, PCR is the only method capable of being deployed at sufficient speed to provide timely feedback on any public health interventions. However, at this point, there is little information on how those PCR assays are being standardised between laboratories. A likely reason is that testing is still limited on a global scale and that detection, not quantification, of monkeypox virus DNA is the main clinical requirement. Yet we should not be complacent about PCR performance. As testing requirements increase rapidly and specimens become more diverse, it would be prudent to ensure PCR accuracy from the outset to support harmonisation and ease regulatory conformance. Lessons from COVID-19 should aid implementation with appropriate material, documentary and methodological standards offering dynamic mechanisms to ensure testing that most accurately guides public health decisions.

Expression of Concern: The pathophysiological and immunological background of the monkeypox virus infection: An update

“…The sequences of the PCR amplicons (F3L, A39R, B2R, and ATI genes) were later sequenced, and it was discovered that they shared the same sequences as the MPXVs. 109 The in-silico-analyzed targets against MPXV in PCR were reported by Huggett et al 110 The targets included F3L, N3R, B6R, C3L, and B7R. In another study, a recombinase polymerase amplification assay was utilized on the MPXV clades in Central and West Africa, which targeted the G2R gene, and yielded relevant results.…”

Mpox diagnostics: Review of current and emerging technologies

“…One correlation study suggests that qPCR C t of ≥35 or ≥DNA 4300 copies/ml corresponds with non‐ or marginal infectivity 47 . Due to a lack of standardization of MPXV qPCR, this finding may not be directly generalizable to other laboratories 29 . Other important applications of MPXV culture include phenotypic susceptibility testing for antivirals, assessment of population immunity through neutralization assays, and assessment of cellular/host tropism in identifying the potential organ or animal reservoir 9 …”

Molecular and immunological diagnosis of Monkeypox virus in the clinical laboratory

“…This PCR assay, if poorly designed, may have false-negative results (below limit of detection) or reduced analytical sensitivity. The monkeypox virus is not a new virus and there are several published assays available, and this is a very different scenario from that of COVID-19 in early 2020 (13). Poxviruses have a lower mutation rate than RNA viruses due to the 3'-5' exonuclease proofreading activity of the viral DNA polymerase in Poxvirus's DNA genome replication (14).…”