Evaluation of analytical performance of the STANDARDTM M10 MPX/OPX assay for the simultaneous DNA detection and clade attribution of Monkeypox virus

Monkeypox virus (MPXV) infection confirmation needs reliable polymerase chain reaction (PCR) assays; in addition, viral clade attribution is a key factor in containment measures, considering a more severe syndrome in clade I and the possibility of simultaneous circulation. This study evaluates the performance of all-in-one STANDARD M10 MPX/OPX (SD BIOSENSOR, South Korea - M10). Frozen samples from 205 subjects were selected and stratified according to routine test results (RealStar® Orthopoxvirus PCR Kit 1.0, Altona DIAGNOTICS, Germany - RS; RS-1): in detail, 100 negative skin lesions (SL) and 200 positive samples at the variable stage of infection were analysed. Positive samples were retested with RS (RS-2). Positive and Negative Percent Agreements (PPA, NPA) were calculated. The median (IQR) Ct values of RS and M10 (OPXV target) assays were highly similar. The PPA of M10 compared to RS-1 was 89.5% considering system interpretation, and 96.0% when the operator classified results as positive if any target was detected; NPA was 100%. Comparing the RS-2 run and M10, an overall concordance of 95.3% between assays was found; however, considering operator interpretation, M10 returned more positive results than RS-2. The occurrence of False-Negative results was likely associated with the influence of thawing on low viral concentration; no False-Positive tests were observed. All samples collected at the time of Mpox diagnosis were positive and M10 correctly attributed the clade (West-Africa/II). The M10 MPX/OPX assay demonstrated high reliability in confirming MPXV infection and clade attribution.

Dynamics of viral DNA shedding and culture viral DNA positivity in different clinical samples collected during the 2022 mpox outbreak in Lombardy, Italy

BACKGROUND

Mpox virus (MPXV) has recently spread outside of sub-Saharan Africa. This large multicentre study was conducted in Lombardy, the most densely populated Italian region accounting for more than 40% of Italian cases. The present study aims to: i) evaluate the presence and the shedding duration of MPXV DNA in different body compartments correlating the MPXV viability with the time to onset of symptoms; ii) provide evidence of MPXV persistence in different body compartment as a source of infection and iii) characterize the MPXV evolution by whole genome sequencing (WGS) during the outbreak occurred in Italy.

MATERIAL AND METHODS

The study included 353 patients with a laboratory-confirmed diagnosis of MPXV infection screened in several clinical specimens in the period May 24th - September 1st, 2022. Viral isolation was attempted from different biological matrices and complete genome sequencing was performed for 61 MPXV strains.

RESULTS

MPXV DNA detection was more frequent in the skin (94.4%) with the longest median time of viral clearance (16 days). The actively-replicating virus in cell culture was obtained for 123/377 (32.6%) samples with a significant higher viral quantity on isolation positive samples (20 vs 31, p < 0.001). The phylogenetic analysis highlighted the high genetic identity of the MPXV strains collected, both globally and within the Lombardy region.

CONCLUSION

Skin lesion is gold standard material and the high viral load and the actively-replicating virus observed in genital sites confirms that sexual contact plays a key role in the viral transmission.

Trend over time of HIV-1 drug resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs) and their drivers: A cohort study from Antiviral Response Cohort Analysis (ARCA)

The rise of HIV-1 drug resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs) threatens the long-term success of NNRTI-based therapies. Our study aims to describe the circulation of major resistance-associated mutations (RAMs) for NNRTIs in people living with HIV (PLWH) in Italy from 2000 to 2020. We included 5982 naïves and 28 505 genotypes from 9387 treatment-experienced PLWH from the Antiviral Response Cohort Analysis (ARCA) cohort. Transmitted drug resistance (TDR) was found in 12.5% and declined from 17.3% in 2000-2003 to 10.9% in 2016-2020 (p = 0.003). Predictors of TDR were viral subtype B [vs. non-B, adjusted odds ratio (aOR) = 1.94, p < 0.001], zenith viral load (VL) (per 1 log10 higher, aOR = 0.86, p = 0.013), nadir CD4 cell count (per 100 cells/μL increase aOR = 0.95, p = 0.013). At least one RAM for NNRTIs among treatment experienced PLWH was detected in 33.2% and pre-treatment drug resistance (PDR) declined from 43.4% in 2000-2003 to 20.9% in 2016-2020 (p < 0.001). Predictors of PDR were sexual transmission route (vs. others, aOR = 0.78, p < 0.001), time since HIV diagnosis (per 1 month longer, aOR = 1.002, p < 0.001), viral subtype B (vs. non B, aOR = 1.37, p < 0.001), VL (per 1 log10 higher, aOR = 1.12, p < 0.001), nadir CD4 count (per 100 cells/μL increase, aOR = 0.91, p < 0.001), previous exposure to any NNRTI (aOR = 2.31, p < 0.001) and a more recent calendar year sequence (any time span > 2008 vs. 2000-2003, any aOR <1, p < 0.001). Circulation of RAMs to NNRTIs declined during the last 20 years in Italy. NNRTIs remain pivotal drugs for the management of HIV-1 due to safety concerns and long-acting options.

First identification of the new SARS-CoV-2 Omicron variant (B.1.1.529) in Italy

We identified the first case in Italy of SARS-CoV-2 B.1.1.529 variant by whole genome sequencing in an Italian subject travelling from Mozambique. Specific mutation profiles deserve further investigations to clarify potential effects on vaccination efficacy. This case highlights the crucial role of rapid and continuous surveillance of SARS-CoV-2 variant circulation.