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.

Prevalence and phenotypic susceptibility to doravirine of the HIV-1 reverse transcriptase V106I polymorphism in B and non-B subtypes.

AIM: To evaluate the prevalence and in vitro susceptibility to doravirine of RT-V106I polymorphism detected in samples collected from drug-naïve subjects. METHODS: Doravirine susceptibility was measured in site-directed mutants (SDMs) containing V106I, V106A, V106 M and Y188L mutations in subtype B (NL4-3, HXB2) and CRF02_AG background and in recombinant viruses with RT harboring V106I alone derived from 50 PLWH. RESULTS: HIV-1 B subtype was detected in 1523/2705 cases. Prevalence of V106I was 3.2% in B and 2.5% in non-B subtypes, and was higher in subtype F (8.1%), and D (14.3%). Fold-changes (FC) in susceptibility for SDMs were below doravirine biological cutoff (3.0) for V106I, but not for V106A, V106 M, and Y188L. Clinically-derived viruses tested included 22 B (median FC 1.2 [IQR 0.9-1.6]) and 28 non-B subtypes (median FC 1.8 [IQR 0.9-3.0]). Nine (18%) viruses showed FC values equal or higher than the doravirine biological FC cutoff. CONCLUSIONS: The prevalence of the HIV-1 RT-V106I polymorphism in MeditRes HIV consortium remains low, but significantly more prevalent in subtypes D and F. V106I minimally decreased the susceptibility to doravirine in SDMs and most clinical isolates. Reduced susceptibility seems to occur at increased frequency in subtype F1, however the clinical impact remains to be investigated.

Factors Associated with Low-Level Viremia in People Living with HIV in the Italian Antiviral Response Cohort Analysis Cohort: A Case-Control Study.

Despite effective antiretroviral therapies (ARTs), a subset of people living with HIV (PLWH) still experience low-level viremia (LLV, i.e., 50-1,000 copies/mL). The present study compared PLWH experiencing LLV with those maintaining virological suppression (VS) and explored the potential impact of preexisting drug resistance and other factors on LLV. We conducted a retrospective, 1:1 matched case-control study within a cohort of drug-experienced VS subjects from the Italian Antiviral Response Cohort Analysis database, followed in the period 2009-2019. Cases were individuals experiencing LLV, while controls were those who maintained VS. Matching was for calendar year of first ART regimen. Preexisting drug resistance was calculated as cumulative genotypic susceptibility score (GSS) according to regimen administered at the observational period start. To explore the effect of cumulative GSS, treated as a binary variable (≥2 and <2) and other factors on LLV, we performed a logistic regression analysis. Within a main population of 3,455 PLWH, 337 cases were selected. Cases were comparable to the controls for both gender and age. However, cases showed that they had experienced a longer time since HIV diagnosis, a higher number of drugs previously administered, lower baseline CD4+ T cell count and a higher zenith viral load (VL). By multivariate analysis, we found that higher zenith VL [adjusted odds ratio (aOR) (95% confidence interval [CI]) 1.30 (1.14-1.48)], a cumulative usage of both PI [aOR (95% CI): 2.03 (1.19-3.48)] and InSTI [aOR (95% CI): 2.23 (1.47-3.38)] and a cumulative GSS <2 [aOR (95% CI) 0.67 (0.46-0.98)], were associated with a higher risk in developing LLV. In current high-efficacy ART era, in drug-experienced PLWH, the predictors of increased risk of LLV were the presence of preexisting drug resistance, higher zenith VL, and previous PI, and InSTI exposure.

SARS-CoV-2 viremia and COVID-19 mortality: A prospective observational study.

BACKGROUND: SARS-CoV-2 viremia has been found to be a potential prognostic factor in patients hospitalized for COVID-19. OBJECTIVE: We aimed to assess the association between SARS-CoV-2 viremia and mortality in COVID-19 hospitalized patients during different epidemic periods. METHODS: A prospective COVID-19 registry was queried to extract all COVID-19 patients with an available SARS-CoV-2 viremia performed at hospital admission between March 2020 and January 2022. SARS-CoV-2 viremia was assessed by means of GeneFinderTM COVID-19 Plus RealAmp Kit assay and SARS-CoV-2 ELITe MGB® Kit using <45 cycle threshold to define positivity. Uni and multivariable logistic regression model were built to assess the association between SARS-CoV-2 positive viremia and death. RESULTS: Four hundred and forty-five out of 2,822 COVID-19 patients had an available SARS-CoV-2 viremia, prevalently males (64.9%) with a median age of 65 years (IQR 55-75). Patients with a positive SARS-CoV-2 viremia (86/445; 19.3%) more frequently presented with a severe or critical disease (67.4% vs 57.1%) when compared to those with a negative SARS-CoV-2 viremia. Deceased subjects (88/445; 19.8%) were older [75 (IQR 68-82) vs 63 (IQR 54-72)] and showed more frequently a detectable SARS-CoV-2 viremia at admission (60.2% vs 22.7%) when compared to survivors. In univariable analysis a positive SARS-CoV-2 viremia was associated with a higher odd of death [OR 5.16 (95% CI 3.15-8.45)] which was confirmed in the multivariable analysis adjusted for age, biological sex and, disease severity [AOR 6.48 (95% CI 4.05-10.45)]. The association between positive SARS-CoV-2 viremia and death was consistent in the period 1 February 2021-31 January 2022 [AOR 5.86 (95% CI 3.43-10.16)] and in subgroup analysis according to disease severity: mild/moderate [AOR 6.45 (95% CI 2.84-15.17)] and severe/critical COVID-19 patients [AOR 6.98 (95% CI 3.68-13.66)]. CONCLUSIONS: SARS-CoV-2 viremia resulted associated to COVID-19 mortality and should be considered in the initial assessment of COVID-19 hospitalized patients.

Impact of SARS-CoV-2 Omicron and Delta variants in patients requiring intensive care unit (ICU) admission for COVID-19, Northern Italy, December 2021 to January 2022.

This multicenter observational study included 171 COVID-19 adult patients hospitalized in the ICUs of nine hospitals in Lombardy (Northern Italy) from December, 1st 2021, to February, 9th 2022. During the study period, the Delta/Omicron variant ratio of cases decreased with a delay of two weeks in ICU patients compared to that in the community; a higher proportion of COVID-19 unvaccinated patients was infected by Delta than by Omicron whereas a higher rate of COVID-19 boosted patients was Omicron-infected. A higher number of comorbidities and a higher comorbidity score in ICU critically COVID-19 inpatients was positively associated with the Omicron infection as well in vaccinated individuals. Although people infected by Omicron have a lower risk of severe disease than those infected by Delta variant, the outcome, including the risk of ICU admission and the need for mechanical ventilation due to infection by Omicron versus Delta, remains uncertain. The continuous monitoring of the circulating SARS-CoV-2 variants remains a milestone to counteract this pandemic.

Concomitant diagnosis of sexually transmitted infections and human monkeypox in patients attending a sexual health clinic in Milan, Italy.

In 2022, many monkeypox (MPX) outbreaks have been documented in countries where MPX was not endemic. It spread all around the world, especially in European Union and United States. While MPX is classically considered to be transmitted through close contact with lesions, the hypothesis of sexual transmission has been proposed. This study considered a total of 49 patients suspected for MPX that were also tested for other sexually transmitted infections (STIs), including Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and Trichomonas vaginalis. The data from coinfected patients suggested that MPXV and STIs might share the same route of inoculum, corroborating the hypothesis of possible sexual transmission for the emerging poxvirus. And like any other STI, MPX should be considered without stigmatization.

Impact of pre-existent drug resistance on virological efficacy of single-tablet regimens in people living with HIV.

Despite the wide use of single-tablet regimens (STRs), few real-life data are available regarding the impact of pre-existent drug resistance on virological failure (VF). We aimed to fill this gap by analysing a large cohort of individuals selected from the ARCA database. The impact on VF of pre-existent resistance-associated mutations (RAMs) and cumulative genotypic susceptibility score (cGSS) before STR start was evaluated through survival analysis. Potential emergence of resistance at VF was also evaluated. Overall, 3916 individuals were included, comprising 678 treatment-naïve (G1), 2309 treatment-experienced aviraemic (G2) and 929 viraemic (G3), of whom 65.2% were treated with a STR based on efavirenz (35.2%) or rilpivirine (30.0%). At 2 years after starting a STR, the overall probability of VF was 5.9% in G1, 8.7% in G2 and 20.8% in G3. No impact of pre-existent resistance on VF was found in G1. The probability of VF was higher in patients with cGSS < 3 (reduced susceptibility to at least one drug) than in those with cGSS = 3 (full susceptibility to STR drugs) both in G2 and G3. A higher probability of VF was also found in the presence of pre-existent M184V (alone or in combination with pre-existent thymidine analogue mutations). Among patients who failed STR, a significant emergence of RAMs was found only in those exposed to EFV/FTC/TDF in G3 (specifically K103N and M184V). Our results confirm a high efficacy of STRs in clinical settings. Pre-existent resistance appears to influence virological efficacy of STRs in treatment-experienced individuals (both aviraemic and viraemic).

First Case of a COVID-19 Patient Infected by Delta AY.4 with a Rare Deletion Leading to a N Gene Target Failure by a Specific Real Time PCR Assay: Novel Omicron VOC Might Be Doing Similar Scenario?

Herein, we report a case of an Italian male infected by Delta sublineage AY.4 harboring an atypical deletion, leading to a N gene target failure (NGTF) by a commercial molecular assay for SARS-CoV-2 diagnosis (AllplexTM SARS-CoV-2 Assay, Seegene). A 59-year-old unvaccinated patient was hospitalized for pulmonary embolism, with first negative results obtained by both molecular and antigen tests. After several days of viral negativity, he presented positive results for E and RdRP/S genes, but negative in N gene. Negativity in N gene was repeatedly confirmed in the following days. Suspecting an infection by the Omicron variant, SARS-CoV-2 genome sequencing was rapidly performed from nasopharyngeal swab by MiSeq and revealed the presence of the Delta sublineage AY.4 variant with an atypical deletion of six nucleotides, leading to G214-G215 deletion in the Nucleocapsid, thus responsible for NGTF. The analysis of GISAID sequences (N = 2,618,373 12 January 2022) showed that G214-G215 deletion is rarely occurring in most circulating Delta lineages and sublineages in the globe and Europe, with an overall prevalence never exceeding 0.2%. Hence, this study highlights the importance to perform SARS-CoV-2 sequencing and to characterize novel mutations/deletions that could jeopardize the proper interpretation of molecular diagnostic tests. Based on these assumptions, the role of deletions in the recently identified Omicron variant deserves further investigation.

First Identification of the New Severe Acute Respiratory Syndrome Coronavirus 2 Omicron Variant (B.1.1.529) in Italy.

We identified the first case in Italy of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 variant, using whole-genome sequencing in an Italian subject traveling 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.

Impact of resistance mutations on efficacy of dolutegravir plus rilpivirine or plus lamivudine as maintenance regimens: a cohort study.

OBJECTIVES: The aim of this study was to evaluate the impact of resistance mutations on efficacy of dolutegravir-based two-drug regimens (2DR). METHODS: Virologically suppressed patients with HIV-1 switching to dolutegravir + lamivudine or rilpivirine or to a dolutegravir-based three-drug regimen (3DR) with pre-baseline genotype were selected. Virological failure (VF) was defined as one HIV-RNA viral load (VL) >200 cps/mL or two consecutive VL >50 cps/mL; treatment failure (TF) was defined as VF or treatment discontinuation (TD). Resistance was defined as at least low-level resistance to at least one drug of the current regimen. Propensity score matching was used to conduct adjusted analyses within a competing risks framework. RESULTS: A total of 971 dolutegravir-based regimens were selected: 339 (34.9%) 2DR and 632 (65.1%) 3DR. The adjusted cumulative 48-week incidence of VF was 4.2% (90% CI 3.1%-5.3%) with 2DR and 4.7% (90% CI 3.5%-5.8%) with 3DR. The cumulative 48-week incidence of TF was 15.8% (90% CI 13.9%-17.9%) with 2DR and 24.5% (90% CI 22.2%-27.0%) with 3DR. For VF, the estimated hazard ratio (HR) for 2DR vs. 3DR was 1.02 (90% CI: 0.78-1.34), with evidence of effect modification by low-level resistance (HR 3.96, 90% CI: 2.10-7.46). The estimated HR of TF for 2DR vs. 3DR was 0.54 (90% CI: 0.48-0.60). The 48-week cumulative incidence of TD was 11.7% (8.7%, 14.6%) in 2DR and 19.6% (16.9%, 22.4%) in 3DR. CONCLUSIONS: Dolutegravir-based 2DR showed high virological efficacy and durability; however, past resistance increased the risk of VF, but not of TD or TF.

[Possible vaccine-induced immune thrombotic thrombocytopenia in a patient with diabetes and chronic kidney disease or random association?]

We report the case of a 75-year-old man who developed acute myocardial infarction 12 hours after the first dose of ChAdOx1 nCov-19 vaccine. The event was associated with a transient decrease of platelet count and the detection of anti-PF4 antibodies approximately 45 days after the event. Vaccine-induced thrombotic thrombocytopenia (VITT) is characterized by the onset of venous or arterial thrombosis in temporal relationship to the administration of anti-Sars-Cov-2 viral vector vaccines (ChAdOx1 nCov-19 and Ad26.COV2.S), thrombocytopenia and the production of anti-PF4 antibodies. It occurs mainly at a young age, even if the median age is 54 years; it is often associated with thrombosis in atypical sites, such as the cerebral sinus. Our reported case does not present all the diagnostic criteria of VITT. However, the close temporal relationship between ChAdOx1 nCov-19 vaccine administration, thrombosis, and concomitant anti-PF4 antibodies positivity makes the case suggestive of a possible slight form of VITT.

Brief Report: Impact of the COVID-19 Pandemic on Virological Suppression in People Living With HIV Attending a Large Italian HIV Clinic.

BACKGROUND: We assessed the impact of the coronavirus disease 2019 (COVID-19) pandemic on HIV suppression rates in people living with HIV (PLWH) attending a large Italian HIV clinic. SETTING: The HIV outpatient clinic of the Infectious Diseases Department of Luigi Sacco Hospital, Milan, Italy, which serves more than 5000 PLWH per year. METHODS: A before and after quasi-experimental study design was used to make a retrospective assessment of the monthly trend of HIV-RNA determinations of ≥50 among the PLWH attending our clinic, with "before" being the period from January 1, 2016 to February 20, 2020, and "after" being the period from February 21, 2020 to December 31, 2020 (the COVID-19 period). Interrupted time series analysis was used to evaluate any changes in the trend. RESULTS: During the study period, 70,349 HIV-RNA viral load determinations were made, and the percentage of HIV-RNA viral load determinations of <50 copies/mL increased from 88.4% in 2016 to 93.2% in 2020 (P < 0.0001). There was a significant monthly trend toward a decrease in the number of HIV-RNA determinations of ≥50 copies/mL before the pandemic (ß -0.084; standard error 0.015; P < 0.001), and this did not significantly change after it started (ß -0.039, standard error 0.161; P = 0.811). CONCLUSIONS: A high prevalence of viral suppression was maintained among the PLWH referring to our clinic, despite the structural barriers raised by the COVID-19 pandemic. The use of simplified methods of delivering care (such as teleconsultations and multiple antiretroviral treatment prescriptions) may have contributed to preserving this continuum.