Identification of a measles variant displaying mutations impacting molecular diagnostics, Geneva, Switzerland, 2023.

Real-time PCR is one of the most widely used techniques to diagnose measles cases. Here we report measles virus variants with three genetic mutations in the reverse primer annealing site of a widely used PCR. The mutations result in a slight loss of the PCR sensitivity. Variants bearing the three mutations presently circulate in different countries since at least the end of 2021. Our findings highlight the usefulness of molecular surveillance in monitoring if oligonucleotides in diagnostic tests remain adequate.

Revisiting Cytomegalovirus Serology in Allogeneic Hematopoietic Cell Transplant Recipients.

BACKGROUND: Allogeneic hematopoietic cell transplant recipients (allo-HCTRs) with positive cytomegalovirus (CMV) serology may have false-positive results due to blood product transfusion-associated passive immunity. METHODS: This single-center cohort study included allo-HCTRs with negative baseline (at malignancy diagnosis) CMV serology and indeterminate/low-positive (CMV IgG titer, ≥0.6-<50 U/mL) pretransplant CMV serology with negative pretransplant plasma CMV DNAemia. The CMV status of those patients was reclassified from R+ to R- (CMVR- reclassification group). We compared those patients to allo-HCTRs with negative (CMV IgG titer <0.6 U/mL) pretransplant CMV IgG (CMVR- group). We describe the number and type of patients whose pretransplant CMV status was reclassified from indeterminate/positive to negative. We reviewed all plasma CMV DNAemia tests performed during the first 6 months posttransplant in both groups to assess the safety of this approach. RESULTS: Among 246 (84.5%) of 291 transplanted patients identified as CMVR+ pretransplant, 60 (24.4%) were reclassified from CMV serology indeterminate (N:10)/low-positive (N:50) to R-. Only 1 of 60 patients (1.67%) in the CMVR- reclassification group versus 3 of 44 (6.8%; P = .30) in the CMVR- group developed CMV DNAemia during the follow-up period. There were no significant differences in the number of CMV DNAemia tests performed, CMV DNAemia range, and time posttransplant between the 2 groups. CONCLUSIONS: One of 4 allo-HCT CMVR+ may be falsely flagged as R+, with significant impact on donor selection and prophylaxis administration. A 2-step approach including CMV serology testing at hematologic malignancy diagnosis in allo-HCT candidates and careful review of pretransplant CMV IgG titers may help correctly classify CMV serology status.

Non-Healing Corneal Ulcer and Uveitis Following Monkeypox Disease: Diagnostic and Therapeutic Challenges.

PURPOSE: The ocular manifestations of Monkeypox virus (Mpox) infection remain incompletely characterized. Our goal is to present a case series of non-healing corneal ulcers with associated uveitis caused by Mpox infection as well as management recommendations for Mpox-related ophthalmic disease (MPXROD). METHODS: Retrospective case series. RESULTS: Two male patients with recent hospitalization for systemic Mpox infection presented with non-healing corneal ulcer associated with anterior uveitis and severe IOP elevation. Despite initiation of conservative medical treatment including corticosteroid treatment for uveitis, in both cases, there was clinical progression with enlarging cornea lesions. Both cases received oral tecovirimat with complete healing of the corneal lesion. CONCLUSIONS: Corneal ulcer and anterior uveitis are rare complications of Mpox infection. Although Mpox disease is generally anticipated to be self-limited, tecovirimat may be an effective intervention in poorly healing Mpox keratitis. Corticosteroids should be used with caution in Mpox uveitis, as they might lead to worsening infection.

Hepatitis E Virus Infection Epidemiology in Recipients of Allogeneic Hematopoietic Cell Transplant.

Among 292 recipients of allogeneic hematopoietic cell transplant (2018-2022), 64 (21.9%) tested positive for anti-hepatitis E virus (HEV) immunoglobulin G. Among 208 recipients tested by plasma/serum HEV polymerase chain reaction (2012-2022), 3 (1.4%) primary HEV infections were diagnosed; in 1 patient, plasma HEV polymerase chain reaction relapsed positive for 100 days. HEV infection remains rare albeit associated with persistent viral replication.

A Case of Mpox Reinfection.

A healthy young man first diagnosed with mpox in May 2022 presented again in November 2022 with anal proctitis and a positive polymerase chain reaction on a rectal swab for Monkeypox virus after a recent trip to Brazil, where he engaged in condomless sexual intercourse with multiple male partners.

Elsberg Syndrome Secondary to Cytomegalovirus Infection in an Immunocompetent Patient: A Case Report.

OBJECTIVES: Infectious lumbosacral radiculitis and myelitis, a clinical entity called Elsberg syndrome, is classically linked to HSV-2 and VZV. Here, we report a case of an Elsberg syndrome caused by primary cytomegalovirus (CMV) infection in an immunocompetent patient. METHODS: Here is a case report at an academic medical center. Cerebral and spinal cord MRI, electroneuromyography, and serum and CSF analysis were performed. RESULTS: We investigated a 31-year-old healthy woman presenting with acute paresthesia of both feet ascending to the pelvic region, urinary retention, and constipation. Neurologic examination revealed symmetrical hyperesthesia of both inferior limbs up to the pelvic region, with patellar and Achilles hyporeflexia. Although MRI was normal, a dysfunction of the S1 left nerve root was observed on electroneurography. CSF analysis was inflammatory. Blood CMV PCR was positive, and anti-CMV IgG/IgM values indicated seroconversion. Taken together, these results strongly suggested an Elsberg syndrome caused by CMV primary infection. After a course of ganciclovir, a marked improvement of the symptoms was observed. DISCUSSION: This case highlights that CMV primary infection can be a cause of Elsberg syndrome in immunocompetent patients. CMV testing should be discussed in these patients to initiate adequate antiviral therapy.

Seroprevalence of anti-SARS-CoV-2 antibodies and cross-variant neutralization capacity after the Omicron BA.2 wave in Geneva, Switzerland: a population-based study.

Background: More than two years into the COVID-19 pandemic, most of the population has developed anti-SARS-CoV-2 antibodies from infection and/or vaccination. However, public health decision-making is hindered by the lack of up-to-date and precise characterization of the immune landscape in the population. Here, we estimated anti-SARS-CoV-2 antibodies seroprevalence and cross-variant neutralization capacity after Omicron became dominant in Geneva, Switzerland. Methods: We conducted a population-based serosurvey between April 29 and June 9, 2022, recruiting children and adults of all ages from age-stratified random samples of the general population of Geneva, Switzerland. We tested for anti-SARS-CoV-2 antibodies using commercial immunoassays targeting either the spike (S) or nucleocapsid (N) protein, and for antibody neutralization capacity against different SARS-CoV-2 variants using a cell-free Spike trimer-ACE2 binding-based surrogate neutralization assay. We estimated seroprevalence and neutralization capacity using a Bayesian modeling framework accounting for the demographics, vaccination, and infection statuses of the Geneva population. Findings: Among the 2521 individuals included in the analysis, the estimated total antibodies seroprevalence was 93.8% (95% CrI 93.1-94.5), including 72.4% (70.0-74.7) for infection-induced antibodies. Estimates of neutralizing antibodies in a representative subsample (N = 1160) ranged from 79.5% (77.1-81.8) against the Alpha variant to 46.7% (43.0-50.4) against the Omicron BA.4/BA.5 subvariants. Despite having high seroprevalence of infection-induced antibodies (76.7% [69.7-83.0] for ages 0-5 years, 90.5% [86.5-94.1] for ages 6-11 years), children aged <12 years had substantially lower neutralizing activity than older participants, particularly against Omicron subvariants. Overall, vaccination was associated with higher neutralizing activity against pre-Omicron variants. Vaccine booster alongside recent infection was associated with higher neutralizing activity against Omicron subvariants. Interpretation: While most of the Geneva population has developed anti-SARS-CoV-2 antibodies through vaccination and/or infection, less than half has neutralizing activity against the currently circulating Omicron BA.5 subvariant. Hybrid immunity obtained through booster vaccination and infection confers the greatest neutralization capacity, including against Omicron. Funding: General Directorate of Health in Geneva canton, Private Foundation of the Geneva University Hospitals, European Commission ("CoVICIS" grant), and a private foundation advised by CARIGEST SA.

Primary HSV-2 Infection Complicated by Radiculomyelitis in a Young Immunocompetent Female Patient with Inherited Chromosomally Integrated HHV-6: A Case Report.

BACKGROUND: HSV-1, HSV-2 and VZV are alpha Herpesviruses, neurotropic viruses that are associated with various neurologic complications upon primary infection or reactivation. Cases of myelitis and radiculomyelitis are rare and appropriate etiologic diagnoses can be tricky. CASE PRESENTATION: Here we describe the case of a young immunocompetent woman who developed painful and extended vesicular genital lesions, with subsequent radiculomyelitis. HSV-1/-2 PCRs in the cerebrospinal fluid were misleadingly negative, whereas HHV-6 PCR was positive. Positive anti-HSV-2 IgM and IgG in serum was consistent with HSV-2 primary infection. On the other hand, the detection of HHV-6 DNA was explained by inherited chromosomally integrated HHV-6. The clinical course was favorable with high-dose IV acyclovir and corticosteroids. CONCLUSION: HSV-2-related radiculomyelitis is a rare clinical entity, which can be difficult to diagnose. In this case report, the causative virus was not detected in the patient's CSF, whereas HHV-6 DNA, non-pathogenic in this situation, was paradoxically positive. The diagnosis was based on the clinical features typical for HSV-2 primary infection, confirmed by the serology results. The delay between the genital lesions and the appearance of the radiculomyelitis, along with the absence of HSV-2 detection in the CSF, suggests a possible immuno-mediated physiopathological process. As for the HHV-6 DNA detection in the patient's CSF, it was explained by inherited chromosomally integrated HHV-6. This case illustrates how both negative and positive clinical virology results need careful interpretation according to the clinical findings.

[Varicella-zoster virus (VZV) acute retinal necrosis and recombinant zoster vaccine]. / Nécrose rétinienne aiguë due au virus de la varicelle et du zona et vaccin recombinant contre le zona.

Varicella zoster virus (VZV) is responsible for chickenpox. Like all herpes viruses, after primary infection it enters into latency and can be reactivated afterwards. Many forms of symptomatic reactivation of VZV exist including acute retinal necrosis (ARN), an ophthalmic emergency which can lead to blindness. ARN is treated starting with high-dose intravenous acyclovir then with oral valaciclovir for a total duration of up to 3 months. Symptomatic reactivations of VZV are public health issues. The new Swiss 2022 vaccination plan includes the recombinant vaccine Shingrix. It effectively prevents VZV symptomatic reactivations even in elderly and immuno suppressed patients.

Le virus de la varicelle et du zona (VZV) est responsable de la varicelle. Comme tous les virus herpétiques, après la primo-infection, il entre en latence et peut se réactiver plus tard. Il existe de nombreuses formes de réactivations symptomatiques du VZV, dont la nécrose rétinienne aiguë (NRA), qui est une urgence ophtalmique pouvant aboutir à la cécité. La NRA est traitée par aciclovir intraveineux à haute dose dans sa prise en charge initiale puis par valaciclovir per os pour une durée totale pouvant aller jusqu'à 3 mois. Les réactivations symptomatiques de VZV sont un enjeu de santé publique. Le nouveau plan de vaccination suisse 2022 intègre le vaccin recombinant Shingrix, qui permet de prévenir efficacement les réactivations symptomatiques de VZV chez les patients même âgés et immunosupprimés.

Diagnostic Accuracy of SARS-CoV-2 Rapid Antigen Detection Testing in Symptomatic and Asymptomatic Children in the Clinical Setting.

Antigen-based rapid diagnostic tests (RDTs) are used in children despite the lack of data. We evaluated the diagnostic performance of the Panbio-COVID-19 Ag Rapid Test Device (P-RDT) in children. Symptomatic and asymptomatic participants 0 to 16 years old had two nasopharyngeal swabs (NPS) for both reverse transcription-PCR (RT-PCR) and P-RDT. A total of 822 participants completed the study, of which 533 (64.9%) were symptomatic. Among the 119 (14.5%) RT-PCR-positive patients, the P-RDT sensitivity was 0.66 (95% confidence interval [CI] 0.57 to 0.74). Mean viral load (VL) was higher among P-RDT-positive patients than negative ones (P < 0.001). Sensitivity was 0.91 in specimens with VL of >1.0E6 IU/ml (95% CI 0.83 to 0.99) and decreased to 0.75 (95% CI 0.66 to 0.83) for specimens >1.0E3 IU/ml. Among symptomatic participants, the P-RDT displayed a sensitivity of 0.73 (95% CI 0.64 to 0.82), which peaked at 1.00 at 2 days post-onset of symptoms (DPOS) (95% CI 1.00 to 1.00), then decreased to 0.56 (95% CI 0.23 to 0.88) at 5 DPOS. There was a trend toward lower P-RDT sensitivity in symptomatic children <12 years (0.62 [95% CI 0.45 to 0.78]) versus ≥12 years (0.80 [95% CI 0.69 to 0.91]; P = 0.09). In asymptomatic participants, the P-RDT displayed a sensitivity of 0.43 (95% CI 0.26 to 0.61). Specificity was 1.00 in symptomatic and asymptomatic children (95% CI 0.99 to 1.00). The overall 73% and 43% sensitivities of P-RDT in symptomatic and asymptomatic children, respectively, was below the 80% cutoff recommended by the World Health Organization. We observed a correlation between VL and P-RDT sensitivity, as well as variation of sensitivity according to DPOS, a major determinant of VL. These data highlight the limitations of RDTs in children, with the potential exception in early symptomatic children ≥12yrs.

Diagnostic accuracy of Panbio rapid antigen tests on oropharyngeal swabs for detection of SARS-CoV-2.

BACKGROUND: Antigen-detecting rapid diagnostic tests (Ag-RDTs) for the detection of SARS-CoV-2 offer new opportunities for testing in the context of the COVID-19 pandemic. Nasopharyngeal swabs (NPS) are the reference sample type, but oropharyngeal swabs (OPS) may be a more acceptable sample type in some patients. METHODS: We conducted a prospective study in a single screening center to assess the diagnostic performance of the Panbio™ COVID-19 Ag Rapid Test (Abbott) on OPS compared with reverse-transcription quantitative PCR (RT-qPCR) using NPS during the second pandemic wave in Switzerland. RESULTS: 402 outpatients were enrolled in a COVID-19 screening center, of whom 168 (41.8%) had a positive RT-qPCR test. The oropharyngeal Ag-RDT clinical sensitivity compared to nasopharyngeal RT-qPCR was 81% (95%CI: 74.2-86.6). Two false positives were noted out of the 234 RT-qPCR negative individuals, which resulted in a clinical specificity of 99.1% (95%CI: 96.9-99.9) for the Ag-RDT. For cycle threshold values ≤ 26.7 (≥ 1E6 SARS-CoV-2 genomes copies/mL, a presumed cut-off for infectious virus), 96.3% sensitivity (95%CI: 90.7-99.0%) was obtained with the Ag-RDT using OPS. INTERPRETATION: Based on our findings, the diagnostic performance of the Panbio™ Covid-19 RDT with OPS samples, if taken by a trained person and high requirements regarding quality of the specimen, meet the criteria required by the WHO for Ag-RDTs (sensitivity ≥80% and specificity ≥97%) in a high incidence setting in symptomatic individuals.

[SARS-CoV-2 screening in travelers: what approach to assess transmission risk ?] / Dépistage de l'infection à SARS-CoV-2 chez les voyageurs - Quelle approche pour évaluer le risque de transmis.

Before a trip, a screening for SARS-CoV-2 infection by RT-PCR is often required and raises the problem of detection of residual viral RNA at distance from the acute infection (post-Covid). At the University Hospital of Geneva, we developed an expertise to distinguish acute from post-Covid infections. Between October and December 2020, 30% of the people tested positive were able to travel because the result corresponded to post-Covid and 65% were put in isolation because of an acute infection with a risk of transmission. To overcome the detection of residual viral RNA by RT-PCR, a rapid antigenic test would be an interesting and less expensive alternative. It could also be performed a few hours before departure.

Avant un voyage, un dépistage de l'infection à SARS-CoV-2 par RT-PCR est souvent exigé et soulève le problème de la détection d'ARN viral résiduel chez une personne à distance de l'infection aiguë (post-Covid). Aux HUG, nous avons développé une expertise permettant de distinguer les infections aiguës des post-Covid. Entre octobre et décembre 2020, 30 % des personnes dépistées positives ont pu voyager car le résultat correspondait à des post-Covid et 65 % ont été mises en isolement en raison d'une infection aiguë avec risque de transmission. Pour pallier la détection de l'ARN viral résiduel par la RT-PCR, un test rapide antigénique serait une alternative intéressante et moins chère. Il pourrait également être effectué juste avant le départ.

Analytical Evaluation of Visby Medical RT-PCR Portable Device for Rapid Detection of SARS-CoV-2.

Extended community testing constitutes one of the main strategic pillars in controlling the COVID-19 pandemic. Reverse transcription PCR (RT-PCR) targeting the SARS-CoV-2 genome on nasopharyngeal swab samples is currently the reference test. While displaying excellent analytical sensitivity and specificity, this test is costly, often requires a substantial turnaround time, and, more importantly, is subject to reagent and other material shortages. To complement this technology, rapid antigen tests have been developed and made available worldwide, allowing cheap, quick, and decentralized SARS-CoV-2 testing. The main drawback of these tests is the reduced sensitivity when RT-PCR is the gold standard. In this study, we evaluate Visby an innovative, portable, easy-to-use RT-PCR point-of-care (POC) diagnostic device. Our retrospective analysis shows that overall, compared to the Cobas 6800 RT-qPCR assay (Roche), this RT-PCR POC technology detects SARS-CoV-2 RNA with 95% sensitivity (95%CI = 86.3-99%) and 100% specificity (95% CI = 80.5-100%). For samples with cycle-threshold values below 31, we observed 100% sensitivity (95% CI = 66.4-100%). While showing an analytical sensitivity slightly below that of a standard RT-qPCR system, the evaluated Visby RT-PCR POC device may prove to be an interesting diagnostic alternative in the COVID-19 pandemic, potentially combining the practical advantages of rapid antigen tests and the robust analytical performances of nucleic acid detection systems.

Diagnostic accuracy of two commercial SARS-CoV-2 antigen-detecting rapid tests at the point of care in community-based testing centers.

OBJECTIVES: Determine the diagnostic accuracy of two antigen-detecting rapid diagnostic tests (Ag-RDT) for SARS-CoV-2 at the point of care and define individuals' characteristics providing best performance. METHODS: We performed a prospective, single-center, point of care validation of two Ag-RDT in comparison to RT-PCR on nasopharyngeal swabs. RESULTS: Between October 9th and 23rd, 2020, 1064 participants were enrolled. The PanbioTM Covid-19 Ag Rapid Test device (Abbott) was validated in 535 participants, with 106 positive Ag-RDT results out of 124 positive RT-PCR individuals, yielding a sensitivity of 85.5% (95% CI: 78.0-91.2). Specificity was 100.0% (95% CI: 99.1-100) in 411 RT-PCR negative individuals. The Standard Q Ag-RDT (SD Biosensor, Roche) was validated in 529 participants, with 170 positive Ag-RDT results out of 191 positive RT-PCR individuals, yielding a sensitivity of 89.0% (95%CI: 83.7-93.1). One false positive result was obtained in 338 RT-PCR negative individuals, yielding a specificity of 99.7% (95%CI: 98.4-100). For individuals presenting with fever 1-5 days post symptom onset, combined Ag-RDT sensitivity was above 95%. Lower sensitivity of 88.2% was seen on the same day of symptom development (day 0). CONCLUSIONS: We provide an independent validation of two widely available commercial Ag-RDTs, both meeting WHO criteria of ≥80% sensitivity and ≥97% specificity. Although less sensitive than RT-PCR, these assays could be beneficial due to their rapid results, ease of use, and independence from existing laboratory structures. Testing criteria focusing on patients with typical symptoms in their early symptomatic period onset could further increase diagnostic value.

Clinical, virologic and immunologic features of a mild case of SARS-CoV-2 reinfection.

OBJECTIVES: To report a case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection 6 months after the first infection in a young healthy female physician. Both episodes led to mild coronavirus disease 2019 (COVID-19). METHODS: SARS-CoV-2 infections were detected by real-time reverse transcriptase PCR (RT-PCR) on nasopharyngeal specimens. Reinfection was confirmed by whole-genome sequencing. Kinetics of total anti-S receptor binding domain immunoglobulins (Ig anti-S RBD), anti-nucleoprotein (anti-N) and neutralizing antibodies were determined in serial serum samples retrieved during both infection episodes. Memory B-cell responses were assessed at day 12 after reinfection. RESULTS: Whole-genome sequencing identified two different SARS-CoV-2 genomes both belonging to clade 20A, with only one nonsynonymous mutation in the spike protein and clustered with viruses circulating in Geneva (Switzerland) at the time of each of the corresponding episodes. Seroconversion was documented with low levels of total Ig anti-S RBD and anti-N antibodies at 1 month after the first infection, whereas neutralizing antibodies quickly declined after the first episode and then were boosted by the reinfection, with high titres detectable 4 days after symptom onset. A strong memory B-cell response was detected at day 12 after onset of symptoms during reinfection, indicating that the first episode elicited cellular memory responses. CONCLUSIONS: Rapid decline of neutralizing antibodies may put medical personnel at risk of reinfection, as shown in this case. However, reinfection leads to a significant boosting of previous immune responses. Larger cohorts of reinfected subjects with detailed descriptions of their immune responses are needed to define correlates of protection and their duration after infection.

Maladies infectieuses.

What's new in infectious diseases in 2020 ? This year has been marked by the COVID-19 pandemic, prompting a review of the current knowledge on SARS-CoV-2 and its management in this article. The results of the Swiss project «â€…PIRATE ¼ indicate non-inferiority between CRP-guided antibiotic durations or fixed 7-day durations and 14-day durations for Gram-negative bacteremia. A Mongolian study did not show any benefit of vitamin D substitution in protecting children from tuberculosis. Baloxavir, a new antiviral against the flu, has been approved by Swissmedic. Finally, new American recommendations for therapeutic monitoring of vancomycin and universal screening for hepatitis C virus have been published.

Que dire des nouveautés en maladies infectieuses en 2020 ? L'année a été marquée évidemment par la pandémie du Covid-19, motivant une revue dans cet article, des connaissances actuelles sur le SARS-CoV-2 et de sa prise en charge. Les résultats du projet suisse PIRATE ont montré une non-infériorité pour les bactériémies Gram négatif entre une antibiothérapie de 7 jours ou guidée par la CRP face à une durée de 14 jours. Une étude mongolienne n'a pas permis de montrer le bénéfice d'une substitution en vitamine D chez les enfants sur l'incidence de la tuberculose. Le baloxavir, un nouvel antiviral contre la grippe, a été approuvé par Swissmedic. Et enfin, des nouvelles recommandations américaines sur le monitoring thérapeutique de la vancomycine et sur le dépistage universel de l'hépatite C ont été publiées.

Puumala Virus Infection in Family, Switzerland.

We report 3 cases of Puumala virus infection in a family in Switzerland in January 2019. Clinical manifestations of the infection ranged from mild influenza-like illness to fatal disease. This cluster illustrates the wide range of clinical manifestations of Old World hantavirus infections and the challenge of diagnosing travel-related hemorrhagic fevers.

Cerebrospinal Fluid Features in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Reverse Transcription Polymerase Chain Reaction (RT-PCR) Positive Patients.

This study analyzed the cerebrospinal fluid features of 31 coronavirus disease 2019 (COVID-19) patients with neurological complications. We observed neither severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in the cerebrospinal fluid, nor intrathecal immunoglobulin G (IgG) synthesis but did observe signs of blood-brain barrier disruption. These results might serve as a basis for a better understanding of SARS-CoV-2 related neuropathogenesis.

Sensitivity of nasopharyngeal, oropharyngeal, and nasal wash specimens for SARS-CoV-2 detection in the setting of sampling device shortage.

In the context of an unprecedented shortage of nasopharyngeal swabs (NPS) or sample transport media during the coronavirus disease 2019 (COVID-19) crisis, alternative methods for sample collection are needed. To address this need, we validated a cell culture medium as a viral transport medium, and compared the analytical sensitivity of SARS-CoV-2 RT-PCR in nasal wash (NW), oropharyngeal swab (OPS), and NPS specimens. Both the clinical and analytical sensitivity were comparable in these three sample types. OPS and NW specimens may therefore represent suitable alternatives to NPS for SARS-CoV-2 detection.