The longest persistence of viable SARS-CoV-2 with recurrence of viremia and relapsing symptomatic COVID-19 in an immunocompromised patient – a case study

Background Immunocompromised patients show prolonged shedding of SARS-CoV-2 in nasopharyngeal swabs. We report a case of a prolonged persistence of viable SARS-CoV-2 associated with clinical relapses of COVID-19 in a patient with mantle-cell lymphoma who underwent treatment with R-BAC (rituximab, bendamustine, cytarabine) with consequent lymphopenia and hypogammaglobulinemia. Methods Nasopharyngeal swabs and blood samples were tested for SARS-CoV-2 by Real time-PCR (RT-PCR). On five positive nasopharyngeal swabs, we performed viral culture and next generation sequencing. We analysed the patients’ adaptive and innate immunity to characterize T and NK cell subsets. Results SARS-CoV-2 RT-PCR on nasopharyngeal swabs samples remained positive for 268 days. All five performed viral cultures were positive and genomic analysis confirmed a persistent infection with the same strain. Viremia resulted positive in three out of four COVID-19 clinical relapses and cleared each time after remdesivir treatment. T and NK cells dynamic was different in aviremic and viremic samples and no SARS-CoV-2 specific antibodies were detected throughout the disease course. Conclusions In our patient, SARS-CoV-2 persisted with proven infectivity for over eight months. Viremia was associated with COVID-19 relapses and remdesivir treatment was effective in viremia clearance and symptoms remission, although it was unable to clear the virus from the upper respiratory airways. During the viremic phase, we observed a low frequency of terminal effector CD8+ T lymphocytes in peripheral blood that are probably recruited in inflammatory tissue for viral eradication. In addition we found a high level of NK cells repertoire perturbation with a relevant involvement during SARS-CoV-2 viremia.

Investigation of Extracellular Vesicles From SARS-CoV-2 Infected Specimens: A Safety Perspective

The coronavirus disease 2019 (COVID-19) pandemic, caused by the SARS-CoV-2 virus, is wreaking havoc around the world. Considering that extracellular vesicles (EVs) released from SARS-CoV-2 infected cells might play a role in a viremic phase contributing to disease progression and that standard methods for EV isolation have been reported to co-isolate viral particles, we would like to recommend the use of heightened laboratory safety measures during the isolation of EVs derived from SARS-CoV-2 infected tissue and blood from COVID-19 patients. Research needs to be conducted to better understand the role of EVs in SARS-CoV-2 infectivity, disease progression, and transmission. EV isolation procedures should include approaches for protection from SARS-CoV-2 contamination. We recommend the EV and virology scientific communities develop collaborative projects where relationships between endogenous EVs and potentially lethal enveloped viruses are addressed to better understand the risks and pathobiology involved.

The longest persistence of viable SARS-CoV-2 with recurrence of viremia and relapsing symptomatic COVID-19 in an immunocompromised patient – a case study

BackgroundImmunocompromised patients show prolonged shedding of SARS-CoV-2 in nasopharyngeal swabs. We report a case of a prolonged persistence of viable SARS-CoV-2 associated with clinical relapses of COVID-19 in a lymphoma patient.MethodsNasopharyngeal swabs and blood samples were tested for SARS-CoV-2 by Real time-PCR (RT-PCR). On five positive nasopharyngeal swabs, we performed viral culture and next generation sequencing. We analysed the patients’ adaptive and innate immunity to characterize T and NK cell subsets.FindingsSARS-CoV-2 RT-PCR on nasopharyngeal swabs samples remained positive with cycle threshold mean values of 22 ± 1·3 for over 8 months. All five performed viral cultures were positive and genomic analysis confirmed a persistent infection with the same strain. Viremia resulted positive in three out of four COVID-19 clinical relapses and cleared each time after remdesivir treatment. T and NK cells dynamic was different in aviremic and viremic samples and no SARS-CoV-2 specific antibodies were detected throughout the disease course.InterpretationIn our patient, SARS-CoV-2 persisted with proven infectivity for over eight months. Viremia was associated with COVID-19 relapses and remdesivir treatment was effective in viremia clearance and symptoms remission, although it was unable to clear the virus from the upper respiratory airways. During the viremic phase, we observed a low frequency of terminal effector CD8+ T lymphocytes in peripheral blood that are probably recruited in inflammatory tissue for viral eradication. In addition we found a high level of NK cells repertoire perturbation with a relevant involvement during SARS-CoV-2 viremia.FundingNone.

Tick-borne encephalitis and its global importance

Tick-borne encephalitis (TBE) is the most important tick-transmitted human viral disease in Europe and Asia with up to 10000 human cases annually. The etiologic agents of TBE are the three subtypes of tick-borne encephalitis virus (TBEV), a member of the genus Flavivirus in the family Flaviviridae. The Far-Eastern subtype and the Siberian subtype are both mainly transmitted by Ixodes persulcatus; the European subtype is mainly transmitted by Ixodes ricinus. Besides tick bite, TBEV can be transmitted by unpasteurised milk from goat, sheep and cattle during the viremic phase of infection by the oral route of infection (alimentary form of TBE). There is no treatment for TBE available, but there are effective and well tolerated vaccines against TBE, which are recommended for people living or travelling to endemic countries with a risk of infection.

Challenges in the Laboratory Diagnosis and Management of Dengue Infections

Dengue fever is considered the most important arthropod-borne viral diseases in terms of morbidity and mortality. An accurate and efficient diagnosis of dengue plays an important role in case confirmation. The virus may be isolated during the viremic phase (within day 5 of illness), from serum, plasma and peripheral blood mononuclear cells. Enzyme linked immunoassay (ELISA) has demonstrated the presence of high levels of dengue NS1 antigen and tests may be performed by enzyme-immunoassays (EIAs) or immune-chromatographic (ICT) methods. These assays are specific with respect to different flaviviruses. Conventional and real time RT PCR, nested PCR, multiplex PCR and Nucleic acid sequence based amplification (NASBA) have been described as sensitive and relatively rapid method of detecting the virus during the early viremic phase. Other tests used include assay of anti-dengue specific IgM and IgG ELISA. Currently no curative treatment in terms of anti-viral drugs is available for dengue and patients are managed with rest and aggressive supportive therapy. Management may be done at home or in the hospital depending on the severity of the illness. Hospital management includes fluid therapy, blood component transfusion and other modalities of treatments like steroids, recombinant factor VII and management of complications. Various vaccines are in trial stages and may become available in the near future.

Spontaneous splenic rupture in dengue fever with non-fatal outcome in an adult

A 26-year-old male presented with fever for five days and abdominal pain for 24 hours. System examination identified a soft abdomen with diffuse tenderness. CT-abdomen findings were consistent with splenic rupture with intra and peri-splenic hematoma. Laboratory investigations showed a platelet count of 40,000 per mm3. In due course he developed hypotension and underwent splenectomy. Non-structural protein 1 (NS1) dengue antigen was positive in the admission sample and IgM dengue antibodies were detected in the follow-up sample. Histopathology of the spleen showed normal architecture with no evidence of hyperplasia, cellular infiltrates or haematological malignancy. Splenic rupture is a rare, but potentially fatal complication of dengue fever and severe dengue which should be suspected when a patient presents with abdominal pain and hypotension. Our case highlights the occurrence of splenic rupture in the viremic phase of dengue illness before the development of IgM antibodies.

Managing patients with sexual transmission of drug-resistant HIV

The transmission of drug-resistant HIV-1 (primary HIV resistance) is a cause of growing concern. The prevalence of drug-resistant variants in patients with primary HIV-1 infection (PHI) ranges from 10 to 36%. Unlike patients with secondary resistance, patients with primary HIV resistance do not show a rapid conversion to wild-type drug-sensitive virus in the absence of treatment. Moreover, primary HIV-1 resistance is associated with higher rates of treatment failure. Rapid diagnosis is important, since early events in PHI may have a critical role in disease progression. An early diagnosis is also essential to prevent HIV-1 transmission during the high viremic phase of PHI. This review focuses on prevalence, basic principles, diagnostic markers, and approaches for the treatment of PHI due to sexual transmission of drug-resistant HIV-1. The aim of the paper is to help clinicians to deal with patients presenting a PHI due to drug-resistant variants.

Viremic Phase in a Leukemic Child After Live Varicella Vaccination

Live varicella vaccine has been shown to be efficacious for prevention of varicella even in immunocompromised children.1-4 Although the site and extent of viral replication in vaccinated hosts have not been fully defined, vaccinees have developed humoral and cellular immunity.1-5 A viremic phase has been demonstrated in immunocompromised and normal children with natural varicella.6,7 However, a viremic phase has not been reported in vaccinated children. We report our observation of viremia in a leukemic child in whom vesicles and hepatitis developed after live varicella vaccination. MATERIALS AND METHODS Human embryonic lung fibroblasts (HEFs) were used for virus isolation. The cells were grown in 25-cm2 plastic tissue culture flasks containing Eagle's minimal essential medium with 7.5% fetal bovine serum.