Sir,
Current international guidelines recommend, for most persons with COVID-19 illness, discontinuation of isolation and precautions after 10 days from the onset of symptoms and after at least 24 h without fever [1]. A longer period of isolation, up to 20 days after symptom onset, is recommended for patients with severe illness. The lack of infectivity in people with duration of symptoms >20 days has important implications for public health policy and in hospital infection control. However, these indications might not apply to immunocompromised patients, who might require more time to obtain viral clearance [2]. For this reason, in such a population, the correct timing of isolation is yet to be ascertained. We therefore wanted to report our experience and the results of literature review focused on prolonged shedding of a viable virus in immunocompromised patients.
We report three cases of immunocompromised patients cared for in our Infectious Disease Unit in Northern Italy – Policlinic IRCCS San Martino University Hospital, Genoa – two with haematologic malignancies and one with rituximab-treated neuromyelitis optica (Table I ), all with persistent reverse transcription–polymerase chain reaction (RT–PCR) positivity in nasopharyngeal swabs after weeks or months from the diagnosis of SARS-CoV-2 infection. These patients had viable virus isolated (cytopathic effect in Vero E6 cells at 48 or 72 h), 238, 37, and 40 days after the first RT–PCR positivity (Allplex 2019 nCOV Seegene – Three Target assay towards genes Envelope/Polymerase/Nucleocapsid, E/RdRp/N).
Table I.
Patient group | Patient ID, Reference | Age (years) | Sex | Baseline condition | Clinical manifestation of SARS-CoV-2 | Days from SARS-COV-2 diagnosis | Gene tested and RT–PCR cycle at positivity | Viraemia | SARS-CoV-2 Vero cell infectivity |
---|---|---|---|---|---|---|---|---|---|
Patients followed up in Genoa | 1 | 70 | M | Mantle cell lymphoma treated with R-BAC | Pneumonia and respiratory failure | 238 | E/RdRp/N 22/22/22 |
Positive | Yes |
2 | 50 | F | Neuromyelitis Optica on rituximab |
Pneumonia and respiratory failure | 37 | E/RdRp/N 28/29/28 |
Positive | Yes | |
3 | 47 | F | IgA multiple myeloma with CNS localizations on D-PACE | Pneumonia without respiratory failure | 40 | E/RdRp/N 19/18/20 |
Negative | Yes | |
Patients described in the literature | Baang et al. [3] | 70 | M | Mantle cell lymphoma on mosunetuzumab + cyclophosphamide, doxorubicin, prednisone, and polatuzumab vedotin | Pneumonia and respiratory failure | 119 | S/Orf1ab 21.5/21.3 | NA | Yes |
MSK3, Aydillo et al. [4] | NA | NA | HSCT/CAR-T-cell therapya | NA | 25 | NA | NA | Yes | |
MSK4, Aydillo et al. [4] | NA | NA | HSCT/CAR-T-cell therapya | NA | 26 | NA | NA | Yes | |
MSK6, Aydillo et al. [4] | NA | NA | HSCT/CAR-T-cell therapya | NA | 61 | NA | NA | Yes | |
MSK8, Aydillo et al. [4] | NA | NA | Haematological malignany not futher defineda | NA | 17 | NA | NA | Yes | |
Nakajima et al. [5] | 47 | M | Follicular lymphoma treated with obinutuzumab plus bendamustine | Pneumonia without respiratory failure | 59 | NAb | NA | Yes | |
Avanzato et al. [6] | 71 | F | Chronic lymphocytic leukaemia and hypogammaglobulinaemia treated with IVIG | Absence of respiratory symptoms | 49 70 |
E 28 E 22 |
NA | Yes | |
Decker et al. [7] | 62 | M | Heart transplantation on cyclosporine, mycophenolate, and prednisone | Absence of respiratory symptoms | 18 21 |
NA | NA | Yes | |
Guetl et al. [8] | NA | NA | X-linked agammaglobulinaemia | Pneumonia and respiratory failure | 44 | 25 | NA | Yes | |
Choi et al. [9] | 45 | M | Antiphospholipid syndrome on glucocorticoids, cyclophosphamide, rituximab, and eculizumab | Pneumonia and respiratory failure | 72 143 |
Orf1ab 27.6 Orf1ab 15.6 |
NA NA |
Yes (day 75) Yes |
R-BAC, rituximab, bendamustine and cytarabine; E, envelope gene; RdRp, polymerase gene; N, nucleocapsid protein gene; CNS, central nervous system; D-PACE, cisplatin, doxorubicin, cyclophosphamide, etoposide; S, spike protein gene; Orf1ab, open reading frame 1a and 1b; HSCT, haematopoietic stem cell transplantation; CAR-T-cell, chimeric-antigen-receptor (CAR)-T-cell; IVIG, intravenous immunoglobulins; NA, not available.
Only aggregated data were available for the cases cited.
1.2×104 copies/assays.
The literature review identified other ten cases of immunocompromised patients in whom viable virus was cultured more than 10 days after the onset of infection, and, in most cases, also after more than 20 days (median: 46.5 days; range: 17–119; Table I). Of note, not only did severely ill patients have a prolonged shedding of viable virus, but also those with mild or asymptomatic infection.
These results advocate for customized public health policies and hospital infection control differentiation, not only based on the severity of COVID-19 illness, but also considering the baseline comorbid conditions and immune competence of the patients. A possible approach could be a test-based (PCR or antigen) strategy, as proposed for some cases of severely immunocompromised patients by the Centers for Disease Control and Prevention (CDC) [1]. However, it should be noted that intermittent negativity of molecular tests has also been reported for immunosuppressed patients and that, as a consequence, the test-based approach might also have gaps [8,9]. Moreover, a shared definition of when considering persons ‘severely immunocompromised’ is not provided by CDC indications, while a prolonged shedding of viable SARS-CoV-2 virus has also been reported outside the settings of haematological malignancies or solid organ transplantation [1,3,8]. Finally, some patients with a positive PCR result might not shed a viable virus, thus prolonging isolation might not be necessary.
In conclusion, special attention should be given to isolation precautions in immunocompromised people with SARS-CoV-2 infection, especially in hospital settings, even if only mild symptoms are present. A longer time-period should be considered before discontinuing precautions than in the immunocompetent, and viral culture might be useful to determine potential contagiousness of people with prolonged RT–PCR positivity in nasopharyngeal swabs.
Conflict of interest statement
None declared.
Funding sources
None.
References
- 1.Centers for Disease Control and Prevention . 2020. Duration of isolation and precautions for adults with COVID-19.https://www.cdc.gov/coronavirus/2019-ncov/hcp/duration-isolation.html Available at: [last accessed January 2021] [Google Scholar]
- 2.Vena A., Taramasso L., Di Biagio A., Mikulska M., Dentone C., De Maria A. Prevalence and clinical significance of persistent viral shedding in hospitalized adult patients with SARS-CoV-2 infection: a prospective observational study. Infect Dis Ther. 2021 Jan 8:1–12. doi: 10.1007/s40121-020-00381-8. [online ahead of print] [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Baang J.H., Smith C., Mirabelli C., Valesano A.L., Manthei D.M., Bachman M.A. Prolonged severe acute respiratory syndrome coronavirus 2 replication in an immunocompromised patient. J Infect Dis. 2021;223:23–27. doi: 10.1093/infdis/jiaa666. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Aydillo T., Gonzalez-Reiche A.S., Aslam S., van de Guchte A., Khan Z., Obla A. Shedding of viable SARS-CoV-2 after immunosuppressive therapy for cancer. N Engl J Med. 2020;383:2586–2588. doi: 10.1056/NEJMc2031670. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Nakajima Y., Ogai A., Furukawa K., Arai R., Anan R., Nakano Y. Prolonged viral shedding of SARS-CoV-2 in an immunocompromised patient. J Infect Chemother. 2021;27:387–389. doi: 10.1016/j.jiac.2020.12.001. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Avanzato V.A., Matson M.J., Seifert S.N., Pryce R., Williamson B.N., Anzick S.L. Case study: prolonged infectious SARS-CoV-2 shedding from an asymptomatic immunocompromised individual with cancer. Cell. 2020;183:1901–1912. doi: 10.1016/j.cell.2020.10.049. e9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Decker A., Welzel M., Laubner K., Grundmann S., Kochs G., Panning M. Prolonged SARS-CoV-2 shedding and mild course of COVID-19 in a patient after recent heart transplantation. Am J Transplant. 2020;20:3239–3245. doi: 10.1111/ajt.16133. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Guetl K., Moazedi-Fuerst F., Rosskopf K., Brodmann M., Krause R., Eller P. SARS-CoV-2 positive virus culture 7 weeks after onset of COVID-19 in an immunocompromised patient suffering from X chromosome-linked agammaglobulinemia. J Infect. 2020 Oct 27;S0163–4453(20):30684–30688. doi: 10.1016/j.jinf.2020.10.025. [online ahead of print] [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Choi B., Choudhary M.C., Regan J., Sparks J.A., Padera R.F., Qiu X. Persistence and evolution of SARS-CoV-2 in an immunocompromised host. N Engl J Med. 2020;383:2291–2293. doi: 10.1056/NEJMc2031364. [DOI] [PMC free article] [PubMed] [Google Scholar]