A case of SARS-CoV-2 reinfection in Ecuador
Authors: Belén Prado-Vivar, Mónica Becerra-Wong, Juan José Guadalupe, Sully Márquez, Bernardo Gutierrez, Patricio Rojas-Silva, Michelle Grunauer, Gabriel Trueba, Verónica Barragán, Paúl Cárdenas
Journal: The Lancet Infectious Diseases (2020)

Cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection have been reported in Hong Kong, Belgium, the Netherlands, and the USA.1To KK-W Hung IF-N Ip JD et al.COVID-19 re-infection by a phylogenetically distinct SARS-coronavirus-2 strain confirmed by whole genome sequencing.Clin Infect Dis. 2020; (published online Aug 25.)https://doi.org/10.1093/cid/ciaa1275Crossref Scopus (436) Google Scholar, 2Tillett RL Sevinsky JR Hartley PD et al.Genomic evidence for reinfection with SARS-CoV-2: a case study.Lancet Infect Dis. 2020; (published online Oct 12.)https://doi.org/10.1016/S1473-3099(20)30764-7Summary Full Text Full Text PDF PubMed Scopus (526) Google Scholar, 3Iwasaki A What reinfections mean for COVID-19.Lancet Infect Dis. 2020; (published online Oct 12.)https://doi.org/10.1016/S1473-3099(20)30783-0Summary Full Text Full Text PDF PubMed Scopus (153) Google Scholar, 4Mulder M van der Vegt DSJM Oude Munnink BB et al.Reinfection of SARS-CoV-2 in an immunocompromised patient: a case report.Clin Infect Dis. 2020; (published online Oct 9.)https://doi.org/10.1093/cid/ciaa1538Crossref PubMed Scopus (49) Google Scholar Here we report the first confirmed case of SARS-CoV-2 reinfection in Ecuador and South America. For full methodological details, see the appendix (pp 1, 2). On May 12, 2020, a 46-year-old man presented in Quito, Ecuador, with 3 days of intense headache and drowsiness. On May 16, he took a rapid antibody test that was positive for IgM and negative for IgG. On May 20, the patient tested positive on RT-PCR (ORF3a gene, Cq=36·85). Subsequently, the patient's symptoms improved, and he tested negative on RT-PCR on June 3 (appendix p 4). On July 20, the patient presented once again with symptoms suggestive of COVID-19. This time the symptoms were more severe and included odynophagia, nasal congestion, fever of 38·5°C, back pain, productive cough, and dyspnoea. He received an RT-PCR test on July 22, with a positive result (N gene, Cq=30·82). Despite having moderate symptoms and dyspnoea, the patient did not require hospitalisation, and his clinical status improved after several days. A fourth RT-PCR test was done on Aug 4, which was negative (appendix p 4). Finally, an ELISA quantitative antibody test was done on Aug 18, showing anti-SARS-CoV-2 IgG (34·1 NovaTec Units [NTU]) and IgM (54·2 NTU; both interpreted as positive). SARS-CoV-2 genome sequencing was done using Oxford Nanopore Technologies' MinION, following the ARTIC Network protocols.5Quick J Grubaugh ND Pullan ST et al.Multiplex PCR method for MinION and Illumina sequencing of Zika and other virus genomes directly from clinical samples.Nat Protoc. 2017; 12: 1261-1276Crossref PubMed Scopus (622) Google Scholar Phylogenetic analysis revealed that the first infection variant belonged to clade 20A and lineage B1.p9, whereas the second infection variant belonged to clade 19B and lineage A.1.1 (appendix p 4). The mutation loci and amino acid changes are described in the appendix (p 5)). No shared mutations were observed between the two sequences, further suggesting that both variants resulted from distinct evolutionary trajectories. Although reinfections with coronaviruses that cause the common cold have been reported previously,6Callow KA Parry HF Sergeant M Tyrrell DAJ The time course of the immune response to experimental coronavirus infection of man.Epidemiol Infect. 1990; 105: 435-446Crossref PubMed Scopus (426) Google Scholar the symptoms of reinfections are usually milder than those of the primary infections. It was therefore surprising that our patient showed more severe disease with the second infection than with the first, especially because the patient did not have any additional clinical conditions that could explain it. Increased severity of second SARS-CoV-2 infections has been reported previously: in a healthy man aged 25 years in Nevada, USA,2Tillett RL Sevinsky JR Hartley PD et al.Genomic evidence for reinfection with SARS-CoV-2: a case study.Lancet Infect Dis. 2020; (published online Oct 12.)https://doi.org/10.1016/S1473-3099(20)30764-7Summary Full Text Full Text PDF PubMed Scopus (526) Google Scholar and in an immunocompromised woman aged 89 years in the Netherlands, which resulted in her death.4Mulder M van der Vegt DSJM Oude Munnink BB et al.Reinfection of SARS-CoV-2 in an immunocompromised patient: a case report.Clin Infect Dis. 2020; (published online Oct 9.)https://doi.org/10.1093/cid/ciaa1538Crossref PubMed Scopus (49) Google Scholar The protective immune response to SARS-CoV-2 infection is not fully understood; however, protection against severe disease has been shown in animal models and inferred in humans infected with the virus.7Ladhani SN Jeffery-Smith A Patel M et al.High prevalence of SARS-CoV-2 antibodies in care homes affected by COVID-19: prospective cohort study, England.EClinicalMedicine. 2020; (published online Nov 5.)https://doi.org/10.1016/j.eclinm.2020.100597Summary Full Text Full Text PDF Scopus (44) Google Scholar Interestingly, the antibody test performed during the first infection event showed the presence of specific anti-SARS-CoV-2 IgM and no IgG. However, it is not possible using conventional antibody tests to determine whether a protective immune response developed. BP-V and MB-W contributed equally. We declare no competing interests. Download .pdf (.29 MB) Help with pdf files Supplementary appendix Structured serological testing is an essential component to investigating SARS-CoV-2 reinfectionWe read with interest Belén Prado-Vivar and colleagues' findings of suspected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection in a 46-year-old man in Ecuador.1 As reported elsewhere,2 Prado-Vivar and colleagues describe a more severe symptomatic course during the second infection than during the first. Understanding factors associated with potential reinfection might enable early decision-making for the clinical management of suspected cases. Reporting of such cases, supported by sequencing, including whole-genome sequencing (WGS), as presented by Prado-Vivar and colleagues, or Sanger sequencing, and preferably viral cell culture, is necessary to identify reinfection rather than prolonged viral shedding. Full-Text PDF