Case description and epidemiological findings
A 39-years-old male patient with chronic cardiovascular disease and diabetes mellitus as history of comorbidities reported two clinical episodes of COVID-19. The first one was on November 30th, 2020, and the second on March 11th, 2021. During the first infection case, the symptoms and clinical signs of the patient had not been reported. However, the patient reported having contact with his brother, who tested positive for SARS-CoV-2 previously. He also visited his father at the hospital in a room shared with other COVID-19 diagnosed patients. In the second episode the patient had dyspnea, fatigue, and respiratory distress as symptoms; and saturation <95% as a clinical sign. The second infection evolved with complications, and the patient was removed to an Intensive Care Unit (ICU) and intubated due to severe loss of pulmonary capacity. The patient unfortunately died on March 19th, 2021.
Diagnostic laboratory findings
Naso-oropharyngeal swab samples (November 30th, 2020 and March 11th, 2021) were received at Laboratório de Microbiologia Molecular of Universidade Feevale, Novo Hamburgo, RS, Brazil, for SARS-CoV-2 diagnostics. Total nucleic acid was extracted with the commercial MagMAX™ CORE Nucleic Acid Purification Kit (Applied biosystems™) kit using the automated equipment KingFisher™ Duo Prime (Thermo Fisher Scientific™). RT-qPCR for SARS-CoV-2 RNA detection targeting E gene was performed according to Charité protocols [10] and was carried out using AgPath-ID One-Step RT-PCR Reagents (Thermo Fisher Scientific™). Both RT-qPCR assays were positive, showing a Ct value of 30.07 (LMM38991) and 18.83 (LMM50731). Additionally, a differential RT-qPCR for P1 lineage [11] that detects ORF 1b deletion (NSP6: S106 del, G107 del, F108 del), was performed. This deletion is a genetic signature of VOCs P.1, B.1.1.7, and B.1.351. The differential RT-qPCR was carried out using AgPath-ID One-Step RT-PCR Reagents (Thermo Fisher Scientific™); primers and probes were used following the same protocol as described by Naveca et al. (2021) [11].
A total of 302 samples was tested with differential RT-qPCR for specific P.1 lineage detection (Ct values for E gene ranging between 10 and 20) randomly distributed over 18 weeks that started on November 30th, 2020 until April 4th, 2021. A total of 183 samples were negative and 119 were positive for P.1. Except for the reinfection patient (who was not analyzed due to the CT value), the circulation of P.1 in RS started was evidenced in our sampling from January 27th, 2021 (Figure 2a). Furthermore, the peak of P.1 lineage detections coincides with the peak of SARS-CoV-2 new cases (Figure 2b), hospitalizations (Figure 2c) and deaths (Figure 2d) in the neighboring region.
This study was approved by the National Committee of Research Ethics and the Institutional Ethical Review Board of the Universidade Feevale (protocol number: 33202820.7.1001.5348), following Brazilian regulations and international ethical standards.
Genome sequencing and bioinformatic analysis
Two high-quality SARS-CoV-2 whole-genome sequences, named LMM38991/2020 and LMM50731/2021 (EPI_ISL_1630158 and EPI_ISL_1629809) were recovered from the same patient for the first infection and reinfection, respectively. Whole genome library preparation was performed using QIAseq SARS-CoV-2 Primer Panel paired for library enrichment and QIAseq FX DNA Library UDI Kit, according to the manufacturer instructions (Qiagen, Hilden, Germany). The sequencing was implemented on an Illumina MiSeq platform using MiSeq Reagent Kit v3 (600-cycle). The FASTQ reads were imported to Geneious Prime, trimmed (BBDuk 37.25), and mapped against the reference sequence hCoV-19/Wuhan/WIV04/2019 (EPI_ISL_402124) available in EpiCoV database from GISAID (https://www.gisaid.org/ 45). Consensus sequences LMM38991/2020 and LMM50731/2021 presented a mean coverage of 1,405x and 1,263x.
The sequences were first classified using the Pangolin COVID-19 Lineage Assigner tool (https://github.com/hCoV-2019/pangolin) [12] indicating the presence of two discordant SARS-CoV-2 lineages: P.1 lineage in the primo-infection (LMM38991/2020; Gisaid access EPI_ISL_ EPI_ISL_1630158) and P.2 lineage (LMM50731/2021; Gisaid access EPI_ISL_1629809) at reinfection. In order to confirm the results, 97 Brazilian SARS-CoV-2 complete genomes and the reference sequence (EPI_ISL_402124) (>29 kb) were retrieved from the GISAID database and aligned with the sequences generated herein. Sequence alignment was performed using Clustal Omega and the reference sequence from Wuhan was applied as outgroup. The Maximum Likelihood phylogenetic analysis under General Time Reversible model allowing for a proportion of invariable sites and substitution rates were inferred empirically in IQ-TREE v2.1.2 web server [13] applying 200 replicates and 1000 bootstrap and the analysis corroborated the previous results. LMM38991/2020 clearly clustered into P.1 lineage while LMM50731/2021 branched into P.2 group (Figure 3). LMM38991/2020 and LMM50731/2021 displayed the typical P.1 and P.2 spike protein E484K mutations and INDELs (Figure 4). LMM38991/2020 presented all 11 typical P.1 amino acid non-synonymous changes in S protein (L18F, T20N, P26S, D138Y, R190S, K417T, E484K, N501Y, D614G, H655Y, T1027I, V1176F) and LMM50731/2021 presented three previously P.2 reported amino acid changes in S protein (E484K, D614G, V1176F) (Figure 4).