Reinfection with SARS-CoV-2: A case report from Libya

Dear editor

We have read with interest the article of Alvarez-Moreno and Rodríguez-Morales regarding post-negative positive SARS-CoV-2 PCR result [1]. On 24th March, Libya confirmed its first COVID-19 case [2].

We hereby present a case of SARS-CoV-2 reinfection recorded in the city of Misurata, Libya mid of October 2020. On July 24, 2020, an 18-years old man visited the rapid response team point with a history of close contact with a confirmed SARS-CoV-2 patient but without any symptoms. A nasopharyngeal swab was collected and tested by reverse transcriptase polymerase chain reaction (RT-qPCR); the result was returned negative. Three days later he developed fever (38 °C), headache, sore throat, cough, shortness of breath and anosmia. On July 28, 2020 another swab was taken and confirmed positive for SARS-CoV-2 using RT-qPCR assay targeting E-gene, RdRP-gene and N-gene, performed with the protocol previously reported by WHO using Rotor gene Q (Qiagen., Germany) [3], and repeated using GeneXpert Dx system Version 6, Xpert Xpress SARS-CoV-2 assay (Cepheid, USA).

Previously, discontinuation of isolation and hospital discharge required two consecutive negative SARS-CoV-2 RT-PCR tests, plus normal body temperature, and improvement of other symptoms. The two nasopharyngeal swabs were collected on 11th and 13th of August and were both negative for SARS-CoV-2 infection, suggesting that the patient was cured of COVID-19.

After 21 days of home isolation, the patient had returned to his normal life until the October 12, 2020 where he complained of fever 39 °C, cough, muscle pain, and severe dyspnea. A nasopharyngeal swab was collected immediately and analyzed by RT-qPCR. The sample was confirmed positive for SARS-CoV-2 with a cycle threshold (Ct) value of 19.7 for the E gene and 22 for the N gene.

The patient has quickly developed more severe symptoms compared to his first infection, with fever exceeding 39 °C for about 4 days, severe cough, hyporexia, dyspnea, and hypoxia (92% oxygen saturation). The patient did not report any other medical condition such as diabetes or cardiovascular disorders. A serological assay using Chemiluminescence Immune Assay (Mindrey CL1000i) revealed no presence of neither IgM nor IgG anti-SARS-CoV-2.

Five days later RT-qPCR test was still positive with a Ct of 23.2 for the E gene and 24.0 for the N gene, with a slight improvement of most symptoms apart from cough. The routine blood and biochemical tests were normal. The serological assay, on the other hand, showed an increase of IgG anti-SARS-CoV-2 antibodies (277.77 IU/mL) compared to the normal expected value. The IgM was slightly higher 1.77 IU/mL than the normal value (1 IU/mL) indicating an infection.

This case presented with more severe symptoms during the second infection; a positive contact history and positive swab results; with more than two months apart. The persistence of positive RT-PCR for SARS-CoV-2 was reported maximum only up to 6 weeks [4]. To date COVID-19 recurrent infection is still rare all over the world [5,6]. Detection of viral RNA in symptomatic patients following complete disappearance of symptoms and full recovery should be considered as reinfection. Sequencing of the whole viral genome of both infections should confirm the reinfection. However, due to the limited facilities at our laboratory this was not possible.