SARS-CoV-2 re-infection: a case report from Qatar

 

Dear Editor,

We read with interest the study of Gousseff et al.¹ The study reported a second acute COVID-19 episode in 11 patients. A novel coronavirus (SARS-CoV-2) caused a pandemic end of 2019. Common signs of SARS-CoV-2 include fever, cough and shortness of breath with no definitive treatment to date.² Reverse transcriptase polymerase chain reaction (RT-PCR)–based assays are the current reference diagnostic test.³ Positive result does not necessitate the presence of infection and viral RNA shedding declines following the resolution of symptoms. Viral nucleic acid could be detectable in throat swabs up to 6 weeks after symptom onset.² Different reports have proposed the reactivation of SARS-CoV-2 infection, with 2 RT-PCR positive results following resolving symptoms and interim RT-PCR negative results.1, 4, 5, 6, 7, 8, 9, 10 Early studies reported patients with negative results having positive results within one week of discharge. Later, reports used 3 weeks (21 days) as the cut-off point, following which another positive RT-PCR result with symptoms would support the possibility of reinfection.¹ A recent report confirmed the possibility of reinfection with genetically distinct SARS-CoV-2 infection in 2 different cases.¹¹ Here we describe a case with 2 positive RT-PCR results in a symptomatic female with 84 days apart, patient had a complete resolution of symptoms and interim negative swab results on day 13.

A 46-year-old female attended primary healthcare settings in Qatar with a history of SARS-CoV-2 contact and sore throat on the 23rd of May 2020. The patient SARS-CoV-2 RT-PCR results swab result was positive. Her vital signs, blood investigations and chest X-ray were normal. The patient had a past medical history of mild asthma, which was controlled with only occasional use of salbutamol inhaler. The patient was admitted to a quarantine facility for observation. The patient PCR swab result was negative on the 5th of June and she was discharged on the 6th June.

On the 11th of August she presented with fever, sore throat and body pain following a second contact with SARS-CoV-2 positive case. SARS-CoV-2 RT-PCR results swab result was inconclusive on 13th August. The patient also reported chest pain, cough, and mild dyspnea. Her vital signs were normal, but blood investigations showed leucocytes of 1.7 × 10⁹ cells per L and lymphocytes 0.9 × 10⁹ cells per L. A repeat COVID-19 PCR swab was positive on the 15th of August with CT value of 25.49. Chest X-ray was normal and patient progression to recovery was unremarkable. She was discharged home on the 29th of August 2020. During both events, the patient received only symptomatic treatment.

Early studies reported that re-detectable positive virus nucleic acid among patients with SARS-CoV-2 with an average duration of 15 days from discharge to a re-positive results.¹² Patients in those early reports did not show signs of infection with the second positive results and had negative swab results within one week later. Researchers have suggested the persistence of viral RNA with no recurrence of infection.

The COCOREC (Collaborative study COvid RECurrences) study suggested that recurrence of infection is likely if the patient has two confirmed SARS-CoV-2 RT-PCR positive results over 15 days apart with one major clinical sign and no other cause to explain the symptoms. The study identified 11 patients similar to our case. The longest time to second positive test results in this cohort of patients was 49 days.¹

Our case presented with symptoms, positive contact history and positive swab results with a timeline significantly longer than any reported case. The persistence of positive RT-PCR for SARS-CoV-2 is reported only up to 6 weeks.¹ A re-infection or to the least a re-activation following long-lasting carriage seems more likely in this patient report. Reports of such occurrences are rare to date in view of the number of worldwide reporting of the infection rates which is reassuring. This case report adds to current evidence of possibility of reinfection and provides a basis for future cohort studies. Detection of viral RNA in symptomatic¹ patients following complete remission of symptoms and full recovery should be considered as reinfection or recurrence at the least.

Informed consent

The patient gave consent for the material to appear in scientific publication.

Ethics statement

The case report received ethical approval from Primary Health Care corporation (PHCC) research committee. The patient consented to publication and reporting is fully anonymized.

Authorship

All Authors have contributed to the drafting and the critical revision of the article. The final version approved by all authors.

Declaration of Competing Interest

None.