Symptomatic Reinfection in Previously Recovered Coronavirus Disease 2019 (COVID-19) Geriatric Patient

Can a patient diagnosed with coronavirus disease 2019 (COVID-19) be infected again? This issue appears to be unsolved. Protective immunity following infection with COVID-19 is still not fully known. In the coming months, an awareness of COVID-19 reinfection will be crucial in directing government and public health policy managements. Here, we present a case of symptomatic reinfection following recovery from COVID-19 in a geriatric patient.


Introduction
ache, throat pain, and his rapid antigen test (RAT) returned positive. On August 19, 2020, the patient needed rehospitalization where his COVID-19 RT-PCR returned positive with a cycle threshold (CT) score of 17 indicative of high viral load, confirming a case of COVID-19 reinfection (Figure 1).

FIGURE 1: Computed tomography (CT) findings in recovered COVID-19 patient
His inflammatory profile revealed CRP of 52.8 mg/L and IL-6 of 20.4 picograms per milliliter (pg/mL). After discussion with the COVID care team, the patient was treated symptomatically. After eight days, the patient became afebrile and no respiratory symptoms observed since then.

Discussion
SARS-CoV-2 is characterized by hyper-cytokinemia, which typically occurs in the second week of COVID-19 and is associated with immunodeficiency as well as hyper inflammation, the latter manifesting as a cytokine storm [7]. COVID-19 was earlier thought to be a respiratory disease, but it has affected multiple organs [8][9][10][11]. A study done by Desai et al. reported that COVID-19 has caused not only physical distress but also had a negative impact on social, economic, and psychological well-being [12]. At present, literature is buzzing with the symptomatic reinfection of SARS-CoV-2 in recovered COVID-19 patients. Previous exposure to SARS-CoV-2 does not necessarily result in total immunity being guaranteed. A study done by Tillett et al. on genomic analysis of SARS-CoV-2 revealed genetically significant variations between each variant associated with each infection case. Furthermore, they also reported that the second infection was clinically more severe than the first and severity might be associated with the viral load, the virulence of the viral strain [13]. A study done by Song et al. has reported that the post-negative positive RT-PCR findings may be due to the identification of ribonucleic acid (RNA) particles rather than reinfection in individuals that have recovered from COVID-19 [14]. Studies have shown that the humoral response can be poor in patients who are asymptomatic at the time of the post-negative positive RT-PCR test and may improve progressively. In all COVID-19 patients, however, IgM and IgG become detectable between the third and fourth weeks of the onset of their clinical disease [6,15]. In our case, IgG antibody was found to be positive while IgM antibody was negative for COVID-19. The confirmation of re-infection has several important implications. First, herd immunity is unlikely to eradicate SARS-CoV-2, although it might make future infections milder than the first infection. Second, the probability of COVID-19 reinfection indicates that, as with other human coronaviruses, COVID-19 could become widespread in some pockets of seasonal outbreaks. Third, vaccinations may not be sufficient to offer a lifetime defense against COVID-19, and even though we create a vaccine, sustainable immuno-protection may require booster dosing. Fourth, vaccine studies may have to be performed in such patients who have recovered from COVID-19 [16]. A vaccination that stimulates cross-protective immunity will be an effective tool for preventing or reducing the severity of disease caused by potential pandemic coronavirus strains. As a result, even if reinfection happens when antibody levels are low, pre-existing T-cell immunity can deter clinically serious disease [17,18]. SARS-CoV-2 epitopes have been identified in previously circulating human coronaviruses, indicating that they may play a role in the immune defense of COVID-19 unexposed and recovering patients [19]. Furthermore, telemedicine may help to reduce the severity of the infection and prompt identification of recurrence cases in patients with comorbidities [20]. In India and around the world, the lack of systematic genomic sequencing of positive cases restricts the advancements in public health monitoring needed to find these cases. Limitations in SARS-CoV-2 screening and testing worsen the ineffective surveillance attempts being made not only to detect COVID-19 but also to achieve actionable genetic monitoring of this agent.

Conclusions
This case of reinfection shows that population transmission herd immunity could be an elusive tactic and the production of vaccines needs to be reoriented towards potential single infection weaning immunity. People must take precaution to prevent SARS-CoV-2 infection irrespective of whether they diagnosed previously or not from the public health perspective. Future studies need to focus on immune responses in vitro after reinfection.

Additional Information Disclosures
Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.