ABSTRACT
Background Coronavirus disease 2019 (COVID-19) was previously thought to have a low reinfection rate, but there are concerns that the reinfection rate will increase with the emergence and spread of mutant variants. This report describes the case of a 36-year-old, non-immunosuppressed man who was infected twice by two different variants of COVID-19 within a relatively short period. Case presentation A 36-year-old Japanese man with no comorbidities was infected with the E484K variant (R.1 lineage) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Symptoms were mild and improved with symptomatic treatment alone. About four months later he presented to another outpatient department with high fever and headache. We diagnosed him as infected with the Alpha variant (B.1.1.7) of SARS-CoV-2 based on SARS-CoV-2 real-time reverse transcription polymerase chain reaction testing (RT-PCR). The patient was hospitalized with high fever. The patient received treatment in the form of anti-inflammatory therapy with corticosteroid and antibacterial chemotherapy. The patient improved without developing severe disease. Conclusion Concerns have been raised that the reinfection rate of COVID-19 will increase with the emergence of mutant variants. Particularly in mild cases, adequate amounts of neutralizing antibodies may not be produced, and reinfection may thus occur. Continued attention to sufficient infection control is thus essential.
ABSTRACT
Background: Coronavirus disease 2019 (COVID-19) was previously thought to have a low reinfection rate, but there are concerns that the reinfection rate will increase with the emergence and spread of mutant variants. This report describes the case of a 36-year-old, non-immunosuppressed man who was infected twice by two different variants of COVID-19 within a relatively short period. Case presentation: A 36-year-old Japanese man with no comorbidities was infected with the E484K variant (R.1 lineage) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Symptoms were mild and improved with symptomatic treatment alone. About four months later he presented to another outpatient department with high fever and headache. We diagnosed him as infected with the Alpha variant (B.1.1.7) of SARS-CoV-2 based on SARS-CoV-2 real-time reverse transcription polymerase chain reaction testing (RT-PCR). The patient was hospitalized with high fever. The patient received treatment in the form of anti-inflammatory therapy with corticosteroid and antibacterial chemotherapy. The patient improved without developing severe disease. Conclusion: Concerns have been raised that the reinfection rate of COVID-19 will increase with the emergence of mutant variants. Particularly in mild cases, adequate amounts of neutralizing antibodies may not be produced, and reinfection may thus occur. Continued attention to sufficient infection control is thus essential.
ABSTRACT
In response to the COVID-19 spread, the way of thinking about the SIR model used in Infectious Disease-Mathematical Epidemiology was compared with that on the linear 1-compartment model with an absorption process used in Pharmacokinetics (PK). The number of infected persons (or drug amount in the body) in different infection (or absorption) rates and recovery (elimination) rates were mathematically simulated using differential equations in the SIR model (or PK model). Although the drug amount in the body (or drug concentration in blood) can be calculated from the dose, the extent of bioavailability and the absorption-and elimination-rate constants, the number of infected persons was related to the number of acceptable persons and infection-and recovery-rate constants. In addition to these values, the number of infected persons was related also to the number of infected persons themselves at that time. Interestingly, no infected persons were counted when the infection rate fell below a certain value and the recovering rate exceeded a certain value (those values were not obviously extreme). Although the analytical method using the SIR model is not the same as that using the 1-compartment PK model with an absorption process, the analytical techniques resemble each other. This study suggests that most pharmacists and pharmaceutical scientists can use PK approach to prevent the present spreading of infectious disease.