A Case Series Describing the Recurrence of COVID-19 in Patients Who Recovered from Initial Illness in Bangladesh

Case report: A successfully treated case of community-acquired urinary tract infection due to Klebsiella aerogenes in Bangladesh

Klebsiella aerogenes, a nosocomial pathogen, is increasingly associated with extensive drug resistance and virulence profiles. It is responsible for high morbidity and mortality. This report describes the first successfully treated case of community-acquired urinary tract infection (UTI) caused by Klebsiella aerogenes in an elderly housewife with Type-2 diabetes (T2D) from Dhaka, Bangladesh. The patient was empirically treated with intravenous ceftriaxone (500 mg/8 h). However, she did not respond to the treatment. The urine culture and sensitivity tests, coupled with bacterial whole-genome sequencing (WGS) and analysis, revealed the bacteria to be K. aerogenes which was extensively drug-resistant but was susceptible to carbapenems and polymyxins. Based on these findings, meropenem (500 mg/8 h) was administered to the patient, who then responded to the treatment and recovered successfully without having a relapse. This case raises awareness of the importance of diagnosis of not-so-common etiological agents, correct identification of the pathogens, and targeted antibiotic therapy. In conclusion, correctly identifying etiological agents of UTI using WGS approaches that are otherwise difficult to diagnose could help improve the identification of infectious agents and improve the management of infectious diseases.

SARS-CoV-2 reinfections during the first three major COVID-19 waves in Bulgaria

BACKGROUND

The COVID-19 pandemic has had a devastating impact on the world over the past two years (2020-2021). One of the key questions about its future trajectory is the protection from subsequent infections and disease conferred by a previous infection, as the SARS-CoV-2 virus belongs to the coronaviruses, a group of viruses the members of which are known for their ability to reinfect convalescent individuals. Bulgaria, with high rates of previous infections combined with low vaccination rates and an elderly population, presents a somewhat unique context to study this question.

METHODS

We use detailed governmental data on registered COVID-19 cases to evaluate the incidence and outcomes of COVID-19 reinfections in Bulgaria in the period between March 2020 and early December 2021.

RESULTS

For the period analyzed, a total of 4,106 cases of individuals infected more than once were observed, including 31 cases of three infections and one of four infections. The number of reinfections increased dramatically during the Delta variant-driven wave of the pandemic towards the end of 2021. We observe a moderate reduction of severe outcomes (hospitalization and death) in reinfections relative to primary infections, and a more substantial reduction of severe outcomes in breakthrough infections in vaccinated individuals.

CONCLUSIONS

In the available datasets from Bulgaria, prior infection appears to provide some protection from severe outcomes, but to a lower degree than the reduction in severity of breakthrough infections in the vaccinated compared to primary infections in the unvaccinated.

Virus blocking textile for SARS-CoV-2 using human body triboelectric energy harvesting

Effective mitigation technology to prevent the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is required before achieving population immunity through vaccines. Here we demonstrate a virus-blocking textile (VBT) that repulses SARS-CoV-2 by applying repulsive Coulomb force to respiratory particles, powered by human body triboelectric energy harvesting. We show that SARS-CoV-2 has negative charges, and a human body generates high output current of which peak-to-peak value reaches 259.6 μA at most, based on triboelectric effect. Thereby, the human body can sustainably power a VBT to have negative electrical potential, and the VBT highly blocks SARS-CoV-2 by repulsion. In an acrylic chamber study, we found that the VBT blocks SARS-CoV-2 by 99.95%, and SARS-CoV-2 in the VBT is 13-fold reduced. Our work provides technology that may prevent the spread of virus based on repulsive Coulomb force and triboelectric energy harvesting.

Factors influencing the performance of rapid SARS‐CoV‐2 antigen tests under field condition

Background

Globally, real‐time reverse transcription–polymerase chain reaction (rRT‐PCR) is the reference detection technique for SARS‐CoV‐2, which is expensive, time consuming, and requires trained laboratory personnel. Thus, a cost‐effective, rapid antigen test is urgently needed. This study evaluated the performance of the rapid antigen tests (RATs) for SARS‐CoV‐2 compared with rRT‐PCR, considering different influencing factors.

Methods

We enrolled a total of 214 symptomatic individuals with known COVID‐19 status using rRT‐PCR. We collected and tested paired nasopharyngeal (NP) and nasal swab (NS) specimens (collected from same individual) using rRT‐PCR and RATs (InTec and SD Biosensor). We assessed the performance of RATs considering specimen types, viral load, the onset of symptoms, and presenting symptoms.

Results

We included 214 paired specimens (112 NP and 100 NS SARS‐CoV‐2 rRT‐PCR positive) to the analysis. For NP specimens, the average sensitivity, specificity, and accuracy of the RATs were 87.5%, 98.6%, and 92.8%, respectively, when compared with rRT‐PCR. While for NS, the overall kit performance was slightly lower than that of NP (sensitivity 79.0%, specificity 96.1%, and accuracy 88.3%). We observed a progressive decline in the performance of RATs with increased Ct values (decreased viral load). Moreover, the RAT sensitivity using NP specimens decreased over the time of the onset of symptoms.

Conclusion

The RATs showed strong performance under field conditions and fulfilled the minimum performance limit for rapid antigen detection kits recommended by World Health Organization. The best performance of the RATs can be achieved within the first week of the onset of symptoms with high viral load.

Factors influencing the performance of rapid SARS-CoV-2 antigen tests under field condition

Background

Globally, real‐time reverse transcription–polymerase chain reaction (rRT‐PCR) is the reference detection technique for SARS‐CoV‐2, which is expensive, time consuming, and requires trained laboratory personnel. Thus, a cost‐effective, rapid antigen test is urgently needed. This study evaluated the performance of the rapid antigen tests (RATs) for SARS‐CoV‐2 compared with rRT‐PCR, considering different influencing factors.

Methods

We enrolled a total of 214 symptomatic individuals with known COVID‐19 status using rRT‐PCR. We collected and tested paired nasopharyngeal (NP) and nasal swab (NS) specimens (collected from same individual) using rRT‐PCR and RATs (InTec and SD Biosensor). We assessed the performance of RATs considering specimen types, viral load, the onset of symptoms, and presenting symptoms.

Results

We included 214 paired specimens (112 NP and 100 NS SARS‐CoV‐2 rRT‐PCR positive) to the analysis. For NP specimens, the average sensitivity, specificity, and accuracy of the RATs were 87.5%, 98.6%, and 92.8%, respectively, when compared with rRT‐PCR. While for NS, the overall kit performance was slightly lower than that of NP (sensitivity 79.0%, specificity 96.1%, and accuracy 88.3%). We observed a progressive decline in the performance of RATs with increased Ct values (decreased viral load). Moreover, the RAT sensitivity using NP specimens decreased over the time of the onset of symptoms.

Conclusion

The RATs showed strong performance under field conditions and fulfilled the minimum performance limit for rapid antigen detection kits recommended by World Health Organization. The best performance of the RATs can be achieved within the first week of the onset of symptoms with high viral load.

Clinical evaluation of SARS-CoV-2 antigen-based rapid diagnostic test kit for detection of COVID-19 cases in Bangladesh

The rapid and early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is key to control the current Coronavirus disease 2019 (COVID-19) pandemic. The present study was conducted to clinically evaluate a rapid diagnostic test (RDT) kit, Standard Q COVID-19 Ag Test (SD Biosensor®, Republic of Korea), with reference to the standard real-time RT-PCR for detection of COVID-19 cases in Bangladesh. Nasopharyngeal swabs were taken from 900 COVID-19 suspected patients. Among them, 34.11% (n = 307) were diagnosed as COVID-19 cases by RT-PCR assay, of which 85% (n = 261) were also detectable using the RDT. The overall sensitivity and specificity of the RDT compared to RT-PCR were 85.02% and 100%, respectively, regardless of age, sex, and type of SARS-CoV-2 variants. Most of the RT-PCR positive cases (94%) were found within the first five days of disease onset, and the sensitivity of RDT was 85.91% for the same samples. The positive predictive value (PPV) of the RDT was 100%, and the negative predictive value (NPV) was 92.8%. The Cohen's kappa value of 0.882 indicated excellent agreement between the RDT and RT-PCR assays. The findings of this study showed the potential use of SARS-CoV-2 antigen-based RDT to expedite the diagnostic process and onward COVID-19 management in Bangladesh.

SARS-CoV-2 Reinfection Is a New Challenge for the Effectiveness of Global Vaccination Campaign: A Systematic Review of Cases Reported in Literature

Reinfection with SARS-CoV-2 seems to be a rare phenomenon. The objective of this study is to carry out a systematic search of literature on the SARS-CoV-2 reinfection in order to understand the success of the global vaccine campaigns. A systematic search was performed. Inclusion criteria included a positive RT-PCR test of more than 90 days after the initial test and the confirmed recovery or a positive RT-PCR test of more than 45 days after the initial test that is accompanied by compatible symptoms or epidemiological exposure, naturally after the confirmed recovery. Only 117 articles were included in the final review with 260 confirmed cases. The severity of the reinfection episode was more severe in 92/260 (35.3%) with death only in 14 cases. The observation that many reinfection cases were less severe than initial cases is interesting because it may suggest partial protection from disease. Another interesting line of data is the detection of different clades or lineages by genome sequencing between initial infection and reinfection in 52/260 cases (20%). The findings are useful and contribute towards the role of vaccination in response to the COVID-19 infections. Due to the reinfection cases with SARS-CoV-2, it is evident that the level of immunity is not 100% for all individuals. These data highlight how it is necessary to continue to observe all the prescriptions recently indicated in the literature in order to avoid new contagion for all people after healing from COVID-19 or becoming asymptomatic positive.

Epidemiologic characteristics of cases with reinfection, recurrence, and hospital readmission due to COVID-19: A systematic review and meta-analysis

Recent studies reported that some recovered COVID‐19 patients have tested positive for virus nucleic acid again. A systematic search was performed in Web of Science, PubMed, Scopus, and Google Scholar up to March 6, 2021. The pooled estimation of reinfection, recurrence, and hospital readmission among recovered COVID‐19 patients was 3, 133, and 75 per 1000 patients, respectively. The overall estimation of reinfection among males compared to females was greater. The prevalence of recurrence in females compared to males was more common. Also, hospital readmission between sex groups was the same. There is uncertainty about long‐term immunity after SARS‐Cov‐2 infection. Thus, the possibility of reinfection and recurrence after recovery is not unexpected. In addition, there is a probability of hospital readmission due to adverse events of COVID‐19 after discharge. However, with mass vaccination of people and using the principles of prevention and appropriate management of the disease, frequent occurrence of the disease can be controlled.

The pooled estimation of re‐infection rate among recovered COVID‐19 patients was 3 per 1000 patients.

The pooled estimation of recurrence rate among recovered COVID‐19 patients was 133 per 1000 patients.

Hospital readmission among recovered COVID‐19 patients was 75 per 1000 patients.

The possibility of re‐infection, recurrence and hospital readmission after recovery is not unexpected. Thus, adherence to principles of prevention besides vaccination is essential.