Reactivation of COVID-19 pneumonia: A report of two cases

Research Progress on the Weak Immune Response to the COVID-19 Vaccine in Patients with Type 2 Diabetes

Coronavirus Disease 2019 (COVID-19) is generally susceptible to the population, highly infectious, rapidly transmitted, and highly fatal. There is a lack of specific drugs against the virus at present and vaccination is the most effective strategy to prevent infection. However, studies have found that some groups, particularly patients with diabetes, show varying degrees of weak immune reactivity to various COVID-19 vaccines, resulting in poor preventive efficacy against the novel coronavirus in patients with diabetes. Therefore, in this study, patients with type 2 diabetes mellitus (T2DM) who had weak immune response to the COVID-19 vaccine in recent years were analyzed. This article reviews the phenomenon, preliminary mechanism, and related factors affecting weak vaccine response in patients with T2DM, which is expected to help in the development of new vaccines for high-risk groups for COVID-19.

Neutralization against Omicron subvariants after BA.5/BF.7 breakthrough infection weakened as virus evolution and aging despite repeated prototype-based vaccination1

BACKGROUND

Omicron had swept the mainland China between December 2022 and January 2023, while SARS-CoV-2 still continued to evolve. To fully prepare for the next wave, it's urgent to evaluate the humoral immune response post BA.5/BF.7 breakthrough infection against predominant sub-lineages among existing vaccination strategies and the elders.

METHOD

This study enrolled a longitudinal young-adult cohort from 2/3-dose vaccination to 1 month after breakthrough infection, and an elder cohort at 1 month after breakthrough infection. Seral samples were collected and tested for humoral immune response to SARS-CoV-2 subvariants including WT, BA.2, BA.5, BF.7, BQ.1.1, CH.1.1, XBB.1.5.

RESULTS

BA.5/BF.7 breakthrough infection induced higher neutralization activity than solely vaccination in all SARS-CoV-2 strains, while the latest Omicron subvariants, BQ.1.1, CH.1.1, XBB.1.5, exhibited the strongest neutralization evasion ability. There was a negative correlation between age and humoral immune response in WT, BA.5, BQ.1.1, and XBB.1.5. Compared to non-vaccination groups, breakthrough infection in two-dose vaccination groups had significantly higher neutralizing antibody against WT, BA.2, BA.5, BF.7 but not to BQ.1.1, CH.1.1, XBB.1.5 while booster dose against the prototype prior-breakthrough would not further significantly enhance individual's humoral responses against the latest Omicron subvariants.

CONCLUSIONS

Newer variants manifest increasing immune evasion from neutralization and repeated prototype-based booster vaccines may not further enhance neutralizing antibody against emerging new variants. Older adults have lower levels of neutralizing antibody. Future vaccination strategies should aim to enhance effective neutralization to contemporary variants.

Impacts of Covid-19 & black fungus on diabetes patients in India

The Novel coronavirus disease Covid-19 is a highly acute respiratory, viral pathogenic and pandemic disease caused by the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) virus which leads to a heavy loss of mankind worldwide. The origin of the virus is not well known as it confirms the transfer of disease from person to person. As the disease is a novel clinical trial of antiviral drugs only seems to be better for emergency pathogenic Covid-19 impacts. The after all effect of Covid-19 results severely elevated glucose levels causing Diabetes Mellitus. The various symptoms of black fungus also report a heavy impact on diabetic patients. The analysis of Covid-19, mucormycosis and Covid vaccines with respect to diabetes is described in the paper.

Evidence of SARS-CoV-2 reinfection: analysis of 35,000 subjects and overview of systematic reviews

BACKGROUND

Reinfection by SARS-CoV-2 is a rare but possible event. We evaluated the prevalence of reinfections in the Province of Modena and performed an overview of systematic reviews to summarize the current knowledge.

METHODS

We applied big data analysis and retrospectively analysed the results of oro- or naso-pharyngeal swab results tested for molecular research of viral RNA of SARS-CoV-2 between 1 January 2021 and 30 June 2021 at a single center. We selected individuals with samples sequence of positive, negative and then positive results. Between first and second positive result we considered a time interval of 90 days to be sure of a reinfection. We also performed a search for and evaluation of systematic reviews reporting SARS-CoV-2 reinfection rates. Main information was collected and the methodological quality of each review was assessed, according to A Measurement Tool to Assess systematic Reviews (AMSTAR).

RESULTS

Initial positive results were revealed in more than 35,000 (20%) subjects; most (28%) were aged 30-49 years old. Reinfection was reported in 1,258 (3.5%); most (33%) were aged 30-49 years old. Reinfection rates according to vaccinated or non-vaccinated subjects were 0.6% vs 1.1% (p < 0.0001). Nine systematic reviews were identified and confirmed that SARS-CoV-2 reinfection rate is a rare event. AMSTAR revealed very low-moderate levels of quality among selected systematic reviews.

CONCLUSIONS

There is a real, albeit rare risk of SARS-CoV-2 reinfection. Big data analysis enabled accurate estimates of the reinfection rates. Nevertheless, a standardized approach to identify and report reinfection cases should be developed.

Characteristics of re-admitted adult patients infected with severe acute respiratory syndrome Coronavirus 2 After initial hospitalization at King Salman Armed Forces Hospital, Tabuk, Saudi Arabia

OBJECTIVES

To describe the clinical characteristics and possible risk factors associated with re-hospitalization within 30 days of discharge among hospitalized adult patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

METHODS

This is a retrospective cohort study conducted at King Salman Armed Forces Hospital (KSAFH), Tabuk, Saudi Arabia over the period between March to November 2020. The study was conducted over 237 patients who had confirmed SARS-CoV-2 and fulfilled the study inclusion criteria (at least 14 years old, with subsequently discharged alive from the hospital) were included.

RESULTS

The commonest presenting symptoms were cough, fever, and dyspnea. The most frequent reported comorbid diseases were diabetes mellitus and hypertension. Half of cases were regarded as severe cases whereas 14.8% were critical cases. The rate of readmission was 5.9%. Older patients were more likely to be readmitted compared to younger patients. Regarding clinical characteristics, critically ill patients were more likely to be readmitted than less severe cases. Patients with unilateral lung shadow in chest x-ray, and those with positive history of Intensive care unit (ICU) admission were more likely to be readmitted compared to their peers. Regarding medical history, the only factor significantly associated with readmission were history of cerebrovascular accident (CVA), as 22.2% of those with CVA history compared to only 1.5% of those without CVA history were more likely to be readmitted. Among laboratory findings, high lymphocytic count (>3 per microliter) was significantly associate with likelihood for readmission.

CONCLUSION

Readmission rate or patients hospitalization initially for Covid-19 was comparable to rates reported by most of other similar international studies. Further longitudinal larger multicentric study is warranted to have clearer image of the situation.

Understanding the challenges to COVID-19 vaccines and treatment options, herd immunity and probability of reinfection

Unlike pandemics in the past, the outbreak of coronavirus disease 2019 (COVID-19), which rapidly spread worldwide, was met with a different approach to control and measures implemented across affected countries. The lack of understanding of the fundamental nature of the outbreak continues to make COVID-19 challenging to manage for both healthcare practitioners and the scientific community. Challenges to vaccine development and evaluation, current therapeutic options, convalescent plasma therapy, herd immunity, and the emergence of reinfection and new variants remain the major obstacles to combating COVID-19. This review discusses these challenges in the management of COVID-19 at length and highlights the mechanisms needed to provide better understanding of this pandemic.

Culturing Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) for Diagnosis and Genome Sequencing

OBJECTIVE

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid detection "re-positive" phenomenon is encountered clinically. The accuracy of a viral nucleic acid test is crucial to prevent reintroduction of the virus into the community. This study evaluated the effect of virus culturing on increasing the sensitivity and specificity of real-time polymerase chain reaction (RT-PCR) detection and viral genomic sequencing.

METHODS

A series of tenfold dilutions of a SARS-CoV-2 viral stock were conducted and cultured for either 24 or 48 hours. The viral load of cultured samples was determined by RT-PCR. The cultured and non-cultured samples of 1x 50% tissue culture infectious dose (TCID50) were sequenced using metagenomic next-generation sequencing. The depth and coverage of SARS-CoV-2 genome were measured.

RESULTS

The lowest viral load detectable in a sample with RT-PCR was 0.01 TCID50. After a 24-h culture, the viral ORF 1ab and N-gene cycle threshold (CT) values were reduced by 4.4 points and 1 point, respectively. One TCID50 viral load of post 24-h culture revealed the sequence depth reached an average of 752 reads, compared with 0.15 in the nonculture; furthermore, the coverage was 99.99% while 6.42% in the nonculture.

CONCLUSION

These results indicate that virus culturing can significantly increase the viral load, which can increase the certainty of true-positive detection of the viral nucleic acids, and improve the quality of virus genomic sequencing.

Clinical manifestations, treatment options, and comorbidities in COVID-19 relapse patients: A systematic review

Introduction

Interest revolving around coronavirus disease 2019 (COVID‐19) reinfection is escalating rapidly. By definition, reinfection denotes severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), PCR redetection, and COVID‐19 recurrence within three months of the initial symptoms. The main aim of the current systematic review was to evaluate the features of COVID‐19 relapse patients.

Materials and methods

For this study, we used a string of terms developed by a skilled librarian and through a systematical search in PubMed, Web of Science, and Embase for eligible studies. Clinical surveys of any type were included from January 2019 to March 2021. Eligible studies consisted of two positive assessments separated by a negative result via RT‐PCR.

Results

Fifty‐four studies included 207 cases of COVID‐19 reinfection. Children were less likely to have COVID‐19 relapse. However, the most patients were in the age group of 20–40 years. Asthenia (66.6%), headache (66.6%), and cough (54.7%) were prevalent symptoms in the first SARS‐CoV‐2 infection. Asthenia (62.9%), myalgia (62.9%), and headache (61.1%) were most frequent in the second one. The most common treatment options used in first COVID‐19 infection were lopinavir/ritonavir (80%), oxygen support (69.2%), and oseltamivir (66.6). However, for the treatment of second infection, mostly antibiotics (100%), dexamethasone (100%), and remdesivir (80%) were used. In addition, obesity (32.5%), kidney failure (30.7%), and hypertension (30.1%) were the most common comorbidities. Unfortunately, approximately 4.5% of patients died.

Conclusion

We found the potency of COVID‐19 recurrence as an outstanding issue. This feature should be regarded in the COVID‐19 management. Furthermore, the first and second COVID‐19 are similar in clinical features. For clinically practical comparison of the symptoms severity between two epochs of infection, uniform data of both are required. We suggest that future studies undertake a homogenous approach to establish the clinical patterns of the reinfection phenomena.

Persisting Symptoms After COVID-19

BACKGROUND

After recovering from coronavirus disease 2019 (COVID-19), a considerable number of patients report long-term sequelae. The epidemiologic data vary widely in the studies published to date, depending on the study design and the patient cohorts analyzed. Using a population-based approach, we report symptoms and clinical characteristics following COVID-19 (long COVID), focusing on symptoms ≥ 12 weeks (post-COVID-19).

METHODS

In three German administrative districts, all adult patients with a diagnosis of COVID-19 confirmed by polymerase chain reaction (PCR) between March and September 2020 (n = 4632) were invited to complete a questionnaire. Predictors for post-COVID-19 were identified by multiple ordinal regression analysis. Study registration: DRKS00023069.

RESULTS

A total of 1459 patients were included in the study, 175 (12%) of whom had been hospitalized for treatment of the acute phase of COVID-19. The prevalence of post-COVID-19 was 72.6% (n = 127) and 46.2% (n = 588) for hospitalized and non-hospitalized patients, respectively. The most frequently occurring long-term symptoms were fatigue (41.5% of all symptoms ≥ 12 weeks, n = 297), physical exhaustion (40.8%, n = 292), difficulty in concentrating (30.6%, n = 219), and loss of the senses of taste (25.9%, n = 185) and smell (25.5%, n = 182). Quality of life was significantly impaired in patients with post-COVID-19. The strongest risk factors for post-COVID-19 were female sex, overall severity of comorbidities, and severity of acute COVID-19.

CONCLUSION

Patients who are not hospitalized also frequently experience continued symptoms following COVID-19. The heterogeneity of symptoms calls for a multi - disciplinary stepped-care approach, for which identification of patients at risk is crucial. A limitation of the study is the lack of a control group.

COVID-19 Reinfection or Relapse? A Retrospective Multicenter Cohort Study from Iran

Background: Returning symptomatic patients with a history of recovered COVID-19 with a new positive SARS CoV-2 PCR test after several weeks to months of a negative PCR result is challenging during the COVID-19 pandemic. Objectives: We aimed to determine such Iranian patients' clinical and laboratory characteristics and discuss possible reasons. Methods: We retrospectively investigated SARS CoV-2 PCR tests in three referral hospitals. All patients who had the following criteria were included in the study: two SARS CoV-2 PCR-positive tests three months apart, no symptoms, a negative PCR test between the two positive tests, and access to the patient and medical information. Then, we retrospectively recorded the clinical and laboratory characteristics of the eligible patients. We also compared the clinical and laboratory features in the first and second episodes. Results: Among 1,899 patients, 37 cases were eligible in the study based on our criteria. The majority of patients were males and nurses. The mean age was 37.54 ± 15.16 years. Weakness, myalgia, and fever were the most frequent clinical symptoms in both episodes. The mean interval between discharge and second presentation was 117 ± 61.42 days. The clinical, radiological, and laboratory characteristics were not significantly different between the two episodes, except for significantly more dexamethasone use in the second episode (P = 0.03). Conclusions: We could not cultivate the virus and perform the phylogenic sequencing of SARS-CoV-2; however, the prolonged interval between the two episodes suggests probable reinfection in our cases. Finally, this clinical phenomenon may be more common in HCW without a significant consequence; however, most cases were HCW who had more compatibility with our criteria due to the availability of their medical information.

Interaction of SARS-CoV-2 with cardiomyocytes: Insight into the underlying molecular mechanisms of cardiac injury and pharmacotherapy

SARS-CoV-2 causes respiratory illness with a spectrum of systemic complications. However, the mechanism for cardiac infection and cardiomyocyte injury in COVID-19 patients remains unclear. The current literature supports the notion that SARS-CoV-2 particles access the heart either by the circulating blood cells or by extracellular vesicles, originating from the inflamed lungs, and encapsulating the virus along with its receptor (ACE2). Both cardiomyocytes and pericytes (coronary arteries) express the necessary accessory proteins for access of SARS-CoV-2 particles (i.e. ACE2, NRP-1, TMPRSS2, CD147, integrin α5β1, and CTSB/L). These proteins facilitate the SARS-CoV-2 interaction and entry into the pericytes and cardiomyocytes thus leading to cardiac manifestations. Subsequently, various signaling pathways are altered in the infected cardiomyocytes (i.e. increased ROS production, reduced contraction, impaired calcium homeostasis), causing cardiac dysfunction. The currently adopted pharmacotherapy in severe COVID-19 subjects exhibited side effects on the heart, often manifested by electrical abnormalities. Nonetheless, cardiovascular adverse repercussions have been associated with the advent of some of the SARS-CoV-2 vaccines with no clear mechanisms underlining these complications. We provide herein an overview of the pathways involved with cardiomyocyte in COVID-19 subjects to help promoting pharmacotherapies that can protect against SARS-CoV-2-induced cardiac injuries.

Distinguishing repeated polymerase chain reaction positivity from re-infections in COVID-19

BACKGROUND

Possibility of reinfection with SARS-CoV-2 changes our view on herd immunity and vaccination and can impact worldwide quarantine policies. We performed real-time polymerase chain reaction (RT-PCR) follow-up studies on recovered patients to assess possible development of reinfections and re-positivity.

METHODS

During a 6-month period, 202 PCR-confirmed recovering COVID-19 patients entered this study. Follow-up RT-PCR tests and symptom assessment were performed 1 month after the initial positive results. Patients who tested negative were tested again 1 and 3 months later. The serum IgG and IgM levels were measured in the last follow-up session.

RESULTS

In the first two follow-up sessions, 82 patients continued their participation, of which four patients tested positive. In the second follow-up 44 patients participated, three of whom tested positive. None of the patients who tested positive in the first and second follow-up session were symptomatic. In the last session, 32 patients were tested and four patients were positive, three of them were mildly symptomatic and all of them were positive for IgG.

CONCLUSIONS

A positive RT-PCR in a recovering patient may represent reinfection. While we did not have the resources to prove reinfection by genetic sequencing of the infective viruses, we believe presence of mild symptoms in the three patients who tested positive over 100 days after becoming asymptomatic, can be diagnosed as reinfection. The immune response developed during the first episode of infection (e.g., IgG or T-cell mediated responses that were not measured in our study) may have abated the symptoms of the reinfection, without providing complete protection.

COVEVOL: Natural Evolution at 6 Months of COVID-19

Many studies have investigated post-COVID symptoms, but the predictors of symptom persistence remain unknown. The objective was to describe the natural course of the disease at 6 months and to identify possible factors favoring the resurgence or persistence of these symptoms. COVEVOL is a retrospective observational descriptive study of 74 patients. All patients with positive SARS-CoV-2 PCR from March 2020 were included. We compared a group with symptom persistence (PS group) with another group without symptom persistence (no-PS group). Fifty-three out of seventy-four patients (71.62%) described at least one persistent symptom at 6 months of SARS-CoV-2 infection. In the PS group, 56.6% were women and the average age was 54.7 years old [21–89.2] ± 16.9. The main symptoms were asthenia (56.6%, n = 30), dyspnea (34%, n = 18), anxiety (32.1% n = 17), anosmia (24.5%, n = 13) and agueusia (15.1% n = 8). Ten patients (13.51%) presented a resurgence in symptoms. Patients in the PS group were older (p = 0.0048), had a higher BMI (p = 0.0071), and were more frequently hospitalized (p = 0.0359) compared to the no-PS group. Odynophagia and nasal obstruction were less present in the inaugural symptoms of COVID-19 in the PS group (p = 0.0202 and p = 0.0332). Persistent post-COVID syndromes are common and identification of contributing factors is necessary for understanding this phenomenon and appropriate management.

Testing Positive for SARS-CoV-2 in Two Countries 105 Days Apart

Recovered COVID-19 patients may test positive for SARS-CoV-2 for a long time from intermittent shedding of viral fragments. A 36-year-old man who tested positive for SARS-CoV-2 in the Czech Republic and recovered tested positive again in Bhutan, 105 days beyond his first positive test. He experienced minimal symptoms and recovered without complications. Although no virological test was conducted to rule out reinfection, the repeat positive test after initial recovery likely resulted from prolonged shedding of dead viral particles than a reinfection.

SARS-CoV-2 reinfection in patients negative for immunoglobulin G following recovery from COVID-19

While many patients infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) eventually produce neutralising antibodies, the degree of susceptibility of previously infected individuals to reinfection by SARS-CoV-2 is currently unknown. To better understand the impact of the immunoglobulin (IgG) level on reinfection in recovered coronavirus disease 2019 (COVID-19) patients, anti-nucleocapsid IgG levels against SARS-CoV-2 were measured in 829 patients with a previously confirmed infection just after their recovery. Notably, 87 of these patients had no detectable IgG concentration. While there was just one case of asymptomatic reinfection 4.5 months after the initial recovery amongst patients with detectable anti-nucleocapsid IgG levels, 25 of the 87 patients negative for anti-nucleocapsid IgG were reinfected within one to three months after their first infection. Therefore, patients who recover from COVID-19 with no detectable anti-nucleocapsid IgG concentration appear to remain more susceptible to reinfection by SARS-CoV-2, with no apparent immunity. Also, although our results suggest the chance is lower, the possibility for recovered patients with positive anti-nucleocapsid IgG findings to be reinfected similarly exists.

Recurrence, Reactivation, or Inflammatory Rebound of SARS-CoV-2 Infection With Acute Vestibular Symptoms: A Case Report and Revision of Literature

A case of recurrent coronavirus disease 2019 (COVID-19) with neurovestibular symptoms was reported. In March 2020, a physician working in an Italian pediatric hospital had flu-like symptoms with anosmia and dysgeusia, and following a reverse transcription PCR (RT/PCR) test with a nasopharyngeal swab tested positive for SARS-CoV-2. After home quarantine, 21 days from the beginning of the symptoms, the patient tested negative in two subsequent swabs and was declared healed and readmitted to work. Serological testing showed a low level of immunoglobulin G (IgG) antibody title and absence of immunoglobulin M (IgM). However, 2 weeks later, before resuming work, the patient complained of acute vestibular syndrome, and the RT/PCR test with mucosal swab turned positive. On the basis of the literature examined and reviewed for recurrence cases and vestibular symptoms during COVID-19, to our knowledge this case is the first case of recurrence with vestibular impairment as a neurological symptom, and we defined it as probably a viral reactivation. The PCR retest positivity cannot differentiate re-infectivity, relapse, and dead-viral RNA detection. Serological antibody testing and viral genome sequencing could be always performed in recurrence cases.

Conundrum of re-positive COVID-19 cases: A systematic review of case reports and case series

Background

The systematic review was conducted to summarize and synthesize evidence from all available case series and case reports published on re-positive COVID-19 cases.

Methods

The systematic review was registered with Prospero (CRD42020210446). PRISMA guidelines were followed for conducting the systematic review. Inclusion criteria for studies included case reports and case series which have documented cases of positive reverse transcriptase polymerase chain reaction (RT-PCR) after a period of clinical improvement or a negative RT-PCR report. Reviews, opinions, and animal studies were excluded. Methodological quality was assessed using the modified Murad scale.

Results

A total of 30 case reports/case series were included in the study, wherein a total of 219 cases were included. In re-positive cases, the age range varied from 10 months to 91 years. The pooled proportion of positive cases after follow-up using random-effects was 12% (95% confidence interval [CI]: 09%-15%). Among the re-positives, a total of 57 cases (26%) had comorbidities. A total of 51 (23.3%) and 17 (7.8%) re-positive cases had been treated with antivirals and corticosteroids, respectively. Only a few studies have confirmed the presence of antibodies after the first episode. Studies that included contact tracing of re-positives did not find any positive cases among close contacts of re-positive cases.

Conclusion

The systemic review found that reinfection is a possibility within 123 days of a negative RT-PCR test in a small number of cases of COVID-19. This has wider ramifications in framing clinical, preventive, and public health policy guidelines.

Recurrent COVID-19 infection in a health care worker: a case report

Background

Recurrent coronavirus disease 2019 (COVID-19) infection is an emerging problem and may prove to be one of the greatest problems in controlling the pandemic in the future. Recurrent infections can be due to reactivation of dormant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or reinfection with similar or different strains of SARS-CoV-2.

Case presentation

Here we present an interesting case of a health care worker working as a laboratory assistant at a COVID-19 laboratory who developed recurrent COVID-19 infection. He did not develop an immune response after the first episode of COVID-19; however, immunoglobulin G (IgG) antibodies were detected after the second episode.

Conclusions

Through this case, we discuss the concept of reactivation and reinfection in the post-COVID period. We suggest that standard guidelines should be established to check for viral shedding and immune response among cured cases of COVID-19 after discharge via serial real-time polymerase chain reaction (RT-PCR) testing and IgG antibody detection. Further, strict hygiene practices should be stressed to these patients with possibility of COVID-19 recurrence.

Reinfection or Reactivation of Severe Acute Respiratory Syndrome Coronavirus 2: A Systematic Review

As the pandemic continues, individuals with re-detectable positive (RP) SARS-CoV-2 viral RNA among recovered COVID-19 patients have raised public health concerns. It is imperative to investigate whether the cases with re-detectable positive (RP) SARS-CoV-2 might cause severe infection to the vulnerable population. In this work, we conducted a systematic review of recent literature to investigate reactivation and reinfection among the discharged COVID-19 patients that are found positive again. Our study, consisting more than a total of 113,715 patients, indicates that the RP-SARS-CoV-2 scenario occurs plausibly due to reactivation, reinfection, viral shedding, or testing errors. Nonetheless, we observe that previously infected individuals have significantly lower risk of being infected for the second time, indicating that reactivation or reinfection of SARS-CoV-2 likely have relatively less impact in the general population than the primary infection.

COVID-19 reinfection in a healthcare worker after exposure with high dose of virus: A case report

Reinfection with COVID-19 is possible after exposure to a high dose of the virus. Due to immunity acquired during the previous infection, light symptoms are expected. The finding indicates importance of continuous protection in healthcare workers.

SARS-CoV-2: big seroprevalence data from Pakistan-is herd immunity at hand?

Purpose

Seroprevalence surveys from different countries have reported SARS CoV-2 antibodies below 20% even in the most adversely affected areas and herd immunity cannot be predicted till more than half of the population gets the disease. The purpose of this survey was to estimate the magnitude of community-based spread of the infection, associated immunity, and the future prospects and proximity to a ‘herd community’.

Methods

The study was undertaken as a cluster randomized, cross-sectional countrywide survey. This largest community-based seroprevalence data of SARS-CoV-2 were collected between 15th and 31st July, 2020 from seven randomly selected cities belonging to the three most populous provinces of Pakistan. The FDA approved kit of ROCHE was used for detection of SARS-CoV-2 antibodies.

Results

Serum samples of 15,390 participants were tested for SARS CoV-2 antibodies with an overall seroprevalence of 42.4%. The seroprevalence ranged from 31.1% to 48.1% in different cities with the highest in Punjab province (44.5%). In univariable analysis, the odds of seropositivity was higher in men compared to women (OR: 1.10, 95% CI: 1.01–1.19, P < 0.05). In multivariable analysis, the risk of being seropositive was lower (OR 0.72, 95% CI: 0.60–0.87, P < 0.01) in younger group (≤ 20 years) than in those aged above 60 years.

Conclusion

The study concluded that despite a reasonable seroprevalence, the country is yet to reach the base minimum of estimations for herd immunity. The durability of immunity though debated at the moment, has shown an evidenced informed shift towards longer side.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-021-01629-2.

COVID-19 and SARS-CoV-2: Everything we know so far – A comprehensive review

Coronavirus disease-2019 (COVID-19) emerged as a unique type of pneumonia outbreak in the Wuhan city of China in 2019 and spread to all its provinces in a matter of days and then to every continent of the world except Antarctica within 3–4 month. This paper aims to comprehensively consolidate the available information about COVID-19 and present all the possible information about this disease in form of a single paper to readers. Unparalleled research and exhaustive studies of everything about the disease and its causative virus, i.e., severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are underway since its emergence. The genome sequence of the virus was made available within a record short time by China, making possible immediate study of its structure and characteristics. The routes of transmission of the disease, signs and symptoms, incubation period, pathogenesis, and pathophysiology have been extensively studied and presented in an organized way in this review paper. The number of confirmed cases and case fatality and mortality rates are updated regularly. The different diagnostic mechanisms have been characterized. Testing and management criteria and protocols have been adopted. Extensive efforts are underway for finding a treatment of the disease and developing a vaccine against it. A number of vaccines are available even in markets in different countries. More and more ways of personal protection, prevention, and mitigation of the disease are being explored and shared. While the outbreak has been declared as pandemic, the response of scientists was timely and enormous; thousands of publications about various aspects and impact of the diseases and its causative virus are there on the World Health Organization database and many more studies are underway. The purpose of writing this review article is to provide a comprehensive summary of the major aspects and important scientific findings so far, about COVID-19 and SARS-CoV-2, in a single article for ready reference.

Symptomatic SARS-CoV-2 Reinfection in a Healthy Healthcare Worker in Italy Confirmed by Whole-Genome Sequencing

This study describes a case of SARS-CoV-2 reinfection confirmed by whole-genome sequencing in a healthy physician who had been working in a COVID-19 hospital in Italy since the beginning of the pandemic. Nasopharyngeal swabs were obtained from the patient at each presentation as part of routine surveillance. Nucleic acid amplification testing was performed on the two samples to confirm SARS-CoV-2 infection, and serological tests were used to detect SARS-CoV-2 IgG antibodies. Comparative genome analysis with whole-genome sequencing was performed on nasopharyngeal swabs collected during the two episodes of COVID-19. The first COVID-19 episode was in March 2020, and the second was in January 2021. Both SARS-CoV-2 infections presented with mild symptoms, and seroconversion for SARS-CoV-2 IgG was documented. Genomic analysis showed that the viral genome from the first infection belonged to the lineage B.1.1.74, while that from the second infection to the lineage B.1.177. Epidemiological, clinical, serological, and genomic analyses confirmed that the second episode of SARS-CoV-2 infection in the healthcare worker met the qualifications for "best evidence" for reinfection. Further studies are urgently needed to assess the frequency of such a worrisome occurrence, particularly in the light of the recent diffusion of SARS-CoV-2 variants of concern.

SARS-CoV-2 Reinfection among Healthcare Workers in Mexico: Case Report and Literature Review

Since the onset of the COVID-19 pandemic, there have been multiple questions regarding reinfections associated with SARS-CoV-2. Healthcare workers on duty, due to overexposure in environments where there are more cases of COVID-19, are more prone to become infected by this virus. Here, we report 4 cases that meet the definition of clinical reinfection by SARS-CoV-2, as well as a literature review on this subject; all occurred in healthcare workers in Acapulco Guerrero, Mexico who provide their services in a hospital that cares for patients with COVID-19. The time between the manifestation of the first and second infection for each case was 134, 129, 107 and 82 days, all patients presented symptomatology in both events. The time between remission of the first infection and onset of second infection was 108, 109, 78 and 67 days for each case, while the time to confirmation by reverse transcription polymerase chain reaction (RT-PCR) between infections was 134, 124, 106 and 77 days. In two of the four cases the reinfection resulted in a more severe case, while in the remaining two cases the manifestation of symptoms and complications was similar to that presented in the first infection. Given this scenario, greater care is needed in the management of the pandemic caused by SARS-CoV-2 to protect healthcare workers and the general public from risks and complications caused by a possible reinfection by SARS-CoV-2.

A systematic review on the recurrence of SARS-CoV-2 virus: frequency, risk factors, and possible explanations

BACKGROUND

Since late 2019, SARS-CoV-2 which leads to coronavirus disease 2019 (COVID-19), has caused thousands of deaths. There are some pieces of evidence that SARS-CoV-2 genome could be re-detectable in recovered patients.

METHODS

We performed a systematic review in the PubMed/Medline database to address the risk of SARS-CoV-2 recurrence. The last update was for 20 November 2020. Among the 1178 initially found articles, 66 met the inclusion criteria and were considered.

FINDINGS

In total, 1128 patients with at least one-time recurrence of SARS-CoV-2 were included. Recurrence rate has been reported between 2.3% and 21.4% in cohort studies, within a mean of 20 (ranged 1-98) days after discharge; younger patients are being affected more. Following the second course of disease, the disease severity decreased or remained unchanged in 97.3% while it increased in 2.6%. Anti-SARS-CoV-2 IgG and IgM were positive in 11-95% and 58.8-100%, respectively. Based on the literature, three possibilities include reactivation of previous disease, reinfection with the same virus, and false negative, which have been discussed in details.

CONCLUSION

There is a relatively notable risk of disease recurrence in previously recovered patients, even those who are immunised against the virus. More studies are required to clarify the underlying cause of this phenomenon.

Robust Neutralizing Antibodies to SARS-CoV-2 Develop and Persist in Subjects with Diabetes and COVID-19 Pneumonia

CONTEXT

Demonstrating the ability to mount a neutralizing antibody response to SARS-CoV-2 in the presence of diabetes is crucial to understand COVID-19 pathogenesis, reinfection potential, and vaccine development.

OBJECTIVE

The aim of this study was to characterize the kinetics and durability of neutralizing antibody (Nab) response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the presence of hyperglycemia.

METHODS

Using a lentiviral vector-based SARS-CoV-2 neutralization assay to measure Nabs, we characterized 150 patients randomly selected from a cohort of 509 patients with confirmed COVID-19 pneumonia. We analyzed Nab response according to the presence of diabetes or hyperglycemia, at the time of hospitalization and during the postdischarge follow-up: 1-, 3-, and 6-month outpatient visits.

RESULTS

Among 150 randomly selected patients 40 (26.6%) had diabetes. Diabetes (hazard ratio [HR] 8.9, P < .001), glucose levels (HR 1.25 × 1.1 mmol/L, P < .001), and glucose variability (HR 1.17 × 0.6 mmol/L, P < .001) were independently associated with an increased risk of mortality. The neutralizing activity of SARS-CoV-2 antibodies in patients with diabetes was superimposable, as for kinetics and extent, to that of patients without diabetes. It was similar across glucose levels and correlated with the humoral response against the SARS-CoV-2 spike protein. Positivity for Nabs at the time of hospital admission conferred protection on mortality, both in the presence (HR 0.28, P = .046) or absence of diabetes (HR 0.26, P = .030). The longevity of the Nab response was not affected by diabetes.

CONCLUSION

Diabetes and hyperglycemia do not affect the kinetics and durability of the neutralizing antibody response to SARS-CoV-2. These findings provide the rational to include patients with diabetes in the early phase of the vaccination campaign against SARS-CoV-2.

A systematic review and meta-analysis of discharged COVID-19 patients retesting positive for RT-PCR

BACKGROUND

With the increased number of patients discharged after having COVID-19, more and more studies have reported cases whose retesting was positive (RP) during the convalescent period, which brings a new public health challenge to the world.

METHODS

We searched PubMed, Web of Science, The Cochrane Library, CNKI, WanFang and VIP from December 1, 2019 to December 31, 2020. The included studies were assessed using JBI critical appraisal tools and Newcastle-Ottawa Scale. The RP rate of discharge patients was analyzed by a meta-analysis. We adhered to PRISMA reporting guideline.

FINDINGS

We have included 117 studies with 2669 RP participants after discharge. The methodological quality of 66 case reports were low to high, 42 case series and 3 cohort study were moderate to high, 3 case-control studies were moderate and 3 cross-sectional studies were low to moderate. The clinical manifestations of most RP patients were mild or asymptomatic, and CT imaging and laboratory examinations were usually normal. The existing risk factors suggest that more attention should be paid to sever patients, elderly patients, and patients with co-morbidities. The summary RP rate was 12·2% (95% CI 10·6-13·7) with high heterogeneity (I²  = 85%).

INTERPRETATION

To date, the causes and risk factors of RP result in discharged patients are not fully understood. High-quality etiological and clinical studies are needed to investigate these issues to further help us to make strategies to control and prevent its occurrence.

Positive SARS-CoV-2 RNA with Significant Inflammatory State and Thrombophilia after 12 Weeks of Initial Diagnosis of COVID-19 Infection

The ongoing COVID-19 pandemic has affected most countries in the world, with significant economic and public health implications. There is rising concern that patients who recover from COVID-19 may be at risk of reinfection. Another potential concern is the uncommon clinical scenario of a patient having persistent SARS-CoV-2 RNA test over 3 months after the initial COVID-19 infection, as the patient presented. Whether presenting as a long-term infection (12 weeks) or reinfection, patients with COVID-19 will continue to have a severe inflammatory and prothrombotic state that could carry potential life-threatening thrombosis.

Are people with uncontrolled diabetes mellitus at high risk of reinfections with COVID-19?

Several cases of positive real time-polymerase chain reaction (RT-PCR) results (called "re-positives") after recovery from COVID-19 have emerged worldwide. These cases could represent patients experiencing a "turn positive" of nucleic acid detection attributed to the high false-negative rate of RT-PCR. On the contrary, in symptomatic patients, the possibility of reactivation or true reinfection remains. We hypothesize that people with uncontrolled diabetes mellitus might be at a high risk of reinfections with COVID-19 attributed to the impaired adaptive immune response. In fact, multiple cases of re-positives/re-infections in people with diabetes mellitus have hitherto been reported.

Is recurrence possible in coronavirus disease 2019 (COVID-19)? Case series and systematic review of literature

Can a patient diagnosed with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) be infected again? This question is still unsolved. We tried to analyze local and literature cases with a positive respiratory swab after recovery. We collected data from symptomatic patients diagnosed with SARS-CoV-2 infection in the Italian Umbria Region that, after recovery, were again positive for SARS-CoV-2 in respiratory tract specimens. Samples were also assessed for infectivity in vitro. A systematic review of similar cases reported in the literature was performed. The study population was composed of 9 patients during a 4-month study period. Among the new positive samples, six were inoculated in Vero-E6 cells and showed no growth and negative molecular test in culture supernatants. All patients were positive for IgG against SARS-CoV-2 nucleoprotein and/or S protein. Conducting a review of the literature, 1350 similar cases have been found. The presumptive reactivation occurred in 34.5 days on average (standard deviation, SD, 18.7 days) after COVID-19 onset, when the 5.6% of patients presented fever and the 27.6% symptoms. The outcome was favorable in 96.7% of patients, while the 1.1% of them were still hospitalized at the time of data collection and the 2.1% died. Several hypotheses have been formulated to explain new positive respiratory samples after confirmed negativity. According to this study, the phenomenon seems to be due to the prolonged detection of SARS-CoV-2 RNA traces in respiratory samples of recovered patients. The failure of the virus to replicate in vitro suggests its inability to replicate in vivo.

Impaired anti-SARS-CoV-2 antibody response in non-severe COVID-19 patients with diabetes mellitus: A preliminary report

BACKGROUND AND AIMS

Patients with diabetes mellitus (DM) often demonstrate impaired antibody response to influenza/hepatitis B vaccines. Hence, we compared anti-SARS-CoV-2 antibody response in non-severe COVID-19 patients with and without type 2 diabetes mellitus (T2DM).

METHODS

Records of non-severe COVID-19 patients admitted at our institution between April 10, 2020 and May 20, 2020 were retrieved. Qualitative detection of total (IgG + IgM) anti-SARS-CoV-2 antibody was performed using electrochemiluminescence immunoassay in plasma samples collected at least 14 days post-polymerase chain reaction (PCR) confirmation of diagnosis.

RESULTS

Thirty-one non-severe COVID-19 patients were included. Nine patients (29%) had T2DM with mean HbA1c at admission of 8.3 ± 1.0%. Anti-SARS-CoV-2 antibody was estimated at a median of 16 (14-17) days post-PCR confirmation of COVID-19 diagnosis. Only three patients (10%) were seronegative, and all had T2DM. Patients with T2DM were more likely to have non-detectable anti-SARS-CoV-2 antibodies than those without DM (p = 0.019).

CONCLUSIONS

COVID-19 patients with T2DM may not undergo seroconversion even after two weeks of diagnosis. Impaired seroconversion could theoretically increase the risk of reinfections in patients with DM. However, the finding requires validation in large-scale studies involving serial estimations of anti-SARS-CoV-2 antibodies in patients with and without DM.

Reinfection risk of novel coronavirus (COVID-19): A systematic ‎review of current evidence

BACKGROUND

There is recently a concern regarding the reinfection and reactivation of previously reCoVered coronavirus disease 2019 (CoVID-19) patients.

AIM

To summarize the recent findings and reports of CoVID-19 reinfection in patients previously reCoVered from the disease.

METHODS

This study was a systematic review of current evidence conducted in August 2020. The authors studied the probable reinfection risk of novel coronavirus (CoVID-19). We performed a systematic search using the keywords in online databases. The investigation adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to ensure the reliability and validity of this study and results.

RESULTS

We reviewed 31 studies. Eight studies described reCoVered patients with reinfection. Only one study reported reinfected patients who died. In 26 studies, there was no information about the status of the patients. Several studies indicated that reinfection is not probable and that post-infection immunity is at least temporary and short.

CONCLUSION

Based on our review, we concluded that a positive polymerase chain reaction retest could be due to several reasons and should not always be considered as reinfection or reactivation of the disease. Most relevant studies in positive retest patients have shown relative and probably temporary immunity after the reCoVery of the disease.

The role of host genetics in susceptibility to severe viral infections in humans and insights into host genetics of severe COVID-19: A systematic review

BACKGROUND

Susceptibility to severe viral infections was reported to be associated with genetic variants in immune response genes using case reports and GWAS studies. SARS-CoV-2 is an emergent viral disease that caused millions of COVID-19 cases all over the world. Around 15 % of cases are severe and some of them are accompanied by dysregulated immune system and cytokine storm. There is increasing evidence that severe manifestations of COVID-19 might be attributed to human genetic variants in genes related to immune deficiency and or inflammasome activation (cytokine storm).

OBJECTIVE

Identify the candidate genes that are likely to aid in explaining severe COVID-19 and provide insights to understand the pathogenesis of severe COVID-19.

METHODS

In this article, we systematically reviewed genes related to viral susceptibility that were reported in human genetic studies (Case-reports and GWAS) to understand the role of host viral interactions and to provide insights into the pathogenesis of severe COVID-19.

RESULTS

We found 40 genes associated with viral susceptibility and 21 of them were associated with severe SARS-CoV disease and severe COVID-19. Some of those genes were implicated in TLR pathways, others in C-lectin pathways, and others were related to inflammasome activation (cytokine storm).

CONCLUSION

This compilation represents a list of candidate genes that are likely to aid in explaining severe COVID-19 which are worthy of inclusion in gene panels and during meta-analysis of different variants in host genetics studies of COVID-19. In addition, we provide several hypotheses for severe COVID-19 and possible therapeutic targets.

COVID-19 vaccine-readiness for anti-CD20-depleting therapy in autoimmune diseases

Although most autoimmune diseases are considered to be CD4 T cell- or antibody-mediated, many respond to CD20-depleting antibodies that have limited influence on CD4 and plasma cells. This includes rituximab, oblinutuzumab and ofatumumab that are used in cancer, rheumatoid arthritis and off-label in a large number of other autoimmunities and ocrelizumab in multiple sclerosis. Recently, the COVID-19 pandemic created concerns about immunosuppression in autoimmunity, leading to cessation or a delay in immunotherapy treatments. However, based on the known and emerging biology of autoimmunity and COVID-19, it was hypothesised that while B cell depletion should not necessarily expose people to severe SARS-CoV-2-related issues, it may inhibit protective immunity following infection and vaccination. As such, drug-induced B cell subset inhibition, that controls at least some autoimmunities, would not influence innate and CD8 T cell responses, which are central to SARS-CoV-2 elimination, nor the hypercoagulation and innate inflammation causing severe morbidity. This is supported clinically, as the majority of SARS-CoV-2-infected, CD20-depleted people with autoimmunity have recovered. However, protective neutralizing antibody and vaccination responses are predicted to be blunted until naive B cells repopulate, based on B cell repopulation kinetics and vaccination responses, from published rituximab and unpublished ocrelizumab (NCT00676715, NCT02545868) trial data, shown here. This suggests that it may be possible to undertake dose interruption to maintain inflammatory disease control, while allowing effective vaccination against SARS-CoV-29, if and when an effective vaccine is available.

Recurrence of SARS-CoV-2 viral RNA in recovered COVID-19 patients: a narrative review

Many studies have shown that re-positive tests for SARS-CoV-2 by RT-PCR in recovered COVID-19 patients are very common. We aim to conduct this review to summarize the clinical and epidemiological characteristics of these patients and discuss the potential explanations for recurrences, the contagiousness of re-detectable positive SARS-CoV-2 virus, and the management of COVID-19 patients after discharge from hospital. The proportion of re-positive tests in discharged COVID-19 patients varied from 2.4 to 69.2% and persisted from 1 to 38 days after discharge, depending on population size, age of patients, and type of specimens. Currently, several causes of re-positive tests for SARS-CoV-2 in recovered COVID-19 patients are suggested, including false-negative, false-positive RT-PCR tests; reactivation; and re-infection with SARS-CoV-2, but the mechanism leading to these re-positive cases is still unclear. The prevention of re-positive testing in discharged patients is a fundamental measure to control the spread of the pandemic. In order to reduce the percentage of false-negative tests prior to discharge, we recommend performing more than two tests, according to the standard sampling and microbiological assay protocol. In addition, specimens should be collected from multiple body parts if possible, to identify SARS-CoV-2 viral RNA before discharge. Further studies should be conducted to develop novel assays that target a crucial region of the RNA genome in order to improve its sensitivity and specificity.

Re-positive coronavirus disease 2019 PCR test: could it be a reinfection?

The coronavirus disease 2019 (COVID-19) outbreak started in December 2019 and rapidly spread around the globe as a major health threat. Several reports on re-positive cases subsequent to discharge from hospitals caught our attention. We aimed to highlight RT-qPCR positivity re-detection after discharge from isolation, with special consideration of the possible reasons behind it. We found that re-positive RT-qPCR assays for severe acute respiratory syndrome coronavirus 2 after previous negative results might be attributed to false-negative laboratory results and prolonged viral shedding, rather than to re-infection. These findings are encouraging and should be validated in a larger cohort.

Late Reactivation of SARS-CoV-2: A Case Report

SARS-CoV-2 is a betacoronavirus that belongs to the family Coronaviridae and the order Nidovirales (1). During December 2019, a series of pneumonia cases caused by a SARS-CoV-2 outbreak was identified in Wuhan, Hubei, China, and rapidly spread across the world. The spectrum of SARS-CoV-2 disease (COVID 19) varies from asymptomatic or paucisymptomatic forms to clinical conditions characterized by respiratory failure that necessitate mechanical ventilation and support in an intensive care unit (ICU), multiorgan and systemic manifestations, and, in terms of sepsis, septic shock, and multiple organ dysfunction syndromes (MODS) (2). Whilst many reports have characterized the clinical, epidemiological, laboratory, and radiological features, as well as treatment and clinical outcomes of patients with COVID-19 pneumonia, information on SARS-CoV-2 reactivation remains unreported. Curative and eradicative therapy for COVID-19 is not currently available (3). We report a case of a patient with PCR-confirmed COVID-19 pneumonia who experienced reactivation after 43 days and negative PCR sampling.

Recurrence or Relapse of COVID-19 in Older Patients: A Description of Three Cases

BACKGROUND

COVID-19 has infected millions of people worldwide, particularly in older adults. The first cases of possible reinfection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were reported in April 2020 among older adults.

DESIGN/SETTING

In this brief report, we present three geriatric cases with two episodes of SARS-CoV-2 infection separated by a symptom-free interval.

PARTICIPANTS

The participants of this brief report are three cases of hospitalized geriatric women.

MEASUREMENTS/RESULTS

We note clinical and biological worsening during the second episode of COVID-19 for all three patients. Also, there is a radiological aggravation. The second episode of COVID-19 was fatal in all three cases.

CONCLUSION

This series of three geriatric cases with COVID-19 diagnosed two times apart for several weeks questions the possibility of reinfection with SARS-CoV-2. It raises questions in clinical practice about the value of testing for SARS-CoV-2 infection again in the event of symptomatic reoccurrence. J Am Geriatr Soc 68:2179-2183, 2020.

Analysis of Risk Factors on Readmission Cases of COVID-19 in the Republic of Korea: Using Nationwide Health Claims Data

In South Korea, 4.5% patients of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were readmitted to hospitals after discharge. However, there is insufficient research on risk factors for readmission and management of patients after discharge is poor. In this study, 7590 confirmed coronavirus disease (COVID-19) patients were defined as a target for analysis using nationwide medical claims data. The demographic characteristics, underlying diseases, and the use of medical resources were used to examine the association with readmission through the chi-square test and then logistic regression analysis was performed to analyze factors affecting readmission. Of the 7590 subjects analyzed, 328 patients were readmitted. The readmission rates of men, older age and patients with medical benefits showed a high risk of readmission. The Charlson Comorbidity Index score was also related to COVID-19 readmission. Concerning requiring medical attention, there was a higher risk of readmission for the patients with chest radiographs, computed tomography scans taken and lopinavir/ritonavir at the time of their first admission. Considering the risk factors presented in this study, classifying patients with a high risk of readmission and managing patients before and after discharge based on priority can make patient management and medical resource utilization more efficient. This study also indicates the importance of lifestyle management after discharge.

Clinical recurrences of COVID-19 symptoms after recovery: Viral relapse, reinfection or inflammatory rebound?

For the first 3 months of COVID-19 pandemic, COVID-19 was expected to be an immunizing non-relapsing disease. We report a national case series of 11 virologically-confirmed COVID-19 patients having experienced a second clinically- and virologically-confirmed acute COVID-19 episode. According to the clinical history, we discuss either re-infection or reactivation hypothesis. Larger studies including further virological, immunological and epidemiologic data are needed to understand the mechanisms of these recurrences.