Asymptomatic COVID-19 Infection Research Articles

SARS-Cov-2 Infection: A New Risk Factor for Pituitary Apoplexy?

Pituitary apoplexy (PA) can arise from haemorrhage or ischaemia of pituitary tissue and is characterized by abrupt onset of headache, visual impairment and hypopituitarism. COVID-19 may be associated with various degrees of vascular complications and, recently, its relationship with PA has been suggested. Cases Presentation Case 1: A 64-year-old male with type 2 diabetes, hypertension and coronary heart disease was admitted to the ER, after several days of asymptomatic COVID-19 infection, with symptoms of PA of a known non-functioning pituitary macroadenoma. The hormonal panel was consistent with anterior panhypopituitarism and the sellar MRI showed haemorrhagic changes of macroadenoma tissue. Transsphenoidal resection of the pituitary lesion was carried out seven days after admission. Although a volumetric reduction of the lesion was apparent during follow-up, some degree of visual symptoms endured. Case 2: An 18-year-old, otherwise healthy, female presented to the ER with symptoms of PA of a recently-diagnosed non-functioning pituitary macroadenoma, after ten days of asymptomatic COVID-19 infection. Central hypocortisolism and hypothyroidism were diagnosed and, after six days, the lesion was surgically resected. At two months follow-up, clinical symptoms had completely resolved, and the hormonal panel was normal. Alongside known risk factors (hypertension, anticoagulation, pregnancy, surgery, etc.), COVID-19 infection might represent an emerging predisposing factor for PA onset. The two cases hereby presented are both significant: the first confirms the role of "classic" vascular predisposing factors for PA, while the second demonstrates that PA might arise also in young patients without known risk factors.

Characteristics of Asymptomatic COVID-19 In SARS-COV-2 Vaccine Trial Screening Participants

Introduction We conducted a Phase I SARS-CoV-2 vaccine trial in March 2022. During the screening, we identified a significant number of asymptomatic COVID-19 cases among the candidate participants. We aimed to highlight the clinical characteristics among these asymptomatic individuals as compared to subjects negative for SARS-CoV-2. Methods This observational study was conducted during participant screening for a Phase I SARS-CoV-2 vaccine trial in Jepara and Mranggen districts in Central Java, Semarang, Indonesia. Participants who reported no symptoms associated with COVID-19, confirmed by physical examinations, were included. Data on laboratory markers were documented. An asymptomatic case was defined as showing no clinical symptoms and signs of SARS-CoV-2 infection with a positive SARS-CoV-2 RT-PCR result. Individuals who tested negative for SARS-CoV-2 were included for comparison. A chi-square test was employed to assess the differences between the two groups, with a p-value <0.05 is considered significant. Results A total of 219 participants were screened and included. One hundred and six participants (48.4%) had positive SARS-CoV-2 RT-PCR results, with mean Ct values of 28.29 +/- 6.74 for the helicase gene. There was no significant difference in demographic characteristics, physical examination, and laboratory findings (p-value >0.05) among individuals with positive and negative SARS-CoV-2. Conclusion In our vaccine trial screening phase, almost half were ineligible due to having asymptomatic SARS-CoV-2 infections. In addition, it is necessary that people with asymptomatic COVID-19 infection still need to be concerned because they have the same transmission potential.

Ramsay Hunt Syndrome in Asymptomatic COVID-19 Infection: A Case Report and a Literature Review

(1) Background: COVID-19 infection has affected almost 6 million people worldwide. Geniculate Ganglion Zoster resulting in Ramsay Hunt Syndrome (RHS) has been rarely described in this context. (2) Methods: Here, a case of RHS in the context of asymptomatic COVID-19 infection is reported followed by a literature review of the previously published cases (PubMed research combining “COVID-19” and “Ramsay Hunt Syndrome” or their abbreviations/synonyms, searching for data published at any time till October 2023). (3) Results: Five cases have been previously published (age range: 25–67 years; n = 3 males). Three patients were known to be immunocompetent prior to infection, one was receiving corticotherapy for lung disease, and one had an unspecified immune status. RHS predominantly involved both facial and vestibulocochlear nerves, with one case exclusively involving the facial nerve as the presented case. Regarding facial nerve palsy, three were right-sided (like the current report) and two were left-sided. Two cases were asymptomatic to COVID-19 (like the present patient), one had mild fatigue, and two had classical COVID-19 symptoms preceding RHS symptoms. Workup included serological testing against Varicella Zoster Virus and PCR assays that can detect the viral DNA in saliva, blood, tears, exudates, and cerebrospinal fluid. The treatment combined antiviral and corticosteroid therapies which yielded heterogeneous outcomes that might be related to some demographic and clinical data. (4) Conclusions: RHS rarely occurs in the context of COVID-19. Early recognition is important. Management seems to be similar to the classical condition. Some data may help predict facial nerve recovery.

Association of the presence of a COVID-19 infection at the time of birth and the rates of exclusive breastfeeding upon discharge in BFHI hospitals: a multicenter, prospective cohort study

BackgroundVery few studies have assessed the association between COVID-19 infection and the rates of exclusive breastfeeding (EBF) upon discharge following the first waves of the pandemic and after initiation of vaccination. The primary objective of this study is to compare the rates of EBF since birth upon discharge in mothers diagnosed with COVID-19 infection at the time of the delivery versus a group of non-infected mothers in maternity hospitals with Baby Friendly Hospital Initiative (BFHI) accreditation. The secondary objectives include determining the rates of any breastfeeding at three and six months of life in both groups, as well as determining the possible factors associated with EBF rates observed upon discharge.MethodsAn observational, Spanish multi-center hospital, prospective cohort study conducted from 1 to 2021 to 31 March 2022 and with follow-up during the first six months of life. Follow-up was performed via telephone contact with calls performed at three and six months. A multivariate logistic regression analysis model was used to identify the factors related to a lower probability of EBF upon discharge.Results308 mother-infant pairs participated in the study, 111 in the cohort of women with COVID infection and 197 in the comparison group. EBF upon discharge was 62.7% in the COVID group vs. 81.2% in the comparison group (p = 0.002); at three months; 52.4% vs. 57.0% (p = 0.33) were performing EBF, with the rates of EBF at six months being 43.0% vs. 39.3% (p = 0.45), respectively. Exposure to COVID-19 at delivery (AOR 5.28; 95% CI 2.01, 13.86), not practicing BF previously (AOR 36.3; 95% CI 7.02, 187.74), birth via Cesarean section (AOR 5.06; 95% CI 1.62, 15.79) and low birth weight of the newborn (AOR 1.01; 95% CI 1.01, 1.01) were associated with a greater risk of not performing EBF upon discharge.ConclusionsMothers with a mild or asymptomatic COVID-19 infection at the time of the delivery were less likely to have exclusively breastfed during their hospital stay than other mothers in these BFHI-accredited hospitals. However, there were no differences in breastfeeding rates between the groups at three and six months postpartum.

RApid Throughput Screening for Asymptomatic COVID-19 Infection With an Electrocardiogram: A Prospective Observational Study

ObjectiveTo evaluate the ability of a neural network to identify severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using point-of-care electrocardiography obtained with a portable device. Patient and MethodsWe enrolled 2827 patients in a prospective observational study, from December 10, 2020, through June 4, 2021, to determine the accuracy of a point-of-care, handheld, smartphone-compatible, artificial intelligence–enabled electrocardiography (ECG) (POC AI-ECG) in detecting asymptomatic SARS-CoV-2 infection using a modified version of an existing deep learning model framework trained on 12-lead ECG data. ResultsStudy participants were 48% (n=1067) female, 79% (n=1749) White, and 7% (n=153) endorsed previous COVID-19 infection. We found the POC AI-ECG algorithm was ineffective for detecting asymptomatic SARS-CoV-2 infection (area under curve, 0.56; 95% CI, 0.46-0.66), failing to adequately discriminate between ECGs performed among participants who tested positive compared to those who tested negative. ConclusionContrary to the prior 12-lead ECG study, a POC AI-ECG failed to reliably identify asymptomatic SARS-CoV-2 infection among adults. This study underscores the importance of prospective testing, assuring similar populations, and using similar signals or data when developing AI-ECG tools. Trial registrationclinicaltrials.gov Identifier: NCT04725097

Limited impact of contact tracing in a University setting for COVID-19 due to asymptomatic transmission and social distancing

Contact tracing is an important tool for controlling the spread of infectious diseases, including COVID-19. Here, we investigate the spread of COVID-19 and the effectiveness of contact tracing in a university population, using a data-driven ego-centric network model constructed with social contact data collected during 2020 and similar data collected in 2010. We find that during 2020, university staff and students consistently reported fewer social contacts than in 2010, however those contacts occurred more frequently and were of longer duration. We find that contact tracing in the presence of social distancing is less impactful than without social distancing. By combining multiple data sources, we show that University-aged populations are likely to develop asymptomatic COVID-19 infections. We find that asymptomatic index cases cannot be reliably discovered through contact tracing and consequently transmission in their social network is not significantly reduced through contact tracing. In summary, social distancing restrictions had a large impact on limiting COVID-19 outbreaks in universities; to reduce transmission further contact tracing should be used in conjunction with alternative interventions.

236 The Hypercoagulable State in COVID-19 and Implications for Free Flap Surgery in the Lower Limb

Abstract Aim COVID-19 associated coagulopathy is widely documented in severe COVID-19 infection and COVID-19 Vaccine-Induced Thrombotic Thrombocytopaenia. However, much of this evidence relates to macrovascular thrombosis with limited evidence on the impact of previous mild, asymptomatic COVID-19 infection, or vaccination on microvascular thrombosis in free tissue transfer. We compared the rate of thrombotic complications in traumatic lower limb injuries requiring free flap reconstruction in the pre- and post-COVID era. Method Adult patients undergoing lower limb free flap reconstruction were identified at a single centre over two three-month periods (2019 and 2021). Standard thromboprophylaxis was used for all patients (intraoperative intermittent pressure devices, post-operative thromboembolic deterrent stockings, and prophylactic low molecular weight heparin until discharge). Thrombotic complications were recorded and compared using a chi-squared test. Results In the pre-COVID cohort, 51 patients underwent 52 free flaps. One flap (1.9%) suffered anastomotic thrombosis resulting in flap compromise. Post-COVID, 39 patients underwent 43 free flaps. Nine flaps suffered anastomotic thrombosis (21%) and one patient suffered a pulmonary embolus. This increase was statistically significant (p = 0.002). In the post-COVID cohort, four patients had a COVID-19 infection and 25 patients (64%) had at least one dose of a COVID-19 vaccine before free flap surgery. No patients had an active COVID-19 infection on admission. Conclusions In the post-COVID era there was an increased rate of thrombotic complications in lower limb free flap patients. Further research is required to delineate the best course of action when planning free tissue transfer for patients who have had previous COVID-19 infection or vaccination.

Identification of Asymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infections Among Healthcare Workers at Sultan Qaboos University Hospital, Oman.

This study aimed to describe the incidence and features of asymptomatic COVID-19 infections among healthcare workers (HCWs) at a tertiary hospital in Oman. This cross-sectional study was conducted between August 2020 and February 2021 among HCWs with no history of COVID-19 infection. An online questionnaire collected sociodemographic and clinical data. COVID-19 infection was diagnosed using nasopharyngeal/throat swabs, which were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Analyses were performed using the Chi-squared test, Fisher's exact test or univariate ordinary least squares regression, as appropriate. A total of 583 HCWs participated in the study, most of whom were female (56.6%), and the mean age was 35 ± 8 years. Only 9.6% (95% confidence interval [CI]: 7.3-12.3%) of the HCWs were at high exposure risk as they were directly involved in the care of COVID-19-infected patients. Overall, 4.1% (95% CI: 2.7-6.1%) of the HCWs screened positive for SARS-CoV-2, of which 20.8% developed symptoms within two weeks. The frequency of SARS-CoV-2 positivity among HCWs working in high-, intermediate-, low- and miscellaneous-risk areas was 1.8% (95% CI: <0.1-9.6%), 2.6% (95% CI: <0.1-6.5%), 5.3% (95% CI: 0.3-9.3%) and 4.8% (95% CI: <0.1-69.3%), respectively. Working in high-risk areas was associated with increased compliance with various infection control strategies (P <0.001). There was a greater frequency of SARS-CoV-2 positivity among HCWs working in low-risk areas, whereas HCWs who worked in high-risk areas were significantly more likely to report increased compliance with infection control strategies.

SARS-COV-2 SEROSURVEY AMONG BULGARIAN HEALTHCARE WORKERS BEFORE AND AFTER VACCINATION

Background: In the response to the current COVID-19 pandemic caused by the novel SARS-CoV-2, one of the groups at higher risk were healthcare workers (HCWs), especially those who worked on the frontline. The presence of SARS-CoV-2 specific IgG antibodies (seropositivity) in certain populations provides better understanding of virus circulation and transmission. Our aim was to study the seroprevalence rates of anti-SARS-CoV-2 antibodies among a group of healthcare workers before and after vaccination/COVID-19 infection. Material and Methods: We determined the presence of SARS-CoV-2 specific IgG and IgA antibodies against S-antigen of by ELISA method. In this study, we enrolled 74 healthcare workers and three months later, 48 of the participants were followed up. At the baseline, none of the participants was vaccinated or had suffered COVID-19. Results: SARS-Cov-2 specific IgG antibodies were found in 32.4% of the participants. Higher prevalence of class IgA antibodies – 44.6% was detected. All samples that were IgG seropositive were also positive or borderline for IgA antibodies. Overall, virus-specific antibodies were not detected in 40.6% of HCWs in the group. During the follow-up (after vaccination and/or COVID-19 infection) high rates of both IgG and IgA seroprevalence were established. SARS-C0V-2 specific IgG antibodies were detected in 95.8% of the participants. Statistically significant difference was found in the levels of IgG and IgA antibodies both before and after vaccination, p&lt;0.0001. Conclusions: Based on detection of anti-SARS-CoV-2 IgG antibodies, seroprevalence of 32.4% was established in an unvaccinated group of HCWs. Our survey demonstrated that asymptomatic COVID-19 infection may induce weaker humoral immune response, with production of IgA but not of IgG antibodies.

Surgical management during three phases of covid-19 pandemic with changing role of thoracic computerized tomography imaging in orthopaedic patient management: Lessons learned by orthopaedic surgeon

The coronavirus (Covid-19) pandemic has ravaged the whole world. It had affected the allied surgical branches that had to reinvent the protocols for patient management. Trauma being inevitable, needed urgent attention. The changing perspectives had a defining role in the direction of arthroplasty too.The pandemic has been considered into three different phases: 1. The acute phase of the lockdown; 2. The intermediate phase of surgical prioritization; 3. The late phase of surgical management post-vaccination.We deliberate on the impact of the pandemic on orthopaedic surgery and the role of Thoracic computerized tomography (Th-CT) imaging during Covid-19 on the surgical practice of orthopaedic surgeons. Th-CT had been useful imaging during the acute phase of lockdown in the pandemic to identify the asymptomatic Covid-19 infection and to gauge the severity of viral infection. We reviewed the guidelines formulated during each step and identified the lessons learned by the practicing orthopaedic surgeon. We further elaborate on the changes in the usage of Th-CT in the subsequent intermediate and late phases of the pandemic for orthopaedic surgeons. The critical consideration remained to achieve an uneventful recovery during the orthopaedic surgical management, to avoid the transmissibility of infection to the surgeon, and to protect the patient from the high morbidity and mortality of Covid-19 related illness. The Covid-19 pandemic has instigated orthopaedists to develop a holistic approach to deal with the new challenges during this pandemic era.

How fit are military hyperbaric personnel after an asymptomatic or mild symptomatic COVID-19 infection? A retrospective study.

In the diving community there is a special need to know if asymptomatic or mild COVID-19 disease impacts the cardiopulmonary functioning of individuals with occupational exposure to extreme environments. To date, no controlled studies have been conducted comparing COVID-19-infected hyperbaric employees and non-COVID-19-infected peers in a military setting. Between June 2020 and June 2021, healthy, hyperbaric, military personnel aged between 18 and 54 years old, who had recovered from asymptomatic or subclinical COVID-19 disease at least one month earlier, were analysed. Non-COVID-infected peers with medical assessments during the same period were used as the control group. Somatometry, spirometry, VO₂ max, and DLCO were measured for each group. No clinically relevant differences in somatometry, lung function tests, and exercise testing were found between the COVID-19 group and the controls. However, the percentage of individuals with a decrease in estimated VO2-max of 10% or more was significantly greater in the COVID group than in the control group (24 vs. 7.8%, P = 0.004). After asymptomatic or mild symptomatic COVID-19 infections, military hyperbaric employees are as fit as those who had not encountered COVID-19. As this research was based on a military population, it cannot be extrapolated to a nonmilitary population. Further studies in nonmilitary populations are necessary to determine the medical relevance of the present findings.

The Difference in Anti-nucleocapsid Protein Antibody Responses Between Vaccinated and Unvaccinated Individuals After Asymptomatic, Mild, or Moderate COVID-19 Infection

Ji Yeun Kim, Hye Hee Cha, Ji Soo Kwon, Jun Ho Cha, Choi Young Jang, Hyun Jung Lee, So Yun Lim, Sung-Han Kim. Korean J healthc assoc Infect Control Prev 2023;28:92-8. https://doi.org/10.14192/kjicp.2023.28.1.92

Asymptomatic COVID-19 presenting with features of mixed pattern acute liver injury in a young healthy female, a case report

COVID-19 associated severe acute liver injury in a young healthy patient has not been reported much in the literature. And currently, there are no standard management guidelines. We want to report a case of acute liver injury of mixed pattern in a young healthy female with asymptomatic COVID-19 infection. She presented with abdominal pain, nausea, vomiting and yellowish discoloration of her skin. Further laboratory investigations revealed mixed pattern liver injury with highly raised liver enzymes. She was managed with N-acetyl cysteine protocol and monitoring of her liver enzymes. Other causes of acute liver injury were ruled out. She remained stable during her hospital stay and follow up. Our aim is to highlight the significance of acute liver injury in COVID 19 patients that may lead to fatal outcomes if not managed and monitored accordingly.

EPH262 Preventing COVID-19 Outbreaks Using Wastewater Surveillance at Long-Term Care Facilities: A Pilot Modelling Study

Site-specific wastewater surveillance could potentially control COVID-19 outbreaks more effectively at long-term care facilities (LTCF). It could identify the presence of pre-symptomatic and asymptomatic COVID-19 infections in the facility and therefore initiate timely outbreak control measures. Besides, compared to repetitive screenings of residents and staff using diagnostic tests, screenings based on positive wastewater test results incur fewer costs and less discomfort. We evaluated the effectiveness of LTCF-site-specific wastewater surveillance in preventing COVID-19 outbreaks, by comparing the scenario where more diagnostic tests were initiated due to positive wastewater test results and the base case of no action. We built a susceptible-infected-cases-recovered model to study COVID-19 transmission at LTCF under the base-case and wastewater surveillance scenario. We used data from an outbreak during the Omicron wave in one LTCF in Edmonton, Canada (December 2021 – March 2022), where wastewater data did not initiate actions. We fit base-case model parameters with daily cases and testing data using the nonlinear least-squares method. We hypothesized 10%-50% more diagnostic tests in the wastewater scenario. We compared the outbreak size, i.e., predicted numbers of infections, to measure the effectiveness. We used the Mann-Whitney U test to identify whether the outbreak size in the wastewater scenario was significantly smaller. Results reported are subject to minor changes as modelling work is ongoing. The number of infections peaked on day 25 in the base case, with 23.8% of individuals being infected. In the wastewater scenario, all hypothesized values resulted in a significantly smaller outbreak size; only 10% more diagnostic tests could lead to 5.4% fewer infections (p=0.03) at the peak. This pilot study demonstrates the potential effectiveness of LTCF-site-specific wastewater surveillance to prevent COVID-19 outbreaks. Future works include engaging policymakers in analyzing specific wastewater-based actions and estimating the costs of controlling COVID-19 to explore the cost-effectiveness of wastewater surveillance.

Clinical Profile and Outcomes of Neonates Exposed to Maternal COVID-19 Infection in a Tertiary Care Centre—A Cohort Study (NeOCoM Study)

Background COVID-19 infection during pregnancy was reported to cause adverse outcomes. Such knowledge stands low quality evidence due to lack of internal controls and inferential statistics. Objectives To assess impact of COVID-19 in pregnancy on fetal and neonatal outcomes. Study Design Prospective analytical cohort study (July 2020 to March 2021). Setting Level III NICU of teaching hospital in India. Participants COVID positive mothers (exposed = 239) each matched with 2 women delivered consecutively by same mode without COVID (unexposed = 478) and enrolled at admission during delivery. Procedure Maternal demographic, comorbidities, and obstetric characteristics; fetal growth, pregnancy complications, and neonatal details of 242 and 482 neonates born to exposed and unexposed mothers respectively were analyzed. Infants were followed until neonatal period. Outcomes Incidence of prematurity was primary outcome. Secondary outcomes were incidence of abortions, IUD, stillbirth, neonatal mortality, neonatal resuscitation at birth, SFD, NICU admission, neonatal morbidities, length of hospitalization, in-hospital mortality, infant positivity rate for SARS COV-2. Results Incidence of prematurity was not significantly different between mothers with and without COVID-19 infection [42(17.3%) vs 94(19.3%), IRR (95%CI) 1.04(0.83,1.31), P = .833]. Neonatal mortality, adverse fetal outcomes, PROM, fetal distress, SGA, neonatal resuscitation, NICU admission did not differ significantly between groups. Gestational hypertension was associated with COVID-19 infection [14(5.9%) vs 11(2.3%), (p=0.014)]. Infant swab positivity was 7%. Swab positivity and neonatal symptoms were associated significantly (10/17(58.8%) vs 7/17(41.1%), P = .0001). Conclusion Asymptomatic COVID-19 infection during pregnancy does not increase adverse fetal and neonatal outcomes. COVID positive neonates become symptomatic and hence need monitoring in health-care facility.

Early Detection of Asymptomatic Covid-19 Infection with Artificial Neural Network Model Through Voice Recording of Forced Cough

SARS-CoV-2 is a virus that spreads the infection known as COVID-19, or Coronavirus 2019. According to data from the World Health Organization as of March 15, 2021, Indonesia has 1,419,455 cumulative cases and 38,426 cumulative deaths, ranking third among countries in terms of fatalities, behind Iran and India. Because COVID-19 was disseminated through direct contact with respiratory droplets from an infected individual, it spread swiftly and widely. According to the American Centers for Disease Control and Prevention, more than 50% of transmission rates are anticipated from asymptomatic individuals. The antigen tests have an accuracy of results ranging from 80–90% and are utilized for early detection of COVID-19. The cost of the antigen test is set to increase as of September 3, 2021, with prices ranging from IDR 99.000 to IDR 109.000; however, researchers are steadfastly searching for the best alternate methods for the early diagnosis of COVID-19. According to MIT News Office, a forced cough recording can identify an asymptomatic COVID-19 infection. Through the vocal recording of a forced cough, this study uses an artificial neural network (ANN) deep learning model to identify asymptomatic COVID-19 patients. The Artificial Neural Network (ANN) can distinguish asymptomatic people from forced cough recordings with an accuracy of up to 98% and a loss value of less than 3% by employing oversampling data. This model can be applied as a free, universal method for the early identification of COVID-19 infection.

Seroprevalence and durability of antibody responses to AstraZeneca vaccination in Ugandans with prior mild or asymptomatic COVID-19: implications for vaccine policy.

The duration and timing of immunity conferred by COVID-19 vaccination in sub-Saharan Africa are crucial for guiding pandemic policy interventions, but systematic data for this region is scarce. This study investigated the antibody response after AstraZeneca vaccination in COVID-19 convalescent Ugandans. We recruited 86 participants with a previous rt-PCR-confirmed mild or asymptomatic COVID-19 infection and measured the prevalence and levels of spike-directed IgG, IgM, and IgA antibodies at baseline, 14 and 28 days after the first dose (priming), 14 days after the second dose (boosting), and at six- and nine-months post-priming. We also measured the prevalence and levels of nucleoprotein-directed antibodies to assess breakthrough infections. Within two weeks of priming, vaccination substantially increased the prevalence and concentrations of spike-directed antibodies (p < 0.0001, Wilcoxon signed rank test), with 97.0% and 66% of vaccinated individuals possessing S-IgG and S-IgA antibodies before administering the booster dose. S-IgM prevalence changed marginally after the initial vaccination and barely after the booster, consistent with an already primed immune system. However, we also observed a rise in nucleoprotein seroprevalence, indicative of breakthroughs six months after the initial vaccination. Our results suggest that vaccination of COVID-19 convalescent individuals with the AstraZeneca vaccine induces a robust and differential spike-directed antibody response. The data highlights the value of vaccination as an effective method for inducing immunity in previously infected individuals and the importance of administering two doses to maintain protective immunity. Monitoring anti-spike IgG and IgA when assessing vaccine-induced antibody responses is suggested for this population; assessing S-IgM will underestimate the response. The AstraZeneca vaccine is a valuable tool in the fight against COVID-19. Further research is needed to determine the durability of vaccine-induced immunity and the potential need for booster doses.

Single SARS virus mutation as a possible cause of the prevalence of asymptomatic COVID-19 infection forms

To explain the prevalence of asymptomatic SARS-CoV-2 infection forms, a hypothesis on a single virus mutation that causes changes in two important factors such as virus infectiousness and pathogenicity is proposed. According to this hypothesis, susceptible and asymptomatic forms affect the rate of change in infectiousness and pathogenicity, thereby influencing the rate of infectivity and the onset of a disease and as a result, altering the ratio of asymptomatic forms to symptomatic cases. With a mathematical model, constructed based on this hypothesis and identified using data from the first wave of COVID-19 in Saint-Petersburg, a correlation between changes in microbiological parameters of the model and changes in a ratio of asymptomatic forms to symptomatic cases is verified. It is concluded that single virus mutation may affect the ratio.

Single SARS Virus Mutation as a Possible Cause of the Predominance of Asymptomatic COVID-19 Infection Forms

Single SARS Virus Mutation as a Possible Cause of the Predominance of Asymptomatic COVID-19 Infection Forms

The effect of Psidium guajava Leaves’ extract for mild and asymptomatic corona virus Disease-19

COVID-19 is an emerging disease that attacks the respiratory and systemic systems. Various treatments have been used for COVID-19, but no antiviral agents seemed to be efficacious. Many medicinal plants are commonly used for viral infections in Indonesia, including the guajava leaf. The study aimed to determine the effects of Psidium guajava extract supplementation on inflammation markers of asymptomatic and mild COVID-19 patients. The conversion time of PCR results was also evaluated. This study was an experimental, single-blinded, randomized clinical trial (ClinicalTrials.gov: NCT04810728) comparing the efficacy of P. guajava extract at the dose of 1000 mg/8h on top of standard treatment with the standard treatment only for asymptomatic and mild COVID-19 subjects. The primary endpoints were neutrophil and lymphocyte percentages as well as the neutrophil/lymphocyte ratio (NLR) on day 7 of the treatment. The secondary endpoints were high-sensitivity c-reactive protein (hs-CRP) level, PCR-based conversion time, and recovery rate at weeks 2 and 4. A total of 90 subjects were enrolled, and there were 40 subjects in the P. guajava (experimental) group and 41 subjects in the control group who completed the research. On day 7, significantly lower percentage of neutrophil (52.4% vs 58.9%, p = 0.002), higher lymphocyte percentage (35.5%, vs 29.7%, p = 0.002), and lower NLR (1.5 vs 2.1, p = 0.001) were demonstrated in the experimental versus control group. The PCR-based conversion time was shorter (14 days vs 16 days, p < 0.001), and recovery rate at 2 and 4 weeks were higher (49% vs 27%, p = 0.03 and 100% vs 82%, p = 0.003, respectively) in the experimental group. There were no differences in the baseline characteristics. P. guajava extract supplementation reduced neutrophil and increased lymphocyte percentages which led to reduced NLR, accelerated PCR-based conversion time, and increased recovery rate in subjects with mild and asymptomatic COVID-19 infection.\\