Covert cases of Severe Acute Respiratory Syndrome Coronavirus 2: An obscure but present danger in regions endemic for Dengue and Chikungunya viruses

Complexity of the COVID-19 pandemic in Maringá

While extensive literature exists on the COVID-19 pandemic at regional and national levels, understanding its dynamics and consequences at the city level remains limited. This study investigates the pandemic in Maringá, a medium-sized city in Brazil's South Region, using data obtained by actively monitoring the disease from March 2020 to June 2022. Despite prompt and robust interventions, COVID-19 cases increased exponentially during the early spread of COVID-19, with a reproduction number lower than that observed during the initial outbreak in Wuhan. Our research demonstrates the remarkable impact of non-pharmaceutical interventions on both mobility and pandemic indicators, particularly during the onset and the most severe phases of the emergency. However, our results suggest that the city's measures were primarily reactive rather than proactive. Maringá faced six waves of cases, with the third and fourth waves being the deadliest, responsible for over two-thirds of all deaths and overwhelming the local healthcare system. Excess mortality during this period exceeded deaths attributed to COVID-19, indicating that the burdened healthcare system may have contributed to increased mortality from other causes. By the end of the fourth wave, nearly three-quarters of the city's population had received two vaccine doses, significantly decreasing deaths despite the surge caused by the Omicron variant. Finally, we compare these findings with the national context and other similarly sized cities, highlighting substantial heterogeneities in the spread and impact of the disease.

Seroprevalence of SARS-CoV-2 in Brazil: A systematic review and meta-analysis

OBJECTIVES

To summarize the data on SARS-CoV-2 seroprevalence surveys conducted in Brazil before the introduction of vaccines METHODS: The authors conducted a systematic review and meta-analysis on the seroprevalence of SARS-CoV-2 infection in Brazil. The present review followed the PRISMA guidelines. The authors searched Medline, Embase, and LILACS databases for serologic surveys conducted in the Brazilian population, in the period from 01/10/2019 to 07/11/2021, without language restrictions. The authors included studies that presented data concerning SARS-CoV-2 antibodies seroprevalence in Brazil and had a sample size ≥50 individuals. Considering the expected heterogeneity between studies, all analyses were performed using the random effects model, and heterogeneity was assessed using the I² statistic RESULTS: Of 586 publications identified in the initial searches, 54 were included in the review and meta-analysis, which contained the results of 135 surveys, with 336,620 participants. The estimated seroprevalence was 11.0%, ranging from 1.0% to 83.0%, with a substantial heterogeneity (I² = 99.55%). In subgroup analyses, the authors observed that the prevalence of SARS-CoV-2 antibodies was 13.0% in blood donors, 9.0% in the population-based surveys, 13% in schoolchildren, and 11.0% in healthcare workers.

CONCLUSIONS

Seroprevalence increases over time. Large differences were observed among the regions of the country. It was higher in the Northern region, decreasing towards the South. The present results may contribute to the analysis of the spread of SARS-CoV-2 infection in the Brazilian population before vaccination, one of the factors that may be influencing the clinical presentation of COVID-19 cases related to the new variants, as well as the effectiveness of the vaccination program.

COVID-19 and dengue coinfection in Latin America: A systematic review

Introduction

Methods

Results

Conclusion

Breastfeeding Practices Before and During the COVID-19 Pandemic in Fortaleza, Northeastern Brazil

BACKGROUND

Physical distancing associated with the COVID-19 pandemic may lead to suboptimal maternal mental health, social support after birth, and infant feeding practices.

RESEARCH AIMS

To compare breastfeeding prevalence in participants who were pregnant at a time when strict physical distancing measures were imposed in Fortaleza, the capital of Ceará state, Brazil, with the pre-pandemic breastfeeding levels, and to assess the association of breastfeeding prevalence with maternal common mental disorders, and sociodemographic and health predictors.

METHOD

A cross-sectional prospective two-group comparison design using two population-based surveys was carried out in Fortaleza before and after the pandemic. Participants (n = 351) who had a live birth in Fortaleza in July or August 2020, and participants (n = 222) who had a child younger than 12 months in 2017 were surveyed. Crude and adjusted multinomial logistic regressions with robust variance were used to estimate risk ratios and 95% confidence intervals (CI).

RESULTS

Similar prevalence of exclusive breastfeeding were observed in 2021 (8.1%) and 2017 (8.5%; p = .790). An increase in predominant (2.2% vs. 13.4%; p < .001) and a decrease in complementary breastfeeding (64.0% vs. 48.4%; p = .037) was observed in 2021, compared to 2017. The prevalence of maternal common mental disorders also increased in 2021 (17.6% vs. 32.5%, p < .001). No statistically significant associations were found between breastfeeding patterns, maternal common mental disorders, and other predictors in 2017 or 2021.

CONCLUSIONS

Participants who delivered during the COVID-19 pandemic delayed solid foods introduction and breastfed predominantly longer than participants during the pre-pandemic period. While common mental disorders significantly increased, they were not associated with differences in breastfeeding.

Neurological Complications of Dengue Fever

PURPOSE OF REVIEW

To discuss the neurological complications of dengue virus (DENV) infection and their pathogenesis.

RECENT FINDINGS

Include recognition of the four different serotypes of DENV and their epidemiology as well as recognition of the expanded dengue syndrome encompassing multisystem involvement in the severe form of the disease including involvement of the central nervous system (CNS). DENV is a neurotropic virus with the ability to infect the supporting cells of the CNS. Neural injury during the acute stage of the infection results from direct neuro-invasion and/or the phenomenon of antibody-dependent enhancement, resulting in plasma leakage and coagulopathy. Immune mechanisms have been implicated in the development of the delayed neurological sequelae through molecular mimicry. A myriad of neurological syndromes has been described as a result of the involvement of the CNS, the peripheral nervous system (PNS), or both. Neurological manifestations in DENV infection are increasingly being recognized, some of which are potentially fatal if not treated promptly. DENV encephalopathy and encephalitis should be considered in the differential diagnosis of other acute febrile encephalopathies, autoimmune encephalitides, and in cases of encephalopathy/encephalitis related to SARS-CoV2 infection, especially in dengue-endemic areas. Acute disseminated encephalomyelitis (ADEM) may be occasionally encountered. Clinicians should be knowledgeable of the expanded dengue syndrome characterized by the concurrent compromise of cardiac, neurological, gastrointestinal, renal, and hematopopoietic systems. Isolated cranial nerve palsies occur rather uncommonly and are often steroid responsive. These neuropathies may result from the direct involvement of cranial nerve nuclei or nerve involvement or may be immune-mediated. Even if the diagnosis of dengue is confirmed, it is absolutely imperative to exclude other well-known causes of isolated cranial nerve palsies. Ischemic and hemorrhagic strokes may occur following dengue fever. The pathogenesis may be beyond the commonly observed thrombocytopenia and include cerebral vasculitis. Involvement of ocular blood vessels may cause maculopathy or retinal hemorrhages. Posterior reversible encephalopathy syndrome (PRES) is uncommon and possibly related to dysregulated cytokine release phenomena. Lastly, any patient developing acute neuromuscular weakness during the course or within a fortnight of remission from dengue fever must be screened for acute inflammatory demyelinating polyneuropathy (AIDP), hypokalemic paralysis, or acute myositis. Rarely, a Miller-Fisher-like syndrome with negative anti-GQ1b antibody may develop.

Potential impact of SARS COV-2 infection on the performance of serological assays used to diagnose arboviral diseases

Background

The COVID-19 pandemic caused by SARS-CoV-2 was first described in December 2019, in China. In addition, there has also been an increase in arboviral infections in recent years. As both infections have similar symptoms, misdiagnosis may occur if both outbreaks occur at the same time.

Objective

Our objective was to assess the potential impact of SARS-CoV-2 infection on diagnostic assays used for arboviral diseases.

Materials and methods

We conducted this study by testing samples obtained during the precovid phase (before November 2019) and during the covid period (after February 2020). Samples were further grouped as those with acute febrile illness (AFI) and those without. All samples were tested for anti SARS-CoV-2 Ab, Chikungunya and Dengue specific IgM antibodies to evaluate potential serological cross-reactions between COVID-19 and Arbovirus specific antibodies.

Results

One sample from the 62 cases of AFI during the pre-covid phase showed seropositivity for SARS-CoV-2 antibodies. Also, in asymptomatic individuals, arboviral seropositivity was significantly higher in the COVID period samples (22%) compared to pre-COVID samples (3%).

Conclusion

Due to similar clinical symptoms and cross reactions in both infections, relying solely on serological testing for arboviral diagnosis may be less sensitive; other clinical and laboratory parameters may be required.

Detection of SARS-CoV-2 antibodies in febrile patients from an endemic region of dengue and chikungunya in Peru

Introduction

The rapid expansion of the novel SARS-CoV-2 virus has raised serious public health concerns due to the possibility of misdiagnosis in regions where arboviral diseases are endemic. We performed the first study in northern Peru to describe the detection of SARS-CoV-2 IgM antibodies in febrile patients with a suspected diagnosis of dengue and chikungunya fever.

Materials and methods

A consecutive cross-sectional study was performed in febrile patients attending primary healthcare centers from April 2020 through March 2021. Patients enrolled underwent serum sample collection for the molecular and serological detection of DENV and CHIKV. Also, serological detection of IgM antibodies against SARS-CoV-2 was performed.

Results

464 patients were included during the study period, of which (40.51%) were positive for one pathogen, meanwhile (6.90%) presented co-infections between 2 or more pathogens. The majority of patients with monoinfections were positive for SARS-CoV-2 IgM with (73.40%), followed by DENV 18.09% and CHIKV (8.51%). The most frequent co-infection was DENV + SARS-CoV-2 with (65.63%), followed by DENV + CHIKV and DENV + CHIKV + SARS-CoV-2, both with (12.50%). The presence of polyarthralgias in hands (43.75%, p<0.01) and feet (31.25%, p = 0.05) were more frequently reported in patients with CHIKV monoinfection. Also, conjunctivitis was more common in patients positive for SARS-CoV-2 IgM (11.45%, p<0.01). The rest of the symptoms were similar among all the study groups.

Conclusion

SARS-CoV-2 IgM antibodies were frequently detected in acute sera from febrile patients with a clinical suspicion of arboviral disease. The presence of polyarthralgias in hands and feet may be suggestive of CHIKV infection. These results reaffirm the need to consider SARS-CoV-2 infection as a main differential diagnosis of acute febrile illness in arboviruses endemic areas, as well as to consider co-infections between these pathogens.

The Role of COVID-19 Vaccinal Status in Admitted Children during OMICRON Variant Circulation in Rio de Janeiro, City-Preliminary Report

Objective: To evaluate COVID-19 vaccination status in admitted children in 2020−2021 and during the OMICRON variant circulation (2022), a period when children older than 12 years of age had received two doses of COVID-19 vaccines. Design: An observational retrospective study. Patients with confirmed COVID-19 were compared in two different periods: 2020−2021 when adolescents aged 12−18 years had not received the complete COVID-19 vaccine, and 2022 when children older than 12 years had received the complete Pfizer-BioNTech vaccine scheme. Setting: Two pediatric hospitals in Rio de Janeiro city. Patients: Children aged < 18 years with confirmed COVID-19. Intervention: None. Main outcome: Vaccination status for COVID-19 on admission. Results: In total, 300 patients were admitted with confirmed COVID-19 (240 in 2020−2021 and 60 in 2022). The distribution of patients according to the age-groups was: 0−2 years (33.3% in 2020−2021 and 53.4% in 2022), 2−5 years (21.7% in 2020−2021 and 10% in 2022), 5−11 years (29.2% in 2020−2021 and 28.3% in 2022), and 12−18 years (15.8% in 2020−2021 and 8.3% in 2022) (p = 0.076). The median length of stay was six days in 2020−2021 and six days in 2022 (p = 0.423). We verified six deaths in the first analysis period and one death in the second one (p = 0.894). Of the 60 children admitted in 2022, 58 (96.7%) did not receive the complete COVID-19 vaccine scheme available. Conclusions: We verified in a “real-world condition” the ability of the Pfizer-BioNTech vaccine to prevent hospitalization in children over 12 years of age.

Impact of the COVID-19 Pandemic on Infectious Diseases in Brazil: A Case Study on Dengue Infections

Brazil is known for being a breeding ground for emerging infectious diseases (EIDs), such as Zika, dengue, and chikungunya. Given that it has been one of the countries most affected by the SARS-CoV-2 pandemic, this article aims to analyze the impact that the COVID-19 pandemic has had on the burden of infectious diseases in Brazil, especially that of dengue. Brazil is a unique territory with a heterogeneous population living in a tropical, wet climate favorable to infectious diseases. In addition, despite being one of the largest emerging economies in the world, the country has been exposed to political instability and a public health system that suffers from large funding shortfalls and a lack of coherent regulation. The findings from this study are multilayered. Firstly, as cases of COVID-19 rose at the start of the pandemic, cases of dengue declined drastically. This may be due, in part, to factors such as seasonal climate and distancing measures. Furthermore, the findings indicate that the diversion of resources away from dengue and other infectious diseases, and mobilization for COVID-19 testing and treatment, likely resulted in a serious underreporting of dengue. While Brazil has incorporated some of the lessons learned from past EID experience in responding to the COVID-19 pandemic, the analysis highlights how the country's structural problems present pitfalls in the epidemiological fight. It was concluded that in a country such as Brazil, where infectious disease outbreaks are only a matter of time, pandemic preparedness should be prioritized over pandemic response.

The Pandemic Experience in Southeast Asia: Interface Between SARS-CoV-2, Malaria, and Dengue

Southeast Asia (SEA) emerged relatively unscathed from the first year of the global SARS-CoV-2 pandemic, but as of July 2021 the region is experiencing a surge in case numbers primarily driven by Alpha (B.1.1.7) and subsequently the more transmissible Delta (B.1.617.2) variants. While initial disease burden was mitigated by swift government responses, favorable cultural and societal factors, the more recent rise in cases suggests an under-appreciation of prior prevalence and over-appreciation of possible cross-protective immunity from exposure to endemic viruses, and highlights the effects of vaccine rollout at varying tempos and of variable efficacy. This burgeoning crisis is further complicated by co-existence of malaria and dengue in the region, with implications of serological cross-reactivity on interpretation of SARS-CoV-2 assays and competing resource demands impacting efforts to contain both endemic and pandemic disease.

Competitive ELISA for a serologic test to detect dengue serotype-specific anti-NS1 IgGs using high-affinity UB-DNA aptamers

Serologic tests to detect specific IgGs to antigens related to viral infections are urgently needed for diagnostics and therapeutics. We present a diagnostic method for serotype-specific IgG identification of dengue infection by a competitive enzyme-linked immunosorbent assay (ELISA), using high-affinity unnatural-base-containing DNA (UB-DNA) aptamers that recognize the four categorized serotypes. Using UB-DNA aptamers specific to each serotype of dengue NS1 proteins (DEN-NS1), we developed our aptamer-antibody sandwich ELISA for dengue diagnostics. Furthermore, IgGs highly specific to DEN-NS1 inhibited the serotype-specific NS1 detection, inspiring us to develop the competitive ELISA format for dengue serotype-specific IgG detection. Blood samples from Singaporean patients with primary or secondary dengue infections confirmed the highly specific IgG detection of this format, and the IgG production initially reflected the serotype of the past infection, rather than the recent infection. Using this dengue competitive ELISA format, cross-reactivity tests of 21 plasma samples from Singaporean Zika virus-infected patients revealed two distinct patterns: 8 lacked cross-reactivity, and 13 were positive with unique dengue serotype specificities, indicating previous dengue infection. This antigen-detection ELISA and antibody-detection competitive ELISA combination using the UB-DNA aptamers identifies both past and current viral infections and will facilitate specific medical care and vaccine development for infectious diseases.

Decrypting the role of predicted SARS-CoV-2 miRNAs in COVID-19 pathogenesis: A bioinformatics approach

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is a highly transmissible virus causing the ongoing global pandemic, COVID-19. Evidence suggests that viral and host microRNAs play pivotal roles in progression of such infections. The decisive impact of viral miRNAs and their putative targets in modulating the transcriptomic profile of its host, however remains unexplored. We hypothesized that the SARS-CoV-2 derived miRNAs can potentially play a contributory role in its pathogenicity and aid in its survival. A series of computational tools predicted 34 SARS-CoV-2 encoded miRNAs and their putative targets in the host. Immune and apoptotic pathways were identified as most enriched pathways. Further investigation using a dataset of SARS-CoV-2 infected cells (available from public repository- GSE150392) revealed that 46 genes related to immune and apoptosis-related functions were deregulated. Of these 46 genes, 42 genes were identified to be significantly up-regulated and 4 genes were down-regulated. In silico analysis revealed all of the these significantly down-regulated genes to be putative targets of 9 out of 34 of our predicted viral miRNAs. Overall, 123 out of 324 genes that are differentially regulated in SARS-CoV2 infected cells, and also identified as putative targets of viral miRNAs, were found to be significantly down-regulated. KEGG pathway analysis using these genes revealed p53 signaling as the most enriched pathway – a pathway that is known to influence immune responses. This study thus provides the theoretical foundation for the underlying molecular mechanisms involved in progression of viral pathogenesis.