Assessment of immune responses to a Comirnaty® booster following CoronaVac® vaccination in healthcare workers.

BACKGROUND: The immunological response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and immunisation is variable. OBJECTIVES: To describe the humoral immune response by correlating IgA and IgG antibodies with NAbs titration following CoronaVac® immunisation and an mRNA (Comirnaty®) booster among healthcare workers (HCWs) and to compare the cytokine and interleukin profiles between HCWs vaccinated with CoronaVac and coronavirus disease 2019 (COVID-19) infected patients. METHODS: Samples from 133 HCWs collected at 20 (T1) and 90 (T2) days after CoronaVac immunisation and 15 (T3) days after a booster dose with the Comirnaty vaccine were analysed for IgA and IgG EIA and neutralisation assay. Cytokine levels from vaccinated individuals at T1 day and COVID-19 patients were compared. FINDINGS: Neutralising antibodies (NAbs) were observed in 81.7% of participants at T1, but only 49.2% maintained detectable NAbs after 90 days. The booster dose increased NAbs response in all participants. The cytokines with the highest levels post-vaccination were IL-6 and MCP-1. The MCP-1, IL-18, and IFN- γ levels were higher in COVID-19 patients than in vaccinated HCWs, while IL-22 levels increased in the vaccinated HCWs group. MAIN CONCLUSIONS: The neutralisation titres in the T2 samples decreased, and antibody levels detected at T2 showed a more significant reduction than the neutralisation. The higher IL-22 expression in immunised individuals compared to those with COVID-19 suggests that IL-22 may be beneficial in protecting against severe disease.

Large-Scale Screening of Asymptomatic Persons for SARS-CoV-2 Variants of Concern and Gamma Takeover, Brazil.

We performed a large-scale severe acute respiratory syndrome coronavirus 2 screening campaign using 2 PCR-based approaches, coupled with variant genotyping, aiming to provide a safer environment for employees of Federal University in Curitiba, Brazil. We observed the rapid spread of the Gamma variant of concern, which replaced other variants in <3 months.

Intrauterine Transmission of SARS-CoV-2.

We documented fetal death associated with intrauterine transmission of severe acute respiratory syndrome coronavirus 2. We found chronic histiocytic intervillositis, maternal and fetal vascular malperfusion, microglial hyperplasia, and lymphocytic infiltrate in muscle in the placenta and fetal tissue. Placenta and umbilical cord blood tested positive for the virus by PCR, confirming transplacental transmission.

SARS-CoV-2 in asymptomatic pregnant women in South Brazil: RT-PCR and serological detection.

OBJECTIVES: This study aims to detect the SARS-CoV-2 infection prevalence in asymptomatic pregnant women. METHODS: A group of 195 asymptomatic pregnant women who attended the prenatal care outclinic and to the obstetric emergency department was tested concomitantly for SARS-CoV-2 by RT-PCR and serological tests. RESULTS: The virus was detected by RT-PCR in two (1.02%) cases and 17 (8.71%) patients had antibodies detected by immunochromatographic tests. CONCLUSIONS: Due to the high risk of this emerging infection in the health of pregnant women, fetuses and newborns, we suggest the universal screening of all pregnant women admitted to hospital through the combined method RT-PCR and serological.

Comparison of Cerebrospinal Fluid Biomarkers for Differential Diagnosis of Acute Bacterial and Viral Meningitis with Atypical Cerebrospinal Fluid Characteristics.

OBJECTIVE: Several cerebrospinal fluid (CSF) biomarkers are used to distinguish between acute bacterial meningitis (BM) and viral meningitis (VM). We compared the ability of lactate and glucose (GL) in CSF and the CSF/blood GL ratio to distinguish between acute BM and VM with typical and atypical CSF characteristics. METHODS: Three hundred and twenty-four CSF reports were included, which were distributed as the acute BM, VM, and normal control groups (n = 63, 139, and 122, respectively). RESULTS: Lactate level in the CSF of acute BM group was 4-fold higher than that in the acute VM and control groups (p < 0.0001). CSF lactate presented higher specificity (92%) and negative predictive value (94%) compared to CSF GL and CSF/blood GL ratio in distinguishing acute BM and VM. Definitive acute BM or VM with atypical CSF cell characteristics was observed in 23.2 and 21.6% of samples, respectively, and these groups showed reduced performance of characteristics of all CSF biomarkers. CSF lactate showed better operational characteristics than those of CSF GL and CSF/blood GL ratio, presenting the highest positive likelihood ratio, and thus aided in the differential diagnosis of VM with atypical CSF. CONCLUSION: The CSF lactate assay can be routinely used in laboratories as a rapid, automated, and easy method that is independent of lactate blood levels.

Human adenovirus meningoencephalitis: a 3-years' overview.

Human adenovirus (HAdV) has been recognized as a significant viral pathogen implicated in neurological diseases, particularly in immunocompromised patients. However, its involvement in meningoencephalitis remains unclear. The aim of this study was to investigate HAdV and other viral co-infections in the cerebrospinal fluid (CSF) of patients suspected of having either meningoencephalitis or encephalitis. A total of 373 CSF samples from patients under clinical suspicion of neurological viral infection were included in this study. HAdV was investigated by conventional or multiplex real-time PCR, for different time periods. The frequency of HAdV central nervous system (CNS) infection was 1.08%, predominating in female patients with a predisposing condition, and presented with HAdV encephalitis. HAdV CNS infection was found to occur during the months of autumn and winter. The frequency of HAdV detected in CSF positive samples increased after the change in the diagnostic method from conventional to multiplex real-time PCR. There were no specific NMRI or EEG characteristics and two CSF samples with HAdV encephalitis had normal CSF WBC count. There were two cases of co-infection with HIV; no other co-infections with enterovirus or herpes family viruses were detected. All patients had good outcome. Although HAdV is rarely observable in CNS infectious syndromes, it must be investigated particularly in immunocompromised patients.

High frequency of multiple HPV types detection in Fanconi anemia patients oral swabs.

BACKGROUND: Fanconi anemia (FA) is a rare genetic disease usually characterized by bone marrow failure and congenital malformations. The risk of development of malignancies in the oral cavity of FA patients, such as squamous cell carcinoma (SCC), increases significantly after a hematopoietic stem cells transplant (HSCT), and may also be linked with the presence of human papillomavirus (HPV) infections in the oral cavity. We investigated the prevalence and the HPV genotypes in oral mucosa of Brazilian FA patients. METHODS AND RESULTS: Oral swabs of 49 FA patients were collected. The median age of patients was 20 years (range 5-44) and 57% were over 18 years. Oral lesions were present in 20% of all patients, being 90% leukoplakia. HPV DNA was detected in 28% (14/49) of patients, and one of them also reported genital HPV lesions. Sixty-seven percent of all patients had undergone HSCT, including 12 patients (86%) of those with HPV results. Multiple HPV types were detected in 78% and 71% of HPV samples by Sanger sequencing and reverse hybridization methods, respectively. The most prevalent HPV types detected were 6, 11, 18, and 68. CONCLUSIONS: HPV prevalence in the oral mucosa of the assessed FA patients was higher than reported in the general population. Additional studies with collection of sequential samples are needed to know the natural history of the presence of multiple HPV types in these individuals and its association with the development of tumors, to evaluate the implementation of preventive measures, such as vaccination, and to guide early treatment.

Molecular characterization and clinical epidemiology of human respiratory syncytial virus (HRSV) A and B in hospitalized children, Southern Brazil.

Human respiratory syncytial virus (HRSV) is a major etiologic agent of pediatric respiratory infections. Genetic variability of its glycoprotein G enables HRSV to evade the immune response and determines its seasonal dissemination. This study reports genetic variability and clinical profiles of HRSV-infected patients from Southern Brazil. Seventy positive samples, 78% type A and 22% type B, were analyzed. Of the patients (median age, 6 months; interquartile range, 2-11 years), 16% had co-morbidities and 17% developed severe disease. The ON1 HRSV genotype first appeared in 2012, and patients infected with this genotype showed an increased tendency to develop severe disease.

Neurological and multiple organ involvement due to Paracoccidioides brasiliensis and HIV co-infection diagnosed at autopsy.

Paracoccidioidomycosis (PCM), caused by Paracoccidioides brasiliensis, is the most prevalent systemic mycosis among immunocompetent patients in Latin America; it is rare in immunocompromised patients. The estimated frequency of central nervous system (CNS) involvement in the HIV/PCM population was 2.5%. We report a case of HIV/P. brasiliensis co-infection, with neurological (NPCM) and multiple organ involvement, indicating a diagnosis of AIDS. PCM diagnosis was established during the autopsy. This is the first described case of HIV/P. brasiliensis co-infection with CNS involvement diagnosed at autopsy. In conclusion, the diagnosis of NPCM is challenging, and it must be considered in the differential diagnosis in HIV-positive patients who reside in or have visited areas in which the condition is endemic and who present with neurological symptoms.

A Retrospective Cross-Sectional Analysis of Viral SARI in Pregnant Women in Southern Brazil.

Pregnant women (PW) are at a higher risk of diseases and hospitalization from viral respiratory infections, particularly influenza and SARS-CoV-2, due to cardiopulmonary and immunological changes. This study assessed the impact of viral respiratory infections on PW hospitalized with severe acute respiratory infection (SARI) prior to the COVID-19 pandemic. It is a cross-sectional study with 42 PW and 85 non-pregnant women (NPW) admitted with SARI to two tertiary hospitals between January 2015 and December 2019. The rates of virus prevalence, SARI hospitalization, length of hospital stay, oxygen supplementation, intensive care unit (ICU) admission, and death were comparable between PW and NPW. A multivariate analysis showed that PW had a higher rate of viral SARI hospitalizations (OR = 2.37; 95% CI = 1.02-5.48) as compared to NPW, with the influenza virus being the most prevalent (aOR = 7.58; 95% CI = 1.53-37.66). The length of hospital stays (aOR = 0.83; 95% CI = 0.73-0.95) and admissions to the ICU (aOR = 0.028; 95% CI = 0.004-0.25) were lower in PW as compared to hospitalized NPW. The influenza virus had a greater impact on the frequency of SARI in the group of PW, and these had a better outcome than NPW due to the earlier antiviral treatment they received.

IgA antibody dynamics in healthcare workers after CoronaVac® vaccination and heterologous Comirnaty® booster dose.

BACKGROUND: This study is aimed at calculating the IgA antibody dynamic range in healthcare workers (HCWs) after immunization with CoronaVac® and Comirnaty® booster dose. METHODS: A total of 118 HCW serum samples from Southern Brazil were collected the day before the first vaccine dose (day 0) and + 20, + 40, + 110, + 200 days following the vaccine's first dose, and + 15 days after a Comirnaty® booster dose. Immunoglobulin A (IgA) was quantified using immunoassays for anti-S1 (spike) protein antibodies (Euroimmun, Lübeck, Germany). RESULTS: Seroconversion for the S1 protein occurred in 75 (63.56%) and 115 (97.47%) HCWs by day + 40 and day + 15 after the booster dose, respectively. There was an absence of IgA antibodies after the booster dose in two (1.69%) HCWs undergoing biannual rituximab administration and one (0.85%) HCW for no apparent reason. CONCLUSION: Complete vaccination showed a significant IgA antibody production response, and the booster dose considerably increased this response.

Influenza A, like Omicron SARS-CoV-2, Is Similarly Detected in Saliva or Nasopharyngeal Samples via RT-qPCR.

After the Coronavirus pandemic, the importance of virus surveillance was highlighted, reinforcing the constant necessity of discussing and updating the methods for collection and diagnoses, including for other respiratory viruses. Although the nasopharyngeal swab is the gold-standard sample for detecting and genotyping SARS-CoV-2 and Influenza viruses, its collection is uncomfortable and requires specialized teams, which can be costly. During the pandemic, non-invasive saliva samples proved to be a suitable alternative for SARS-CoV-2 diagnosis, but for Influenza virus the use of this sample source is not recognized yet. In addition, most SARS-CoV-2 comparisons were conducted before the Omicron variant emerged. Here, we aimed to compare Influenza A and Omicron RT-qPCR analysis of nasopharyngeal swabs and saliva self-collection in paired samples from 663 individuals. We found that both nasopharyngeal swab and saliva collection are efficient for the diagnosis of Omicron (including sub-lineages) and for Influenza A, with high sensitivity and accuracy (>90%). The kappa index is 0.938 for Influenza A and 0.905 for SARS-CoV-2. These results showed excellent agreement between the two samples reinforcing saliva samples as a reliable source for detecting Omicron and highlighting saliva as a valid sample source for Influenza detection, considering this cheaper and more comfortable alternative.

Antibody response following a Comirnaty booster dose in CoronaVac vaccinated individuals.

Serum samples from 106 health care workers were analyzed by enzyme-linked immunosorbent assay (ELISA) test 15 days after a booster dose. A total of 99% of the participants showed a significant increase in the anti-S1 IgG index. The significant humoral response was observed 15 days after the heterologous dose of Comirnaty in most the subjects, regardless of having comorbidities. The administration of a third booster dose is suggested 5 months after the second vaccine dose of the initial vaccine.

Dynamic of humoral response to SARS-CoV-2 anti-Nucleocapsid and Spike proteins after CoronaVac vaccination.

This study aimed to calculate the seroconversion rate and IgG antibody dynamic range of the CoronaVac vaccine in healthcare workers (HCWs) after immunization. Serum samples from 133 HCWs from Southern Brazil were collected 1 day before (Day 0) and +10, +20, +40, + 60, +110 days after administering the vaccine's first dose. Immunoglobulin G (IgG) was quantified using immunoassays for anti-N-protein (nucleocapsid) antibodies (Abbott, Sligo, Ireland) and for anti-S1 (spike) protein antibodies (Euroimmun, Lübeck, Germany). Seroconversion by day 40 occurred in 129 (97%) HCWs for the S1 protein, and in 69 (51.87%) HCWs for the N protein. An absence of IgG antibodies (by both methodologies), occurred in 2 (1.5%) HCWs undergoing semiannual rituximab administration, and also in another 2 (1.5%) HCWs with no apparent reason. This study showed that CoronaVac has a high seroconversion rate when evaluated in an HCW population.

Comparison of SARS-CoV-2 molecular detection in nasopharyngeal swab, saliva, and gargle samples.

The nasopharyngeal swab is a gold standard for detecting SARS-CoV-2. However, the inconvenience of this method compelled us to compare its efficiency with saliva and gargle samples, which we collected sequentially from 229 individuals. Saliva outperformed gargle samples, constituting a reliable RNA viral source with similar performance to nasopharyngeal samples.

SARS-CoV-2 Delta and Omicron Variants Surge in Curitiba, Southern Brazil, and Its Impact on Overall COVID-19 Lethality.

Screening efforts and genomic surveillance are essential tools to evaluate the course of the COVID-19 pandemic and assist the public healthcare system in dealing with an increasing number of infections. For the analysis of COVID-19 cases scenarios in Curitiba, Paraná, Brazil, we performed a diagnosis of positive cases, coupled with genotyping, for symptomatic and asymptomatic members of the Federal University of Paraná. We achieved over 1000 samples using RT-qPCR for diagnosis. The posterior genotyping allowed us to observe differences in the spread of strains in Curitiba, Brazil. The Delta variant was not associated with an infection wave, whereas the rapid Omicron variant spread became dominant in less than one month. We also evaluated the general vaccination coverage in the state, observing a striking reduction in lethality correlated to the vaccinated fraction of the population; although lower lethality rates were not much affected by the Omicron variant wave, the same effect was not translated in the number of infections. In summary, our results provide a general overview of the pandemic's course in Paraná State and how there was reduction in lethality after a combination of multiple infection waves and a large-scale vaccination program.

Severe acute respiratory syndrome coronavirus 2 infection among healthcare workers in a tertiary public hospital in Curitiba, Brazil.

BACKGROUND: We aimed to describe the clinical characteristics of coronavirus disease 2019 (COVID-19) among healthcare workers (HCWs) in Curitiba, Brazil. METHODS: Upper respiratory samples from 1077 HCWs were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using reverse transcription polymerase chain reaction from June 16, 2020 to December 9, 2020. RESULTS: Overall, 32.7% of HCWs were infected. The positivity rates in symptomatic and asymptomatic HCWs were 39.2% and 15.9%, respectively. Hospital departments categorized as high-risk for exposure had the highest number of infected HCWs. CONCLUSIONS: Early diagnosis and isolation of infected HCWs remain key in controlling SARS-CoV-2 transmission because HCWs in close contact with COVID-19 patients are more likely to be infected than those who are not.

Quantification of cerebrospinal fluid lactic acid in the differential diagnosis between HIV chronic meningitis and opportunistic meningitis.

BACKGROUND: Approximately 40% of HIV infected patients have chronic meningitis at various stages during the infection, 59% are asymptomatic. This is a diagnosis of exclusion and a confounding factor in cerebrospinal fluid (CSF) analysis, any other causes of chronic meningitis by opportunistic or co-infection must be ruled out. The aim of this study was to analyze CSF lactic acid (LA) as an adjuvant biomarker in chronic meningitis due to HIV. METHODS: CSF LA was quantified in 223 CSF samples by the Dimension AR (Dade Behring, Deerfield, IL, USA), distributed into nine groups: 1) HIV positive with an increase in CSF WBCs (n=17); 2) HIV positive with normal CSF (n=20); 3) enterovirus meningitis (n=33); 4) Herpesviridae meningoencephalitis (n=30); 5) fungal meningitis (n=25); 6) tuberculosis (TB) meningitis (n=17); 7) toxoplasmosis (n=18); 8) neurosyphilis (n=6); 9) control group (n=57). RESULTS: CSF LA (median; IQR) was higher in samples with TB meningitis (5.5; 2.9-7.5 mmol/L) and Cryptococcus neoformans meningitis (3.9; 2.7-5.8 mmol/L) compated with samples with HIV chronic meningitis (1.7; 1.4-1.9 mmol/L) and other groups (p ≤ 0.0001). For the diagnosis of HIV chronic meningitis, using a cut-off of 3.5 mmol/L, CSF LA showed high sensitivity and negative predictive value, although low specificity. CONCLUSIONS: CSF LA helps to discriminate between C. neoformans or TB meningitis and HIV chronic meningitis: CSF LA can be included with the methods currently used to identify these specific pathogens, though it does not replace them. It is rapid, inexpensive and easy to perform, and can be used in developing countries.

Clinical performance of amperometry compared with enzymatic ultra violet method for lactate quantification in cerebrospinal fluid.

OBJECTIVES: The differential diagnosis between acute bacterial meningitis (BM) and viral meningitis (VM) is crucial for treatment and prognosis. Cerebrospinal fluid (CSF) lactate (LA) is considered a good biomarker for differentiating BM from VM. The objective of this study was to compare the clinical performance of amperometry, which is not validated for measurement of LA in CSF samples, with a validated method (enzymatic ultra violet), for their ability to discriminate between acute BM and VM. METHODS: It was a retrospective, descriptive comparative study, 320 CSF reports were included; LA was quantified in CSF using either Dimension AR machine (Dade Behring) or amperometry (RAPID Point 500, Siemens). All samples with bacteria (n=54) or virus (n=139) identified, compared with a control with normal CSF (n=127). RESULTS: CSF LA levels were comparable for amperometry or enzymatic methods on each group studied, in a wide range of LA levels; it was capable to distinguish BM from VM independent of the method used to quantify. CONCLUSIONS: The findings support the use of the amperometric method in measuring LA concentrations in CSF in a wide range of values. Amperometry is a less expensive method, validated for blood, easily available in small laboratories including in limited resources countries.