Effectiveness of mass dengue vaccination with CYD-TDV (Dengvaxia®) in the state of Paraná, Brazil: integrating case-cohort and case-control designs.

Background: CYD-TDV (Dengvaxia®) was the first dengue vaccine approved, launched in Brazil in 2015 for individuals aged 9-44 years. We aimed to estimate the effectiveness of CYD-TDV in preventing symptomatic dengue cases during a campaign targeting individuals aged 15-27 years in selected municipalities in Paraná, Brazil. Additionally, we examined whether a history of dengue, as recorded by the surveillance system, modified the vaccine's effectiveness. Methods: We conducted a case-cohort analysis comparing the frequency of vaccination, with at least one dose of CYD-TDV, in individuals with dengue confirmed by RT-PCR, identified by the surveillance system during 2019 and 2020, with the vaccination coverage in the target population. Moreover, in a case-control design using weighted controls, we assessed the documented history of dengue as a modifier of the vaccine's effectiveness. We used a logistic random-effects regression model, with data clustered in municipalities and incorporating covariates such as the incidence of dengue before the campaign, age, and sex. We calculated vaccine effectiveness (VE) as (1-relative risk) x 100%. Findings: 1869 dengue cases were identified, which had a vaccination frequency significantly lower than the overall vaccination coverage in the target population (50.3% vs. 57.2%, respectively; overall VE: 21.3%; 95% confidence interval [CI]: 13.4%-28.4%). In individuals with a documented history of dengue, vaccination had a VE of 71% (95% CI: 58%-80%) in reducing the incidence of dengue. However, vaccination was not associated with a significant reduction in the overall dengue case risk in individuals without a documented history of dengue (VE: 12%; 95% CI: -21% to 36%). In this last stratum, vaccination was associated with reduced cases due to DENV-1 and DENV-4, but an excess of DENV-2 cases. Interpretation: Vaccination led to a significant reduction in reported dengue cases within the target population. The case-control design suggested that this reduction was primarily driven by the benefits observed in individuals with a documented history of dengue. In endemic regions with limited serological testing facilities, a previous history of dengue diagnosis recorded by epidemiological surveillance could be used to triage candidates for CYD-TDV vaccination. Funding: Research supported by Sanofi.

Clinical and microbiological profile of health care-associated infections in a tertiary hospital: Comparison between a cohort of hospitalized patients during prepandemic and COVID-19 pandemic periods.

BACKGROUND: During the COVID-19 pandemic, health service practices underwent significant changes, impacting the occurrence of health care-associated infections (HAIs). This study presents the epidemiology of bacterial infections and compares clinical data on nosocomial infections in hospitalized patients before and during the pandemic. METHODS: A unicentric, observational, retrospective cohort study was conducted with descriptive analyses on the microorganism identification and resistance profile. Patient's clinical data who had hospital-acquired infection (HAI), during their hospitalization in a tertiary hospital before and during the COVID-19 pandemic was compared by descriptive and inferential analyses. RESULTS: A total of 1,581 bacteria were isolated from 1,183 hospitalized patients. Among patients coinfected with COVID-19, there was a statistically significant increase in HAI-related deaths (P < .001) and HAI caused by multidrug-resistant organisms (P < .001), mainly by Acinetobacter baumannii and Staphylococcus aureus. A higher odds ratio of HAI-related deaths compared to the prepandemic period was observed (odds ratio 6.98 [95% confidence interval 3.97-12.64]). CONCLUSIONS: The higher incidence of multidrug-resistant bacteria and increased deaths due to HAI, especially in patients with COVID-19 coinfection, might be related to various factors such as increased workload, broad-spectrum antibiotic use, and limited resources. The pandemic has changed the profile of circulating bacteria and antimicrobial resistance. Prevention strategies should be considered to reduce the impact of these infections.

Predictors of Severity of Influenza-Related Hospitalizations: Results From the Global Influenza Hospital Surveillance Network (GIHSN).

BACKGROUND: The Global Influenza Hospital Surveillance Network (GIHSN) has since 2012 provided patient-level data on severe influenza-like-illnesses from >100 participating clinical sites worldwide based on a core protocol and consistent case definitions. METHODS: We used multivariable logistic regression to assess the risk of intensive care unit admission, mechanical ventilation, and in-hospital death among hospitalized patients with influenza and explored the role of patient-level covariates and country income level. RESULTS: The data set included 73 121 patients hospitalized with respiratory illness in 22 countries, including 15 660 with laboratory-confirmed influenza. After adjusting for patient-level covariates we found a 7-fold increase in the risk of influenza-related intensive care unit admission in lower middle-income countries (LMICs), compared with high-income countries (P = .01). The risk of mechanical ventilation and in-hospital death also increased by 4-fold in LMICs, though these differences were not statistically significant. We also find that influenza mortality increased significantly with older age and number of comorbid conditions. Across all severity outcomes studied and after controlling for patient characteristics, infection with influenza A/H1N1pdm09 was more severe than with A/H3N2. CONCLUSIONS: Our study provides new information on influenza severity in underresourced populations, particularly those in LMICs.

Assessing the impact of the Gamma variant on COVID-19 patient admissions in a southern Brazilian tertiary hospital-A comparison of dual pandemic phases.

Since the first case of COVID-19, Brazil has undergone infection waves with distinct characteristics. The description of new variants has alerted the emergence of more contagious or virulent viruses. The variant of concern Gamma emerged in Brazil and caused an epidemic wave, but its spread outside the country was limited. We report the clinical-epidemiological profile of hospitalized patients with COVID-19 by comparing two periods. A retrospective cohort study was performed. The primary outcome was to assess individuals with COVID-19 admitted in wards and intensive care units at the academic hospital of the Federal University of Parana (CHC-UFPR) between March 2020 and July 2021, correlating demographic, clinical-epidemiologic, and survival data with the most prevalent viral variant found in each period. We used Kaplan-Meier analysis to estimate the probability of survival and ROC curves to evaluate laboratory tests to find a cutoff point for poor outcomes. Data from 2,887 individuals were analyzed, 1,495 and 1,392 from the first and second periods, respectively. Hospitalization predominated among males in both periods, and the median age was significantly lower in the second one. The frequency of comorbidities was similar. Various demographic factors, clinical assessments, and laboratory tests were examined in relation to greater severity. When comparing the two periods, we observed predominance of the Wild virus during the first wave and the Gamma variant during the second, with no significant difference in outcomes. The findings suggest that despite the association of many factors with increased severity, the temporal variation between the two periods did not result in a notable divergence in the measured outcomes. The COVID-19 pandemic has lasted for a long time, with periods marked by peaks of cases, often caused by the emergence of viral variants, resulting in higher infection rates and rapid dissemination but, for variant Gamma, no apparent greater virulence.

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.

Analysis of Clostridioides difficile Infection in Children with Diarrhea in Two Hospitals in Southern Brazil.

Clostridioides difficile infection (CDI) has been increasingly observed in children, but there is a lack of epidemiological and molecular data on CDI in Latin America. This prospective cohort study aimed to investigate the role of CDI in children with diarrhea. It included 105 children with antimicrobial-associated diarrhea (AAD) and analyzed the molecular characteristics of strains isolated from two hospitals in southern Brazil between 2017 and 2020. Fecal samples from the participants were tested for glutamate dehydrogenase (GDH) and A/B toxins using a rapid enzyme immunoassay. GDH-positive samples underwent automated real-time polymerase chain reaction and toxigenic culture. Toxigenic C. difficile isolates were selected for whole genome sequencing. Out of the 105 patients, 14 (13.3%) met the criteria for CDI. Children with a history of previous CDI and the presence of mucus in their stool were more likely to have CDI. Metronidazole was the most used treatment (71.4%), and three patients (23.1%) experienced CDI recurrence (rCDI). Although the number of sequenced isolates was limited, a wide diversity of sequence types (ST) was observed. In addition to toxin genes (tcdA, tcdB, cdtA, and cdtB), the isolates also exhibited virulence factors involved in adhesion (cwp66, groEL, slpA, fbpA/fbp68) and immune evasion (rmlA, rmlB, rmlC, gnd, rfbA-1), along with multiple resistance factors (gyrA mutation, norA, ermB, dfrF, and vanG). These findings highlight the prevalence and recurrence of CDI among hospitalized children. Longitudinal studies are needed to better understand the characteristics of CDI-associated diarrhea and its impact on the healthcare system in this population.

Development of an anti-SARS-CoV-2 monoclonal antibody panel and its applicability as a reagent in high-throughput fluorescence reduction neutralization and immunohistochemistry assays.

Since its emergence in late 2019, coronavirus disease 2019 (COVID-19) has caused millions of deaths and socioeconomic losses. Although vaccination significantly reduced disease mortality, it has been shown that protection wanes over time, and that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) may escape vaccine-derived immunity. Therefore, serological studies are necessary to assess protection in the population and guide vaccine regimens. A common measure of protective immunity is the presence of neutralizing antibodies (nAbs). However, the gold standard for measuring nAbs (plaque reduction neutralization test, or PRNT) is laborious and time-consuming, limiting its large-scale applicability. We developed a high-throughput fluorescence reduction neutralization assay (FRNA) to detect SARS-CoV-2 nAbs. Because the assay relies on immunostaining, we developed and characterized monoclonal antibodies (mAbs) to lower costs and reduce the assay's vulnerability to reagent shortages. Using samples of individuals vaccinated with COVID-19 and unvaccinated/pre-pandemic samples, we showed that FRNA results using commercial and in-house mAbs strongly correlated with those of the PRNT method while providing results in 70% less time. In addition to providing a fast, reliable, and high-throughput alternative for measuring nAbs, the FRNA can be easily customized to assess SARS-CoV-2 VOCs. Additionally, the mAb we produced was able to detect SARS-CoV-2 in pulmonary tissues by immunohistochemistry assays.

Age Differences in Comorbidities, Presenting Symptoms, and Outcomes of Influenza Illness Requiring Hospitalization: A Worldwide Perspective From the Global Influenza Hospital Surveillance Network.

Background: The Global Influenza Hospital Surveillance Network (GIHSN) was established in 2012 to conduct coordinated worldwide influenza surveillance. In this study, we describe underlying comorbidities, symptoms, and outcomes in patients hospitalized with influenza. Methods: Between November 2018 and October 2019, GIHSN included 19 sites in 18 countries using a standardized surveillance protocol. Influenza infection was laboratory-confirmed with reverse-transcription polymerase chain reaction. A multivariate logistic regression model was utilized to analyze the extent to which various risk factors predict severe outcomes. Results: Of 16 022 enrolled patients, 21.9% had laboratory-confirmed influenza; 49.2% of influenza cases were A/H1N1pdm09. Fever and cough were the most common symptoms, although they decreased with age (P < .001). Shortness of breath was uncommon among those <50 years but increased with age (P < .001). Middle and older age and history of underlying diabetes or chronic obstructive pulmonary disease were associated with increased odds of death and intensive care unit (ICU) admission, and male sex and influenza vaccination were associated with lower odds. The ICU admissions and mortality occurred across the age spectrum. Conclusions: Both virus and host factors contributed to influenza burden. We identified age differences in comorbidities, presenting symptoms, and adverse clinical outcomes among those hospitalized with influenza and benefit from influenza vaccination in protecting against adverse clinical outcomes. The GIHSN provides an ongoing platform for global understanding of hospitalized influenza illness.

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.

Laboratory diagnosis of Clostridioides difficile infection in symptomatic patients: what can we do better?

The laboratory diagnosis of Clostridioides difficile infection (CDI) is challenging since this bacteria may be detected in healthy people and toxin production detection is not sensitive enough to be used alone. Thus, there is no single test with adequate sensitivity and specificity to be used in laboratory diagnosis. We evaluated the performance of tests used in the diagnosis of CDI in symptomatic patients with risk factors in hospitals in southern Brazil. Enzyme immunoassays (EIA) for glutamate dehydrogenase antigen (GDH) and toxins A/B, real-time polymerase chain reaction (qPCR), GeneXpert system, and a two-step algorithm comprising GDH/TOXIN EIA performed simultaneously followed by GeneXpert for outliers were evaluated. Toxigenic strain in stool culture was considered CDI positive (gold standard). Among 400 samples tested, 54 (13.5%) were positive for CDI and 346 (86.5%) were negative. The diagnosis of the two-step algorithm and qPCR had an excellent performance with an accuracy of 94.5% and 94.2%, respectively. The Youden index showed that GeneXpert as a single test (83.5%) and the two-step algorithm (82.8%) were the most effective assays. Diagnosing CDI and non-CDI diarrhea could be successfully attained by the combination of clinical data with accuracy of laboratory tests.

Genetic Diversity of Norovirus in Children with Acute Gastroenteritis in Southwest Nigeria, 2015-2017.

Norovirus (NoV) is a leading cause of viral gastroenteritis globally, especially in children below five years. Epidemiological studies on the diversity of NoV in middle- and low-income countries, including Nigeria, are limited. This study aimed to determine the genetic diversity of NoV in children below five years with acute gastroenteritis at three hospitals in Ogun State, Nigeria. A total of 331 fecal samples were collected from February 2015 to April 2017, while 175 were randomly selected and analyzed using RT-PCR, partial sequencing and phylogenetic analyses of both the polymerase (RdRp) and capsid (VP1) genes. NoV was detected in 5.1% (9/175; RdRp) and 2.3% (4/175; VP1) of samples, with 55.6% (5/9) co-infection with other enteric viruses. A diverse genotype distribution was identified, and GII.P4 was the dominant RdRp genotype detected (66.7%), with two genetic clusters, followed by GII.P31 (22.2%). The rare GII.P30 genotype (11.1%) was detected at a low rate for the first time in Nigeria. Based on the VP1 gene, GII.4 was the dominant genotype (75%), with two variants, Sydney 2012 and possibly New Orleans 2009, co-circulating during the study. Interestingly, both intergenotypic, GII.12(P4) and GII.4 New Orleans(P31), and intra-genotypic, GII.4 Sydney(P4) and GII.4 New Orleans(P4), putative recombinant strains were observed. This finding suggests the first likely report of GII.4 New Orleans(P31) in Nigeria. In addition, GII.12(P4) was first described in Africa and globally in this study, to the best of our knowledge. This study provided insights into the genetic diversity of NoV circulating in Nigeria, which would be useful for ongoing and future vaccine design and monitoring of emerging genotypes and recombinant strains.

Respiratory syncytial virus: host genetic susceptibility and factors associated with disease severity in a cohort of pediatric patients.

BACKGROUND: Respiratory syncytial virus (RSV) infections are the leading cause of hospitalization in young children. We assessed the epidemiology, severity, clinical characteristics, molecular profile and genetic factors of RSV infections compared to acute respiratory illness (ARI) caused by other respiratory viruses. METHODS: Prospective cohort study was conducted from 2017 to 2018 with children under 2 years old hospitalized with ARI. Detection of respiratory viruses was carried out using RT-PCR. RSVs were genotyped via nucleotide sequencing, and host interleukin 28B (IL28B) single nucleotide polymorphisms (SNPs) were determined using SNP TaqMan® Genotyping Assays. RESULTS: A total of 468 children were included; 288 (61.5%) had an infection by a single virus: 202 (70.1%) cases by RSV followed by rhinovirus 36 (12.5%) and influenza 16 (5.6%). Of the RSV cases, 36% were genotyped with a higher prevalence of RSV B (62.1%). The RSV group presented median age of 2.7 months (1.6-6.8), higher frequency in: intensive care unit admission (p = 0.004), mechanical ventilation use (p = 0.018), wheezing (p < 0.001), antimicrobial use (p < 0.001) and low oxygen saturation (p < 0.001). Prematurity (27.2%) was the most frequent comorbidity. RSV patients without comorbidities demonstrated a higher frequency in the combination of IL28B rs12979860 CT/IL28B rs8099917 TG and IL28B rs12979860 TT/IL28B rs8099917 TT genotypes. Viral coinfection was detected in 27 (5.7%) children, with the most frequent being RSV and rhinovirus (14.2%). CONCLUSIONS: This study highlighted the burden of RSV infection in children under 2 years of age, without comorbidities, with a higher need for pediatric ICU admission. Some IL28B allele combinations had a significant association with RSV frequency of infections.

Prevalence and Seasonality of Clostridiodes difficile over 12 Years at a Tertiary Hospital in Brazil.

Clostridioides difficile is the main pathogen responsible for antibiotic-associated diarrhea in adults. Besides its challenging diagnosis, C. difficile infection (CDI) causes substantial morbidity and mortality. Commercially, there are assays with different targets and performances in sensitivity and specificity. The objectives of this study were to: (1) evaluate the prevalence and seasonal variability of CDI rates at a tertiary hospital in southern Brazil over 12 years and (2) determine the impact of using a two-step algorithm test in the laboratory diagnosis. Between January 2007 and May 2019, fecal samples from 2275 patients were analyzed in a cross-sectional study. Four commercial tests were adopted for the diagnosis of CDI, the immunochromatographic test for toxin A from 2007 to 2010; the enzyme-linked immunosorbent assay method for toxins A and B from 2011 to March 2017; and the rapid enzyme immunoassay (EIA) for GDH and toxins A and B, associated with a Polymerase Chain Reaction (PCR) for the toxin B gene from June 2017 to 2019. The annual prevalence was 8.7% from 2007 to March 2017, increasing between June 2017 and 2019 to 14.7% when the C. diff Quik Chek Complete + GeneXpert C. difficile (two-step algorithm) test was adopted. The number of samples (691) and percentage of CDI cases (10.5%) were higher in winter, but the difference has no statistical significance (P > 0.05). An accurate diagnosis and adequate knowledge of the local seasonality of CDI allow the effective implementation of prevention and control strategies for nosocomial CDI, in addition to effective treatment for patients.

The Joint Initiative for Teaching and Learning on Global Health Challenges and One Health experience on implementing an online collaborative course.

The "Joint Initiative for Teaching and Learning on Global Health Challenges and One Health" piloted the online course "Global Health Challenges and One Health in 2021. The present work documents this experience, lessons learned, and the future outlook of the course. A descriptive study was conducted based on the evaluations performed with the enrolled students and course coordinators. Of 30 enrolled students from graduate programs of six institutions from Brazil, Germany, Mozambique, and Kosovo, two unenrolled, and nine failed for not completing the activities. Therefore, 19 (63%) students completed the course. Some challenges identified were language and technology access barriers, difficulty scheduling group meetings due to different time zones, and high workload per credit in some institutions. Activities in groups conducted synchronously, such as debates, journal clubs, and case studies, were highlighted as those with higher impact in the learning process, having more participation of students when carried in small groups. Some students reported the establishment of research and work partnerships with other participants from partner institutions. The experience reinforces the importance of international exchange to improve collaboration between institutions and the impact of working in small interprofessional groups to develop technical, intercultural, and interdisciplinarity competencies necessary to human resources working with the One Health approach. The success of such international educational initiatives depends on overcoming barriers to implementation, which can be detected in institutional and course levels. Therefore, continuing evaluation of the course and improvements must be performed and involve all participants.

High-Flow Nasal Cannula Therapy in Patients With COVID-19: Predictive Response Factors.

BACKGROUND: COVID-19 pneumonia has been responsible for many ICU patients' admissions with hypoxemic respiratory failure, and oxygen therapy is one of the pillars of its treatment. The current pandemic scenario has limited the availability of ICU beds and access to invasive ventilation equipment. High-flow nasal cannula (HFNC) can reduce the need for orotracheal intubation compared with conventional oxygen therapy, providing better results than noninvasive respiratory support. However, HFNC use has been controversial due to concerns about the benefits and risks of aerosol dispersion. In this context, we evaluated the performance of the HFNC therapy in patients with COVID-19 and investigated factors that can predict favorable responses. METHODS: A prospective observational study was conducted, which included hospitalized adult subjects with COVID-19 in the respiratory wards who needed oxygen therapy. Clinical and laboratory parameters were collected to compare HFNC therapy use and the outcomes. RESULTS: In 6 months, 128 subjects were included and the success rate of HFNC therapy was 53%. Logistic regression analysis showed that the Charlson comorbidity score, need for oxygen flow, [Formula: see text], and breathing frequency predicted therapy failure. The mortality rate increased among the non-responders versus the responders (47% vs 3%), 48% of failure occurred in the first 24 h of the HFNC therapy. A ROX (respiratory frequency - oxygenation) index > 4.98 in 6 h and > 4.53 in 24 h predicted success of the HFNC therapy with an area under the curve of 0.7, and a ROX index < 3.47 predicted failure with 88% of specificity. CONCLUSIONS: HFNC in the subjects with COVID-19 was associated with reduced mortality and improved oxygenation in the subjects with respiratory distress. Close monitoring of specific parameters defines eligible patients and rapidly identifies those in need of invasive ventilatory support.

HIV, syphilis, hepatitis B and C in key populations: results of a 10-year cross-sectional study, Southern Brazil.

OBJECTIVE: Although the development of prevention and treatment strategies for sexually transmitted infections in key groups has improved over the years, they still remain a challenge for health systems worldwide. In this context, the objective of this study is to assess the seroprevalence in the tested population, with an emphasis on key populations, aiming at identifying the participants' profile and consequently the development of testing strategies. METHODS: The present study analyzed the seroprevalence of HIV, syphilis, and hepatitis B and C, and the epidemiological profiles of key and general populations tested at a reference public health facility for sexually transmitted infections testing and counseling in the city of Curitiba, Southern Brazil. A cross-sectional study was conducted to report data from 2010 to 2019. RESULTS: A total of 67,448 samples were analyzed, 9,086 of these tested positive, 3,633 (56%) for HIV, 4,978 (77%) for syphilis, 340 (5%) for hepatitis C virus (HCV), and 135 (2%) for hepatitis B virus (HBV). Overall, most of the participants were men (79 to 87%), and predominantly white. For HIV and syphilis, the predominant age groups were 21-30 years old (48 and 50%), HBV 21-40 years old (31%), and HCV 41-60 years old (25%). A high seroprevalence of HIV and syphilis was observed in the investigated key populations with a higher frequency in sex workers, men who have sex with men, and transgender. CONCLUSION: The progressive increase in syphilis cases emphasizes the need for effective interventions to enhance adherence to the use of condoms, and to expand diagnosis and treatment for these key populations.

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.

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.

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.

Thirty-day readmission rates in a cohort of people living with HIV in southern Brazil, 2015 to 2017.

BACKGROUND: The intense use of antiretroviral therapy (ART) has reduced morbidity and mortality of HIV infection. In Brazil, the specific contribution of diseases related to HIV infection leading to hospital admission and readmission is not well known. AIMS: The study aimed to determine the clinico-epidemiological profile, 30-day readmission rate, and factors associated with this outcome in a cohort of adults with HIV infection in southern Brazil. METHODS: Unicentric retrospective cohort, with data collection through the review of medical records and databases. RESULTS: We analyzed 574 index hospitalizations and 451 individuals. Of these, 57.6% were men and the mean (±SD) age was 42.2 ± 12.3 years. Only 43.4% used ART regularly and low CD4 count and high frequency of detectable viral load were observed. HIV/AIDS-related diseases were identified in 55.2%, and tuberculosis was the most frequent etiology leading to index hospitalization. We found a 30-day readmission rate of 11.5% and hospitalization for HIV/AIDS-related illness was associated with a higher risk for the outcome. CONCLUSIONS: These findings highlight the need to expand resources for prevention, early diagnosis, retention, and treatment of people living with HIV in the region to reduce HIV/AIDS-associated diseases and possibly minimize consequent hospital readmission of these individuals.