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.

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.

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.

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.

Standardisation and validation of an in-house quantitative real-time polymerase chain reaction (qPCR) assay for the diagnosis of Clostridioides difficile infection.

OBJECTIVES: Clostridioides difficile is an emerging enteric pathogen that causes nosocomial diarrhoea in adults. The excessive cost of commercial molecular tests restricts the access of developing countries to its diagnosis. This study aimed to develop and validate in-house quantitative polymerase chain reaction (qPCR) targeting the C. difficile toxin B gene (tcdB) using two detection methodologies-SYBR Green and hydrolysis probes-for the diagnosis of C. difficile infection (CDI). METHODS: Glutamate dehydrogenase (GDH) plus toxigenic culture was the standard reference diagnostic method. The SYBR Green method and hydrolysis probes were used to study 392 samples simultaneously to assess the diagnostic value of these real-time PCR assays in detecting CDI from clinical samples. RESULTS: The SYBR Green and hydrolysis probe assays showed 97.9% and 87.5% sensitivity; 99.1% and 100.0% specificity; 94.0% and 100.0% positive predictive value; 99.7% and 98.3% negative predictive value; and 99.0% and 98.5% accuracy, respectively. CONCLUSIONS: The two qPCR methodologies evaluated could offer an adequate tool as part of an algorithm in the laboratory diagnosis of CDI.