Value of platelet count in the early diagnosis of nosocomial invasive fungal infections in premature infants

The Role of Rotational Thromboelastometry in Early Detection of the Hemostatic Derangements in Neonates with Systemic Candida Infection

BACKGROUND

Systemic Candida infection (SCI) is the third most common cause of late-onset sepsis in Neonatal Intensive Care Units (NICU). While platelet involvement in fungal infections has been extensively studied, evaluation of the hemostatic mechanism in Candida infections, especially in neonates, has not been widely investigated. The aim of the current study was to evaluate the hemostatic profile of neonates with SCI through rotational thromboelastometry (ROTEM), a laboratory method that assesses the viscoelastic properties of blood.

METHODS

This is a single-centered prospective cohort study including a group of neonates with SCI (n = 21); the control group consisted of healthy neonates (n = 24). Demographics, clinical parameters, and laboratory data were recorded at the disease onset. Neonatal scores for the assessment of disease severity (Modified NEOMOD, nSOFA, and NeoBAT) were also calculated. ROTEM parameters of neonates with SCI were compared to those of healthy neonates.

RESULTS

ROTEM parameters differed between neonates with SCI and healthy neonates, indicating a hypocoagulable profile of infected neonates. Specifically, neonates with SCI had significantly prolonged clotting time (CT) and clot formation time (CFT), as well as lower clot amplitude at 10 min (A10) and maximum clot firmness (MCF) when compared to healthy neonates (p values < 0.05), findings that remained consistent after adjusting for confounding factors such as gestational age, birth weight, and sex. In addition, a strong correlation was noted between ROTEM parameters and disease severity based on the modified NEOMOD, nSOFA, and NeoBAT scores.

CONCLUSIONS

ROTEM parameters revealed a hypocoagulable profile in neonates during the early stages of SCI, which is also associated with disease severity. The results of this study highlight the need for monitoring of hemostatic status of this vulnerable group of patients and indicate that ROTEM analysis may have a role in the early detection of the hemostatic derangements associated with SCI in neonates, in order to ensure timely diagnosis and targeted therapeutic intervention.

Updates in Laboratory Identification of Invasive Fungal Infection in Neonates

Invasive fungal infection (IFI) in immunocompromised neonates is significantly associated with high morbidity and mortality and has become the third most common infection in Neonatal Intensive Care Units. The early diagnosis of IFI for neonatal patients is difficult because of the lack of specific symptoms. The traditional blood culture remains the gold standard in clinical diagnosis for neonatal patients but it requires a long duration, which delays treatment initiation. Detections of fungal cell-wall components are developed for early diagnosis but the diagnostic accuracy in neonates needs to be improved. PCR-based laboratory methods, such as real-time PCR, droplet digital PCR, and the cationic conjugated polymer fluorescence resonance energy transfer (CCP-FRET) system, distinguish the infected fungal species by their specific nucleic acids and show a high sensitivity and specificity. Particularly, the CCP-FRET system, which contains a cationic conjugated polymer (CCP) fluorescent probe and pathogen-specific DNA labeled with fluorescent dyes, could identify multiple infections simultaneously. In the CCP-FRET system, the CCP and fungal DNA fragments can self-assemble into a complex with an electrostatic interaction and the CCP triggers the FRET effect under ultraviolet light to make the infection visible. Here, we summarize the recent laboratory methods for neonatal IFI identification and provide a new perspective for early clinical fungal diagnosis.

Platelets in pediatric and neonatal sepsis: novel mediators of the inflammatory cascade

Sepsis, a dysregulated host response to infection, has been difficult to accurately define in children. Despite a higher incidence, especially in neonates, a non-specific clinical presentation alongside a lack of verified biomarkers has prevented a common understanding of this condition. Platelets, traditionally regarded as mediators of haemostasis and thrombosis, are increasingly associated with functions in the immune system with involvement across the spectrum of innate and adaptive immunity. The large number of circulating platelets (approx. 150,000 cells per microlitre) mean they outnumber traditional immune cells and are often the first to encounter a pathogen at a site of injury. There are also well-described physiological differences between platelets in children and adults. The purpose of this review is to place into context the platelet and its role in immunology and examine the evidence where available for its role as an immune cell in childhood sepsis. It will examine how the platelet interacts with both humoral and cellular components of the immune system and finally discuss the role the platelet proteome, releasate and extracellular vesicles may play in childhood sepsis. This review also examines how platelet transfusions may interfere with the complex relationships between immune cells in infection. IMPACT: Platelets are increasingly being recognised as important "first responders" to immune threats. Differences in adult and paediatric platelets may contribute to differing immune response to infections. Adult platelet transfusions may affect infant immune responses to inflammatory/infectious stimuli.

Risk factors and clinical analysis of peripherally inserted central catheter-related fungal colonization in premature infants

We aimed to analyze the risk factors of positive peripherally inserted central catheter (PICC)-related fungal colonization in preterm infants. This retrospective study collected data from 2018 to 2020. The enrolled infants who underwent PICC insertion were born at < 32 weeks’ gestation or birth weight < 1500 g. The demographics, PICC-related characteristics, and treatment information were collected. Univariate and multivariate analyses were performed to investigate risk factors for PICC-related fungal colonization. The receiver operating characteristic (ROC) curve was used to determine the optimal cut-off values for the duration of antibiotics and parenteral nutrition. In total, 124 premature infants underwent PICC insertion. Among them, 19 patients had positive results of fungi on the PICC tips. The duration of antibiotics (odds ratio [OR] 1.16, 95% confidence interval [CI] 1.02–1.31), parenteral nutrition infusion (OR 1.27, 95% CI 1.05–1.54), and postnatal glucocorticoid exposure (OR 9.48, 95% CI 1.06–84.98) were independent risk factors for fungal colonization in PICCs. The ROC curves showed that the risk increased after 15 days of antibiotic use and 28 days of parenteral nutrition infusion. Appropriate clinical management should be used to prevent fungal colonization and fungemia.

Analysis of risk factors of PICC-related bloodstream infection in newborns: implications for nursing care

Background

It is necessary to analyze the characteristics and risk factors of catheter-related bloodstream infection (CRBSI) in newborns with peripherally inserted central catheter (PICC).

Methods

Newborns undergoing PICC catheterization in the neonatal department of our hospital from January 1, 2020 to January 31, 2021 were included. The characteristics of newborns with and without CRBSI newborns were compared and analyzed. Logistic regression analyses were performed to evaluate the risk factors of CRBSI in newborns with PICC.

Results

Three hundred eighty-six newborns with PICC were included, of whom 41 newborns had the CRBSI, the incidence of CRBSI in newborns with PICC was 10.62%. There were significant differences regarding the birth weight, durations of PICC stay, 5-min Apgar score, site of PICC insertion of PICC between CRBSI and no CRBSI group (all P < 0.05), and there were no significant differences regarding the gender, gestational age, cesarean section, mechanical ventilation and length of hospital stay between CRBSI and no CRBSI group (all P > 0.05). Escherichia coli (26.08%) and Staphylococcus aureus (23.92%) were the most common CRBSI pathogens in newborns with PICC. Logistic regression analysis indicated that birth weight ≤ 1500 g (OR 1.923, 95% CI 1.135–2.629), durations of PICC stay ≥ 21 days (OR 2.077, 95% CI 1.024–3.431), 5-min Apgar score ≤ 7 (OR 2.198, 95% CI 1.135–3.414) and femoral vein insertion of PICC (OR 3.044, 95% CI 1.989–4.306) were the independent risk factors of CRBSI in neonates with PICC (all P < 0.05).

Conclusion

For newborns with low birth weight, longer durations of PICC stay and femoral vein PICC insertion, they may have higher risks of CRBSI, and medical staff should take targeted measures to reduce the development of CRBSI.

Clinical Analysis of Intravenous and Oral Sequential Treatment With Voriconazole for Candida Central Nervous System Infection in Six Premature Infants

Objective: The aim of the study was to observe the clinical efficacy and safety of intravenous and oral sequential treatment with voriconazole for Candida central nervous system (CNS) infection in premature infants.

Methods: The study included retrospective analysis of the clinical data of six premature infants with Candida CNS infection admitted to the neonatology department in Shanghai Children’s Hospital between November 2016 and November 2019. By reviewing the characteristics of voriconazole based on the literature, it showed that infants without gastrointestinal dysfunction could be effectively treated by intravenous and oral sequential therapy with voriconazole (both 7 mg/kg/dose, every 12 h). Clinical manifestations, the time required for the cerebrospinal fluid (CSF), blood culture, nonspecific infection markers such as platelets and C-reactive protein (CRP) to turn normal, and drug-related side effects were observed and recorded in the process of treatment. All data were statistically analyzed by T test and Mann–Whitney U test.

Results: A total of six premature infants were diagnosed with Candida CNS infection, two cases were diagnosed by a positive CSF culture and four cases were clinically diagnosed. Blood culture was positive for Candida in five cases. Among the 6 patients, 4 cases were Candida albicans and 2 cases were Candida parapsilosis. All the six cases were cured. After 3–5 days of treatment, symptoms such as lethargy, apnea, and feeding intolerance were improved and disappeared; a repeated blood culture turned negative in 3–7 days; CSF returned to normal in 15 ± 9 days on an average. Brain abscess, meningeal inflammation, and other infectious lesions were cleared on cranial magnetic resonance imaging (MRI) after treatment. The average total course of voriconazole was 61 ± 29 days, and the average oral treatment was 28 ± 15 days. No Candida recurrence was found during the treatment, and no drug-related side effects such as skin rash, liver and kidney function impairment, or visual abnormalities were found. The white blood cells, CSF glucose/plasma glucose ratio, and protein in CSF were significantly improved after the treatment (p < 0.05). No statistically significant difference was identified in the liver and kidney function indexes (p > 0.05).

Conclusion: Voriconazole is a relatively safe and effective alternative treatment for Candida CNS infection in preterm infants. No severe drug-related side effects were detected.

Severe retinopathy of prematurity is associated with early post-natal low platelet count

Pathophysiology of retinopathy of prematurity (ROP) still presents a gap. Lately blood tests parameters of premature infants have been measured at different times of ROP, attempting to detect correlations with ROP development and progression. So far, very early post-natal biomarkers, predictive of ROP outcome, have not been detected. Our purpose is to evaluate, in the earliest post birth blood sample, the correlation between routinely dosed blood parameters and ROP outcome. 563 preterm babies, screened according to ROP guidelines, were included and classified in conformity with ET-ROP study in "Group 1" (ROP needing treatment), "Group 2" (ROP spontaneously regressed) and "noROP" group (never developed ROP). The earliest (within an hour after delivery) blood test parameters routinely dosed in each preterm infant were collected. Platelet count was decreased in Group 1 versus noROP group (p = 0.0416) and in Group 2 versus noROP group (p = 0.1093). The difference of thrombocytopenic infants among groups was statistically significant (p = 0.0071). CRP was higher in noROP versus all ROPs (p = 0.0331). First post-natal blood sample revealed a significant thrombocytopenia in ROP needing treatment, suggesting a role of platelets in the pathophysiology and progression of ROP, possibly considering it as a predictive parameter of ROP evolution.

The assessment of phagocytic and bactericidal activity of platelets and plasma bactericidal activity in late preterm newborns*

Background

The aim of the study was to compare the phagocytic and bactericidal properties of blood platelets and the plasma bactericidal activity in 66 late preterm (LPN) and 74 full-term newborns (FTN).

Materials/Methods

Blood samples were collected from the umbilical artery. Bacteria of the Staphylococcus aureus ATCC 6538P were used for the tests.

Results

Platelet counts in LPN vs FTN were the following: 225 vs 258.5 (×103/μL), p = 0.003. The percentage of phagocytic platelets was the following: Me = 1.1 in LTN vs Me = 1.1 in FTN. The phagocytic index was the following: Me = 1 for both LPN and FTN. The phagocytic properties of platelets increased as the birth weight increased. The bactericidal activity of platelets was the following: Me = 0; (average = 0.7) in LPN vs Me = 0; (average = 0.8) in FTN. The median plasma bactericidal activity in LPN was 41.6 vs 43.8, in FTN, p = 0.027. The bactericidal capacity of plasma increased with increasing fetal age and birth weight of newborns. sP-selectin was: 63.9 ng/ml in LPN vs 71 ng/ml in FTN, p = 0.026. IL-6 in LPN was 3.6 vs 3.9 (pg/ml) in FTN, p = 0.02.

Conclusion

Late preterm newborns have lower defensive capacity against infection than full-term newborns, due to lower platelets count, lower plasma bactericidal activity and lower sP-selectin concentration, which cooperates with neutrophils, monocytes in fighting against infection. All newborns had similar phagocytic and bactericidal properties of platelets.

Analysis of the Clinical Features of Intrauterine Ureaplasma urealyticum Infection in Preterm Infants: A Case-Control Study

Objective: To analyze the clinical characteristics of intrauterine Ureaplasma urealyticum (UU) infection in premature infants. Method: In this single-center retrospective case-control study, 291 preterm infants born in our hospital and hospitalized in our department and gestational age no more than 32 weeks, birth weight no more than 2000 g were included from January 2019 to January 2021. Lower respiratory tract secretion, gastric fluid and urine were collected for UU RNA detection within 48 h after birth. Intrauterine UU infection is defined by at least one positive UU-PCR test of secreta or excreta of preterm infants after birth. The UU infection group included 86 preterm infants and the non-UU infection group included 205 preterm infants. We compared their clinical features, hemogram changes and disease outcomes using statistical analyses. Results: The clinical characteristics of premature infants such as the duration of oxygen use and ventilator use in hospital were significantly prolonged in the UU infection group (P < 0.05). The levels of leukocytes, platelet and procalcitonin in the UU infection group were significantly higher than in the non-UU infection group (P < 0.05). In terms of preterm complications, only the incidences of bronchopulmonary dysplasia, retinopathy of prematurity and metabolic bone disease in premature infants in the UU infection group were significantly higher than those in the non-UU infection group (P < 0.05). The mode of delivery, maternal premature rupture of membranes, and postnatal leukocyte level were independent risk factors for UU infection, while gestational hypertension was a protective factor for UU infection. The level of leukocytes in postnatal hemogram of premature infants could be used as a diagnostic index of UU infection, but the diagnostic accuracy was poor. Conclusion: In our study, UU infection can increase the incidence of bronchopulmonary dysplasia, retinopathy of prematurity and metabolic bone disease in preterm infants, but have no effect on the incidence of necrotizing enterocolitis, intracranial hemorrhage, white matter damage and other diseases in preterm infants. For high-risk premature infants, UU should be detected as soon as possible after birth, early intervention and drug treatment necessarily can improve the prognosis as much as possible.

Update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA 9: suitability of taxonomic units notified to EFSA until September 2018

The qualified presumption of safety (QPS) procedure was developed to provide a harmonised generic pre-evaluation to support safety risk assessments of biological agents performed by EFSA's Scientific Panels. The taxonomic identity, body of knowledge, safety concerns and antimicrobial resistance were assessed. Safety concerns identified for a taxonomic unit are, where possible and reasonable in number, reflected by 'qualifications' which should be assessed at the strain level by the EFSA's Scientific Panels. During the current assessment, no new information was found that would change the previously recommended QPS taxonomic units and their qualifications. Between April and September 2018, the QPS notification list was updated with 48 microorganisms from applications for market authorisation. Of these, 30 biological agents already had QPS status, 15 were excluded from the QPS exercise by the previous QPS mandate (five filamentous fungi) or from further evaluations within the current mandate (two notifications of Enterococcus faecium, one of Streptomyces spp. and seven of Escherichia coli). One taxonomic unit was (re)evaluated: Pseudomonas fluorescens had been previously evaluated in 2016, and was now re-evaluated within this mandate. The revision of the literature supports the previously identified safety concerns (e.g. production of biocompounds with antimicrobial activity and virulence features), preventing the inclusion of P. fluorescens in the QPS list. Mycobacterium setense and Komagataeibacter sucrofermentans were evaluated for the first time. M. setense cannot be considered for the QPS assessment because there are significant safety concerns. K. sucrofermentans (Acetobacter xylinus subsp. sucrofermentans) can be proposed for the QPS list but only for production purposes. The QPS status of Corynebacterium glutamicum is confirmed with the qualification extended to other production purposes.