Role of Early Onset Neutropenia in Development of Candidemia in Premature Infants

The effect of herbal medicine in innate immunity to Candida albicans

Candida albicans (C. albicans) is an opportunistic pathogenic fungus that often causes mucosal and systemic infections. Several pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), have been implicated in the host recognition of C. albicans. These PRRs recognize the pathogen-associated molecular patterns (PAMPs) of C. albicans to activate innate immune cells, thereby rapidly inducing various inflammatory responses by activating intracellular signaling cascades. Herbal medicine and its active components deserve priority development due to their low toxicity and high antibacterial, antiviral and antifungal activities. This review discussed the activities of herbal compounds against C. albicans and their related mechanisms, especially their regulatory role on innate immune cells such as neutrophils, macrophages, and dendritic cells (DCs) implicated in C. albicans infections. Our work aims to find new therapeutic drugs and targets to prevent and treat diseases caused by C. albicans infection with the mechanisms by which this fungus interacts with the innate immune response.

Invasive Fungal Diseases in Africa: A Critical Literature Review

Invasive fungal diseases (IFDs) are of huge concern in resource-limited settings, particularly in Africa, due to the unavailability of diagnostic armamentarium for IFDs, thus making definitive diagnosis challenging. IFDs have non-specific systemic manifestations overlapping with more frequent illnesses, such as tuberculosis, HIV, and HIV-related opportunistic infections and malignancies. Consequently, IFDs are often undiagnosed or misdiagnosed. We critically reviewed the available literature on IFDs in Africa to provide a better understanding of their epidemiology, disease burden to guide future research and interventions. Cryptococcosis is the most encountered IFD in Africa, accounting for most of the HIV-related deaths in sub-Saharan Africa. Invasive aspergillosis, though somewhat underdiagnosed and/or misdiagnosed as tuberculosis, is increasingly being reported with a similar predilection towards people living with HIV. More cases of histoplasmosis are also being reported with recent epidemiological studies, particularly from Western Africa, showing high prevalence rates amongst presumptive tuberculosis patients and patients living with HIV. The burden of pneumocystis pneumonia has reduced significantly probably due to increased uptake of anti-retroviral therapy among people living with HIV both in Africa, and globally. Mucormycosis, talaromycosis, emergomycosis, blastomycosis, and coccidiomycosis have also been reported but with very few studies from the literature. The emergence of resistance to most of the available antifungal drugs in Africa is yet of huge concern as reported in other regions. IFDs in Africa is much more common than it appears and contributes significantly to morbidity and mortality. Huge investment is needed to drive awareness and fungi related research especially in diagnostics and antifungal therapy.

Leukopenia and Neutropenia at Birth and Sepsis in Preterm Neonates of <32 Weeks' Gestation

OBJECTIVE

This study aimed to evaluate associations between leukopenia or neutropenia at birth and risk of sepsis in very preterm neonates.

STUDY DESIGN

We conducted a retrospective unmatched cohort study of neonates of <32 weeks' gestation. Those with leukopenia (≤5,000/µL) were compared with a unmatched cohort without leukopenia. Comparisons were also made for patients with neutropenia and without neutropenia. The outcomes were early-onset sepsis, late-onset sepsis, and mortality.

RESULTS

We identified 271 neonates with leukopenia at birth and 271 without. Multivariable analyses identified higher odds of early-onset sepsis (adjusted odds ratio [AOR] = 4.85, 95% confidence interval [CI]: 1.29-18.20) in leukopenic neonates. Of neonates with leukopenia, 183 had both leukopenia and neutropenia and were associated with the highest odds of early-onset sepsis (AOR = 6.94, 95% CI: 1.77-27.15) compared with those with neither or with either alone.

CONCLUSION

Leukopenia, neutropenia, and both leukopenia and neutropenia at birth were associated with early-onset sepsis in very preterm neonates.

KEY POINTS

· Leukopenia and neutropenia combined at birth was associated with highest odds of early-onset sepsis.. · Leukopenia or neutropenia were associated with sepsis in preterm neonates.. · The risk of infection persist throughout neonatal stay in NICU..

Invasive candidiasis in Africa, what is the current picture?

Invasive candidiasis is a serious, progressive, and potentially deadly infection that can affect the brain, heart, bones, eyes, and other parts of the body. It is associated with risk factors such as the use of indwelling medical devices and prolonged hospital stay, and broad-spectrum antibiotics use. It is especially seen in immunocompromised individuals such as patients with prolonged hospital stay, gastrointestinal surgery, haematological malignancies, and respiratory diseases. We have conducted a systematic search of literature using a select group of database and appropriate search words and found that in Africa, there are 18,293 documented/reported cases of invasive candidiasis in the last few decades (1976-2021) and 16,636(91%) were cases of candidaemia. South Africa had the highest number of reported cases - 15,002(82%), which may be due to underreporting of cases in other countries. HIV positive persons with invasive candidiasis in Africa accounted for 1,052(5.8%). C. albicans was the most frequently isolated species 6,328(32.6%), followed by Candida parapsilosis 5,910(30.4%), and Candida auris 1,505(7.8%). Due to the affordability and availability of blood culture, it was used for diagnosis in most of the studies examined, while a few studies combined other techniques and just 3 studies from 2 countries used serological tests. Echinocandins are recommended as first-line therapy but are only available in 12 countries and are highly priced. The use of fluconazole because of its availability and relatively inexpensive nature has led to increased resistance of Candida species to the drug.

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.

Invasive Candida Infections in Neonates after Major Surgery: Current Evidence and New Directions

Infections represent a serious health problem in neonates. Invasive Candida infections (ICIs) are still a leading cause of mortality and morbidity in neonatal intensive care units (NICUs). Infants hospitalized in NICUs are at high risk of ICIs, because of several risk factors: broad spectrum antibiotic treatments, central catheters and other invasive devices, fungal colonization, and impaired immune responses. In this review we summarize 19 published studies which provide the prevalence of previous surgery in neonates with invasive Candida infections. We also provide an overview of risk factors for ICIs after major surgery, fungal colonization, and innate defense mechanisms against fungi, as well as the roles of different Candida spp., the epidemiology and costs of ICIs, diagnosis of ICIs, and antifungal prophylaxis and treatment.

Immune Sensing of Candida albicans

Candida albicans infections range from superficial to systemic and are one of the leading causes of fungus-associated nosocomial infections. The innate immune responses during these various infection types differ, suggesting that the host environment plays a key role in modulating the host–pathogen interaction. In addition, C. albicans is able to remodel its cell wall in response to environmental conditions to evade host clearance mechanisms and establish infection in niches, such as the oral and vaginal mucosa. Phagocytes play a key role in clearing C. albicans, which is primarily mediated by Pathogen Associated Molecular Pattern (PAMP)–Pattern Recognition Receptor (PRR) interactions. PRRs such as Dectin-1, DC-SIGN, and TLR2 and TLR4 interact with PAMPs such as β-glucans, N-mannan and O-mannan, respectively, to trigger the activation of innate immune cells. Innate immune cells exhibit distinct yet overlapping repertoires of PAMPs, resulting in the preferential recognition of particular Candida morphotypes by them. The role of phagocytes in the context of individual infection types also differs, with neutrophils playing a prominent role in kidney infections, and dendritic cells playing a prominent role in skin infections. In this review, we provide an overview of the key receptors involved in the detection of C. albicans and discuss the differential innate immune responses to C. albicans seen in different infection types such as vulvovaginal candidiasis (VVC) and oral candidiasis.