Fidaxomicin for the treatment of Clostridioides difficile in children

Fidaxomicin is an oral narrow-spectrum novel 18-membered macrocyclic antibiotic that was initially approved in 2011 by the US FDA for the treatment of Clostridioides difficile infections (CDI) in adults. In February 2020, the FDA approved fidaxomicin for the treatment of CDI in children age >6 months. In adults, fidaxomicin is as efficacious as vancomycin in treating CDI and reduces the risk of recurrent CDI. An investigator-blinded, randomized, multicenter, multinational clinical trial comparing the efficacy and safety of fidaxomicin with vancomycin in children was recently published confirming similar findings as previously reported in adults. Fidaxomicin is the first FDA-approved treatment for CDI in children and offers a promising option for reducing recurrent CDI in this population.

Toilet plume aerosol generation rate and environmental contamination following bowl water inoculation with Clostridium difficile spores

INTRODUCTION

Clostridium difficile is the leading cause of health care-associated gastric illness. Environmental contamination with C difficile spores is a risk factor for contact transmission, and toilet flushing causes such contamination. This work explores toilet contamination persistence and environmental contamination produced over a series of flushes after contamination.

METHODS

A flushometer toilet was seeded with C difficile spores in a sealed chamber. The toilet was flushed 24times, with postflush bowl water samples and settle plates periodically collected for culturing and counting. Air samples were collected after each of 12 flushes using rotating plate impactors.

RESULTS

Spores were present in bowl water even after 24 flushes. Large droplet spore deposition accumulated over the 24-flush period. Droplet nuclei spore bioaerosol was produced over at least 12 flushes.

CONCLUSIONS

Toilets contaminated with C difficile spores are a persistent source of environmental contamination over an extended number of flushes.

Pathogen transfer through environment-host contact: an agent-based queueing theoretic framework

Queueing theory studies the properties of waiting queues and has been applied to investigate direct host-to-host transmitted disease dynamics, but its potential in modelling environmentally transmitted pathogens has not been fully explored. In this study, we provide a flexible and customizable queueing theory modelling framework with three major subroutines to study the in-hospital contact processes between environments and hosts and potential nosocomial pathogen transfer, where environments are servers and hosts are customers. Two types of servers with different parameters but the same utilization are investigated. We consider various forms of transfer functions that map contact duration to the amount of pathogen transfer based on existing literature. We propose a case study of simulated in-hospital contact processes and apply stochastic queues to analyse the amount of pathogen transfer under different transfer functions, and assume that pathogen amount decreases during the inter-arrival time. Different host behaviour (feedback and non-feedback) as well as initial pathogen distribution (whether in environment and/or in hosts) are also considered and simulated. We assess pathogen transfer and circulation under these various conditions and highlight the importance of the nonlinear interactions among contact processes, transfer functions and pathogen demography during the contact process. Our modelling framework can be readily extended to more complicated queueing networks to simulate more realistic situations by adjusting parameters such as the number and type of servers and customers, and adding extra subroutines.

Molecular detection of Clostridium difficile on inert surfaces from a Costa Rican hospital during and after an outbreak

BACKGROUND

Hospital transmission of Clostridium difficile is fostered by contamination of surfaces and medical equipment with spores highly resistant to disinfectants and regular cleaning procedures. Despite the outbreaks and fatalities that C difficile causes, its epidemiology has not been studied in hospitals from middle- and low-income countries. To tackle this knowledge gap, the detection frequency of C difficile DNA on inert surfaces of a major Costa Rican hospital during and after an outbreak was compared.

METHODS

We used a presence-absence real-time polymerase chain reaction to detect a fragment of the tpi gene of C difficile on 21 surface samples collected during an outbreak and 54 surface samples taken 2 years later at the same hospital.

RESULTS

C difficile DNA was detected in 40% of the 75 environmental samples analyzed. Whereas 71% of the samples collected during the outbreak were positive, only 28% of the samples obtained 2 years after the outbreak gave the same result. This 2.5× ratio was maintained when the comparison was restricted to the wards that were sampled both during and after the outbreak (72% vs 35%, P = .016).

CONCLUSIONS

Our results show that environmental surfaces in the hospital analyzed are continuously being contaminated with C difficile DNA and that their level of contamination is higher during an outbreak than after it.

Clostridium difficile infection: epidemiology, diagnosis and understanding transmission

Clostridium difficile infection (CDI) continues to affect patients in hospitals and communities worldwide. The spectrum of clinical disease ranges from mild diarrhoea to toxic megacolon, colonic perforation and death. However, this bacterium might also be carried asymptomatically in the gut, potentially leading to 'silent' onward transmission. Modern technologies, such as whole-genome sequencing and multi-locus variable-number tandem-repeat analysis, are helping to track C. difficile transmission across health-care facilities, countries and continents, offering the potential to illuminate previously under-recognized sources of infection. These typing strategies have also demonstrated heterogeneity in terms of CDI incidence and strain types reflecting different stages of epidemic spread. However, comparison of CDI epidemiology, particularly between countries, is challenging due to wide-ranging approaches to sampling and testing. Diagnostic strategies for C. difficile are complicated both by the wide range of bacterial targets and tests available and the need to differentiate between toxin-producing and non-toxigenic strains. Multistep diagnostic algorithms have been recommended to improve sensitivity and specificity. In this Review, we describe the latest advances in the understanding of C. difficile epidemiology, transmission and diagnosis, and discuss the effect of these developments on the clinical management of CDI.

Role of the environment in the transmission of Clostridium difficile in health care facilities

Recent data demonstrate that the contaminated hospital surface environment plays a key role in the transmission of Clostridium difficile. Enhanced environmental cleaning of rooms housing Clostridium difficile-infected patients is warranted, and, if additional studies demonstrate a benefit of "no-touch" methods (eg, ultraviolet irradiation, hydrogen peroxide systems), their routine use should be considered.