scholarly journals Effectiveness of Screening Hospital Admissions to Detect Asymptomatic Carriers of Clostridium difficile: A Modeling Evaluation

2014 ◽  
Vol 35 (8) ◽  
pp. 1043-1050 ◽  
Author(s):  
Cristina Lanzas ◽  
Erik R. Dubberke
Keyword(s):  
Clostridium Difficile ◽  
Hospital Admissions ◽  
Control Strategies ◽  
Turnaround Time ◽  
Current Control ◽  
Hospital Ward ◽  
Transmission Model ◽  
Baseline Scenario ◽  
Asymptomatic Carriers ◽  
Contact Precautions

ObjectiveBoth asymptomatic and symptomatic Clostridium difficile carriers contribute to new colonizations and infections within a hospital, but current control strategies focus only on preventing transmission from symptomatic carriers. Our objective was to evaluate the potential effectiveness of methods targeting asymptomatic carriers to control C. difficile colonization and infection (CDI) rates in a hospital ward: screening patients at admission to detect asymptomatic C. difficile carriers and placing positive patients into contact precautions.MethodsWe developed an agent-based transmission model for C. difficile that incorporates screening and contact precautions for asymptomatic carriers in a hospital ward. We simulated scenarios that vary according to screening test characteristics, colonization prevalence, and type of strain present at admission.ResultsIn our baseline scenario, on average, 42% of CDI cases were community-onset cases. Within the hospital-onset (HO) cases, approximately half were patients admitted as asymptomatic carriers who became symptomatic in the ward. On average, testing for asymptomatic carriers reduced the number of new colonizations and HO-CDI cases by 40%–50% and 10%–25%, respectively, compared with the baseline scenario. Test sensitivity, turnaround time, colonization prevalence at admission, and strain type had significant effects on testing efficacy.ConclusionsTesting for asymptomatic carriers at admission may reduce both the number of new colonizations and HO-CDI cases. Additional reductions could be achieved by preventing disease in patients who are admitted as asymptomatic carriers and developed CDI during the hospital stay.

scholarly journals Factors Associated with Clostridioides (Clostridium) Difficile Infection and Colonization: Ongoing Prospective Cohort Study in a French University Hospital

2021 ◽  
Vol 18 (14) ◽  
pp. 7528
Author(s):  
Nagham Khanafer ◽  
Philippe Vanhems ◽  
Sabrina Bennia ◽  
Géraldine Martin-Gaujard ◽  
Laurent Juillard ◽  
...  
Keyword(s):  
Cohort Study ◽  
Clostridium Difficile ◽  
Good Clinical Practice ◽  
University Hospital ◽  
Factors Associated ◽  
Contact Precautions ◽  
Institutional Review ◽  
Virulent Strains ◽  
Scientific Meetings ◽  
Hospital Acquired

Introduction: Clostridioides (Clostridium) difficile can be isolated from stool in 3% of healthy adults and in at least 10% of asymptomatic hospitalized patients. C. difficile, the most common cause of hospital-acquired infectious diarrhea in the developed world, has re-emerged in recent years with increasing incidence and severity. In an effort to reduce the spread of the pathogen, published recommendations suggest isolation and contact precautions for patients suffering from C. difficile infection (CDI). However, asymptomatic colonized patients are not targeted by infection control policies, and active surveillance for colonization is not routinely performed. Moreover, given the current changes in the epidemiology of CDI, particularly the emergence of new virulent strains either in the hospital or community settings, there is a need for identification of factors associated with colonization by C. difficile and CDI. Methods and analysis: We are carrying out a prospective, observational, cohort study in Edouard Herriot Hospital, Hospices Civils de Lyon, a 900-bed university hospital in Lyon, France. All consecutive adult patients admitted on selected units are eligible to participate in the study. Stool samples or rectal swabs for C. difficile testing are obtained on admission, every 3–5 days during hospitalization, at the onset of diarrhea (if applicable), and at discharge. Descriptive and logistic regression analyses will be completed to mainly estimate the proportion of asymptomatic colonization at admission, and to evaluate differences between factors associated with colonization and those related to CDI. Ethics: The study is conducted in accordance with the ethical principles of the Declaration of Helsinki, French law, and the Good Clinical Practice guidelines. The study protocol design was approved by the participating units, the ethics committee and the hospital institutional review board (Comité de protection des personnes et Comission Nationale de l’Informatique et des Libertés; N°: 00009118). Dissemination: The results of this study will be disseminated by presenting the findings locally at each participating ward, as well as national and international scientific meetings. Findings will be shared with interested national societies crafting guidelines in CDI.

scholarly journals Phylogenetic Complexity of Morphologically Identified Anopheles squamosus in Southern Zambia

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 146
Author(s):  
Jordan Hoffman ◽  
Ilinca Ciubotariu ◽  
Limonty Simubali ◽  
Twig Mudenda ◽  
William Moss ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Catchment Area ◽  
Control Strategies ◽  
Light Trap ◽  
Current Control ◽  
Control Measures ◽  
Morphological Identification ◽  
The Past ◽  
Blood Meal Source ◽  
Residual Malaria Transmission

Despite dramatic reductions in malaria cases in the catchment area of Macha Hospital, Choma District, Southern Province in Zambia, prevalence has remained near 1–2% by RDT for the past several years. To investigate residual malaria transmission in the area, this study focuses on the relative abundance, foraging behavior, and phylogenetic relationships of Anopheles squamosus specimens. In 2011, higher than expected rates of anthropophily were observed among “zoophilic” An. squamosus, a species that had sporadically been found to contain Plasmodium falciparum sporozoites. The importance of An. squamosus in the region was reaffirmed in 2016 when P. falciparum sporozoites were detected in numerous An. squamosus specimens. This study analyzed Centers for Disease Control (CDC) light trap collections of adult mosquitoes from two collection schemes: one performed as part of a reactive-test-and-treat program and the second performed along a geographical transect. Morphological identification, molecular verification of anopheline species, and blood meal source were determined on individual samples. Data from these collections supported earlier studies demonstrating An. squamosus to be primarily exophagic and zoophilic, allowing them to evade current control measures. The phylogenetic relationships generated from the specimens in this study illustrate the existence of well supported clade structure among An. squamosus specimens, which further emphasizes the importance of molecular identification of vectors. The primarily exophagic behavior of An. squamosus in these collections also highlights that indoor vector control strategies will not be sufficient for elimination of malaria in southern Zambia.

scholarly journals Mosquito Control Priorities in Florida—Survey Results from Florida Mosquito Control Districts

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 947
Author(s):  
Rishi Kondapaneni ◽  
Ashley N. Malcolm ◽  
Brian M. Vazquez ◽  
Eric Zeng ◽  
Tse-Yu Chen ◽  
...  
Keyword(s):  
State Government ◽  
Mosquito Control ◽  
Control Strategies ◽  
Mosquito Species ◽  
Research Priorities ◽  
Current Control ◽  
Control Programs ◽  
Common Control ◽  
Surveillance Programs ◽  
Research Questions

Florida lies within a subtropical region where the climate allows diverse mosquito species including invasive species to thrive year-round. As of 2021, there are currently 66 state-approved Florida Mosquito Control Districts, which are major stakeholders for Florida public universities engaged in mosquito research. Florida is one of the few states with extensive organized mosquito control programs. The Florida State Government and Florida Mosquito Control Districts have long histories of collaboration with research institutions. During fall 2020, we carried out a survey to collect baseline data on the current control priorities from Florida Mosquito Control Districts relating to (1) priority control species, (2) common adult and larval control methods, and (3) major research questions to address that will improve their control and surveillance programs. The survey data showed that a total of 17 distinct mosquito species were considered to be priority control targets, with many of these species being understudied. The most common control approaches included truck-mounted ultra-low-volume adulticiding and biopesticide-based larviciding. The districts held interest in diverse research questions, with many prioritizing studies on basic science questions to help develop evidence-based control strategies. Our data highlight the fact that mosquito control approaches and priorities differ greatly between districts and provide an important point of comparison for other regions investing in mosquito control, particularly those with similar ecological settings, and great diversity of potential mosquito vectors, such as in Florida. Our findings highlight a need for greater alignment of research priorities between mosquito control and mosquito research. In particular, we note a need to prioritize filling knowledge gaps relating to understudied mosquito species that have been implicated in arbovirus transmission.

scholarly journals A modeling study to inform screening and testing interventions for the control of SARS-CoV-2 on university campuses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ben Lopman ◽  
Carol Y. Liu ◽  
Adrien Le Guillou ◽  
Andreas Handel ◽  
Timothy L. Lash ◽  
...  
Keyword(s):  
Cumulative Incidence ◽  
Disease Surveillance ◽  
Control Strategies ◽  
Transmission Model ◽  
University Administrators ◽  
Modeling Framework ◽  
University Campuses ◽  
School Year ◽  
Flexible Modeling ◽  
Resource Requirements

AbstractUniversity administrators face decisions about how to safely return and maintain students, staff and faculty on campus throughout the 2020–21 school year. We developed a susceptible-exposed-infectious-recovered (SEIR) deterministic compartmental transmission model of SARS-CoV-2 among university students, staff, and faculty. Our goals were to inform planning at our own university, Emory University, a medium-sized university with around 15,000 students and 15,000 faculty and staff, and to provide a flexible modeling framework to inform the planning efforts at similar academic institutions. Control strategies of isolation and quarantine are initiated by screening (regardless of symptoms) or testing (of symptomatic individuals). We explored a range of screening and testing frequencies and performed a probabilistic sensitivity analysis. We found that among students, monthly and weekly screening can reduce cumulative incidence by 59% and 87%, respectively, while testing with a 2-, 4- and 7-day delay between onset of infectiousness and testing results in an 84%, 74% and 55% reduction in cumulative incidence. Smaller reductions were observed among staff and faculty. Community-introduction of SARS-CoV-2 onto campus may be controlled with testing, isolation, contract tracing and quarantine. Screening would need to be performed at least weekly to have substantial reductions beyond disease surveillance. This model can also inform resource requirements of diagnostic capacity and isolation/quarantine facilities associated with different strategies.

Clostridium difficile—Associated Diarrhea, an Emerging Epidemic: Therapeutic Options

2007 ◽  
Vol 20 (4) ◽  
pp. 347-353
Author(s):  
Christopher R. Emerson
Keyword(s):  
Clostridium Difficile ◽  
Hospital Admissions ◽  
Treatment Options ◽  
Infectious Diarrhea ◽  
First Line ◽  
Oral Vancomycin ◽  
Considerable Morbidity ◽  
Clostridium Difficile Associated Diarrhea ◽  
Pharmacologic Agents ◽  
Oral Metronidazole

Clostridum difficile—associated disease (CDAD) is the leading cause of infectious diarrhea and is associated with considerable morbidity and mortality. The incidence is estimated to range from 3.4 to 8.4 cases per 1000 hospital admissions, and it has become a growing problem at many institutions. Treatment options for CDAD are limited due to a paucity of new pharmacologic agents and studies examining other potential treatments. Historically oral metronidazole and oral vancomycin have been used as first-line agents in the treating CDAD, however recent reports of treatment failure and recurrence with these agents have surfaced. These reports illustrate a need for novel pharmacologic agents and a thorough review of currently available agents that may have activity against C difficile. Available data on the treatment of CDAD were extracted and reviewed to outline the appropriate management of CDAD.

scholarly journals 1839. Contact Precautions’ Effects on MRSA Transmission in Department of Veterans Affairs Hospitals

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S46-S46
Author(s):  
Karim Khader ◽  
Alun Thomas ◽  
Lindsay D Visnovsky ◽  
Damon Toth ◽  
Lindsay T Keegan ◽  
...  
Keyword(s):  
Transmission Rate ◽  
Veterans Affairs ◽  
Transmission Model ◽  
Clinical Test ◽  
Department Of Veterans Affairs ◽  
Median Percentage ◽  
Contact Precautions ◽  
Day Range ◽  
Clinical Culture ◽  
Acute Care Facilities

Abstract Background In 2007, the Department of Veterans Affairs (VA) implemented the methicillin-resistant Staphylococcus aureus (MRSA) Prevention Initiative nationally in acute care facilities (ACFs). The initiative included universal nasal surveillance for MRSA colonization and implementation of contact precautions (CP) for identified carriers for the duration of their stay. Despite subsequent declines in MRSA infection rates in the VA, debate on CP efficacy continues, due to limited and inconclusive direct evidence. This study estimated CP impact on MRSA transmission in the VA. Methods We analyzed 1 year of data from 36 VA ACFs in 2014 using a Bayesian transmission model. The data included admission, discharge, and surveillance and clinical test results for MRSA. Per the MRSA Prevention Initiative protocol that placed known carriers on CP, we assumed patients were on CP starting 12 hours after a positive surveillance test, 24 hours after a positive clinical culture, or at admission if the patient had a positive test within 365 days prior to admission. Our model produced estimates of ward-specific transmission rate, surveillance test sensitivity, importation probability, and the CP effect parameter (CPe). For CPe < 1, CP reduced transmission. Additionally, we combined the estimates of CPe using a random-effects model with inverse variance weights to derive pooled estimates and corresponding standard errors. Results Facility size varied with a median daily census of 70 patients per day (range: 44–111). During the study period, 144,386 individuals were admitted into one of 36 ACFs, for 215,207 total admissions. The median percentage of admissions requiring contact precautions was 11.0% (range: 6.4%–16.1%). The estimated CPe was less than one in each of the 36 facilities with a median of 0.43 (range: 0.25–0.68). Our pooled estimate of CPe across all facilities was 0.47 (95% CI; 0.40, 0.55). Conclusion We found evidence of reduced MRSA transmission from patients on CP. This result was statistically significant in 5 of the 36 facilities and our pooled estimate suggests contact precautions could reduce the transmission rate by half. Further work is needed to account for imperfect compliance with CP, and for patients on CP for other reasons. Disclosures All Authors: No reported Disclosures.

scholarly journals Multiple horizontal acquisitions of plant genes in the whitefly Bemisia tabaci

2022 ◽  
Author(s):  
Clément Gilbert ◽  
Florian Maumus
Keyword(s):  
Bemisia Tabaci ◽  
Control Strategies ◽  
Purifying Selection ◽  
Amino Acid Identity ◽  
Current Control ◽  
Eukaryote Evolution ◽  
Plant Genes ◽  
Insect Interactions ◽  
High Level ◽  
Open Question

The extent to which horizontal gene transfer (HGT) has shaped eukaryote evolution remains an open question. Two recent studies reported four plant-like genes acquired through two HGT events by the whitefly Bemisia tabaci, a major agricultural pest (Lapadula et al. 2020; Xia et al. 2021). Here, we performed a systematic search for plant-to-insect HGT in B. tabaci and uncovered a total of 50 plant-like genes deriving from at least 24 independent HGT events. Most of these genes are present in three cryptic B. tabaci species, show high level of amino-acid identity to plant genes (mean = 64%), are phylogenetically nested within plant sequences, and are expressed and evolve under purifying selection. The predicted functions of these genes suggest that most of them are involved in plant-insect interactions. Thus, substantial plant-to-insect HGT may have facilitated the evolution of B. tabaci towards adaptation to a large host spectrum. Our study shows that eukaryote-to-eukaryote HGT may be relatively common in some lineages and it provides new candidate genes that may be targeted to improve current control strategies against whiteflies.

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