Control of endemic nosocomial Legionnaires' disease by using sterile potable water for high risk patients

SUMMARYIn a setting where potable water is contaminated with Legionella pneumophila serogroup 1, we performed two case control studies. The first case control study consisted of 17 cases of nosocomial Legionnaires' disease (LD) and 33 control (the patients who were admitted to the ward where the case was admitted immediately before and after the case) subjects. Cases had a higher mortality rate 65% vs 12% (P < 0.004); were more likely to have received assisted ventilation (P < 0.00001); to have nasogastric tubes (P < 0.0004) and to be receiving corticosteroids or other immunosuppressive therapy (P < 0.0001). Based on the results of this study, sterile water was used to flush nasogastric tubes and to dilute nasogastric feeds. Only 3 cases of nosocomial LD occurred during the next year compared with 12 the previous year (P < 0.0001). Nine cases subsequently occurred and formed the basis for the second case-control study. Eighteen control subjects were those patients admitted to the same unit where the case developed LD, immediately before and after the case. The mortality rate for the cases was 89% vs 6% for controls (P < 0.00003). The only other significant difference was that cases were more likely to be receiving corticosteroids or other immunosuppressive therapy 89% vs 39% ( < 0.01). We hypothesized that microaspiration of contaminated potable water by immunocompromised patients was a risk factor for nosocomial Legionnaires' disease. From 17 March 1989 onwards such patients were given only sterile potable water. Only two cases of nosocomial LD occurred from June 1989 to September 1990 and both occurred on units where the sterile water policy was not in effect. We conclude that aspiration of contaminated potable water is a possible route for acquisition of nosocomial LD in our hospital and that provision of sterile potable water to high risk patients (those who are receiving corticosteroids or other immunosuppressive drugs; organ transplant recipients or hospitalized in an intensive care unit) should be mandatory.

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Rapid-deployment aortic valve replacement in high-risk patients: A case-control study

Journal of Cardiovascular and Thoracic Research ◽

10.34172/jcvtr.2021.10 ◽

2021 ◽

Vol 13 (1) ◽

pp. 23-27

Author(s):

Adama Sawadogo ◽

An Vinh Bui-Duc ◽

Nicolas D'Ostrevy ◽

Lionel Camilleri ◽

Kasra Azarnoush

Keyword(s):

High Risk ◽

Aortic Valve ◽

Aortic Valve Replacement ◽

Case Control Study ◽

Case Control ◽

Study Group ◽

High Risk Patients ◽

Risk Patients ◽

Rapid Deployment ◽

Control Study

Introduction: Aortic valve stenosis is the most frequent cardiac valve pathology in the western world. In high-risk patients, conventional aortic valve replacement (C-AVR) carries high rates of morbidity and mortality. In the last few years, rapid-deployment valves (RDV) have been developed to reduce the surgical risks. In this work, we aimed to compare the mid-term outcomes of rapid-deployment AVR (RD-AVR) with those of the C-AVR in high-risk patients. Methods: This retrospective case-control study identified 23 high-risk patients who underwent RD-AVR between 12/2015 to 01/2018. The study group was compared with a control group of 46 patients who were retrospectively selected from a database of 687 C-AVR patients from 2016 to 2017 which matched with the study group for age and Euro SCORE II. Results: RD-AVR group presented more cardiovascular risk factors. Euro SCORE II was higher in the RD-AVR group (P=0.06). In the RD-AVR group, we observed significantly higher mean prosthetic size (P<0.001). In-hospital mortality was zero in RD-AVR group versus 2 deaths in C-AVR group. Hospital stay was longer in the RD-AVR group with statistical significance (P=0.03). In the group AVR with associated cardiac procedures, while comparing subgroups RD-AVR versus C-AVR, early mean gradient was lower in the first cited (P=0.02). The overall mean follow-up was 10.9 ± 4.3 months. Conclusion: The RD-AVR technique is reliable and lead to positive outcomes. This procedure provides a much larger size with certainly better flow through the aortic root. It is an alternative to C-AVR in patients recognized to be surgically fragile.

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Clinical, Laboratory, and Radiological Features Indicative of Novel Coronavirus Disease (COVID-19) in Emergency Departments – A Multicentre Case-Control Study in Hong Kong

10.20944/preprints202005.0285.v1 ◽

2020 ◽

Author(s):

Rex Pui Kin Lam ◽

Kevin Kei Ching Hung ◽

Eric Ho Yin Lau ◽

Chun Tat Lui ◽

Kin Ling Chan ◽

...

Keyword(s):

Hong Kong ◽

High Risk ◽

Chest Radiography ◽

Case Control Study ◽

Clinical Laboratory ◽

Case Control ◽

Patient Reported ◽

Risk Patients ◽

Early Testing ◽

Control Study

(1) Background: It is unclear whether the reported presenting clinical features of coronavirus disease 2019 (COVID-19) are useful in identifying high-risk patients for early testing and isolation in the emergency department (ED). We aimed to compare the exposure history, clinical, laboratory, and radiographic features of ED patients who tested positive and negative for COVID-19; (2) Methods: We conducted a case-control study in seven EDs during the first five weeks of the COVID-19 outbreak in Hong Kong. Thirty-seven laboratory-confirmed COVID-19 patients were compared with 111 age- and gender-matched controls; (3) Results: There were no significant differences in patient characteristics and reported symptoms between the groups, except patient-reported fever. A positive travel history or contact history was the most significant predictor for COVID-19 infection. After adjustment for age and presumed location of acquiring the infection in Wuhan/Hubei, patient-reported fever (OR 2.6, 95% CI 1.1 to 6.3), delayed presentation (OR 5.0, 95% CI 2.0 to 12.5), having medical consultation before ED presentation (OR 7.4, 95% 2.9 to19.1), thrombocytopenia (OR 4.0, 95% CI 1.6 to 9.7), raised lactate dehydrogenase (OR 5.9, 95% CI 1.9 to 18.5), haziness, consolidation or ground-glass opacity on chest radiography (OR 5.6, 95% CI 2.0 to 16.0), and bilateral changes on chest radiography (OR 13.2, 95% CI 4.7 to 37.4) were associated with a higher odds of COVID-19 separately while neutrophilia was associated with a lower odds (OR 0.3, 95% CI 0.1-0.8); and (4) Conclusions: This study highlights several features that may be useful in identifying high-risk patients for early testing and isolation while waiting for test result. Further studies are warranted to verify the findings.

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