Surveillance of microbiological contamination and correct use of protective lead garments

BACKGROUND

Healthcare associated infections are an important threat of Public Health. Several studies investigated the possible role played by the hospital environment in the transmission of nosocomial pathogens. In addition to the "classic" nosocomial surfaces, some researches focused their attention on "alternative" surfaces. Little is known about the protective lead garments used in operating rooms.

STUDY DESIGN

This study was conducted in three phases to investigate the microbiological contamination and the normal use of these garments. In the first step, we administered a questionnaire to know the frequency and the type of sanitation. Then, in the second step, we conducted the microbiological samplings and, finally, in the third step, we carried out a surveillance on the use of these garments during the surgical procedures.

METHODS

In the first step, we administered the questionnaire through direct interview. For microbiological sampling we used sterile swabs, the normal growth media and the API Identification System (bioMérieux).

RESULTS

The study showed that the garments are sanitized only in 66.7% of the cases with a non-defined frequency. Moreover, a bacterial contamination was found on 88 garments with a positivity of 80.7% and the units with the higher rate of contamination were Urology, Orthopedics, Neuroradiology and Intensive Cardiac Care. Finally, 100% of the surgical team members wore sterile disposable shirts above the protective lead garments while this was never true for the rest of the nursing and anaesthesia team.

CONCLUSIONS

To prevent the contamination of these garments, it is important to develop appropriate sanitation procedures and to store them in special cabinets also subjected to sanitation. Finally, it is necessary to focus on the correct use of the protective lead garments.

Campylobacter: from microbiology to prevention

In last years, Campylobacter spp has become one of the most important foodborne pathogens even in high-income countries. Particularly, in Europe, Campylobacteriosis is, since 2005, the foodborne disease most frequently notified and the second in USA, preceded by the infection due to Salmonella spp. Campylobacter spp is a commensal microorganism of the gastrointestinal tract of many wild animals (birds such as ducks and gulls), farm animals (cattle and pigs) and companion animals (such as dogs and cats) and it is responsible for zoonoses. The transmission occurs via the fecal-oral route through ingestion of contaminated food and water. The disease varied from a watery diarrhea to a severe inflammatory diarrhea with abdominal pain and fever and can be burdened by some complications. The main recognized sequelae are Guillain-Barré Syndrome (GBS), the Reactive Arthritis (REA) and irritable bowel syndrome (IBS). Recently, many cases of Campylobacter spp isolated from human infections, showed an important resistance to various antibiotics such as tetracyclines and fluoroquinolones. For these reasons, the prevention of this infection plays an essential role. Many preventive measures exist to limit the transmission of the pathogens and the subsequent disease such as the health surveillance, the vaccination of the poultry and the correct food hygiene throughout the entire production chain. A global surveillance of Campylobacteriosis is desirable and should include data from all countries, including notifications of cases and the microbiological data typing of strains isolated from both human and animal cases.

Humidifiers for oxygen therapy: what risk for reusable and disposable devices?

INTRODUCTION

Nosocomial pneumonia accounts for the vast majority of healthcare-associated infections (HAI). Although numerous medical devices have been discussed as potential vehicles for microorganisms, very little is known about the role played by oxygen humidifiers as potential sources of nosocomial pathogens. The purpose of this research was to evaluate the safety of the reuse of humidifiers by analysing the rate of microbial contamination in reusable and disposable oxygen humidifiers used during therapy, and then discuss their potential role in the transmission of respiratory pathogens.

METHODS

Water samples from reusable and disposable oxygen humidifiers were collected from different wards of the University Hospital of Messina, Italy, where nosocomial pneumonia has a higher incidence rate due to the "critical" clinical conditions of inpatients. In particular, we monitored the Internal Medicine and Pulmonology wards for the medical area; the General Surgery and Thoracic and Cardiovascular Surgery wards for the surgical area and the Intensive Care Unit and Neonatal Intensive Care Unit for the emergency area. The samples were always collected after a period of 5 days from initial use for both types of humidifiers. Samples were processed using standard bacteriological techniques and microbial colonies were identified using manual and automated methods.

RESULTS

High rates of microbial contamination were observed in samples from reusable oxygen humidifiers employed in medical (83%), surgical (77%) and emergency (50%) areas. The most relevant pathogens were Pseudomonas aeruginosa, amongst the Gram-negative bacteria, and Staphylococcus aureus, amongst the Gram-positive bacteria. Other pathogens were detected in lower percentage. The disposable oxygen humidifier samples showed no contamination.

CONCLUSIONS

This research presents evidence of the high rate and type of microbial contamination of reusable humidifiers employed for oxygen therapy. These devices may thus be involved in the transmission of potential pathogens. It could be important, for the prevention of nosocomial pneumonia, to replace them with singleuse humidifiers for which the absence of microbial contamination has been confirmed.

Management of two influenza vaccination campaign in health care workers of a university hospital in the south Italy

BACKGROUND

In Europe, flu remains one of the major public health problems. Healthcare workers (HCWs) are a category at high-risk of contracting the infection and infecting their patients; consequently, for this category, vaccination is highly recommended. Unfortuntely, coverage levels remain insufficient with rates ranging between 4 and 40.

STUDY DESIGN

The purpose of our work was to evaluate the adherence of HCWs to the influenza vaccination and to carry out a combination of educational and motivational interventions in order to increase the rate of adherence to the vaccination in this workers' category.

METHODS

We conducted two different influenza vaccination campaigns, 2014-2015 and 2015-2016. The study was divided in two steps. In the first, preliminary step, an anonymous questionnaire was administered to HCWs containing a set of questions in order to gain information about the number of subjects willing to undergo the vaccination and the reasons that led others toits rejection. In the second step, vaccination campaigns were carried out preparing an appropriate vaccination calendar that was communicated to all interested Units and vaccination points located in various wards.

RESULTS

We found a slightly improved compliance trend, from an average of 2.3% in the previous years to 3.3% in 2014 and 7.4% in 2015.

CONCLUSIONS

Despite the observed increase, the adherence remains very low. We found that the main causes of this result are the fear of adverse effects, the negligence and indolence of the same workers and a lack of risk perception of contracting the disease and transmitting it to patients. Our work stressed the importance of offering correct information and of meeting the needs of HCWs, often unable to leave their ward for the excess workload. This could be, in future years, one of the possible solutions to increase vaccination adherence.

Seroprevalence of hev antibodies in a sample of pregnant women in the city of Messina

BACKGROUND

Hepatitis E virus (HEV) is widespread in developing countries and the disease is also increasing in the developed ones. This infection in pregnancy can cause spontaneous abortion and neonatal death in 56% of newborns.

STUDY DESIGN

The study was conducted on a sample of 352 pregnant women, 326 Italian and 26 foreign, in order to confirm the presence of HEV in our territory, to analyze wrong habits of the population and to suggest preventive actions against the risk to contract the infection during pregnancy.

METHODS

We asked all women under study to fill an anonymous questionnaire immediately before taking a venous blood samples to determine the presence of anti-HEV antibodies. The questionnaire contained a set of questions to gain information about lifestyles and risk factors to contract HEV.

RESULTS

The questionnaire revealed that a portion of the tested women have risk behaviours, as consumption of raw or undercooked food, eating unwashed food and traveling to endemic areas. The percentage of women positive for HEV antibodies was 3.4%, in agreement with national data; all the women were Italian.

CONCLUSIONS

This study confirms the circulation of HEV in the city of Messina. For this reason, it is highly recommended to disseminate hygienic and appropriate behaviours and feeding habits in order to prevent the risk to contract the infection.

Response to anti-HBV vaccine and 10-year follow-up of antibody levels in healthcare workers

BACKGROUND

Despite improvements in public health and antiviral treatments, vaccination is still the most effective means of prevention of hepatitis B virus (HBV) infection. However, little is known about the duration of protection given by the anti-HBV vaccine. Healthcare workers represent a category at risk not only of contracting infection but also of being a source of contagion to patients.

OBJECTIVES

To assess individual responses to the anti-HBV vaccine and duration of protection 10 years after its administration in a cohort of healthcare workers employed by the University Hospital 'G. Martino' in Messina, Italy.

METHODS

One hundred and seventy medical staff who had been vaccinated following an incident carrying risk of HBV infection were included in this study. The group was followed over a 10-year period, and HBV antibody levels were assessed using an automated microparticle enzyme immunoassay.

RESULTS

Protective antibody levels (≥10 mIU/ml) were found in 65% of subjects who had completed the full vaccine schedule (three doses) and in 35% of subjects who had only received one or two doses of anti-HBV vaccine. Moreover, 10 years after vaccination, HBV antibody levels were inversely related to age at vaccination (P < 0.001). No differences were found between males and females.

CONCLUSIONS

This study, in line with the literature, shows the importance of completing the full vaccine schedule (three doses). Moreover, in order to have an effective and durable antibody response and avoid the risk of contracting HBV after an injury at work, it is important to recommend anti-HBV vaccination at a young age, ideally during childhood in accordance with the national vaccination policy.

Structural and functional properties of hemocyanin from Cyanagraea praedator, a deep-sea hydrothermal vent crab

Cyanagraea praedator (Crustacea: Decapoda: Brachyura) is an endemic species of the East Pacific Rise hydrothermal vents, living in the upper part of black smoker chimneys. Because we were seeking species that have made respiratory adaptations to the hydrothermal environment, we looked at Cyanograea hemocyanin (Hc) and determined its quaternary structure and the oxygen-binding properties in relation to temperature, pH, and lactate. C. praedator Hc is composed of dodecamers and hexamers, with dodecamers formed by the perpendicular association of two hexamers. The composition of these polymers was determined by electrophoresis and, for the first time, by electrospray mass spectrometry. Dodecamers and hexamers are composed of six subunits common to the two forms, with molecular mass ranging from 75,008 Da to 75,534 Da. In addition, we found two dodecamer-specific subunits, at 75,419 Da and 75,629 Da. The native hemocyanin possesses a high oxygen affinity (P(50) varies between 4 and 10 Torr at pH 7.5, 15 degrees C) and a large Bohr coefficient (Delta log P(50)/DeltapH approximately -1.8). Oxygen affinity is not affected by lactate or, surprisingly, temperature between 5 degrees C and 35 degrees C (DeltaH = 1.16 kJ/mol(1) 5-35 degrees C). Dialysis of native hemolymph elicited a significant increase in Hc-O(2) affinity (DeltaP(50) = 2.5 Torr at pH 7.5), an effect opposite the usual trend observed for crustacean hemocyanins. In this article these functional properties are interpreted in relation to characteristics of the environment.

Restoration of lateral hand grasp using natural sensors

A closed-loop control system for controlling the key grip of a C6 tetraplegic patient was developed. Natural sensors served as the source of the feedback signal. The neural signals from cutaneous receptors were picked up by an implanted cuff electrode placed around the radial branch of the median nerve innervating the lateral part of the index finger. Mechanical stress applied to the skin, like pressure and slips, resulted in an increase in amplitude of the recorded neural signal. The goal of the study was to determine whether the recorded neural signals were able to indicate the slip of an object during lateral grasp and whether the slip could be stopped by increasing the grasp force through functional electrical stimulation of the thumb adductor and flexor.

Somatosensory control of precision grip during unpredictable pulling loads. II. Changes in load force rate

In the previous paper regarding the somatosensory control of the human precision grip, we concluded that the elicited automatic grip force adjustments are graded by the amplitude of the imposed loads when restraining an 'active' object subjected to unpredictable pulling forces (Johansson et al. 1992a). Using the same subjects and apparatus, the present study examines the capacity to respond to imposed load forces applied at various rates. Grip and load forces (forces normal and tangential to the grip surfaces) and the position of the object in the pulling direction (distal) were recorded. Trapezoidal load force profiles with plateau amplitudes of 2 N were delivered at the following rates of loading and unloading in an unpredictable sequence: 2 N/s, 4 N/s or 8 N/s. In addition, trials with higher load rate (32 N/s) at a low amplitude (0.7 N) were intermingled. The latencies between the start of the loading and the onset of the grip force response increased with decreasing load force rate. They were 80 +/- 9 ms, 108 +/- 13 ms, 138 +/- 27 ms and 174 +/- 39 ms for the 32, 8, 4 and 2 N/s rates, respectively. These data suggested that the grip response was elicited after a given minimum latency once a load amplitude threshold was exceeded. The amplitude of the initial rapid increase of grip force (i.e., the 'catch-up' response) was scaled by the rate of the load force, whereas its time course was similar for all load rates. This response was thus elicited as a unit, but its amplitude was graded by afferent information about the load rate arising very early during the loading. The scaling of the catch-up response was purposeful since it facilitated a rapid reconciliation of the ratio between the grip and load force to prevent slips. In that sense it apparently also compensated for the varying delays between the loading phase and the resultant grip force responses. However, modification of the catch-up response may occur during its course when the loading rate is altered prior to the grip force response or very early during the catch-up response itself. Hence, afferent information may be utilized continuously in updating the response although its motor expression may be confined to certain time contingencies. Moreover, this updating may take place after an extremely short latency (45-50 ms).(ABSTRACT TRUNCATED AT 400 WORDS)

Somatosensory control of precision grip during unpredictable pulling loads. I. Changes in load force amplitude

In manipulating 'passive' objects, for which the physical properties are stable and therefore predictable, information essential for the adaptation of the motor output to the properties of the current object is principally based on 'anticipatory parameter control' using sensorimotor memories, i.e., an internal representation of the object's properties based on previous manipulative experiences. Somatosensory afferent signals only intervene intermittently according to an 'event driven' control policy. The present study is the first in a series concerning the control of precision grip when manipulating 'active' objects that exert unpredictable forces which cannot be adequately represented in a sensorimotor memory. Consequently, the manipulation may be more reliant on a moment-to-moment sensory control. Subjects who were prevented from seeing the hand used the precision grip to restrain a manipulandum with two parallel grip surfaces attached to a force motor which produced distally directed (pulling) loads tangential to the finger tips. The trapezoidal load profiles consisted of a loading phase (4 N/s), plateau phase and an unloading phase (4 N/s) returning the load force to zero. Three force amplitudes were delivered in an unpredictable sequence; 1 N, 2 N and 4 N. In addition, trials with higher load rate (32 N/s) at a low amplitude (0.7 N), were superimposed on various background loads. The movement of the manipulandum, the load forces and grip forces (normal to the grip surfaces) were recorded at each finger. The grip force automatically changed with the load force during the loading and unloading phases. However, the grip responses were initiated after a brief delay. The response to the loading phase was characterized by an initial fast force increase termed the 'catch-up' response, which apparently compensated for the response delay--the grip force adequately matched the current load demands by the end of the catch-up response. In ramps with longer lasting loading phases (amplitude greater than or equal to 2 N) the catch-up response was followed by a 'tracking' response, during which the grip force increased in parallel with load force and maintained an approximately constant force ratio that prevented frictional slips. The grip force during the hold phase was linearly related to the load force, with an intercept close to the grip force used prior to the loading. Likewise, the grip force responses evoked by the fast loadings superimposed on existing loads followed the same linear relationship.(ABSTRACT TRUNCATED AT 400 WORDS)