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Close encounters in a pediatric ward: measuring face-to-face proximity and mixing patterns with wearable sensors.

Isella L, Romano M, Barrat A, Cattuto C, Colizza V, Van den Broeck W, Gesualdo F, Pandolfi E, Ravà L, Rizzo C, Tozzi AE - PLoS ONE (2011)

Bottom Line: The majority of contacts were of brief duration, but long and frequent contacts especially between patients and caregivers were also found.The obtained results are particularly useful for the study of the spread of respiratory infections, for monitoring critical patterns, and for setting up tailored prevention strategies.Proximity-sensing technology should be considered as a valuable tool for measuring such patterns and evaluating nosocomial prevention strategies in specific settings.

View Article: PubMed Central - PubMed

Affiliation: Complex Networks and Systems Group, Institute for Scientific Interchange Foundation, Torino, Italy.

ABSTRACT

Background: Nosocomial infections place a substantial burden on health care systems and represent one of the major issues in current public health, requiring notable efforts for its prevention. Understanding the dynamics of infection transmission in a hospital setting is essential for tailoring interventions and predicting the spread among individuals. Mathematical models need to be informed with accurate data on contacts among individuals.

Methods and findings: We used wearable active Radio-Frequency Identification Devices (RFID) to detect face-to-face contacts among individuals with a spatial resolution of about 1.5 meters, and a time resolution of 20 seconds. The study was conducted in a general pediatrics hospital ward, during a one-week period, and included 119 participants, with 51 health care workers, 37 patients, and 31 caregivers. Nearly 16,000 contacts were recorded during the study period, with a median of approximately 20 contacts per participants per day. Overall, 25% of the contacts involved a ward assistant, 23% a nurse, 22% a patient, 22% a caregiver, and 8% a physician. The majority of contacts were of brief duration, but long and frequent contacts especially between patients and caregivers were also found. In the setting under study, caregivers do not represent a significant potential for infection spread to a large number of individuals, as their interactions mainly involve the corresponding patient. Nurses would deserve priority in prevention strategies due to their central role in the potential propagation paths of infections.

Conclusions: Our study shows the feasibility of accurate and reproducible measures of the pattern of contacts in a hospital setting. The obtained results are particularly useful for the study of the spread of respiratory infections, for monitoring critical patterns, and for setting up tailored prevention strategies. Proximity-sensing technology should be considered as a valuable tool for measuring such patterns and evaluating nosocomial prevention strategies in specific settings.

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Related in: MedlinePlus

Boxplots for the distributions of cumulative contact durations  between individuals belonging to given role pairs (horizontal axis), given the occurrence of a contact.Here we only consider non-zero values of , and contact durations are expressed in seconds and are normalized to a 24-hour interval. On normalizing, the experimental resolution of 20 seconds yields the lowest value of 2.5 seconds visible in the figure. As usual, the bottom and top of the boxes correspond to the 25th and 75th percentiles, and the horizontal segment indicates the median. The ends of the whiskers correspond to the 5th and 95th percentiles. The dots are outliers located outside the 90% confidence interval, i.e., events falling below the 5th percentile or above the 95th percentile.
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pone-0017144-g004: Boxplots for the distributions of cumulative contact durations between individuals belonging to given role pairs (horizontal axis), given the occurrence of a contact.Here we only consider non-zero values of , and contact durations are expressed in seconds and are normalized to a 24-hour interval. On normalizing, the experimental resolution of 20 seconds yields the lowest value of 2.5 seconds visible in the figure. As usual, the bottom and top of the boxes correspond to the 25th and 75th percentiles, and the horizontal segment indicates the median. The ends of the whiskers correspond to the 5th and 95th percentiles. The dots are outliers located outside the 90% confidence interval, i.e., events falling below the 5th percentile or above the 95th percentile.

Mentions: The computed quantities show large heterogeneities among individuals of the same class and across the various days of the study. Figure 3A reports the probability density function (number of events in each bin divided by the bin width) of the number of contacts obtained for each class of participants. The distribution for a given class is defined as the probability that a randomly selected participant of that class has established a total of contacts with any other individual during a given day. Large fluctuations are visible in the number of contacts per individual, varying over 2 or 3 orders of magnitude, and the largest fluctuations are observed in the case of patients and caregivers. Figure 3B reports the probability density functions of the cumulative time in contact, for individuals of each class. The longest durations, up to nearly 4 hours, are observed for contacts that involve at least one patient or one caregiver. The observed broad probability distributions are typical of human-driven systems and have been already observed elsewhere [25], [26]. Figure 4 shows boxplots for the distributions of cumulative contact durations between pairs of individuals belonging to given categories. Overall, about 95% of the contacts have a cumulated duration of less than 4 minutes.


Close encounters in a pediatric ward: measuring face-to-face proximity and mixing patterns with wearable sensors.

Isella L, Romano M, Barrat A, Cattuto C, Colizza V, Van den Broeck W, Gesualdo F, Pandolfi E, Ravà L, Rizzo C, Tozzi AE - PLoS ONE (2011)

Boxplots for the distributions of cumulative contact durations  between individuals belonging to given role pairs (horizontal axis), given the occurrence of a contact.Here we only consider non-zero values of , and contact durations are expressed in seconds and are normalized to a 24-hour interval. On normalizing, the experimental resolution of 20 seconds yields the lowest value of 2.5 seconds visible in the figure. As usual, the bottom and top of the boxes correspond to the 25th and 75th percentiles, and the horizontal segment indicates the median. The ends of the whiskers correspond to the 5th and 95th percentiles. The dots are outliers located outside the 90% confidence interval, i.e., events falling below the 5th percentile or above the 95th percentile.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3046133&req=5

pone-0017144-g004: Boxplots for the distributions of cumulative contact durations between individuals belonging to given role pairs (horizontal axis), given the occurrence of a contact.Here we only consider non-zero values of , and contact durations are expressed in seconds and are normalized to a 24-hour interval. On normalizing, the experimental resolution of 20 seconds yields the lowest value of 2.5 seconds visible in the figure. As usual, the bottom and top of the boxes correspond to the 25th and 75th percentiles, and the horizontal segment indicates the median. The ends of the whiskers correspond to the 5th and 95th percentiles. The dots are outliers located outside the 90% confidence interval, i.e., events falling below the 5th percentile or above the 95th percentile.
Mentions: The computed quantities show large heterogeneities among individuals of the same class and across the various days of the study. Figure 3A reports the probability density function (number of events in each bin divided by the bin width) of the number of contacts obtained for each class of participants. The distribution for a given class is defined as the probability that a randomly selected participant of that class has established a total of contacts with any other individual during a given day. Large fluctuations are visible in the number of contacts per individual, varying over 2 or 3 orders of magnitude, and the largest fluctuations are observed in the case of patients and caregivers. Figure 3B reports the probability density functions of the cumulative time in contact, for individuals of each class. The longest durations, up to nearly 4 hours, are observed for contacts that involve at least one patient or one caregiver. The observed broad probability distributions are typical of human-driven systems and have been already observed elsewhere [25], [26]. Figure 4 shows boxplots for the distributions of cumulative contact durations between pairs of individuals belonging to given categories. Overall, about 95% of the contacts have a cumulated duration of less than 4 minutes.

Bottom Line: The majority of contacts were of brief duration, but long and frequent contacts especially between patients and caregivers were also found.The obtained results are particularly useful for the study of the spread of respiratory infections, for monitoring critical patterns, and for setting up tailored prevention strategies.Proximity-sensing technology should be considered as a valuable tool for measuring such patterns and evaluating nosocomial prevention strategies in specific settings.

View Article: PubMed Central - PubMed

Affiliation: Complex Networks and Systems Group, Institute for Scientific Interchange Foundation, Torino, Italy.

ABSTRACT

Background: Nosocomial infections place a substantial burden on health care systems and represent one of the major issues in current public health, requiring notable efforts for its prevention. Understanding the dynamics of infection transmission in a hospital setting is essential for tailoring interventions and predicting the spread among individuals. Mathematical models need to be informed with accurate data on contacts among individuals.

Methods and findings: We used wearable active Radio-Frequency Identification Devices (RFID) to detect face-to-face contacts among individuals with a spatial resolution of about 1.5 meters, and a time resolution of 20 seconds. The study was conducted in a general pediatrics hospital ward, during a one-week period, and included 119 participants, with 51 health care workers, 37 patients, and 31 caregivers. Nearly 16,000 contacts were recorded during the study period, with a median of approximately 20 contacts per participants per day. Overall, 25% of the contacts involved a ward assistant, 23% a nurse, 22% a patient, 22% a caregiver, and 8% a physician. The majority of contacts were of brief duration, but long and frequent contacts especially between patients and caregivers were also found. In the setting under study, caregivers do not represent a significant potential for infection spread to a large number of individuals, as their interactions mainly involve the corresponding patient. Nurses would deserve priority in prevention strategies due to their central role in the potential propagation paths of infections.

Conclusions: Our study shows the feasibility of accurate and reproducible measures of the pattern of contacts in a hospital setting. The obtained results are particularly useful for the study of the spread of respiratory infections, for monitoring critical patterns, and for setting up tailored prevention strategies. Proximity-sensing technology should be considered as a valuable tool for measuring such patterns and evaluating nosocomial prevention strategies in specific settings.

Show MeSH
Related in: MedlinePlus