Computational fluid dynamics study on the influence of an alternate ventilation configuration on the possible flow path of infectious cough aerosols in a mock airborne infection isolation room

When infectious epidemics occur, they can be perpetuated within health care settings, potentially resulting in severe health care workforce absenteeism, morbidity, mortality, and economic losses. The ventilation system configuration of an airborne infection isolation room is one factor that can play a role in protecting health care workers from infectious patient bioaerosols. Though commonly associated with airborne infectious diseases, the airborne infection isolation room design can also impact other transmission routes such as short-range airborne as well as fomite and contact transmission routes that are impacted by contagion concentration and recirculation. This article presents a computational fluid dynamics study on the influence of the ventilation configuration on the possible flow path of bioaerosol dispersal behavior in a mock airborne infection isolation room. At first, a mock airborne infection isolation room was modeled that has the room geometry and layout, ventilation parameters, and pressurization corresponding to that of a traditional ceiling-mounted ventilation arrangement observed in existing hospitals. An alternate ventilation configuration was then modeled to retain the linear supply diffuser in the original mock airborne infection isolation room but interchanging the square supply and exhaust locations to place the exhaust closer to the patient source and allow clean air from supply vents to flow in clean-to-dirty flow paths, originating in uncontaminated parts of the room prior to entering the contaminated patient's air space. The modeled alternate airborne infection isolation room ventilation rate was 12 air changes per hour. Two human breathing models were used to simulate a source patient and a receiving health care worker. A patient cough cycle was introduced into the simulation, and the airborne infection dispersal was tracked in time using a multi-phase flow simulation approach. The results from the alternate configuration revealed that the cough aerosols were pulled by the exhaust vent without encountering the health care worker by 0.93 s after patient coughs and the particles were controlled as the aerosols' flow path was uninterrupted by an air particle streamline from patient to the ceiling exhaust venting out cough aerosols. However, not all the aerosols were vented out of the room. The remaining cough aerosols entered the health care worker's breathing zone by 0.98 s. This resulted in one of the critical stages in terms of the health care worker's exposure to airborne virus and presented the opportunity for the health care worker to suffer adverse health effects from the inhalation of cough aerosols. Within 2 s, the cough aerosols reentered and recirculated within the patient and health care worker's surroundings resulting in pockets of old contaminated air. By this time, coalescence losses decreased as the aerosol were no longer in very close proximity and their movement was primarily influenced by the airborne infection isolation room airflow patterns. In the patient and health care worker's area away from the supply, the fresh air supply failed to reach this part of the room to quickly dilute the cough aerosol concentration. The exhaust was also found to have minimal effect upon cough aerosol removal, except for those areas with high exhaust velocities, very close to the exhaust grill. Within 5-20 s after a patient's cough, the aerosols tended to break up to form smaller sized aerosols of less than one micron diameter. They remained airborne and entrained back into the supply air stream, spreading into the entire room. The suspended aerosols resulted in the floating time of more than 21 s in the room due to one cough cycle. The duration of airborne contagion in the room and its prolonged exposure to the health care worker is likely to happen due to successive coughing cycles. Hence, the evaluated alternate airborne infection isolation room is not effective in removing at least 38% particles exposed to health care worker within the first second of a patient's cough.

Influenza Vaccination of Healthcare Workers in the United States, 1989-2002

Objectives.

We sought to estimate influenza vaccination coverage among healthcare workers (HCWs) in the United States during 1989-2002 and to identify factors associated with vaccination in this group. The Advisory Committee on Immunization Practices (ACIP) recommends annual influenza vaccination for HCWs to reduce transmission of influenza to patients at high risk for serious complications of influenza.

Design.

Analysis of cross-sectional data from 1989-2002 surveys conducted by the National Health Interview Survey (NHIS). The outcome measure was self-reported influenza vaccination in the past 12 months. Bivariate and multivariate analysis of 2002 NHIS data.

Setting.

Household interviews conducted during 1989-2002, weighted to reflect the noninstitutionalized, civilian US population.

Participants.

Adults aged 18 years or older participated in the study. A total of 2,089 were employed in healthcare occupations or settings in 2002, and 17,160 were employed in nonhealthcare occupations or settings.

Results.

The influenza vaccination rate among US HCWs increased from 10.0% in 1989 to 38.4% in 2002, with no significant change since 1997. In a multivariate model that included data from the 2002 NHIS, factors associated with a higher rate of influenza vaccination among HCWs aged 18-64 years included age of 50 years or older (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1-2.1), hospital employee status (OR, 1.5; 95% CI, 1.2-1.9), 1 or more visits to the office of a healthcare professional in the past 12 months (OR, 1.5; 95% CI, 1.1-2.2), receipt of employer-provided health insurance (OR, 1.5; 95% CI, 1.1-2.1), a history of pneumococcal vaccination (OR, 3.9; 95% CI, 2.5-6.1), and history of hepatitis B vaccination (OR, 1.9; 95% CI, 1.4-2.4). Non-Hispanic black persons were less likely to be vaccinated (OR, 0.6; 95% CI, 0.5-0.9) than non-Hispanic white persons. There were no significant differences in vaccination levels according to HCW occupation category.

Conclusions.

Influenza immunization among HCWs reached a plateau during 1997-2002. New strategies are needed to encourage US HCWs to receive influenza vaccination to prevent influenza illness in themselves and transmission of influenza to vulnerable patients.

Preventing Nosocomial Influenza by Improving the Vaccine Acceptance Rate of Clinicians

Objectives:

To assess the effects of interventions to prevent transmission of influenza and to increase employee compliance with influenza vaccination.

Design:

The change in the proportion of hospitalized patients with laboratory-confirmed nosocomial influenza was observed over time and assessed using chi-square for trend analysis. The association between nosocomial influenza in patients and healthcare worker (HCW) compliance with vaccine was assessed by logistic regression.

Setting:

A 600-bed, tertiary-care academic hospital.

Methods:

After an outbreak of influenza A at this hospital in 1988, a mobile cart program was instituted with increased efforts to motivate employees to be vaccinated and furloughed when ill as well as new measures to prevent nosocomial spread.

Results:

HCW vaccination rates increased from 4% in 1987–1988 to 67% in 1999–2000 (P < .0001). Proportions of nosocomially acquired influenza cases among employees or patients both declined significantly (P < .0001). Logistic regression analysis revealed a significant inverse association between HCW compliance with vaccination and the rate of nosocomial influenza among patients (P < .001).

Conclusion:

A mobile cart vaccination program and an increased emphasis on HCWs to receive the vaccine were associated with a significant increase in vaccine acceptance and a significant decrease in the rate of nosocomial influenza among patients.

Attitudes and Practices Regarding Influenza Vaccination Among Healthcare Workers Providing Services to Individuals With Spinal Cord Injuries and Disorders

Objective:

To examine influenza vaccination status and predictors for vaccine receipt among healthcare workers (HCWs) caring for patients with spinal cord injuries and disorders.

Design:

Cross-sectional, nationwide anonymous survey.

Setting:

Twenty-three Veterans Affairs spinal cord injury centers.

Participants:

One thousand five hundred fifty-six HCWs.

Methods:

The primary outcome was staff vaccination status. Independent variables included staff demographic and employment characteristics, health status, attitudes and beliefs about the vaccine, and implications for its use.

Results:

The staff vaccination rate was 51%. Leading motivators of vaccine receipt were self-protection (77%) and patient protection (49%). The most common reasons for nonreceipt were concerns about side effects (49%), preventive quality (20%), and inconvenience (14%). Logistic regression results suggested that age of 50 years or older (OR, 1.47; P = .021), male gender (OR, 2.50; P < .001), strong belief in vaccine effectiveness (OR, 19.03; P = .008), and importance of HCW vaccination (OR, 20.50; P = .005) significantly increased the probability of vaccination. Recommending the vaccine to coworkers, patients, or patients' families was also associated with HCW vaccination (OR, 3.20; P < .001). Providers who did not believe the vaccine was protective (P < .001) or effective P < .001) were less likely to recommend it to patients.

Conclusions:

Strategies to increase vaccination rates among HCWs should address concerns about side effects, effectiveness, and protective value of the vaccine and access to it. The impact of provider recommendations should be stressed. Vaccination and subsequent prevention of illness may limit morbidity and mortality, thus benefiting HCWs, healthcare facilities, and patients.

Correlates of improved influenza vaccination of healthcare personnel: a survey of hospitals in Louisiana

OBJECTIVE

To describe practices for influenza vaccination of healthcare personnel (HCP) with emphasis on correlates of increased vaccination rates.

DESIGN

Survey.

PARTICIPANTS

Volunteer sample of hospitals in Louisiana.

METHODS

All hospitals in Louisiana were invited to participate. A 17-item questionnaire inquired about the hospital type, patients served, characteristics of the vaccination campaign, and the resulting vaccination rate.

RESULTS

Of 254 hospitals, 153 (60%) participated and were included in the 124 responses that were received. Most programs (64%) required that HCP either receive the vaccine or sign a declination form, and the rest were exclusively voluntary (36%); no program made vaccination a condition of employment. The median vaccination rate was 67%, and the vaccination rate was higher among hospitals that were accredited by the Joint Commission; provided acute care; served children, pregnant women, oncology patients, or intensive care unit patients; required a signed declination form; or imposed consequences for unvaccinated HCP (the most common of which was to require that a mask be worn on patient contact). Hospitals that provided free vaccine, made vaccine widely available, advertised the program extensively, required a declination form, and imposed consequences had the highest vaccination rates (median, 86%; range, 81%-91%).

CONCLUSIONS

The rate of influenza vaccination of HCP remains low among the hospitals surveyed. Recommended practices may not be enough to reach 90% vaccination rates unless a signed declination requirement and consequences are implemented. Wearing a mask is a strong consequence. Demanding influenza vaccination as a condition of employment was not reported as a practice by the participating hospitals.

[Determinants of influenza vaccination in health staff: 2009-2010 season]

OBJECTIVES

To determine vaccination coverage against seasonal influenza and the new A (H1N1) influenza virus among healthcare personnel during the 2009-2010 season and to identify its determining factors.

METHODS

We performed a cross-sectional study among healthcare staff at the General University Hospital in Alicante (Spain) during the 2008-2009 and 2009-2010 influenza vaccination campaigns. The 2009-2010 vaccination campaign was subdivided into two phases. In the first phase, from 1st October to 19th November, 2009, the seasonal influenza vaccine was administered; in the second phase, from 16th November to 30th December, 2009, vaccination against the new A (H1N1) influenza virus was performed. Each of the vaccine programs was preceded by a specific vaccination promotion campaign. Healthcare staff were asked to complete a brief self-administered questionnaire containing a list of reasons for being vaccinated. Coverage during both vaccination campaigns was calculated, and the results, both overall and for each profession, were then compared using a Chi-square test.

RESULTS

Coverage against seasonal influenza was 31% and that against the new A (H1N1) influenza virus was 22.2% (p<0.05); these percentages were 36% and 34% respectively in medical personnel (NS), 33% and 24% respectively in nursing personnel (p<0.001), and 21% and 12% respectively in nursing assistants (p<0.001). The main reason given for being vaccinated was self-protection.

CONCLUSIONS

The low coverage achieved is a public health problem. Specific intervention programs should be implemented.

Controversies in vaccine mandates

Policies that mandate immunization have always been controversial. The controversies take different forms in different contexts. For routine childhood immunizations, many parents have fears about both short- and long-term side effects. Parental worries change as the rate of vaccination in the community changes. When most children are vaccinated, parents worry more about side effects than they do about disease. Because of these worries, immunization rates go down. As immunization rates go down, disease rates go up, and parents worry less about side effects of vaccination and more about the complications of the diseases. Immunization rates then go up. For teenagers, controversies arise about the criteria that should guide policies that mandate, rather than merely recommend and encourage, certain immunizations. In particular, policy makers have questioned whether immunizations for human papillomavirus, or other diseases that are not contagious, should be required. For healthcare workers, debates have focused on the strength of institutional mandates. For years, experts have recommended that all healthcare workers be immunized against influenza. Immunizations for other infections including pertussis, measles, mumps, and hepatitis are encouraged but few hospitals have mandated such immunizations-instead, they rely on incentives and education. Pandemics present a different set of problems as people demand vaccines that are in short supply. These issues erupt into controversy on a regular basis. Physicians and policy makers must respond both in their individual practices and as advisory experts to national and state agencies. The articles in this volume will discuss the evolution of national immunization programs in these various settings. We will critically examine the role of vaccine mandates. We will discuss ways that practitioners and public health officials should deal with vaccine refusal. We will contrast responses of the population as a whole, within the healthcare setting, and in the setting of pandemic influenza.

Seasonal influenza risk in hospital healthcare workers is more strongly associated with household than occupational exposures: results from a prospective cohort study in Berlin, Germany, 2006/07

BACKGROUND

Influenza immunisation for healthcare workers is encouraged to protect their often vulnerable patients but also due to a perceived higher risk for influenza. We aimed to compare the risk of influenza infection in healthcare workers in acute hospital care with that in non-healthcare workers over the same season.

METHODS

We conducted a prospective, multicentre cohort study during the 2006/07 influenza season in Berlin, Germany. Recruited participants gave serum samples before and after the season, and completed questionnaires to determine their relevant exposures and possible confounding factors. The main outcome measure was serologically confirmed influenza infection (SCII), defined as a fourfold or greater rise in haemagglutination inhibition antibody titres to a circulating strain of influenza (with post-season titre at least 1:40).Weekly mobile phone text messages were used to prompt participants to report respiratory illnesses during the influenza season. A logistic regression model was used to assess the influence of potential risk factors.

RESULTS

We recruited 250 hospital healthcare workers (mean age 35.7 years) and 486 non-healthcare workers (mean age 39.2 years) from administrative centres, blood donors and colleges.Overall SCII attack rate was 10.6%. Being a healthcare worker was not a risk factor for SCII (relative risk 1.1, p = 0.70). The final multivariate model had three significant factors: living with children (odds ratio [OR] 3.7, p = 0.005), immunization (OR 0.50, p = 0.02), and--among persons living in households without children--ownership of a car (OR 3.0, p = 0.02). Living with three or more children (OR 13.8, p < 0.01) was a greater risk than living with one or two children (OR 5.3, p = 0.02). 30% of participants with SCII reported no respiratory illness. Healthcare workers were at slightly higher risk of reporting any respiratory infection than controls (adjusted OR 1.3, p = 0.04, n = 850).

CONCLUSIONS

Our results suggest that healthcare workers in hospitals do not have a higher risk of influenza than non-healthcare workers, although their risk of any respiratory infection is slightly raised. Household contacts seem to be more important than exposure to patients. Car ownership is a surprise finding which needs further exploration. Asymptomatic infections are common, accounting for around a third of serologically confirmed infections.

Influenza in the neonatal intensive care unit

Influenza has historically been an uncommon illness in the newborn period, although epidemic outbreaks in neonatal intensive care units have been described. There is currently significant concern about the possibility of a new pandemic of influenza in the near future. During a pandemic neonates are likely to be exposed, with significant illness more likely in pre-term newborns due to reduced levels of passively transferred protective maternal antibodies. While newer therapies have been shown to be effective in reducing the severity of illness in adults and children, such therapies are untried in neonates. Supportive care and measures to contain and prevent spread of infection may well be the most important measures in the event of a neonate acquiring influenza, including the avian variety.

Use of a mobile cart influenza program for vaccination of hospital employees

OBJECTIVE

Rates of annual influenza vaccination of healthcare workers (HCWs) remained low in our university hospital. This study was conducted to evaluate the impact of a mobile cart influenza vaccination program on HCW vaccination.

METHODS

From 2000 to 2002, the employee health service continued its annual influenza vaccination program and the mobile cart program was implemented throughout the institution. This program offered influenza vaccination to all employees directly on the units. Each employee completed a questionnaire. Vaccination rates were analyzed using the Mantel-Haenszel test.

RESULTS

The program proposed vaccination to 50% to 56% of the employees. Among the nonvaccinated employees, 52% to 53% agreed to be vaccinated. The compliance with vaccination varied from 61% to 77% among physicians and medical students and from 38% to 55% among nurses and other employees. Vaccination of the chief or associate professor of the unit was associated with a higher vaccination rate of the medical staff (P < .01). Altogether, the vaccination program led to an increase in influenza vaccination among employees from 6% in 1998 and 7% in 1999 before the mobile cart program to 32% in 2000, 35% in 2001, and 32% in 2002 (P < .001).

CONCLUSIONS

The mobile cart program was associated with a significantly increased vaccination acceptance. Our study was able to identify HCW groups for which the mobile cart was effective and highlight the role of the unit head in its success.

Improving influenza immunization rates among healthcare workers caring for high-risk pediatric patients

OBJECTIVE

To assess influenza vaccination rates of healthcare workers (HCWs) in neonatal intensive care units (NICUs), pediatric intensive care units (PICUs), and oncology units in Pediatric Prevention Network (PPN) hospitals.

PARTICIPANTS

Infection control practitioners and HCWs in NICUs, PICUs, and oncology units.

METHODS

In November 2000, posters, electronic copies of a slide presentation, and an influenza fact sheet were distributed to 32 of 76 PPN hospitals. In January 2001, a survey was distributed to PPN hospital participants to obtain information about the immunization campaigns. On February 7, 2001, a survey of influenza immunization was conducted among HCWs in NICU, PICU, and oncology units at participating hospitals.

RESULTS

Infection control practitioners from 19 (25%) of the 76 PPN hospitals completed the surveys. The median influenza immunization rate was 43% (range, 12% to 63%), with 7 hospitals exceeding 50%. HCWs (n = 1123) at 15 PPN hospitals completed a survey; 53% of HCWs reported receiving influenza immunization. Immunization rates varied by work site: 52% in NICUs and PICUs compared with 60% in oncology units. Mobile carts and PPN educational fact cards were associated with higher rates among these subpopulations (P < .001) (361 [63%] of 575 vs 236 [44%] of 541 for mobile carts; 378 [60%] of 633 vs 219 [45%] of 483 for fact cards).

CONCLUSION

Despite delayed distribution of influenza vaccine during the 2000-2001 season, immunization rates at 7 hospitals and among HCWs in high-risk units exceeded the National Association of Children's Hospitals and Related Institutions goal of 50%.

Influenza in the intensive care unit

Influenza remains an important epidemic viral infection. Thousands of deaths occur and billions of dollars are spent each year with influenza-related illnesses. Morbidity and mortality are largely attributed to respiratory complications that may require intensive care unit (ICU) admission. Medical and neonatal ICUs, transplant units, chronic-care wards, and nursing homes are at increased risk for nosocomial outbreaks of influenza, which are characterized by abrupt onset and rapid spread. In this article, the authors review the current concepts, recent advances, and management strategies in influenza-associated pneumonia. Pertinent issues to the critical care practitioner are discussed in detail.

Influenza vaccination of staff in aged care facilities in the ACT: how can we improve the uptake of influenza vaccine?

OBJECTIVE

To examine the self-reported uptake of influenza vaccine by staff in residential aged care facilities in the Australian Capital Territory (ACT), and the factors influencing vaccine uptake by staff.

METHODS

Two confidential cross-sectional surveys were conducted in all (n = 19) residential aged care facilities in the ACT in June 2000. An interview with directors of each facility collected information on the institutional policy and practices for influenza vaccination. An anonymous postal survey of staff collected information on self-reported influenza vaccination status and staff awareness and attitudes to the vaccination.

RESULTS

All directors were interviewed (n = 19) and 50% of staff questionnaires (n = 587) were completed. Of respondents, 28% reported receiving influenza vaccine for the 2000 influenza season. Uptake of the vaccine was associated with particular policies and practices of facilities such as: organisation of vaccination for staff (OR 2.52, CI 1.38-4.59, p < 0.001); provision of reminders to staff (OR 2.73, CI 1.70-4.06, p < 0.001); and provision of information on the need for vaccination (OR 1.94, CI 1.03-3.67, p < 0.001). Other factors significantly associated with influenza vaccine uptake included: previous uptake of the vaccine (OR 52.2, CI 35.2-77.4, p < 0.001), vaccination arranged by the workplace (OR 4.02, CI 2.66-6.07, p < 0.001), and awareness of recommendations for staff employed in aged care facilities (OR 3.66, CI 2.28-5.85, p < 0.001). The main reasons given for not receiving the vaccine were the belief that it had significant side effects (42%, n = 146), and concerns about its effectiveness (32%, n = 109).

CONCLUSIONS

This study identified a number of factors that can be incorporated into strategies and programs to improve uptake of influenza vaccine by staff in residential aged care facilities.

Transmission of influenza: implications for control in health care settings

Annual influenza epidemics in the United States result in an average of >36,000 deaths and 114,000 hospitalizations. Influenza can spread rapidly to patients and health care personnel in health care settings after influenza is introduced by visitors, staff, or patients. Influenza outbreaks in health care facilities can have potentially devastating consequences, particularly for immunocompromised persons. Although vaccination of health care personnel and patients is the primary means to prevent and control outbreaks of influenza in health care settings, antiviral influenza medications and isolation precautions are important adjuncts. Although droplet transmission is thought to be the primary mode of influenza transmission, limited evidence is available to support the relative clinical importance of contact, droplet, and droplet nuclei (airborne) transmission of influenza. In this article, the results of studies on the modes of influenza transmission and their relevant isolation precautions are reviewed.

Disruption of services in an internal medicine unit due to a nosocomial influenza outbreak

OBJECTIVE

To describe a nosocomial influenza A outbreak, how it was managed, what impact it had on subsequent delivery of health care, and the additional charges attributable to it

DESIGN

Prospective cohort study and microbiological investigation.

SETTING

One internal medicine unit in an acute care, university-affiliated hospital.

PARTICIPANTS

Twenty-three patients and 22 staff members from February 28 to March 6, 1999.

RESULTS

Attack rates were 41% (9 of 22) among patients and 23% (5 of 22) among staff members, with 3 of 14 cases being classified as "certain." The influenza virus isolates were typed as A/SYDNEY/5/97 (H3N2). The index case was a patient who shared a room with the first nosocomial case. Vaccination rates for influenza virus were 43% (10 of 23) among patients and 36% (8 of 22) among staff members. The outbreak resulted in staff members' taking 14 person-days of sick leave. Furthermore, 8 scheduled admissions were postponed and all emergency admissions were suspended for 11 days. Hospital charges attributable to the influenza outbreak totaled $34,179 and the average extra charge per infected patient was $3,798.

CONCLUSIONS

Nosocomial influenza outbreaks increase charges and alter the quality of care delivered in acute care settings. Strategies for their prevention need to be evaluated in acute care settings.

Clinical and economic evaluation of rapid influenza a virus testing in nursing homes in calgary, Canada

The incremental benefits and costs of a rapid influenza A virus infection diagnostic service were studied in nursing homes in Calgary, Canada, during a single influenza season. The service was used to test 159 patients with suspected infection in a group of "experimental" nursing homes and results were compared with those for a group of "control" homes. An equal number of cases of influenza were identified in each group. Twenty-eight patients (17.6%) had confirmed cases, and 63 patients (39.6%) had probable cases. A rapid viral test result was provided much faster for patients in the experimental homes (P=.005). Both groups had the same median attack rate for influenza A virus. In experimental homes, the duration of the outbreak was shorter (P=.03), and the cost of laboratory testing and the total cost (less the hospital cost) tended to be lower (P<.2). The rapid testing service also tended to lower the overall use of resources.

Influenza in the acute hospital setting

Influenza poses special hazards inside healthcare facilities and can cause explosive outbreaks of illness. Healthcare workers are at risk of acquiring influenza and thus serve as an important reservoir for patients under their care. Annual influenza immunisation of high-risk persons and their contacts, including healthcare workers, is the primary means of preventing nosocomial influenza. Despite influenza vaccine effectiveness, it is substantially underused by healthcare providers. Influenza can be diagnosed by culturing the virus from respiratory secretions and by rapid antigen detection kits; recognition of a nosocomial outbreak is important in order to employ infection-control efforts. Optimal control of influenza in the acute-care setting should focus upon reducing potential influenza reservoirs in the hospital, including: isolating patients with suspected or documented influenza, sending home healthcare providers or staff who exhibit typical symptoms of influenza, and discouraging persons with febrile respiratory illness from visiting the hospital during a known influenza outbreak in the community. (Note: influenza and other respiratory viruses can cause non-febrile illness but are still transmissible.) The antiviral M2 protein inhibitors (amantadine, rimantadine) and neuraminidase inhibitors (zanamivir, oseltamivir) have proven efficacy in treating and preventing influenza illness; however, their role in the prevention and control of influenza in the acute hospital setting remains to be more fully studied.

Exposure Workups

Exposure workups are an important responsibility for infection control personnel. A well-designed plan for investigating exposures, which includes appropriate algorithms, will enable infection control personnel to evaluate exposures rapidly and consistently so that nosocomial transmission is minimized. Infection control personnel should use their own data to develop policies and procedures that suit the needs of their facility. After they have imple-merited the plan, infection control personnel should continue to collect data on exposures so they can continuously improve their performance.