The incidence, duration, risk factors, and age-based variation of missed opportunities to diagnose pertussis: A population-based cohort study

OBJECTIVE

To estimate the incidence, duration and risk factors for diagnostic delays associated with pertussis.

DESIGN

We used longitudinal retrospective insurance claims from the Marketscan Commercial Claims and Encounters, Medicare Supplemental (2001-2020), and Multi-State Medicaid (2014-2018) databases.

SETTING

Inpatient, emergency department, and outpatient visits.

PATIENTS

The study included patients diagnosed with pertussis (International Classification of Diseases [ICD] codes) and receipt of macrolide antibiotic treatment.

METHODS

We estimated the number of visits with pertussis-related symptoms before diagnosis beyond that expected in the absence of diagnostic delays. Using a bootstrapping approach, we estimated the number of visits representing a delay, the number of missed diagnostic opportunities per patient, and the duration of delays. Results were stratified by age groups. We also used a logistic regression model to evaluate potential factors associated with delay.

RESULTS

We identified 20,828 patients meeting inclusion criteria. On average, patients had almost 2 missed opportunities prior to diagnosis, and delay duration was 12 days. Across age groups, the percentage of patients experiencing a delay ranged from 29.7% to 37.6%. The duration of delays increased considerably with age from an average of 5.6 days for patients aged <2 years to 13.8 days for patients aged ≥18 years. Factors associated with increased risk of delays included emergency department visits, telehealth visits, and recent prescriptions for antibiotics not effective against pertussis.

CONCLUSIONS

Diagnostic delays for pertussis are frequent. More work is needed to decrease diagnostic delays, especially among adults. Earlier case identification may play an important role in the response to outbreaks by facilitating treatment, isolation, and improved contact tracing.

Occupational Health Update: Evaluation and Management of Exposures and Postexposure Prophylaxis

Health care personnel (HCP) are at risk of exposure to infectious agents depending on their job duties and other factors. Risks include percutaneous exposure to blood-borne pathogens via sharp injuries (eg, human immunodeficiency virus, hepatitis B virus, hepatitis C virus); exposure by direct contact, droplet, or airborne transmission of pathogens through direct patient care (eg, pertussis, invasive meningococcus infections, tuberculosis); and through indirect contact transmission related to the contaminated health care environment (eg, Clostridioides difficile). Occupational health programs must effectively identify and respond to potential exposures and provide guidance to HCP on postexposure prophylaxis.

Incidence of Healthcare-Associated Influenza-Like Illness After a Primary Care Encounter Among Young Children

BACKGROUND

Despite potential respiratory virus transmission in pediatric clinics, little is known about the risk of healthcare-associated viral infections attributable to outpatient encounters. We evaluated whether exposure to a pediatric clinic visit was associated with subsequent influenza-like illness (ILI).

METHODS

Using electronic health record data, we conducted a retrospective cohort study of all children aged <6 years who presented to a provider in a 29-clinic pediatric primary care network for a non-ILI-related encounter over 2 respiratory virus seasons (September 1, 2012, to April 30, 2014). We defined a risk period for potential healthcare-associated (HA) ILI of 1 to 8 days after a non-ILI clinic visit and identified all cases of ILI to compare the incidences of ILI visits 1 to 8 days after a non-ILI encounter and those of visits >8 days after a non-ILI encounter.

RESULTS

Among 149987 children <6 years of age (mean age, 2.5 years) with ≥1 non-ILI visit during the study period, 531928 total encounters and 13951 (2.9%) ILI encounters were identified; 1941 (13.9%) occurred within the HA-ILI risk window. The incidence rate ratios (IRRs) for ILI 1 to 8 days after compared with ILI >8 days after a non-ILI visit during season 1 were 1.36 (95% confidence interval, 1.22-1.52) among children ≥2 years of age and 1.01 (95% confidence interval, 0.93-1.09) among children <2 years of age. Estimates remained consistent during season 2 and with a risk window of 3, 4, or 9 days.

CONCLUSIONS

Pediatric clinic visits during a respiratory virus season were significantly associated with an increased incidence of subsequent ILI among children aged 2 to 6 years but not among those aged <2 years. These findings support the hypothesis that respiratory virus transmission in a pediatric clinic can result in HA ILI in young children.

Occupational Health Update: Focus on Preventing the Acquisition of Infections with Pre-exposure Prophylaxis and Postexposure Prophylaxis

Health care personnel are commonly exposed to infectious agents via sharp injuries (eg, human immunodeficiency virus, hepatitis B virus, and hepatitis C virus), direct patient care (eg, pertussis and meningococcus), and the contaminated environment (eg, Clostridium difficile). An effective occupational program is a key aspect of preventing acquisition of an infection by offering the following: (1) education of health care personnel regarding proper handling of sharps, early identification and isolation of potentially infectious patients, and hand hygiene; (2) assuring immunity to vaccine-preventable diseases; and, (3) immediate availability of a medical evaluation after a nonprotected exposure to an infectious disease.

Pertussis: Microbiology, Disease, Treatment, and Prevention

Pertussis is a severe respiratory infection caused by Bordetella pertussis, and in 2008, pertussis was associated with an estimated 16 million cases and 195,000 deaths globally. Sizeable outbreaks of pertussis have been reported over the past 5 years, and disease reemergence has been the focus of international attention to develop a deeper understanding of pathogen virulence and genetic evolution of B. pertussis strains. During the past 20 years, the scientific community has recognized pertussis among adults as well as infants and children. Increased recognition that older children and adolescents are at risk for disease and may transmit B. pertussis to younger siblings has underscored the need to better understand the role of innate, humoral, and cell-mediated immunity, including the role of waning immunity. Although recognition of adult pertussis has increased in tandem with a better understanding of B. pertussis pathogenesis, pertussis in neonates and adults can manifest with atypical clinical presentations. Such disease patterns make pertussis recognition difficult and lead to delays in treatment. Ongoing research using newer tools for molecular analysis holds promise for improved understanding of pertussis epidemiology, bacterial pathogenesis, bioinformatics, and immunology. Together, these advances provide a foundation for the development of new-generation diagnostics, therapeutics, and vaccines.

Low Prevalence of Pertussis Among Children Admitted With Respiratory Symptoms During Respiratory Syncytial Virus Season

Pertussis may go unrecognized during respiratory syncytial virus (RSV) epidemics. Nosocomially transmitted pertussis can be severe in infants. Polymerase chain reaction (PCR) screening may identify infants with pertussis on admission, allowing for preemptive isolation. In a random sample, 1 (0.6%) of 166 children admitted to the hospital during RSV season were Bordetella pertussis PCR positive during a nonepidemic period. These data show that screening may not be useful when pertussis prevalence is low.

Modelling the return on investment of preventively vaccinating healthcare workers against pertussis

Background

Healthcare workers (HCWs) are at particular risk of acquiring pertussis and transmitting the infection to high-risk susceptible patients and colleagues. In this paper, the return on investment (ROI) of preventively vaccinating HCWs against pertussis to prevent nosocomial pertussis outbreaks is estimated using a hospital ward perspective, presuming an outbreak occurs once in 10 years.

Methods

Data on the pertussis outbreak on the neonatology ward in 2004 in the Academic Medical Center Amsterdam (The Netherlands) was used to calculate control costs and other outbreak related costs. The study population was: neonatology ward staff members (n = 133), parents (n = 40), neonates (n = 20), and newborns transferred to other hospitals (n = 23). ROI is presented as the amount of Euros saved in averting outbreaks by investing one Euro in preventively vaccinating HCWs. Sensitivity analysis was performed to study the robustness of the ROI. Results are presented at 2012 price level.

Results

Total nosocomial pertussis outbreak costs were €48,682. Direct control costs (i.e. antibiotic therapy, laboratory investigation and outbreak management control) were €11,464. Other outbreak related costs (i.e. sick leave of HCWs; restrictions on the neonatology ward, savings due to reduced working force required) accounted for €37,218. Vaccination costs were estimated at €12,208. The ROI of preventively vaccinating HCWs against pertussis was 1:4, meaning 4 Euros could be saved by every Euro invested in vaccinating HCWs to avert outbreaks. ROI was sensitive to a lower vaccine price, considering direct control costs only, average length of stay of neonates on the neonatology ward, length of patient uptake restrictions, assuming no reduced work force due to ward closer and presuming more than one outbreak to occur in 10 years’ time.

Conclusion

From a hospital ward perspective, preventive vaccination of HCWs against pertussis to prevent nosocomial pertussis outbreaks results in a positive ROI, presuming an outbreak occurs once in 10 years.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-0800-8) contains supplementary material, which is available to authorized users.

Healthcare Workers' Knowledge and Attitudes About Pertussis and Pertussis Vaccination

Objective.

To determine knowledge and attitudes about pertussis and pertussis vaccination among healthcare workers (HCWs).

Design.

Self-administered, Web-based survey.

Setting.

Tertiary-care academic medical center.

Participants.

Medical center employees who participated in direct patient care were recruited to complete the survey through institutional e-mail.

Results.

Of 14,893 potentially eligible employees, 1,819 (12%) completed the survey. Most respondents (87%) did not plan to receive the pertussis vaccine. Intent to receive vaccination (which included recent history of vaccination) was associated with the following 4 factors: receipt of a physician recommendation for vaccination (odds ratio [OR], 9.01), awareness of Centers for Disease Control and Prevention recommendations for pertussis vaccination for HCWs (OR, 6.89), receipt of encouragement to be vaccinated from a coworker (OR, 4.72), the belief that HCWs may spread pertussis to patients and family (OR, 1.80). Two factors were negatively associated with intent to receive vaccination: the presence of children in the HCW's home (OR, 0.69) and employment as a nurse (OR, 0.59). Reasons cited by those who did not intend to receive vaccination included lack of a personal recommendation for vaccination (78%), receipt of vaccination as a child (51%), and perception that there was no significant risk for contracting pertussis (38%).

Conclusions.

Of the HCWs surveyed, only 13% intended to receive the pertussis vaccine. A perceived lack of recommendation for vaccination and inaccurate conceptions about pertussis and pertussis vaccination were cited as reasons HCWs did not intend to be vaccinated. Institutional pertussis vaccination campaigns should focus on the risks of healthcare-associated pertussis and new recommendations for pertussis vaccination.

Health care worker exposures to pertussis: missed opportunities for prevention

OBJECTIVE

Pediatric health care workers (HCWs) are at particular risk for pertussis exposure, infection, and subsequent disease transmission to susceptible patients. This cross-sectional study describes the epidemiology of occupational exposures to pertussis and identifies factors that may inform interventions to promote effective implementation of infection prevention and control (IPC) guidelines.

METHODS

We abstracted data from occupational health (OH) and IPC records for pertussis cases that resulted in an exposure investigation in a large quaternary pediatric care network, January 1, 2002 to July 18, 2011. We calculated the frequency of occupational exposures and measured associated characteristics. To assess the frequency of potential missed exposures, we reviewed electronic health record (EHR) data identifying laboratory-confirmed pertussis cases not documented in OH or IPC records.

RESULTS

A total of 1193 confirmed HCW pertussis exposures were associated with 219 index cases during the study period. Of these, 38.8% were infants <6 months old and 7 were HCWs. Most (77.5%) of exposures occurred in the emergency department or an ambulatory site; 27.0% of exposures occurred after documented initiation of IPC precautions. We identified 450 laboratory-confirmed pertussis cases through EHR review, of which 49.8% (N = 224) had no OH or IPC investigation. The majority of uninvestigated cases (77.2%) were from ambulatory sites.

CONCLUSIONS

Occupational exposures to pertussis occur frequently in pediatric health care settings despite appropriate IPC guidelines. Interventions are needed to ensure consistent implementation of IPC practices and timely identification and reporting of pertussis index cases to prevent HCW exposures and potential transmission to patients.

Hospital epidemiology and infection control in acute-care settings

Health care-associated infections (HAIs) have become more common as medical care has grown more complex and patients have become more complicated. HAIs are associated with significant morbidity, mortality, and cost. Growing rates of HAIs alongside evidence suggesting that active surveillance and infection control practices can prevent HAIs led to the development of hospital epidemiology and infection control programs. The role for infection control programs has grown and continues to grow as rates of antimicrobial resistance rise and HAIs lead to increasing risks to patients and expanding health care costs. In this review, we summarize the history of the development of hospital epidemiology and infection control, common HAIs and the pathogens causing them, and the structure and role of a hospital epidemiology and infection control program.

Concurrent summer influenza and pertussis outbreaks in a nursing home in Sydney, Australia

OBJECTIVE

To report on the investigation of a summer outbreak of acute respiratory illness among residents of a Sydney nursing home.

DESIGN

An epidemiologic and microbiological investigation of the resident cohort at the time of the outbreak and medical record review 5 months later.

SETTING

A nursing home located in Sydney, Australia, during February to July 1999.

PATIENTS

The cohort of residents present in the nursing home at the time of the outbreak.

INTERVENTIONS

Public health interventions included recommendations regarding hygiene, cohorting of residents and staff, closure to further admissions, and prompt reporting of illness; and virologic and serologic studies of residents.

RESULTS

Of the 69 residents (mean age, 85.1 years), 35 fulfilled the case definition of acute respiratory illness. Influenza A infection was confirmed in 19 residents, and phylogenetic analysis of the resulting isolate, designated H3N2 A/Sydney/203/99, showed that it differed from strains isolated in eastern Australia during the same period. Serologic evidence of Bordetella infection was also found in 10 residents; however, stratified epidemiologic analysis pointed to influenza A as the cause of illness.

CONCLUSIONS

The investigation revealed an unusual summer outbreak of influenza A concurrent with subclinical pertussis infection. Surveillance of acute respiratory illness in nursing homes throughout the year, rather than solely during epidemic periods, in combination with appropriate public health laboratory support, would allow initiation of a timely public health response to outbreaks of acute respiratory illness in this setting.

Infections Associated with Health-care Personnel: Vaccine-preventable Diseases and Bloodborne Pathogens

Health-care personnel (HCP) are at risk for infection from occupational exposure, and can transmit infectious pathogens to patients and other personnel. The risk of disease acquisition depends on factors including the virulence of the causative organism, the mode of pathogen transmission, and the immune competency of the exposed individual. This article reviews the management of occupational exposure, infection, and strategies for the prevention of transmission of selected vaccine-prevent- able diseases (varicella zoster virus, influenza, pertussis) and bloodborne pathogens (hepatitis B virus, hepatitis C virus, human immunodeficiency virus). Recommended strategies include surveillance, vaccination, infection control measures, and postexposure prophylaxis. Improved detection, management, and prevention strategies are needed to reduce the risk of trans- mission of infection to HCP.

Usefulness of pulsed-field gel electrophoresis in assessing nosocomial transmission of pertussis

During a 2-week period, three infants with a cough lasting at least 8 days with whoops, were admitted to the pediatric unit; Bordetella pertussis was isolated from nasopharyngeal aspirates collected from the three infants. Approximately 1 week later, a nurse working on the same unit developed influenza-like symptoms followed by whooping cough; B pertussis was isolated. Isolates from the nurse and from one of the infants were shown to be indistinguishable by pulsed-field gel electrophoresis. These data demonstrate that B pertussis transmission to healthcare workers is possible and emphasize the need to use respiratory protection devices (Droplet Precautions) for healthcare workers having close contact with infected children.

Nosocomial pertussis in healthcare workers from a pediatric emergency unit in France

OBJECTIVE

After pertussis was diagnosed in July 1997 in a 55-year-old nurse (case) from a pediatric emergency unit who had a respiratory illness and paroxysmal cough for 5 weeks, an epidemiological investigation was initiated to determine if other healthcare workers (HCWs) from the same unit also had pertussis.

DESIGN

Interviews were conducted to assess symptoms occurring in the previous months. Two sera were collected 2 to 3 months apart for 59 of 61 HCWs of the unit. The IgG response to pertussis toxin was determined using Western blot assay.

SETTING

Pediatric emergency unit (61 HCWs) of a 2,500-bed university hospital.

RESULTS

There was a total of 10 (5 confirmed and 5 probable) cases of pertussis identified in this outbreak. Nine HCWs (15%) had results suggesting recent or acute pertussis. To avoid transmission to patients and other HCWs, all HCWs with cough were treated for 14 days with erythromycin, and those having acute cough were given a 5-day sick leave. Despite these measures, a new acute pertussis case was identified in a 41-year-old nurse, with a positive culture from nasopharyngeal aspirates. Thus, all HCWs in the unit were prescribed spiramycin for 10 days to prevent any further spread of pertussis.

CONCLUSION

Pertussis should be considered a threat to HCWs who are in contact with children. For HCWs, diagnosis of pertussis should be made on a clinical basis, giving greater importance to sensitivity of diagnosis criteria, and on early bacterial identification by culture of the organism or by polymerase chain reaction.

RECOMMENDATIONS

In case of pertussis in an HCW, all staff in the unit who have had unprotected and intensive contact with that person should be provided with macrolide treatment to stop any transmission to colleagues and to young patients. Furthermore, the possibility of providing these HCWs with acellular pertussis vaccines warrants further investigation.