Measures to Control an Outbreak of Pertussis in a Neonatal Intermediate Care Nursery After Exposure to a Healthcare Worker

Background.

Hospitalized premature infants are particularly vulnerable to morbidity and mortality from pertussis. Effective prevention and investigative and control measures are not well described.

Objective.

To identify the source of nosocomial pertussis in a 2-month-old premature infant in a neonatal intermediate care nursery (ICN) and to critically review the investigation and outbreak control measures.

Setting.

An ICN and a neonatal intensive care unit.

Methods.

We queried healthcare workers (HCWs) and family members about cough illness and contacted potentially exposed patients to determine whether they had symptoms of pertussis. Culture and polymerase chain reaction (PCR) testing forBordetella pertussiswere performed by the hospital laboratory with specimens collected from symptomatic patients and HCWs. Levels of pertussis toxin immunoglobulin G antibodies were measured in HCWs with cough of at least 14 days' duration at a public health laboratory. Extensive control measures were instituted.

Results.

Four ICN HCWs met the clinical case definition for presence of pertussis. Serologic test results were positive for 3 of the HCWs. The primary case patient was a 36-year-old HCW with a cough illness of 3-weeks' duration that was accompanied by paroxysms, whoop, posttussive emesis, and pneumothorax. Among the 4 affected HCWs, the duration of cough illness prior to identification of the infant index patient ranged from 11 to 25 days. Outbreak control measures included isolation of the infant case patient, furlough and treatment of symptomatic HCWs, administration of chemoprophylaxis to contacts, and surveillance for additional cases. Seventy-two infant patients and 72 HCWs were exposed and were given antibiotic prophylaxis. One additional case of pertussis, confirmed by PCR and culture, occurred in a resident physician who declined prophylaxis; she had cared for the index patient but had no contact with symptomatic HCWs.

Conclusion.

HCWs or patients may serve as the source of pertussis in nosocomial outbreaks, which can result in substantial morbidity and outlay of resources for control measures. Our review suggested that a diagnosis of pertussis should be an early consideration for HCWs with cough illness. Targeted pertussis immunization of HCWs, employee health policies that provide for testing and furlough of HCWs with prolonged cough, and monitoring of HCWs for compliance with infection control measures could reduce the morbidity and costs associated with pertussis outbreaks. These measures will require evaluation of their effectiveness.

Preventing the Spread of Pertussis in Pediatric Healthcare Settings

The surge in pertussis incidence in recent years underscores a critical need for effective plans to prevent transmission in pediatric healthcare settings. Adolescents and adults are common sources of infection for unimmunized or incompletely immunized infants and children with waning immunity. Despite documented outbreaks being limited in size, pertussis poses a threat to pediatric healthcare facilities due to the risk for widespread transmission, potentially severe complications among vulnerable patient populations, and high outbreak control-related costs. Healthcare personnel, visitors, and parents have been identified as sources of outbreaks, underscoring the importance of coordinated efforts to prevent transmission in these settings. This comprehensive review demonstrates that the risk of pertussis transmission in pediatric healthcare settings warrants heightened focus on strategies to recognize disease earlier, improve diagnostic evaluation, and facilitate effective contact tracing and post-exposure prophylaxis measures. This review suggests that healthcare personnel can play a significant role in the prevention of healthcare-associated pertussis.

A cocooning project to protect newborns from pertussis

The Pertussis Cocooning Project was created through a collaborative effort by a health care organization and a State Department for Public Health to decrease community pertussis rates and protect infants from the deadly effects of pertussis. Free pertussis immunizations are provided to all mothers who give birth at the health care organization and to all infants' family members and caregivers older than 18 years.

Healthcare workers as vectors of infectious diseases

Nosocomial infections cause considerable morbidity and mortality. Healthcare workers (HCWs) may serve as vectors of many infectious diseases, many of which are not often primarily considered as healthcare-associated. The probability of pathogen transmission to patients depends on several factors, such as the characteristics of a pathogen, HCW and patient. Pathogens with high transmission potential from HCWs to patients include norovirus, respiratory infections, measles and influenza. In contrast, human immunodeficiency virus (HIV) and viral hepatitis are unlikely to be transferred. The prevention of HCW-associated transmission of pathogens include systematic vaccinations towards preventable diseases, continuous education, hand hygiene surveillance, active feedback and adequate staff resources.

Clinical and economic effects of pertussis outbreaks

BACKGROUND

The reported incidence of pertussis is increasing, especially among the adolescent population. Current outbreak management strategies include investigating cases, contact follow-up, diagnostic testing, and antibiotic prophylaxis and treatment. The cost of these methods is substantial and can be attributed to the mobilization within public health departments to control the outbreaks.

METHODS

Through an extensive review of the literature, the clinical and economic effects of pertussis outbreaks in various nonhousehold settings are discussed.

RESULTS

The reported incidence of pertussis among adolescents and adults in the United States since the early 1980s continues to rise. The challenges of preventing and controlling pertussis outbreaks involve diagnosing pertussis in a timely, accurate, and standardized fashion and understanding the true burden of disease in different age and socioeconomic groups. The economic effects of pertussis have been demonstrated to be significant to individuals and communities, both locally and globally. Costs associated with pertussis often include diagnostic testing, hospitalization, emergency and/or medical office visits, antibiotic and symptomatic treatment, lost work days, and other reductions in productivity. In outbreak settings, increased surveillance, antibiotic prophylaxis, isolation of infected cases, and enhanced communication and education add to the economic burden of this disease. The potential opportunity to apply the use of pertussis booster vaccination to these populations, particularly among adolescents, likely would reduce the occurrence of pertussis and minimize the clinical and economic repercussions of pertussis outbreaks.

CONCLUSIONS

In the near future, it is anticipated that evaluating the effects of a licensed acellular pertussis booster vaccine in persons > or =10 years of age will become routine in pertussis prevention and outbreak-control activities.

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.