Pertussis: adults as a source in healthcare settings

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.

Adult Pertussis Is Hazardous for the Newborn

We report 4 cases involving the likely transmission of pertussis from parents to newborns in a hospital setting. The adoption of proper infection control measures and targeted screening of parents may reduce the potential for such transmission.

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.

Seroprevalence study of B. pertussis infection in health care workers in Catalonia, Spain

Pertussis is a re-emerging infection in countries with high infant immunization coverage. Healthcare workers (HCW) are exposed and can transmit the infection to especially-vulnerable patients. Therefore, pertussis vaccination of HCW is recommended. Between June 2008 and December 2010, 460 HCW from hospital and primary healthcare centers were recruited to determine susceptibility to pertussis. IgG antibodies against pertussis (anti-pertussis ab) were measured, using a routine technique that detects antibodies against pertussis including pertussis toxin (PT) and filamentous hemagglutinin (FHA). Positive results were confirmed with a more-specific technique that only assesses anti-PT IgG antibodies. The median age was 42 years (range, 21-65), 77.3% were female. 172 were nurses, 133 physicians, 60 other clinical workers and 95 non-clinical workers. None had received pertussis vaccination since childhood. The overall prevalence of anti-pertussis antibodies was 51.7%, (95% CI 47.1-56.4). Anti-PT antibodies were determined in the 220 HCW with positive anti-pertussis antibodies: 4 (1.8%) were negative and 33 (15%) had a high titer (≥ 45 IU/mL). No significant differences between the prevalence of anti-pertussis antibodies or anti-TP antibodies were found according to age, type of occupation or type of center. Our study confirms the need for vaccination of HCW because at least half are susceptible to pertussis. High anti-PT titers found in 15% of seropositive HCW showed that they had had recent contact with B. pertussis.

Nosocomial pertussis in neonatal units

Pertussis remains a public health concern in many countries despite high vaccination coverage rates. Nosocomial outbreaks of pertussis continue to occur in neonatal units. Neonates and young infants admitted to neonatal intensive care units constitute a pool of susceptible high-risk patients given their prematurity, inadequate immune response and the fact that they are too young to have completed their primary vaccination series against pertussis. This article reviews nosocomial pertussis in neonates and infants, focusing on the role of healthcare workers (HCWs). Outbreaks in neonatal units are often traced to HCWs and are associated with serious morbidity or even a fatal outcome among susceptible young infants. A high index of suspicion is required for early recognition and isolation of patients admitted with suspected or proven pertussis, as well as for HCWs with a compatible clinical syndrome, regardless of vaccination status. Contact investigation is also essential in order to guide administration of post-exposure prophylaxis. Recommendations for a booster vaccination for HCWs are in place in several countries; however, the need of HCWs for lifelong immunity against pertussis cannot be fulfilled by the current vaccine.

Immunisation practices in infants born prematurely: neonatologists' survey and clinical audit

AIM

To determine Australian neonatologists' recommendations for the immunisation of ex-preterm infants and compare their actual immunisation status with recommended Australian guidelines.

METHODS

A self-administered nine-part questionnaire of current immunisation practices was sent to all Neonatologists in Australia (2006). A complementary retrospective immunisation audit was conducted in two tertiary neonatal units in Melbourne. Hospital records and the Australian Childhood Immunisation Register (ACIR) were reviewed; consenting parents were interviewed and primary care physicians' vaccination records were requested. A random sample of preterm infants born between July 2003 and June 2005 at <32 weeks' gestation were selected.

RESULTS

(i) Neonatologists Survey: The response rate was 68% and the majority of neonatologists (89%) were aware of the current guidelines, but adherence to them varied from 43% to 79%. One-fifth of neonatologists personally do not receive annual influenza vaccination; and (ii) Immunisation Audit: Conducted between October 2006-May 2007 it included: 100 hospital records; 97 ACIR records; 47 parent interviews and 43 primary care vaccination records. Overall vaccination coverage was 90% at 12 months of age. Only 20% (10/50) of infants with chronic lung disease received an influenza vaccination. Vaccines were delayed by greater than one month in 15% of participants for the 2 month DTPa vaccine and 43% at 6 months.

CONCLUSIONS

The neonatologists survey highlighted variable adherence with immunisation guidelines. The audit confirmed preterm infants are frequently experiencing delayed vaccination and recommended additional vaccinations are often not being received. Formulation of strategies to ensure complete and timely immunisation are required, including better utilisation of the ACIR.

Pertussis vaccination for health care workers

Pertussis, an acute respiratory infection caused by Bordetella pertussis, classically manifests as a protracted cough illness. The incidence of pertussis in the United States has been increasing in recent years. Immunity wanes after childhood vaccination, leaving adolescents and adults susceptible to infection. The transmission of pertussis in health care settings has important medical and economic consequences. Acellular pertussis booster vaccines are now available for use and have been recommended for all adolescents and adults. These vaccines are safe, immunogenic, and effective. Health care workers are a priority group for vaccination because of their increased risk of acquiring infection and the potential to transmit pertussis to high-risk patients. Health care worker vaccination programs are likely to be cost-effective, but further research is needed to determine the acceptability of pertussis vaccines among health care workers, the duration of immunity after booster doses, and the impact of vaccination on the management of pertussis exposures in health care settings.

A modified "cover your cough" campaign prevents exposures of employees to pertussis at a children's hospital

BACKGROUND

In the 4th quarter of 2004, there was an increase in patients seeking medical care for pertussis symptoms at the Children's Hospital, Omaha, NE. The Hospital Epidemiology service noted a sharp rise in exposures of Children's Hospital employees to these patients, requiring employee testing, prophylactic antibiotic prescriptions, and relief from duty.

METHODS

Initial efforts at employee education failed to prevent the exposures. An exposure-control plan was then initiated by placing "Cover Your Cough" posters (in English and Spanish) describing appropriate cough etiquette at entrances to the emergency room, outpatient clinics, and hospital lobby. In addition, personal protective equipment (PPE) including child- and adult-sized masks, hand sanitizers, and tissues were provided at these stations for patients and their attendants.

RESULTS

Prior to the initiation of the above exposure control measures, there were 166 reports of employee exposure to patients and other employees with pertussis symptoms during a 4-week period. Of these, 140 were given prophylactic antibiotics, and 31 underwent diagnostic testing for pertussis and required paid time off from work. The cost of antibiotics and diagnostic testing was $17,407.00. After the introduction of the modified "Cover Your Cough" campaign, the number of employee exposures declined significantly to 37 in the next 4-week period. Notably, the number of patients tested for pertussis during the second 4-week period was 290 compared to 162 in the first 4-week period, indicating continuation of the epidemic.

CONCLUSIONS

Availability of PPE along with posters regarding cough etiquette at entry points of the hospital interrupted employee exposure to patients/personnel with pertussis symptoms significantly, when an employee educational initiative alone was unable to achieve this outcome.

Whooping cough: are health-care workers putting children at risk?

AIM

To explore the attitudes and knowledge of health-care workers (HCW) towards whooping cough and an adult whooping cough booster for HCW.

METHODS

HCW at Fairfield Health Service, who had clinical contact with infants or children, were sent a self-administered questionnaire.

RESULTS

Questionnaires were completed by 135 staff, giving a response rate of 74%. Thirty-five per cent were not known to be immunised against whooping cough. Fifty-nine per cent of doctors were known to be immunised, 33% of allied health staff and 28% of nurses. The rates of immunisation between the professional groups were significantly different (chi2 = 8.2 with 2 degrees of freedom; P = 0.017). Thirty-nine per cent of HCW did not know that primary immunisation did not provide lifelong protection. Twenty-seven per cent did not agree that HCW should be offered an adult whooping cough booster. Staff who felt at risk of contracting whooping cough were more likely to recommend that a booster should be offered (OR 2.71; 95% CI 1.22-6.04; P = 0.019). Doctors were less likely to recommend that a booster should be offered (OR 0.36; 95% CI 0.15-0.87; P = 0.028).

CONCLUSIONS

HCW have low rates of immunity to whooping cough and misconceptions about whooping cough infection and immunisation. Over a quarter of HCW did not agree that a booster should be offered. An ongoing education programme addressing the attitudes and misconceptions identified in this study is a crucial component of the campaign to increase the uptake of adult whooping cough booster immunisation by HCW.

Nosocomial pertussis: costs of an outbreak and benefits of vaccinating health care workers

BACKGROUND

In September 2003, 17 symptomatic cases of pertussis among health care workers (HCWs) resulted from a 1-day exposure to an infant who was later confirmed to have pertussis. These HCWs identified 307 close contacts. The hospital implemented extensive infection-control measures. The objective of this study was to determine direct and indirect costs incurred by the hospital and symptomatic HCWs as a result of the September 2003 outbreak and to estimate possible benefits of vaccinating HCWs from the hospital perspective.

METHODS

We determined costs by interviewing infection-control and hospital personnel, reviewing billing records, and surveying symptomatic HCWs. We calculated the benefits and costs of a vaccination program for HCWs, using a probabilistic model to estimate the number of pertussis exposures that would require control measures annually. Sensitivity and threshold analyses were performed.

RESULTS

The outbreak cost to the hospital was 74,870 dollars. The total measured cost of the outbreak was 81,382 dollars, including costs incurred by HCWs (6512 dollars). Our model predicted that vaccinating HCWs against pertussis would prevent >46% of exposures from HCWs with pertussis per year and would provide net savings. The benefit for the hospital was estimated to be 2.38 times the dollar amount invested in vaccinating HCWs. The number of exposures prevented and the benefit-cost ratio were sensitive to the number of exposures identified, the incidence of pertussis among HCWs, and HCW turnover.

CONCLUSIONS

A single nosocomial pertussis outbreak resulted in substantial disruption and costs to the hospital and to HCWs. Our model suggests that cost savings and benefits could be accrued by vaccinating HCWs against pertussis.

Pertussis in Infants, Children, and Adolescents: Diagnosis, Treatment, and Prevention

Pertussis, or "whooping cough," caused by the gram-negative pleomorphic bacillus Bordetella pertussis, is a highly contagious, potentially life-threatening respiratory tract illness that has re-emerged worldwide as a cause of substantial morbidity and mortality in infants, children, and adolescents, despite high vaccination rates. Increased awareness and reporting, in addition to the availability of better diagnostic tests, partially explain the recent resurgence of pertussis. However, waning immunity after childhood immunization has resulted in a growing pool of susceptible adolescents and adults who are capable of transmitting pertussis to vulnerable unvaccinated or incompletely vaccinated infants. An acellular pertussis vaccine booster for adolescents has been recommended in the United States and other industrialized countries. Active immunization and early diagnosis are crucial in the management of pertussis.

Progress in the Diagnosis, Prevention, and Treatment of Pertussis

Pertussis ("whooping cough"), caused by the gram- negative pleomorphic bacillus Bordetella pertussis, is a highly contagious, potentially life-threatening respiratory tract illness that has re-emerged worldwide as a cause of substantial morbidity and mortality in infants, children, and adolescents, even in countries with high vaccination rates. Waning immunity after immunization during childhood has been associated with a growing pool of susceptible adolescents and adults who are capable of transmitting pertussis to vulnerable unvaccinated or incompletely vaccinated infants. The use of acellular pertussis vaccine boosters in adolescents has been proposed and is likely to be recommended. Active immunization and improved methods for early diagnosis are key in the management of pertussis, and represent the most rapidly evolving aspects of this disease.