The Health Protection Surveillance Centre wishes to alert the public and clinicians of an increase of pertussis notifications in infants (babies < 12 months) for the first 20 weeks of 2016. Provisional data for 2016 weeks 1-20 is presented here in this report.

Background

Pertussis is a vaccine preventable disease. The HSE implements a national immunisation programme to provide pertussis vaccine to the Irish population. Since 2012, pregnant women in Ireland have been recommended pertussis vaccine at weeks 27-36 of their pregnancy to protect their babies from pertussis disease in the first months of their baby’s life. An HSE audit of pertussis vaccination during pregnancy in 2013 reported that only 6.4% of postnatal women had received the pertussis vaccine during their pregnancy (unpublished data). At this time in 2016, anecdotal reports suggest that many mothers are still not aware of this recommendation and therefore not availing of the opportunity to provide this protection to their baby.

Summary of pertussis in 2016

For the first 20 weeks of 2016, a total of 51 pertussis notifications (all ages) were made to the national Computerised Infectious Disease Reporting system (CIDR). This compares to 49 cases (all ages) for the same time period in 2015. However, in 2016 an increased proportion of all cases were reported among infants. To date 51% of all pertussis notifications are infant cases (n=26) compared to 25% (n=12) in 2015. (Figure 1)

Figure 1. Pertussis notifications in infants (cumulative), for weeks 1-20, 2015 and 2016

Pertussis cases in infants weeks 1-20 2016 (provisional)

Of the 26 infant pertussis notifications reported during this time, 25 cases were reported as confirmed. The median age of cases was 3 months (range 1-8 months). For 19 cases information was available on hospitalisation; 13 of whom were hospitalised. Dates of admission and discharge were provided for seven of those hospitalised; the median length of stay for these infants was 4 days (range 3-15 days). One infant died as a result of pertussis.

Information on vaccination status of the child was available for 25 of the 26 infant cases; 17 were unvaccinated; 6 of these infant cases were not eligible for vaccination as they were < 2 months of age. (Figure 2). (Note: Pertussis vaccination of infants is recommended for all infants (unless contraindicated) at 2, 4, 6 months of age).

Figure 2. Pertussis cases (infants) by infant’s vaccination status and age at notification, weeks 1-20 2016 (n=25)

Information on maternal antenatal pertussis vaccination was available for 20 of the 26 infant cases. None of the mothers reported receiving pertussis vaccination during their pregnancy. 

Key points

• During the first 20 weeks of 2016, Ireland has seen an increase in pertussis notifications in infants. There was one infant death reported as a result of this disease.
• Since 2012, the National Immunisation Advisory Committee of the RCPI (NIAC) has recommended pertussis vaccination of mothers during pregnancy to protect the infant from pertussis disease in the first months of life.
• Since 2013 pertussis vaccine has been available free of charge for pregnant women from the HSE National Cold Chain Service. All women are required to pay an administration fee. 
• All health care professionals (GPs, practice nurses, midwives and obstetricians) who provide care and advice to pregnant women are in a unique position to recommend pertussis vaccination to pregnant women and therefore improve protection to infants in the first months of life.
• Infants should be vaccinated against pertussis according to the national immunisation schedule (2, 4, 6, months of age).

HSE HPSC wishes to raise awareness among pregnant women, and their health care providers of the increase in pertussis, particularly in young infants, so that mothers request pertussis vaccination during the antenatal period (weeks 27-36 ideally) from their primary care provider. Vaccination is the most effective way to prevent pertussis in the infant during the first months of life.

For more information on pertussis vaccination recommendations please click here

Information on whooping cough (pertussis) vaccine for pregnant women is located here

Further information on pertussis is available here