Whooping cough rising in vaccinated children
19 November 2010
As the number of whooping cough (pertussis) cases continues to rise around Australia, the disease is increasingly being seen in vaccinated primary school-aged children, experts say.
NSW Health recently alerted GPs that babies were at risk from older siblings whose immunity from vaccination may have waned, and warned pertussis "can occur in fully vaccinated children" (NSW GP alert, 14 Oct 2010).
Notifiable diseases data show Australia has recorded more than 24,000 pertussis cases to date this year, compared with 29,000 in 2009.
However, Professor Peter McIntyre, director of the National Centre for Immunisation Research and Surveillance, said while Australia appeared to be "swimming in pertussis", the high figures partly reflected more widespread use of PCR testing. (PCR, or polymerase chain reaction, is more sensitive than older tests as it detects bacterial DNA.)
While infant deaths remained a concern, the ratio of deaths to cases remained low, Professor McIntyre said. "Because pertussis is occurring in immunised kids, it’s less infectious [and] less severe disease", he explained.
Reinstatement of the 18-month pertussis booster or other tweaks to the schedule may be needed, because while the newer acellular pertussis vaccine was efficacious and had fewer side effects than whole cell vaccine, protection waned earlier, he said.
The Australian Technical Advisory Group on Immunisation (ATAGI) was currently considering whether changes to the immunisation schedule were desirable, a spokesperson said.
Meanwhile, immunisation providers were advised they could administer the pertussis-containing vaccine from as early as 6 weeks of age "in exceptional circumstances, such as a pertussis epidemic", he said.
Professor McIntyre said recent Australian research suggested 4 out of 11 pertussis deaths in 10 years could have been prevented if babies received their first dose of vaccine at 6 weeks (Pediatr Infect Dis J 2010 Aug 31, online).
The Federal Health Department said in the last 3 years, 5 babies younger than 6 weeks have died from pertussis.
Last Reviewed: 19 November 2010
- Foxwell AR, McIntyre P, Quinn H, et al. Severe pertussis in infants: estimated impact of first vaccine dose at 6 versus 8 weeks in Australia. Pediatr Infect Dis J 2010 Aug 31. [Epub ahead of print]. http://www.ncbi.nlm.nih.gov/pubmed/20811313 (accessed 19 Nov 2010).
NSW Health. NSW GP ALERT - whooping cough (pertussis). Sydney: NSW Health, 14 October 2010. http://www.health.nsw.gov.au/resources/publichealth/infectious/whoopingcough/pdf/WHOOPING_COUGH_GP_FAX_141010.pdf (accessed 19 Nov 2010).
