Credit CDC
# 6902
Reports of Pertussis or `whooping cough’ have been on the ascendant around the globe the past few years, including in the United States, Australia, and the UK.
Over the past few months I’ve blogged on the UK’s record setting year for Whooping cough several times, including:
HPA: Whooping Cough Cases Remain High
Today, a little bit of encouraging news, as the number of new Pertussis cases reported by the HPA have declined for the second month in a row. It is too early, however, to read much into what this means for the rest of 2013.
Cases of whooping cough decline after record numbers in 2012
1 February 2013
There were 9,741* confirmed cases of whooping cough reported in England and Wales in 2012, according to figures published today by the Health Protection Agency (HPA). The total figure for 2012 is almost 10 times higher than the number of cases reported in 2011 (1,119) and in 2008 (902) – the last peak year before this current outbreak.
The December figures show a decrease for the second month running in cases of whooping cough with 832 confirmed cases reported compared with 1,168 cases in November 2012. One further death in an infant with laboratory confirmed whooping cough was reported in December bringing the 2012 total number of deaths in babies under three months to 14.
The highest number of cases were reported in those aged 15 and over, with a total of 8,059 cases in 2012, compared to 740 cases in 2011 and 493 cases in 2008.
Dr. Mary Ramsay, head of immunisation at the HPA, said: “The December figures show another welcome decrease in the overall number of whooping cough cases since the peak in October. However, it is very important to note that we usually see a reduction in cases of whooping cough at this time of year so this decrease is in line with normal seasonal patterns.
Before we pop the Champaign corks, it is important to note that the total number of cases reported during the month of December (n=832) is nearly double the total reported in all of 2010 (n=422).
Still, any decline is welcome news.
The reasons behind the spike in Pertussis cases are complex, and not completely understood, but some factors may include:
- lower vaccination uptakes
- the move away from whole cell pertussis vaccines to safer – but less broadly protective - acellular vaccines in the 1990s
- evolutionary changes in the Bordetella pertussis bacteria.
Recent evidence published in the NEJM suggests that protection from the newer acellular pertussis vaccine – introduced in the early 1990s – may wane sooner than previously suspected.
Waning Protection after Fifth Dose of Acellular Pertussis Vaccine in Children
Nicola P. Klein, M.D., Ph.D., Joan Bartlett, M.P.H., M.P.P., Ali Rowhani-Rahbar, M.D., M.P.H., Ph.D., Bruce Fireman, M.A., and Roger Baxter, M.D.
N Engl J Med 2012; 367:1012-1019 September 13, 2012DOI: 10.1056/NEJMoa1200850
In November of last year, in JAMA: Waning Pertussis Vaccine Effectiveness Over Time, we saw another study that found that the protective effect of the Pertussis vaccine begins to wane after the fifth dose (normally given at age 5) is received, leaving 7 to 10 year olds at greater risk of infection.
For more information, the CDC maintains an extensive Whooping Cough website, including audio files designed to help you identify the often distinctive `whooping’ sound made by those infected.
Pertussis (Whooping Cough)
And from the Advisory Committee on Immunization Practices (ACIP) this week we get recommendations that adults aged 65 and older and pregnant women receive the Tdap vaccine.
Advisory Committee on Immunization Practices (ACIP) Recommended Immunization Schedule for Adults Aged 19 Years and Older — United States, 2013
Supplements
February 1, 2013 / 62(01);9-19(EXCERPT)
For tetanus, diphtheria, and acellular pertussis (Tdap) vaccine, recommendations have been expanded to include routine vaccination of adults aged 65 years and older and for pregnant women to receive Tdap vaccine with each pregnancy. The ideal timing of Tdap vaccination during pregnancy is during 27–36 weeks' gestation. This recommendation was made to increase the likelihood of optimal protection for the pregnant woman and her infant during the first few months of the infant's life, when the child is too young for vaccination but at highest risk for severe illness and death from pertussis
