What are the reasons why pertusis, a vaccine-preventable disease, is epidemic?
According to an editorial by James Cherry (NEJM 2012; 367: 785-87), there are four main reasons.
- 1) Increased awareness
- 2) Easier detection with PCR assays
- 3) Increased use of less potent vaccines, mainly DTaP
- 4) Possible genetic changes in B pertusis
Useful epidemiology information:
- 13-20% of adolescents and adults with prolonged cough have B pertusis.
- Lowest incidence was reported in 1973: 1 per 100,000.
- In prevaccine era, B pertusis had pattern of epidemics every 2 to 5 years, with peak incidence of 157 per 100,000.
- In 2010, incidence was 9 per 100,000
- Neither infection or immunization provides lifelong immunity
- We need to use the vaccines we have. This is necessary to avoid the ‘frightening rates of complications and death’ associated with pertusis in infants.
- Consider starting immunization at an earlier age –1st three doses could be completed by 3 months of age
- Improved vaccines are needed
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