Observations regarding historical accounts of pneumococcal diseases due to serotypes 1 and 3.

Surveillance of the serotypes causing invasive pneumococcal diseases in the UK has indicated increasing incidence of serotype 1- and serotype 3-related disease in recent years. The introduction of a pneumococcal conjugate vaccine to the paediatric vaccination schedule in 2006, which did not cover these serotypes, has been regarded as a contributing factor. Serotypes 1 and 3 were perhaps the most extensively studied pneumococcal serotypes in the early twentieth century when pneumococcal serotyping began. Such historical observations are pertinent to our understanding of contemporary disease manifestations for these serotypes as many parallels can be seen between their behaviour in the early twentieth century and the early twenty-first century. There are many relevant lessons to be learned from these pre-antibiotic era descriptions and the observations of our predecessors.