Table 3.

Detailed age distribution of the whole population supplying samples and of positive pertussis cases for children younger than 5 years as serodiagnosed in 1990, 1995, 2002, and 2009

Age1990199520022009
No. of samplesNo. positiveNo. of samplesNo. positiveNo. of samplesNo. positiveNo. of samplesNo. positive
<6 mo225172230300
6 mo–1 yr420491693130
1–2 yr4711325443290
2–3 yr133135140110
3–4 yr275195131170
4–5 yr225156104202
Total1732914524173111202