Haemophilus influenzae type b disease - reported number of casesFootnote 1 and incidence rates, Canada, 1979-2010Footnote 2 - Text Equivalent

This image is a histogram showing the reported number of cases of Haemophilus influenzae type b ( Hib ) in Canada over time. A superimposed graph shows the incidence rates of Haemophilus influenzae type b ( Hib ) in Canada over time. The x axis represents the time between 1979 and 2010. The y axis on the left represents the reported number of cases starting from 0 at the bottom to 1200 at the top. The y axis on the right represents incidence rates per 100,000 starting with 0 at the bottom to 4 at the top. The bars represent the reported number of cases and the blue line shows the Hib incidence rate. In 1979, the reported number of Hib meningitis cases was 220. The Hib meningitis cases steadily escalated to about 510 by 1985. The reported number of invasive Hib cases hit a peak of almost 900 by 1989. The PRP-D was introduced in 1988

. According to a note at the bottom of the histogram, PRP-D is the Hib conjugate vaccine containing purified polyribosylribitol phosphate capsular polysaccharide of Hib covalently bound to diphtheria protein. The reported number of cases sharply declined to about 530 in the year 1990, and steadily to a low of about 30 in 1999. The number remained stable around that level until 2010.

The incidence rate of Hib was close to 1 per 100,000 in 1979, rising steadily to 2 per 100,000 population in 1985. All invasive disease caused by Hib reached an incidence rate of 2.7 by 1986. By the time the Hib conjugate vaccine PRP-D was introduced in 1988, the incidence rate was 3 per 100,000. The peak incidence rate of all invasive disease caused by Hib in Canada was about 3.7 in the year 1989. Since then, the incidence declined sharply and steadily over the years. The rate was about 1 in 1992 and dropped below 0.5 per 100,000 by 1993. The rate fell close to 0.1 in 1999, and remained around 0.2 during the years 2000 to 2008. By 2010, the incidence was no more than 0.1 per 100,000.

A note at the bottom of the table indicates that case data have been "obtained from the Canadian Notifiable Disease Surveillance System" and "population data obtained from Statistics Canada July 1st annual estimates." It also mentions that "data for 2009 and 2010 are preliminary."

Another note clarifies that