Laboratory reports of Haemophilus influenzae by age group and serotype: England and Wales, July to September 2014
Updated 27 February 2015
In the third quarter of 2014 (July to September) there was a total of 96 laboratory reports of invasive Haemophilus Influenzae. This represents a 55% decrease in cases compared to the previous quarter (n=173) and a similar number of cases compared to the third quarter of 2013 (n=93).
Of the samples which underwent serotyping (n=75), 81% were non-capsulated Haemophilus Influenzae (ncHi), a further 15% were serotype a, e, or f, and 4% were serotype b (Hib). There was a 2-fold increase in the proportion of serotype a, e, or f cases and 9% decrease in the proportion of ncHi cases compared to the third quarter of 2013 when: 89% of serotyped samples were ncHi, 7% were serotype a, e, or f, and 4% were Hib.
Age group was well reported (see table). Of the laboratory-confirmed cases during the third quarter: 84% were aged 15 years and over; 7% were 1 to 4 year of age; and 4% were either under 1 year of age or 5 to 14 years of age. This differed from the third quarter of 2013 when: 92% were aged 15 years and over; 4% were under 1 year of age; 2% were 1 to 4 years of age; and 1% was 5 to 15 years of age. There was a 4-fold increase in cases among children aged 1 to 14 years compared to the third quarter of 2013; this was due to an increase in the number of ncHi and Hib cases from 1 to 7, and 0 to 2 year-olds, respectively. Among those aged 15 years and over there was an increase in the number of a, e, or f cases from 4 to 9; however, the number of ncHi and Hib cases decreased from 57 to 51, and 3 to 1, respectively.
During this quarter, 69% of cases in children under 15 years were ncHi (n=9/15). There were 2 cases of Hib in this age-group: a 1-year-old who presented with tonsillitis and an immunocompromised 5 -year-old who presented with pneumonia. Both were unimmunised and made a full recovery. In comparison, during the third quarter of 2013 there was 1 case of Hib in a partially immunised 5 to 14 year old child.
1. Age distribution of laboratory-confirmed cases of Haemophilus Influenzae by serotype, England and Wales, third quarter 2014 (and 2013)
Serotype | Age-group | Total, third quarter 2014 (2013) | ||||
---|---|---|---|---|---|---|
<1y | 1-4y | 5-14y | 15+ | nk | ||
b | – (–) | 1 (–) | 1 (–) | 1 (3) | – (–) | 3 (3) |
nc | 2 (4) | 4 (–) | 3 (1) | 51 (57) | 1 (–) | 61 (62) |
a,e,f | 1 (–) | 1 (1) | – (–) | 9 (4) | – (–) | 11 (5) |
Not typed | 1 (–) | 1 (1) | – (–) | 19 (22) | – (–) | 21 (23) |
Total | 4 (4) | 7(2) | 4 (1) | 80 (86) | 1 (–) | 96 (93) |
Notes: “ –” Indicates that testing yielded no positives. Percentages may not add up to 100 due to rounding.