Invasive Haemophilus influenzae disease: 2022 annual report shows increased number of cases

In 2022 a significant rise in confirmed cases of invasive Haemophilus influenzae disease has been observed, totalling 3,967 cases. This figure marks a substantial increase from the previous two years, with 1,694 cases reported in 2021 and 1,849 in 2020. The surge in cases has been observed in parallel with the lifting of COVID-19 restrictions and measures as the microbes causing diseases returned into circulation, which suggests a correlation between the two events.

Infants under one year old have been the most affected while the second most affected age group was individuals aged 65 and over.A slight increase was specifically observed in cases of Haemophilus influenzae type b (Hib) in 2022, which constituted 9.1% (211 cases) of the total cases, compared to 7% (153 cases) in 2018. Invasive Haemophilus influenzae is a bacterium that can cause serious bacterial infections, particularly in the case of the type B strain (HiB).

The infections can range from mild respiratory illnesses to severe invasive diseases such as meningitis and septicemia. It affects both children and adults, with young children being most at risk. Haemophilus influenzae type B is the leading cause of meningitis mortality in non-immunised populations.

Safe and effective Hib vaccines have been available since the 1980s and all EU/EEA countries include these vaccines in their routine childhood immunisation programmes. Vaccination has significantly reduced the rates of the disease and has practically eliminated meningitis caused by the bacteria in infants and young children.

Along national recommendations, all children are recommended to receive the Hib vaccine before they are six months old and a booster dose when they are one year old.