Get to know each other together
Haemophilus influenzae
With the arrival of winter, various respiratory infectious diseases are frequent, and Haemophilus influenzae disease should not be underestimated.
What is Haemophilus influenzae?
Haemophilus influenzae was first discovered in 1892 from the sputum of influenza patients, so it has been mistaken for the pathogen that causes influenza, and due to its "bloodthirsty" properties, it was named "Haemophilus influenzae". It was not until 1933, when the influenza virus was isolated, that it was determined that it was not the causative agent of influenza.
Haemophilus influenzae was divided into capsulated and non-capsulated polysaccharides according to the presence or absence of capsulated polysaccharides. According to the differences in the structure and antigenicity of capsular polysaccharides, Haemophilus influenzae with capsular was divided into six serotypes. Haemophilus influenzae type b (Hib) is the most pathogenic, and about 95% of invasive Haemophilus influenzae diseases were caused by Hib before the introduction of Hib conjugate vaccines.
Haemophilus influenzae diseaseMode of transmission
What is it?Who is susceptible?
Humans are the only known host of Haemophilus influenzae. Haemophilus influenzae adheres to and colonizes the human respiratory tract, conjunctiva, and mucosa, and only a small number of carriers will develop into clinical patients. Infection is transmitted through respiratory droplets or direct contact with respiratory secretions. Although Haemophilus influenzae infection can occur at any age, its incidence is closely related to age, with more than 90% of invasive cases occurring in children under 5 years of age, with children aged 6 to 11 months particularly susceptible.
What diseases can Haemophilus influenzae cause?
Haemophilus influenzae is a common cause of severe illness in children worldwide and can lead to many types of clinical infections, the most common of which are pneumonia and meningitis. Haemophilus influenzae type b is considered to be the number one killer of children worldwide, and Haemophilus influenzae type b is one of the leading causes of pneumonia in children in developing countries (second only to Streptococcus pneumoniae) and the leading cause of acute bacterial meningitis in infants and young children under five years of age.
How to prevent Haemophilus influenzae disease?
01 Universal precautions
Practice good personal hygiene.
02 Targeted preventive measures
Vaccination is an effective way to prevent Haemophilus influenzae, and all currently available Haemophilus influenzae vaccines are aimed at infectious diseases caused by HiB. Commonly used HiB-containing vaccines include HiB conjugate vaccine, acellular diphtheria-pertussis Haemophilus influenzae type b combination vaccine (DTAP-HIB quadruple vaccine), adsorbed acellular diphtheria-pertussis inactivated polio, and Haemophilus influenzae type b conjugate vaccine (DTACP-IPV HIB quintuple vaccine). The scope of action and immunization procedures of different vaccines are different, and parents need to choose vaccination according to the instructions under the guidance of doctors.
Contributed by Che Jie, Xu Li, Han Fuyi, and Shao Zhujun, Institute of Infectious Diseases, China Center for Disease Control and Prevention.