Haemophilus influenzae

Cause: Bacterium Haemophilus influenzae. Invasive disease due to any of the 6 capsular types, including type b (Hib) in a child under 5 years of age, is reportable.

Illness and treatment: Invasive syndromes can include meningitis, bacteremia, epiglottitis, pneumonia, or bone and joint infections. Symptoms of meningitis include fever, headache, stiff neck, vomiting, light sensitivity and confusion. About 10% of cases surviving H. influenzae meningitis have permanent neurological damage. Treatment is with antibiotics.

Sources: Humans, including asymptomatic carriers, are the reservoir and transmit through respiratory droplets or direct contact.

Additional risks: Unimmunized or underimmunized infants and children are at risk, especially when they are taken into crowded settings.

Prevention: Immunization of all infants prevents H. influenzae type b infection. Respiratory and hand hygiene prevent transmission.

Recent Washington trends: 4 to 13 cases (due to all serotypes) are reported annually.

Purpose of Reporting and Surveillance

To correctly identify the serotype of invasive Haemophilus influenzae (HI) organisms in children under 5 years old.
To monitor the effectiveness of immunization programs and vaccines and to assess progress toward elimination of pediatric H. influenzae serotype B (Hib) invasive disease
To identify children exposed to Hib cases and closely observe them for signs of illness
To recommend antibiotic prophylaxis and/or immunization to appropriate contacts of Hib cases
To identify additional cases and establish risk factors for cases of non-Hib invasive H. influenzae disease.

Legal Reporting Requirements

Health care providers and Health care facilities: immediately notifiable to local health jurisdiction; only invasive cases under 5 years old are reportable.
Laboratories: immediately notifiable to local health jurisdiction; only cases under 5 years old are reportable; submission required – isolate or if no isolate available, specimen associated with positive result, within 2 business days (see Section 1C2).
Local health jurisdictions: notifiable to the Washington State Department of Health (DOH) Communicable Disease Epidemiology (CDE) within 7 days of case investigation completion or summary information required within 21 days.