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Ebola: Information for U.S. Healthcare Workers and Settings

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Disease Name: Haemophilus influenzae

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Please review the Idaho Reportable Disease Rules (IDAPA 16.02.10) for the most up-to-date information.

Overview / Case Definition

H. influenzae causes a variety of clinical symptoms some of which may depend on the presence of the bacterial capsule. Until the availability of the Hib vaccine, H. influenzae b was the main cause of meningitis in children aged between 6 months and 5 years. Hib disease is not common beyond 5 years of age. Older children, adolescents, and adults can also be infected. The infection initially causes a runny nose, low grade fever, and headache (1-3 days). Due to its invasive nature, the organism enters the circulation and crosses the blood-brain barrier, resulting in a rapidly progressing meningitis (stiff neck), convulsions, coma, and death. Among Hib case in children, 3%–6% are fatal.

Timely treatment for Hib may prevent coma and death, but the patient may still suffer from permanent hearing loss or other long-term neurological sequelae (up to 20% of patients who survive Hib meningitis). Invasive H. influenzae may also cause bacteremia or sepsis, pneumonia, septic arthritis, osteomyelitis, pericarditis, cellulitis, and epiglottitis; the latter results in the obstruction of the upper airway and suffocation.

Humans are the only known reservoirs; the major reservoir of Hib is young infants and toddlers. Transmission occurs by inhalation of respiratory tract droplets or by direct contact with nasal and throat secretions. The nasopharynx is the most common portal of entry. Neonates can acquire infection by aspiration of amniotic fluid or contact with genital tract secretions containing the bacteria. Organisms colonize the nasopharynx and might remain only transiently or for several months in the absence of symptoms. Hib does not survive in the environment on inanimate surfaces.


Daycare Facility

A person who is diagnosed with invasive disease caused by Haemophilus influenzae must not work in an occupation providing personal care to children, or attend a daycare facility as long as the disease is in a communicable form.


A person who is diagnosed with invasive disease caused by Haemophilus influenzae must not work in any occupation where there is direct contact with students or attend a private, parochial, charter, or public school as long as the disease is in a communicable form.


Within one working day

Reportable by Healthcare and Labs:

Reportable by Food Service Facility:

Suspect Reportable: Yes

Reporting Timeframe: Within one working day

Diagnosis / Testing

The Centers for Disease Control and Prevention (CDC) recently released best practice guidance for clinical laboratories using Polymerase Chain Reaction (PCR) for the diagnosis of invasive Haemophilus influenzae (Hi) or Neisseria meningitidis (Nm).  This guidance was released after CDC became aware of recent instances in which it was not possible to determine whether cases of meningitis were part of a cluster due to the lack of serogroup data, hampering public health efforts to control possible outbreaks of the disease.

Many sites within the Idaho Sentinel Laboratory Network are adopting commercial molecular diagnostics such as the BioFire Film Array or ARUP PCR products.  These products enable the rapid detection of Hi and Nm genes but do not provide information about the serotype of the agent, which is critical for public health investigation and response. 

Idaho Bureau of Laboratories is requesting laboratories using PCR for the diagnosis of Hi and Nm to:

  1. select assays capable of detecting and differentiating all Hi serotypes (serotypes a-f) and all Nm serogroups common in the United States,  or
  2. send either reactive primary specimens or isolates to our reference bacteriology laboratory so that we may culture, confirm, and serotype them. 


Chemoprophylaxis with rifampin for household contacts is no longer indicated if all contacts aged less than 4 years are fully immunized against Hib disease.

Chemoprophylaxis of all household members (including the index case) regardless of age is recommended in households with one or more infants younger than 12 months of age who has not received the primary series, with a child aged <48 months of age who is inadequately vaccinated, or with an immunocompromised child.

Additional Information

Click to Call South Central Public Health District

Click to Call the Idaho State Epidemiologist

Click to Call Idaho State Communications