Haemophilus Influenzae

1. Assure case is on respiratory droplet precautions.

2. Complete the front part of the Reportable Disease Case Report (Yellow Card), the CDC meningitis and bacteremia case report form and attach copies of laboratory reports.

3. Assure that isolate is sent to OLS.

4. Identify contacts of index case for whom prophylaxis is recommended.

1. All suitable household contacts, including adults, when the household contains a contact that is younger than 48 months (four years) of age whose immunization status with conjugate vaccine is incomplete. A household contact is defined as a person residing with the index patient or a non resident who spent four or more hours with the index case for at least five of the seven days preceding the day of hospital admission of the index case.

2. All members of a household with a child younger than 12 months of age, even if the primary series has been given.

3. All occupants of a household with an immunocompromised child, irrespective of the child’s Hib immunization status.

4. Nursery and child care contacts, irrespective of age, when two or more cases of invasive disease have occurred within 60 days.

5. Index case, if treated with regimes other than cefotaxime or ceftriaxone, should receive chemoprophylaxis before discharge

6. Chemoprophylaxis is not recommended for the following:

1. Occupants of household with no children younger than four years of age other than the index patient.

2. Occupants of households when all household contacts younger than 48 months of age have completed their Hib immunization series.

3. Nursery and child care center contacts of one index case, especially those older than two years of age.

4. Pregnant women

6. Bring unvaccinated or undervaccinated infants/toddlers up to date with their immunization.

Disease Control Objectives

To prevent secondary cases by:

1. Isolation of the case until 24 hours after the start of appropriate chemoprophylaxis.

2. Appropriate prophylaxis of contacts.

Prevent cases of disease by encouraging full immunization of all infants per the ACIP approved schedule.

1. To identify demographic characteristics and risk factors of infected persons with Haemophilus influenza invasive disease.

2. To identify the types of infections associated with invasive Haemophilus influenza isolates.

3. To distinguish failure of the Haemophilus influenza type b (Hib) vaccine from failure to vaccinate as the more significant risk factor for disease.

Before the introduction of effective vaccines, Haemophilus influenzae type b (Hib) was the leading cause of bacterial meningitis and other invasive bacterial disease among children <5 years of age. Approximately one in 200 children developed invasive Hib disease before the age of 5 years. Two-thirds of cases were among children <18 months of age.

Since 1988 when Hib conjugate vaccines were introduced, the incidence of invasive Hib disease in infants and young children has declined by 99%. There is evidence that Hib vaccines decrease the rate of carriage of Hib among vaccinated children, therefore decreasing the chance that unvaccinated children will be exposed.

Haemophilus influenza can have many manifestations including:

Meningitis:

Signs and symptoms include fever, headache, nausea, vomiting, stiff neck, sensitivity to light (photophobia), nuchal rigidity, seizures, coma; and in infants, poor feeding and a bulging fontanelle.

Epiglottis:

Signs and symptoms include sudden onset of sore throat, fever, and shortness of breath, progressing rapidly to difficulty swallowing and pooling and drooling of saliva due to the obstructed airway.

Pneumonia:

Signs and symptoms include severe shortness of breath, rapid heart rate, fever, cough and evidence of pneumonia by chest radiograph.

Septic Arthritis:

Signs and symptoms of swelling, warmth, pain with movement and decreased mobility of a single large weight-bearing joint.

Haemophilus influenzae serotype a-f with serotype b (Hib) is the most common.

This organism causes meningitis, epiglottitis, pneumonia, septic arthritis, cellulitis, pericarditis, empyema, osteomyelitis. Serotype a and c-f rarely cause meningitis.

Humans are the only know reservoir of this organism.

Droplet infection and discharge from the upper respiratory tract during the infectious period. Most common portal of entry is the nasopharynx.

Unknown, probably short, 2-4 days.

As long as the organism is present, even in the absence of nasal discharge. This could be for prolonged periods of time. Noninfectious within 24 to 48 hours after the start of effective antibiotics.

Increased rates of Haemophilus influenzae that may or may not be linked epidemiologically are considered an outbreak. Outbreaks of H. influenzae occur in propagated form. Propagated outbreaks are those that involve person-to-person transmission and result in two or more generations of cases. Haemophilus influenzae outbreaks of this nature are generally recognized after a larger than expected number of cases of H. influenzae are reported within a limited time period. Since the incubation period of H. influenzae is short, probably 2-4 days, and the infectious period can last until the patient is started on an effective antibiotic, the onset dates for cases with a common source are usually spread over several days to a week.

Clinical case definition:

Invasive disease caused by H. influenzae may produce any of several clinical syndromes including meningitis, bacteremia, epiglottitis, or pneumonia.

Isolation of H. Influenzae from a normally sterile site (e.g., blood or CSF or, less commonly, joint, pleural, or pericardial fluid.)

Confirmed:   a clinically compatible case that is laboratory confirmed.

Probable:     a clinically compatible case with detection of H. influenzae type b antigen in CSF

Comment:   Positive antigen testing results from urine or serum samples are unreliable for diagnosis of H. influenzae disease.

Isolation of H. influenzae in a culture from blood, CSF, or any other normally sterile bodily fluid (e.g., blood or CSF or, less commonly, joint, pleural, or pericardial fluid.) A fluid specimen collected from a normally sterile site should have a Gram’s stain that will show small gram-negative, nonmotile, nonspore-forming coccobacillus. For suspected H. influenzae chocolate agar should be used. Serology is not used to diagnose invasive H. influenzae type b cases as the antibodies are not induced in young children and not reliably induced in older individuals.

• Proportion of cases with complete demographic information.

• Proportion of cases with type of infection and specimen source reported.

• Proportion of cases with vaccine history reported.

• Proportion of cases with antibiotic sensitivity profile reported.

• Median number of days between date of onset of clinical symptoms and date of report to public health authorities.

• Proportion of cases with known serotype.