Haemophilus Influenzae Infections in Children

Introduction:

Haemophilus influenzae is a bacterium that causes several manifestations in children and adults. Some of the clinical manifestations caused by Haemophilus influenzae can also be life-threatening. The incidence of Haemophilus influenzae infections has reduced significantly due to the advent of proper immunization schedules. However, children are still susceptible to some infections caused by this bacteria.

What Is Haemophilus Influenzae Infection in Children?

Haemophilus influenzae (H. influenzae) is categorized into six serotypes (a to f) based on the polysaccharide capsule that surrounds the bacteria. Serotype b (Haemophilus influenzae b) is considered the most infectious and life-threatening among kids. Another type responsible for causing infections in children is the non-typeable H. influenzae (NTHi) strain. This strain is more pathogenic as there are no available vaccines against these strains.

How Does Haemophilus Influenzae Infection Occur in Children?

People infected with Haemophilus influenzae tend to spread the infection to kids through sneezing and coughing, during which the bacterium-laden droplets reach the children nearby. The bacteria reach the nasopharynx and start producing colonies within the nasopharynx. From this site, Haemophilus influenzae spread to other body parts via the circulating blood to cause varied manifestations. The main causative factor that causes widespread disease is the presence of polysaccharide capsules in encapsulated strains that facilitate the escape from the host immune response.

What Are the Clinical Manifestations of Haemophilus Influenzae Infection in Children?

Depending on the infective serotype and location of colonization, the following manifestations are seen in kids.

Meningitis

Haemophilus influenzae infection in the brain can cause inflamed meninges (protective sheath that covers the brain). This is serious and caused by serotype b of H. influenzae bacteria. The main symptoms that children exhibit after getting infected with Haemophilus influenzae b in the meninges are:

• Fever.

• Irritability.

• Stiffness in muscles.

• Headache.

• Vomiting.

• Disorientation.

• Lethargy.

• Stiffness in the neck region.

• Headaches.

• Fontanelles may bulge out in infants.

• Loss of hearing.

• Intellectual disability.

Since a vital organ like the brain is damaged, meningitis secondary to H. influenzae can cause death in advanced cases in children.

Otitis Media

Inflamed middle ear can be caused due to H. influenzae infections in children. This is mostly caused by non-typeable H. influenzae (NTHi) strains. Symptoms in kids are:

• Purulent discharge from the ear.

• Pulling sensation.

• Ear pain.

• Loss of balance.

• Nasal congestion.

• Cough.

• Difficulty in hearing.

Pneumonia

Pneumonia due to Haemophilus influenzae is very common in children. Initial symptoms like fever and cough may be noted in affected kids. However, in children with unnoticed or neglected symptoms, there can be pus formation within the lungs (empyema) and can ultimately lead to failure in the respiratory process.

Conjunctivitis

The inner lining of the eye becomes inflamed due to H. influenzae colonization in the eyes. This causes:

• Eye redness.

• Burning sensation.

• Swelling.

• Fluid discharge from the eyes.

• Altered vision.

• Increased light sensitivity.

Sinusitis

In young children, sinusitis caused by Haemophilus influenzae can cause a runny nose that persists for more than ten days. Other symptoms caused are:

• Fever.

• Cough.

• Swelling around eyes.

• Facial pain.

• Headache.

• Bad breath.

• Sore throat.

• Nasal discharge passes down to the throat.

Epiglottitis

The most serious disease caused by Haemophilus influenzae is the infection and inflammation of epiglottis in children. This can cause the airway to be obstructed in the affected kids. Associated symptoms are:

• Sore throat.

• Cough.

• Difficulty breathing.

• Voice changes.

• Drooling.

• The child may always tend to open the mouth even after forceful closure.

Septicemia

The toxic products produced by Haemophilus influenzae can spread through the blood and can cause high fever (greater than 103 degrees Fahrenheit) and chills in children. The children may also have rapid and difficult breathing along with altered mental status and loss of consciousness. This can subsequently lead to a severe reduction in blood pressure and result in septic shock (organ failure due to septic products in blood).

How to Diagnose Haemophilus Influenzae Infections in Children?

Physicians can diagnose infections caused by Haemophilus influenzae based on the medical history given by the parents. In children who can cooperate, a sample of the secretions can be obtained for culture to diagnose the infectious agent and give appropriate medicines.

• A sample of blood or cerebrospinal fluid can be obtained from the affected child. Isolating H. influenzae and determining the particular serotype involved in the disease's causation can help in the adept treatment process.

• A more sensitive tool is the polymerase chain reaction that detects the DNA of Haemophilus influenzae in the obtained specimens of the kids.

• Antigen detection tests are also available to diagnose Haemophilus influenzae b infections. This can be specifically useful in meningitis cases.

How to Treat Haemophilus Influenzae Infections in Children?

• Third-generation cephalosporins will be given to children who have meningitis due to H. influenzae. Bacterial sensitivity to the particular antibiotic should also be confirmed in the children. Based on this, the choice of antibiotic can be altered.

• Corticosteroids will be given in rare cases where children are susceptible to have advanced neurological complications due to inflammation.

• Children who have severe pneumonia and epiglottitis require hospitalization to get antibiotics through an intravenous route.

• Recurrent episodes of otitis media in children due to H. influenzae require tympanostomy tube placement (placing ear tubes in the middle ear).

• For septicemia and septic shock, intravenous antibiotics along with fluid replacement and resuscitation care will be the management strategy for affected children.

How to Prevent Haemophilus Influenzae Infection in Children?

Vaccination against serotype b of Haemophilus influenzae (Hib) has greatly reduced the incidence of this deadly infection in children (as Hib is the most life-threatening strain). The primary vaccination dose for Hib will be given during the second and fourth month of the babies or second, fourth, and sixth month (based on the brand of vaccine administered). The booster for this vaccine will be given anytime between 12 and 15 months of age. A baby who has not received vaccination against Hib till five years of age will not require immunization.

Other Prevention Strategies Include:

• Preventing contact with sick people.

• Taking prophylactic antibiotics after doctor’s advice regarding the same.

• Eradicating the infection completely through public health interventions.

• Creating awareness about safe practices.

Conclusion:

Overall, the deadly states of Haemophilus influenzae infection can be prevented through proper immunization. However, there can always be a chance for disease causation by NTHi and non-b serotypes. So, proper knowledge about the infectious state and preventive measures is very much needed to avoid infections like Haemophilus influenzae.