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Haemophilus influenzae Disease Symptoms and Complications

Key points

  • Haemophilus influenzae can cause many different types of infections.
  • Symptoms depend on the part of the body that's infected.
  • Serious infections can result in long-term health problems and death.
  • Complications aren't common for mild infections.
A mother snuggles with her sick child.

Symptoms

Experts don't know how long it takes after H. influenzae enter a person's body for someone to get sick. However, it could take as little as a few days before symptoms appear.

Symptoms of H. influenzae disease depend on which part of the body is infected. Generally, the symptoms are similar to other bacterial infections in that part of the body.

Serious infections

Pneumonia

Symptoms of pneumonia (a lung infection) usually include:

  • Fever, chills, or sweating
  • Cough
  • Shortness of breath or difficulty breathing
  • Chest pain
  • Headache
  • Muscle pain or aches
  • Excessive tiredness

Bloodstream infection

Symptoms of bloodstream infection usually include:

  • Fever and chills
  • Excessive tiredness
  • Pain in the belly
  • Diarrhea or nausea with or without vomiting
  • Anxiety
  • Shortness of breath or difficulty breathing
  • Altered mental status (confusion)

A bloodstream infection from H. influenzae can occur with or without other infections, such as pneumonia or meningitis.

Meningitis

Symptoms of meningitis typically include sudden onset of:

  • Fever
  • Headache
  • Stiff neck
  • Nausea with or without vomiting
  • Photophobia (eyes being more sensitive to light)
  • Altered mental status (confusion)

Babies with meningitis may:

  • Be irritable
  • Vomit
  • Feed poorly
  • Appear to be slow or inactive
  • Have abnormal reflexes

Mild infections

Ear infections

Symptoms of ear infections can include:

  • Ear pain
  • A red, swollen ear drum
  • Fever
  • Sleepiness

Bronchitis

Bronchitis is when the airways that carry air to the lungs get inflamed or swell. Symptoms of bronchitis can include:

  • Coughing with or without mucus
  • Soreness in the chest
  • Excessive tiredness
  • Mild headache
  • Mild body aches
  • Sore throat

Complications and when to seek help

Serious infections can result in sepsis, long-term problems, or death. Sepsis is a life-threatening emergency resulting from the body's extreme response to infection.

Long-term problems can include:

  • Brain damage or hearing loss from meningitis.
  • Loss of limbs from bloodstream infections.

Complications are rare and not usually severe for mild infections like bronchitis and ear infections.

When to seek medical care‎

Call a healthcare provider right away if you think you or your child might have a serious H. influenzae infection.

Resources

Meningitis

Pneumonia

Sepsis

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Content Source:
National Center for Immunization and Respiratory Diseases; Division of Bacterial Diseases