What is the Difference Between Haemophilus influenzae and Influenza Virus

The main difference between Haemophilus influenzae and influenza virus is that H. influenzae is a bacterium that causes meningitis, epiglottitis, and pneumonia, whereas the influenza virus is a virus that causes the disease influenza.

H. influenzae and influenza virus are two pathogens that cause diseases. Vaccines can prevent these diseases.

Key Areas Covered

1. What is Haemophilus influenzae
– Definition, Facts, Importance
2. What is Influenza Virus
– Definition, Facts, Importance
3. Similarities Between Haemophilus Influenzae and Influenza Virus
– Outline of Common Features
4. Difference Between Haemophilus Influenzae and Influenza Virus
– Comparison of Key Differences

Key Terms  

Haemophilus influenzae, Influenza Virus

What is Haemophilus influenzae

H. influenzae is a Gram-negative bacterium that can cause mild ear infections to severe bloodstream infections. It causes a type of invasive infection that infects the parts of the body not susceptible to germs, such as fluids around the brain and spine. It can cause meningitis, bacteremia, pneumonia, epiglottis, cellulitis, and infectious arthritis. Moreover, H. influenzae is non-motile. It belongs to the family Pasteurellaceae. Also, it is 0.3 to 1 micrometer long. Since it is a Gram-negative bacterium, its peptidoglycan layer is thin. And the outer membrane has lipopolysaccharides. Furthermore, being a mesophilic bacterium, it grows at 35°C and 37 °C.

Figure 1: H. Influenzae

Furthermore, the polysaccharide capsule and the bacterium’s outer membrane allow protection and colonization. H. influenza serotypes include a, b, c, d, e, and f. H. influenzae type b is the most common form, mostly in children. Importantly, H. influenzae is resistant to penicillin. However, amoxicillin and clavulanic acid respond in mild infections. Hib vaccine is the recommended form of prevention in children under age 5.

What is Influenza Virus

Influenza virus is another type of virus that causes respiratory illness. It contains a negative-sense, single-stranded DNA virus. Therefore, the genome of the influenza virus serves as the template for mRNA synthesis. Also, the influenza genome is segmented. It encodes nine major proteins. Also, the symptoms of the influenza virus include fever, sore throat, runny nose, muscle pain, headache, coughing, and fatigue. Symptoms occur one to four days after the infection. It causes diarrhea and vomiting in children. Subsequent bacterial infection can cause pneumonia. Acute respiratory distress syndrome, encephalitis, meningitis, asthma, and cardiovascular disease are the other complications of the influenza virus.

Figure 2: Infleunza Virus

Moreover, influenza viruses A, B, C, and D are the four types. Aquatic birds serve as the primary source of the influenza A virus. It is also widespread in mammals, including humans and pigs. Both influenza B and C viruses infect humans. Cattle and pigs show influenza D virus infections. Meanwhile, influenza A and B viruses show seasonal epidemics.

Similarities Between Haemophilus influenzae and Influenza Virus

• H. influenzae and influenza virus are two pathogens that cause diseases.
• Vaccines prevent these diseases. 

Difference Between Haemophilus influenzae and Influenza Virus

Definition

H. influenzae is a Gram-negative, non-motile, coccobacillary, facultatively anaerobic, capnophilic pathogenic bacterium. Meanwhile, the influenza virus is a virus that causes respiratory infections in the nose, throat, and lungs.

Type of Organism

H. influenzae is a bacterium, while influenza virus is a virus.   

Importance

H. influenzae causes meningitis, epiglottitis, and pneumonia, while the influenza virus causes influenza flu. 

Conclusion

In brief, H. influenzae and influenza virus are two pathogens. They cause diseases. Vaccines can prevent these diseases. H. influenzae is a bacterium that causes meningitis, epiglottitis, and pneumonia. In comparison, the influenza virus is a virus that causes the influenza disease. Therefore, the main difference between Haemophilus influenzae and influenza virus is the type of organism.  

References:

1. Centers for Disease Control and Prevention. (2022b, March 4). Haemophilus influenzae: Types of infection. Centers for Disease Control and Prevention. 
2. Centers for Disease Control and Prevention. (2022b, October 24). Key facts about influenza (flu). Centers for Disease Control and Prevention. 

Image Courtesy:

1. “Haemophilus influenzae sputum 1000x edited” By Microman12345 – Own Work (CC-BY SA 4.0) via Commons Wikimedia
2. “EM of influenza virus” By CDC – Own work (Public Domain) via Commons Wikimedia