Patricia was called at work by a woman at the local daycare center. She told Patricia to come and pick up her son because he was not feeling well. Her son, three-and-a-half-year-old Marshall, had been feeling tired and achy when he woke up. While at daycare, his cheeks had become red and he was warm to touch. He did not want to play with his friends, and by the time Patricia arrived, he was crying. Later that afternoon, Marshall’s condition worsened. He had fever, chills, a sore throat, runny nose, and a dry hacking cough. Suspecting Marshall had influenza, Patricia wrapped him up and took him to the community health care clinic.
- Why did Marshall’s presentation lead Patricia to think he had influenza and not a cold? Why is it important to medically evaluate and diagnose a potential influenza infection?
- Describe the pathophysiology of the influenza virus. Outline the properties of influenza A antigens that allow them to exert their effects in the host.
- Marshall may be at risk at contracting secondary bacterial pneumonia. Why is this so? Explain why cyanosis may be a feature associated with pneumonia.
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Introduction:
The following answers address a scenario where a three-and-a-half-year-old child is suspected of having influenza. The answers explain why the symptoms presented by the child suggest influenza and not a cold, describe the pathophysiology of the influenza virus and its properties, and explain the risk of contracting secondary bacterial pneumonia.
1) Marshall’s presentation led Patricia to think he had influenza and not a cold because he had symptoms beyond what is typically seen in a common cold. Specifically, he had a fever, chills, and a dry hacking cough in addition to a runny nose and sore throat. These symptoms are more commonly associated with influenza than a cold. It is important to medically evaluate and diagnose a potential influenza infection because it is a serious illness that can lead to complications such as pneumonia, hospitalization, and even death. Early diagnosis can lead to early treatment, potentially reducing the severity and duration of symptoms and preventing further spread of the virus.
2) The influenza virus is a lipid-envelope virus that belongs to the Orthomyxoviridae family. It has two major surface antigens: hemagglutinin (HA) and neuraminidase (NA). The HA antigen allows the virus to attach and enter host cells, while the NA antigen helps the virus to leave the infected cells and spread to other cells. The virus can mutate rapidly through antigenic shift and antigenic drift, making it difficult to develop effective vaccines and antiviral treatments. Influenza A viruses are the most common type, and their antigens can infect both humans and animals, potentially leading to pandemics.
3) Marshall may be at risk of contracting secondary bacterial pneumonia because influenza weakens the immune system, making it easier for bacteria to cause infections. The pneumonia can be caused by Streptococcus pneumoniae, Staphylococcus aureus, or Haemophilus influenzae. Cyanosis may be a feature associated with pneumonia because it indicates poor oxygenation of the blood due to fluid accumulation in the lungs. The body’s immune response to the bacterial infection can cause inflammation and fluid build-up in the alveoli, leading to difficulty breathing and decreased oxygen transport in the blood.
