Answer :
Final answer:
Immunodeficiency occurs when the immune system is compromised, often due to disease-causing pathogens like HIV that target key immune cells, making an individual more susceptible to infections.
Explanation:
When a host's immune system is impaired by another disease-causing pathogen, a condition called immunodeficiency can occur. This happens when the immune system is unable to respond effectively to pathogens. Diseases such as HIV wage a direct attack on the immune system, targeting key cells like the T helper (TH) cells, and reducing the body's ability to combat infections. Pathogens like Streptococcus pneumoniae and Staphylococcus aureus have evolved strategies like producing protective capsules and toxins to inhibit and kill immune cells, respectively. Moreover, the immune system can be weakened by certain lifestyle factors or disorders, such as obesity, alcoholism, or drug abuse. As a result, immunocompromised individuals are more susceptible to infections that would otherwise be controlled by a healthy immune system.
When a host's immune system is impaired by another disease-causing pathogen, the individual becomes more susceptible to opportunistic infections and other diseases due to a weakened immune response.
A compromised immune system, often weakened by chronic infections like HIV, cancer, or other immune-suppressing conditions, loses its ability to effectively fight off pathogens.
This makes the host more vulnerable to infections that wouldn't normally cause disease in a healthy individual, known as opportunistic infections. These infections can be more severe and harder to treat, as the body's natural defenses are diminished.
Additionally, the impaired immune system may struggle to recognize and eliminate cancerous cells, leading to an increased risk of malignancies. This condition can result in a complex interplay of diseases, where the immune system's inability to function optimally exacerbates the host's overall health decline.