Final answer:
Primary aspergillosis results from inhaling Aspergillus spores, possibly leading to systemic infection, while secondary aspergillosis occurs when the immune system is compromised. Iatrogenic and nosocomial diseases originate from medical procedures and hospital settings, respectively. Primary pathogens cause disease in healthy individuals, while opportunistic pathogens infect those with weakened defenses.
Step-by-step explanation:
The sources of infection for primary and secondary cutaneous aspergillosis involve different pathogenetic mechanisms. The primary aspergillosis infection often arises when an individual inhales airborne spores of the fungus Aspergillus. This can lead to a systemic infection if the spores become lodged in the lungs or sinuses, eventually disseminating, in severe cases, through the bloodstream to the skin, among other tissues. On the other hand, secondary infection occurs when an individual with a weakened immune system, perhaps due to a different primary infection or after the use of antibiotics which disrupt the protective microbiota, develops a subsequent skin infection from Aspergillus. This again can be from spores, but the key element is the compromised state of the body's defenses.
Iatrogenic diseases, like nosocomial diseases, are a result of medical procedures and hospital environments, respectively. An iatrogenic condition might stem from the introduction of pathogens during wound care or surgery, incurring an infection such as necrotizing fasciitis if the area becomes contaminated with bacteria. Nosocomial infections are related to hospital settings where multiple pathogens, a concentration of vulnerable patients, and antibiotic-resistant strains are more prevalent.
A primary pathogen causes disease in a healthy individual, whereas an opportunistic pathogen takes advantage of a compromised immune system to cause disease. Conditions such as AIDS, cancer treatments, diabetes, or prolonged antibiotic use can create opportunities for such pathogens to cause infections.