Final answer:
The excerpt emphasizes the importance of understanding how infectious diseases spread, the stages at which they are most transmissible, and how modern factors like global travel and urban density contribute to infectiousness. It also highlights the roles of diagnosis, treatment, and prevention measures.
Step-by-step explanation:
The information in the excerpt contributes to the meaning and power of the word infectiousness by illustrating the spread of infectious diseases, their impact on individuals, and how factors such as population density and hygiene practices influence the transmission and progression of diseases. It mentions that the transmissibility of an infection during the five periods of a disease varies depending on the pathogen and the disease, highlighting how meningitis patients, for instance, can be contagious during different stages compared to other illnesses. Furthermore, the excerpt discusses historical aspects and how the rise in population density, especially in urban settings, has facilitated the transmission of infections.
The passage also notes that in modern times, factors like global travel can increase the potential for disease spread, emphasizing the importance of correct diagnosis, treatment, and preventive measures like handwashing and vaccinations to control infectious diseases. These insights underscore the significance of understanding the various elements that contribute to infectiousness to effectively manage and prevent disease outbreaks.