Question

on the mode of communication of cholera by john snow (excerpt) it used to be generally assumed, that if cholera were a catching or communicable disease, it must spread by effluvia given off from the patient into the surrounding air, and inhaled by others into the lungs. this assumption led to very conflicting opinions respecting the disease. a little reflection shows, however, that we have no right thus to limit the way in which a disease may be propagated, for the communicable diseases of which we have a correct knowledge spread in very different manners. pathology indicates manner of communication a consideration of the pathology of cholera is capable of indicating to us the manner in which the disease is communicated. if it were ushered in by fever, or any other general constitutional disorder, then we should be furnished with no clue to the way in which the morbid poison enters the system; whether, for instance, by the alimentary canal, by the lungs, or in some other manner, but should be left to determine this point by circumstances unconnected with the pathology of the disease. but from all that i have been able to learn of cholera, both from my own observations and the descriptions of others, i conclude that cholera invariably commences with the affection of the alimentary canal. the disease often proceeds with so little feeling of general illness, that the patient does not consider himself in danger, or even apply for advice, till the malady is far advanced. 16 select the correct answer. which statement best expresses the central idea of the passage? a. cholera is most likely not a communicable disease. b. cholera is a communicable disease that little is known about. c. cholera shows little symptoms until the illness is far advanced. d. cholera is most likely spread through the alimentary canal.

Explanation:

The passage first mentions the common - assumed but incorrect way of cholera's spread, then states that considering cholera's pathology can indicate its mode of communication. It concludes that cholera invariably starts with the affection of the alimentary canal. Option B best captures the idea that cholera is a communicable disease with much still unknown about its spread, and the passage explores its mode of communication.

Answer:

B. Cholera is a communicable disease that little is known about.