Which of the following is NOT a symptom of severe organophosphate and carbamate insecticide poisoning?

The selection of chest discomfort as the answer is correct because it is not typically listed as a symptom of severe organophosphate and carbamate insecticide poisoning. The more common and direct effects of these insecticides involve the nervous system and can include symptoms such as running nose and drooling, which are indicative of excessive secretion due to the overstimulation of the nervous system. Dyspnea, or difficulty breathing, aligns with the respiratory distress that can occur with poisoning. Lastly, coma and death can result from the severe effects of organophosphates and carbamates, particularly due to their ability to inhibit acetylcholinesterase, leading to a buildup of acetylcholine and subsequent toxicity.

In summary, while symptoms like excessive salivation and respiratory distress are directly connected to this type of poisoning, chest discomfort is not a primary or typical symptom associated with organophosphate and carbamate toxicity.