**Core Concept**
Leptospira icterohemorrhagica is a species of bacteria that causes Weil's disease, a severe form of leptospirosis. This disease is typically transmitted through contact with water or soil contaminated with the urine of infected animals.

**Why the Correct Answer is Right**
Leptospira bacteria are shed in the urine of infected animals, such as rodents, and can survive for several weeks in moist environments. Humans become infected when they come into contact with water or soil contaminated with the bacteria, often through cuts or abrasions on the skin, or through mucous membranes. The bacteria can also be transmitted through contact with water that has been contaminated with the urine of infected animals.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the transmission of Leptospira icterohemorrhagica.
**Option B:** This option is incorrect because Leptospira bacteria are not transmitted through the air.
**Option C:** This option is incorrect because Leptospira bacteria are not transmitted through contaminated food.

**Clinical Pearl / High-Yield Fact**
Weil's disease is a serious and potentially life-threatening condition that requires prompt medical attention. It is essential for individuals who work with animals or in environments where they may be exposed to contaminated water or soil to take precautions to prevent infection.

**Correct Answer:** D.