Leptospirosis is transmitted by:
**Core Concept**
Leptospirosis is a zoonotic disease caused by the bacterium *Leptospira*, which is transmitted to humans through contact with contaminated water or soil. This infection primarily affects the kidneys and liver, leading to symptoms such as fever, headache, and muscle aches.
**Why the Correct Answer is Right**
The correct answer is water contaminated with the urine of infected animals, particularly rats. This occurs when the bacteria are shed into the environment through the urine of infected animals. Humans can become infected through contact with contaminated water, which can occur through swimming, wading, or drinking contaminated water. The bacteria can also enter the body through cuts or abrasions on the skin.
**Why Each Wrong Option is Incorrect**
* **Option A:** While leptospirosis can be transmitted through contact with contaminated soil, this is not the primary mode of transmission. Soil can become contaminated with the bacteria through the urine of infected animals, but it is not the most direct or common route of infection.
* **Option B:** Mosquitoes are not vectors for leptospirosis. This is a common misconception, as mosquitoes are vectors for other diseases such as malaria and dengue fever.
* **Option C:** Leptospirosis is not transmitted through the air. The bacteria are not airborne and do not become airborne through respiratory secretions or other means.
**Clinical Pearl / High-Yield Fact**
Leptospirosis is a common cause of fever and kidney failure in travelers to tropical and subtropical regions. It is essential to take precautions when swimming or wading in contaminated water, such as wearing protective clothing and avoiding contact with animals that may be infected.
**Correct Answer: D. Water contaminated with the urine of infected animals.**