The organism most commonly causing genital filariasis in most part of Bihar and easteran U.P.is –
**Core Concept**
Genital filariasis is a type of parasitic infection caused by filarial worms, which are transmitted to humans through the bite of an infected mosquito. In Bihar and eastern Uttar Pradesh, a specific species of filarial worm is responsible for this condition.
**Why the Correct Answer is Right**
The organism most commonly causing genital filariasis in most parts of Bihar and eastern Uttar Pradesh is Wuchereria bancrofti. This species of filarial worm is transmitted to humans through the bite of an infected Culex or Anopheles mosquito. The adult worms reside in the lymphatic system, causing blockage of lymphatic vessels and leading to genital filariasis. The microfilariae of W. bancrofti are excreted in the urine and are detectable in the peripheral blood, especially at night.
**Why Each Wrong Option is Incorrect**
* **Option A:** Brugia malayi is another species of filarial worm that causes lymphatic filariasis, but it is more commonly found in southern India and not typically associated with genital filariasis in Bihar and eastern Uttar Pradesh.
* **Option B:** Loa loa is a type of filarial worm that causes loiasis, which is characterized by the presence of a worm in the eye or subcutaneous tissue, but it is not typically associated with genital filariasis.
* **Option C:** Mansonella perstans is a type of filarial worm that causes mansonellosis, but it is not typically associated with genital filariasis.
**Clinical Pearl / High-Yield Fact**
The nocturnal periodicity of W. bancrofti microfilariae is a key diagnostic feature, and blood samples collected at night are more likely to contain microfilariae.
**Correct Answer: C. Loa loa is a type of filarial worm that causes loiasis, which is characterized by the presence of a worm in the eye or subcutaneous tissue, but it is not typically associated with genital filariasis.