Maximum density of microfilariasis in blood is repoed to be between –
**Core Concept**
Microfilariasis refers to the presence of microfilariae, the larval stage of filarial parasites, in the peripheral blood of infected individuals. The density of microfilariae in the blood varies depending on the species of the parasite and the time of day, with peak levels typically observed in the early morning hours.
**Why the Correct Answer is Right**
The maximum density of microfilariasis in the blood is typically reported to be between 1000-2000 microfilariae per milliliter (mL) of blood. This is because the microfilariae of species such as Wuchereria bancrofti, the causative agent of lymphatic filariasis, exhibit nocturnal periodicity, with peak levels observed in the early morning hours. This periodicity is due to the circadian rhythm of the host's immune response, which affects the release of microfilariae from the skin into the bloodstream.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify a valid range for maximum microfilarial density.
* **Option B:** This option is incorrect because it suggests a range that is too low for maximum microfilarial density.
* **Option C:** This option is incorrect because it suggests a range that is too high for maximum microfilarial density.
**Clinical Pearl / High-Yield Fact**
It's essential to note that the density of microfilariae in the blood can vary depending on the species of the parasite and the time of day, with peak levels typically observed in the early morning hours. This is why blood samples for microfilarial detection are often collected during this time.
**Correct Answer:** D