FILARIAL WORMS Flashcards
What classification do filarial worms fall under despite their distinct characteristics?
- Filarial worms are still classified as nematodes.
Which characteristics apply to filarial worms?
A) Arthropod borne
B) MOT: Skin inoculation “Bites”
C) Extraintestinal parasites/nematodes
D) All of the above
D) All of the above
What is the reproductive characteristic of female filarial worms?
- Female filarial worms are viviparous, meaning they do not have an egg stage but instead give birth to larvae.
What is the diagnostic stage of filarial worms found in humans, displaying periodicity in their appearance in the blood?
- Microfilaria, which can be sheathed or unsheathed, manifests as the diagnostic stage due to its rhythmic presence in the bloodstream.
In the life cycle of filarial worms, which larval stage is most mature in the vector before being transmitted to humans?
- The rhabditoid larva (third-stage larva) is the most developed larval stage within the vector before transmission to humans occurs.
What is the typical specimen used to detect filariasis?
- Blood.
What stages of filarial worms are found in a human host?
- A person infected with filarial worms harbors larval forms in their blood, adult worms in their lower lymphatics, and microfilariae
- Which circulate in the blood exhibiting periodicity. The microfilariae may appear sheathed or unsheathed depending on their periodicity.
What is the diagnostic stage of Filarial worms and the typical specimen used for detecting filariasis?
- The diagnostic stage of Filarial worms is the Microfilaria.
- While blood is the usual specimen for detecting filariasis, Onchocerca requires a biopsy known as Skin snips for accurate diagnosis.
Describe the life cycle of Microfilaria in filarial worms.
- L3 Larva will be introduced by the vector through skin inoculation. Inside the body, larva
migrates to the tissue and becomes adult. - The adult worms may reside in the lymphatic, subcutaneous tissue or internal body cavities.
Adult female worms lay alive microfilariae in which it may be released in the body via blood meal by the arthropod vector. - L1 transforms until L3 in body of the blood sucking insects and repeat life cycle.
What is the habitat of the adult Wuchereria bancrofti?
- Lower lymphatics.
What stage of Wuchereria bancrofti is infective to humans and vectors?
- The infective stage for humans is the third stage larva (L3), while for vectors, it’s the microfilaria.
- The mode of transmission is through skin inoculation via bites.
What is the habitat of adult B. malayi filarial worms, and what stages are infective to humans and vectors, respectively?
- The adult B. malayi filarial worms inhabit the upper lymphatics.
- The infective stage to humans is the third-stage larva (L3), while to the vector, it is the microfilaria.
- The mode of transmission is through skin inoculation via bites.
What is the habitat of the adult L. loa filarial worm?
- Habitat: Subcutaneous tissues
- Infective Stage: Third stage larva (L3) is infective to man; Microfilaria is infective to the vector.
- Mode of Transmission (MOT): Skin inoculation through bites
Which filarial worm primarily inhabits body cavities?
- It resides in body cavities and has the third stage larva as the infective stage to humans and microfilaria for the vector.
- Its mode of transmission involves skin inoculation through bites.
Where does M. ozzardi primarily reside within the human body, and what is its infective stage to humans and vectors?
- Inhabits body cavities and reaches its infective stage for humans as the third stage larva (L3).
- It’s most infectious to humans during this stage. For vectors, it becomes infective in the form of microfilaria. The transmission mode typically involves skin inoculation through “bites.”
