Filarial Worms: Transmission, Diagnosis, and Treatment

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Questions and Answers

Describe the distinctive feature of filarial worms regarding their mode of transmission.

Filarial worms require an arthropod vector for transmission.

What is the primary diagnostic stage for blood and tissue nematodes, and how is it typically diagnosed?

The primary diagnostic stage is the microfilariae, typically diagnosed through blood collection or skin snips.

Explain the role of the sheath in microfilariae and name one sheathed microfilariae.

The sheath is a translucent eggshell remnant covering the body of the microfilaria. Wuchereria bancrofti is one of the sheathed microfilariae.

What is meant by 'periodicity' in the context of microfilariae, and provide an example of a filarial worm exhibiting nocturnal periodicity.

Periodicity refers to the rhythmical appearance of microfilariae in peripheral blood. Wuchereria bancrofti is nocturnal. Signup and view all the answers

Name three clinical manifestations generally caused by filarial diseases.

Hydrocele, lymphedema, and elephantiasis. Signup and view all the answers

What is the purpose of using 2% formalin in Knott's method for diagnosing filarial infections?

The 2% formalin is used to lyse red blood cells, concentrating microfilariae and white blood cells for easier identification. Signup and view all the answers

How does DEC (Diethylcarbamazine) work in the treatment of filariasis, and against which stages of the worm is it effective?

DEC kills both microfilariae and some adult worms of Wuchereria bancrofti and Brugia malayi. Signup and view all the answers

What preventative measures are recommended for abaca workers to reduce the risk of filarial infection?

Wearing long sleeve shirts and using mosquito repellents or nets, along with vector control (insecticides) are recommended. Signup and view all the answers

How do the nuclei in the tail region differ between Wuchereria bancrofti and Brugia malayi microfilariae, as observed in Giemsa-stained blood films?

W. bancrofti has no nuclei in its pointed tail, while B. malayi has two distinct nuclei that bulge the cuticle in the tail tip. Signup and view all the answers

What is river blindness, and what is the vector and causative agent?

River blindness is another name for Onchocerciasis. It is caused by Onchocerca volvulus and is transmitted by blackflies (Simulium spp.). Signup and view all the answers

Flashcards

Microfilariae

Pre-larval stage or embryos produced by filarial worms.

Adult Filarial Worms

Threadlike, creamy white worms, varying in length from 2-50 cm