(M) Nematoda: Filarial Worms (Module-based) Flashcards
referred as blood and tissue-inhabiting nematodes, live in the tissues and/or body cavities of a vertebrate host including man
Filarial worms
(male/female worm) larviparous and insect vectors are needed for transmission of the infection
Female worms
The laid larvae are called?
microfilariae
The time of the day whereby blood and other tissue fluids contains abundant number of microfilariae, as compared to other hours, is called
which is of great value in the timing of when to get clinical specimen to produce high yield of positive results
periodicity
known to be an endosymbiont of filarial worms, including W. bancrofti, B. malayi and O. volvulus
Wolbachia bacteria
This is sucked by the insect vector, pass through the gut’s wall and into the hemocele of the insect.
microfilariae
What stage goes into some parts of the vector’s mouth or salivary glands.
3rd stage filiform larva (L3)
causative agent of Bancroftian’s filariasis
Wuchereriabancrofti
It is highly endemic in Amoean Ellice, Tokelau, and Fiji Islands.
Wuchereria bancrofti
It is also found in Burma, India, Saudi Arabia, Mauritius, Egypt, West and East Africa, and Congo.
Wuchecheria bancrofti
Males: 40mm long x 0.1mm in diameter with sharply curved posterior.
Females: 80-100mm x 0.24-0.30mm with vulva at cervical region, single
uterus, but all the remaining reproductive organs are paired.
Microfilaria: 244-296um long x 7.5-10um in diameter, sheathed, with graceful curves, rounded anterior, pointed caudal part, smooth cuticle, and body
nuclei are equidistant and regularly distributed.
Wuchecheria bancrofti
causes Malayan filariasis
BRUGIA MALAYI
It is endemic in India, Sri Lanka, Sumatra, Java, Borneo, Celebes, Malaysia, the Philippines, Thailand, North Vietnam, China, South Korea, and Japan.
Brugia malayi
causing Calabar or Fugitive swelling involves the eyes with microfilariae that exhibit diurnal periodicity
Loa loa
Endemic in west and Central Africa, especially Nigeria, Cameroon, and Zaire, and vectors are species of tabanid flies of genus Chrysops.
Loa loa
vectors of W. bancrofti & B. malayi
Mansonia
Aedes
Anopheles
Cules
Females measure 43-55mm long, 130-170um (diameter)
Males 13-23mm long x 70-80um in breadth
Microfilaria 177-230um, sheathed, with a kinky body, unevenly distributed
body nuclei, two prominent terminal nuclei which is diagnostic.
BRUGIA MALAYI
Vectors of Loa loa
Sp. of tabanid flies of genus Chrysops
Adult worm inhabiting subcutaneous tissues have a pair of lateral papillae and two pairs of sub-median papillae, all of which are sessile and are small. The skin has small bosses, which are not seen in males.
Loa loa
Male: measure 30-34 mm long by 0.35-0.43 mm in diameter
Females: 40-70 mm by 0.5 mm
Microfilaria: measures 250-300 x 6-8um with uneven distribution of body
nuclei that extend to the tip of the tail.
Loa loa
producing onchocerciasis or river blindness, with microfilariae in lymphatic fluids and both adults and microfilariae may be found in the skin and subcutaneous tissues where they produce fibrous nodules.
Onchocerca volvulus
Onchocerca volvulus commonly known as
Convoluted filaria
Vectors of Onchocerca volvulus
Black flies of genus simulium
Adult worms are white, opalescent, and transparent, with distinct transverse striations of the cuticle. Males are 19-24mm long x 130-210um in diameter. Females are 3.5-50mm x 270-400um in diameter. Microfilariae are 315-360um by 6um with both ends free of nuclei.
Onchocerca volvulus