Wuchereria bancrofti
Wuchereria bancrofti | |
---|---|
Microfilaria of Wuchereria bancrofti, from a patient seen in hematoxylin . The microfilaria is sheathed, its body is gently curved, and the tail is tapered to a point. The nuclear column (the cells that constitute the body of the microfilaria) is loosely packed, the cells can be visualized individually and do not extend to the tip of the tail. The sheath is slightly stained with hematoxylin.
| |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Nematoda |
Class: | Chromadorea |
Order: | Rhabditida |
Family: | Onchocercidae |
Genus: | Wuchereria |
Species: | W. bancrofti
|
Binomial name | |
Wuchereria bancrofti Cobbold, 1877
|
Wuchereria bancrofti is a
Morphology
As a
The microfilaria is a miniature adult, and retains the egg membrane as a sheath, and is often considered an advanced embryo. It measures 280 μm long and 25 μm wide. It appears quite structureless in vivo, but histological staining makes its primitive gut, nerve ring, and muscles apparent.[6]
Lifecycle
W. bancrofti carries out its
The microfilariae are transferred into a
History
The effects of W. bancrofti were documented early in ancient texts. Ancient Greek and Roman writers noted the similarities between the enlarged limbs and thickened, cracked skin of infected individuals to that of elephants, hence the name elephantiasis to describe the disease.[citation needed]
In 1862 in Paris, Jean-Nicolas Demarquay found what appeared to be nematode worms in the fluid aspirated from a hydrocele in a young man from Havana, Cuba. Unaware of this observation, three years later in Bahia, Brazil, Otto Wucherer found these same worms but this time in urine from a woman with chyluria. Ignorant of both these observations, Timothy Lewis in India in 1870 found them in the urine of an Indian with chyluria then two years later found them in blood. Some of Lewis's specimens were examined in the same year in England by George Busk who named them Filaria sanguinis hominis.[9] In 1876 and 1877, Joseph Bancroft in Brisbane, Australia found adult worms in lymphatic abscesses in patients with larvae in the blood. He sent them to Spencer Cobbold in London who named them Filaria Bancrofti. Patrick Manson in Xiamen, China (then called Amoy) made two important observations. Firstly he discovered in 1877 that if Culex quinquefasciatus and Aedes aegypti mosquitoes fed on a person with larvae (microfilariae) in the blood, they moulted twice in the insects' abdomen and became larger worms now called infective larvae. Secondly, he found in 1879 that the blood-dwelling forms had a nocturnal periodicity with large numbers appearing in the blood around midnight with minimal numbers in the middle of the day. This coincided with the biting habits of these mosquitoes. Manson surmised that infected mosquitoes drowned and infective larvae were ingested in water. In 1899, Thomas Bancroft in Brisbane fed laboratory-reared mosquitoes on a patient with microfilaraemia, kept them for 16 days, then sent some specimens to George Low in London. Low prepared histological sections of the mosquitoes and found that the larvae migrated from the abdomen to the thorax to the salivary glands then passed down the proboscis suggesting that infective larvae were injected at a subsequent mosquito bite. In 1902, Thomas Bancroft proved that this was the mode of transmission using a related worm, Dirofilaria immitis, and generated adult worms in experimentally infected dogs. In 1921, Léon Seurat erected the genus Wuchereria and placed this worm in it as Wuchereria bancrofti.[10]
W. bancrofti is speculated to have been brought to the New World by the slave trade.[11] Once it was introduced to the New World, this filarial worm disease persisted throughout the areas surrounding Charleston, South Carolina, until its sudden disappearance in the 1920s.[12]
References
- PMID 12076624.
- ^ "Wuchereria bancrofti: The causative agent of Bancroftian Filariasis". ww.nematodes.org. Archived from the original on 3 January 2019. Retrieved 20 February 2014.
- PMID 25412180.
- ^ "Ending the neglect to attain the Sustainable Development Goals: A road map for neglected tropical diseases 2021–2030". www.who.int. Retrieved 5 April 2023.
- ^ "Lymphatic Filariasis". Stanford University. Retrieved 20 February 2014.
- ^ ISBN 9780702053061.)
{{cite book}}
: CS1 maint: multiple names: authors list (link - ISBN 9781435448162.
- ISBN 9788172253172.
- ISBN 0-85198-689-7.
- ISBN 978-0-19-964102-4.
- PMID 15463229.
- PMID 3300389.