1. Phylum Acanthocephala and Filaria Worm
Group:1
Members:
A. Sylnice Urey Abu Swaray
Arnold Flahn Micelia A. Clarke
Mariama Bah Brenda Mulbah
Giftee J Roumi Michelle Gwaikolo
Stella Maris Polytechnic University
Mother Pattern College of Health Sciences
UN Drive
Monrovia, Liberia
August. 10, 2022
2. Learning Objectives
• Know what are Acanthocephalans and Faliria
Worms
• Some characteristics
• Unique features
• Pathogenicity
• Distribution world wide
• Types of Acanthocephalans and Faliria Worms
• Transmission and susceptible hosts
3. Outline
• Overview of Acanthocephala and Filaria Worm
• Characteristics
• Phylogenetic and Evolutionary history
• Reproduction and life cycle
• Diagnosis
• Epidemiology
• Prevention
• Treatment
4. Overview of Acanthocephalans
• Greek- Acantha(prickle) & Kephale(a head)
• Spiny headed or Thorny headed Worms
• Earliest description by Italian Author Francesco
Redi(1684)
• Joseph Koelreuter proposed the name(1771)
• Karl Rudolphi (1809) formally named them
• Medium sized phylum with about 1,330 species
usually small and unsegmented
• Most are 25mm or 1 inch long
5. Overview Cont.
• Phylogenetic analysis
• Closely related to the rotifers especially Bdelloidea
and Monogononta.
• Widely distributed and occurs where insect are
eaten for dietary, medicinal purposes
• Eg: Macracanthorynchus ingens is endemic to
raccoon.
6. Characteristics
• All are parasites
• Bilaterally symmetrical and Vermiform
• Body has more than 2 cell layers, tissues or organs
• Body cavity is pseudocoelom
• Syncytial Epidermis with few giant nuclei
• Has nervous system with a ganglion and paired nervous
• Reproduce Sexually and gonochoristicly with viviparous
embryos
7. Characteristics Cont.
• Adults parasitize on vertebrates which are
definitive hosts
• Larvae live in arthropods as intermediate hosts
• Exhibit sexual dimorphism
8. Anatomy and Morphology
• Has nervous system
with a ganglion
• Has no respiratory and
circulatory system
11. Pathogenesis
• Disease:
Acanthocephaliasis
• Causative agent:
Acanthocephalans
• Description: Infection of
the digestive system
• Symptoms: early
infections may be
asymptomatic. Clinical
symptoms are severe
• Abdominal pain
• Effects: Fibrotic nodules.
• Inflamed intestine leads
to necrotic and
degenerative changes in
mucosal epithelium
• Peritonitis and death of
host
13. Prevention and control
• Standard Lab safety protocols
• Avoid their eggs because aberrant infection occur
in humans
• Practice hygiene
14. General characteristics
• All species are terrestrial
• Intermediate hosts are terrestrial insects and
myriapods
• predatory birds and mammals are the primary hosts.
Class Archiacanthocephala
15. Hook covered proboscis
Eight cement glands in the males
Characterised by lemnisci and body wall
The lemnisci have nuclei which divides without
spindle formation.
16.
17. Class Eoacanthocephala
Characteristics
The presence of giant subcuticular nuclei
Body spine
Lacunar vessels are dorsal and lateral
Cement gland of male is a single and syncitial
organ with a cement resevoir
Proboscis hooks are arranged in circles
Eggs are ellipsoidal
18. These worms are parasitic in cold blooded
vertebrates(turtle and fish)
Persistent ligament sac in females
Two orders: Gyracanthocephala and
Neoechinorhynchida
19.
20. Phylum Palaeacanthocephala
• It is known as the “
ancient thornheads”.
• They feed mainly on fish,
aquatic bird and
mammals.
• They are characterized by
their lateral longitudinal
lacunar canals.
21. Palaeacanthocephala cont.
• The nuclei of the
hypodermis is
fragmented.
• Their males have two -
seven cement glands.
• Their proboscis are
retractable.
22. Palaeacanthocephala cont.
• The single- ligament sac
rapture upon the sexual
maturation of the
female.
• They have 17 families.
• Their number of genera
known are 104.
• They have 884 species.
23. Polymorphida
• This is an order of
acanthocephala.
• The feed on fish and
aquatic birds.
• Their proboscis is
spheroid and cylindrical.
• They consist of 3
families:
Centrorhynchidae,
Plagiorhynchidae and
polymorphidae.
• They have 20 genera .
25. Overview
Parasitic nematodes
Dwell within the lymphatic and subcutaneous
tissues of up to 170 millions people world wide
Larvae are parasitic
Consider the second leading cause of permanent and
longterm disability
Larvae are transmitted through mosquito bite
Characterized by fever, chills,headache and skin
lesions
Humans are the only definitive host
26. Signs and symptoms of Filarial worms
• Acute inflammation of lymphatic vessels
• High temperature
• Shaking chills
• Body aches
• Swollen of lymph
• Progressive Edema
• Breasts, arms and legs
27. Causes of Filarial worms
• It is cause by: The
round worm parasite
(nematode)
• Including:
• The wuchereria
bancrofti and
• The Brugia malayi
28. Affected populations of Filarial
worms
• Filarial worms disease is common in tropical regions
of the world.
• The organism w.bancrofti is present through out
Asia, Africa, China, and south America.
• The B. Malayi is seen in Southern and Southeast
Asia.
• It is extremely rare in North America.
29. Diagnosis and Treatment of
Filarial worms
Diagnosis
• Requires examination
of a blood smear.
• The best sample is
obtained at night.
•
• Identification of
microfilariae
Treatment
• Filarial worms can be
treated by the major anti
-parasiticide drugs:
• Ivermectin
• Albendazole and
• Diethylcarbamazine
30. Morphology
• Their bodies are elongated, narrow, filiform, and
cylindrical in shape.
• Both of their ends are tapering.
• Surrounded by two rows of ten sessile papillae.
• The posterior end contains anus as it terminal end.
• The male measures 2.5-4cm in length with 0.1mm in
thickness.
• Life span of filarial worm is believed to be about 2-3
months.
• Females are 65 to 100mm long and only 0.25mm in
diameter.
32. Habitat of Filarial worms
• Found only in the lymphatic vessels and lymph
nodes of man only.
• Most common in tropical and sub tropicals
regions.
• They also live in Subcutaneous nodules.
33. Diseases caused by Filarial worms
1. Mumu
2. Loiasis ( calabar swellings)
3. Dirofilariasis(human infection by dog heart worm)
and
4. Onchocerciasis(river blindness)
34. Types of filarial worms
There are three major types of filarial worms, they
are:
1. Lymphatic filariasis
2.Subcutaneous filariasis and
3.Serous cavity filariasis
39. Pathogenesis
• Infection caused by W. bancrofti is
termed as wuchereriasis or
bancroftian filariasis
• This disease affects the lymphatic
system
The disease can present as:
• Classical filariasis
• Occult filariasis
41. Diagnosis
• Microfilaria in blood or
specimen obtain at night.
• Microfilaria Presence in
• Chylous urine
• Exudates of lymph varix and
hydrocele fluid.
• Radiology
42. Treatments
• Anthelmintic
• Antibiotics
• Vaccine
• Supportive treatments
Prevention and control:
•Mass deworming
•Dichlorodiphenyltrichloroethane
(DDT)
•Detection and treatment of carriers.
43. Brugia timori
General Characteristics
Brugia timori causes the disease
“Timor filariasis”
This disease was discovered in
1965 and the causative agent was
identified in 1977
Anopheles barbirostris is its primary
vector
No known animal reservoir host
44. Cont’d
Its life cycle is very similar to W. bancrofti
and B. malayi, leading to the nocturnal periodicity
of the disease symptom
B. timori filariasis causes acute fever and chronic
lymphedema ng to the nocturnal periodicity
of the disease symptom
Eosinophilia is common during the acute
stages infection
B. timori microfilariae have nuclei that extend to the tip
of the tail, slightly larger than B. malayi microfilariae
45. Epidemiology
B. timori found only in the Lesser Sunda Islands of
Indonesia.
Confined in areas inhibited by its mosquito vectors
Microfilariae was found in the blood of 157 of 586
individuals(27%), with 77 of hem (13%) exhibiting
lymphedema of the leg from a study done in Mainang Villag
Allor Island.
46. Reproduction
Mosquitoes ingest the infective
filariform from an infected host
Microfilariae penetrate the midgut of
the mosquito, migrating to the muscle
tissue.
Two moults into infective filariform
larvae.
Filariform larvae will move to the
mouthparts of the mosquito
The larvae enter the host’s
circulation
Migrate to lymphatic vessels,
developing into microfilariae
producing adults.
Infective filariform enters the
circulation of the host to repeat
its life cycle
48. symbiotic relationship
Wolbachia spp. is an obligate intracellular
endosymbiont of Brugia Spp.
Supports essenential biochemical pathways in B.
timori
49. Onchocerca volvulus, the "convoluted filaria';
or the "blinding filaria" producing
onchocerciasis or "river blindness" was first
described by Leuckart in 1893.
It affects about 40 million people, mainly in
tropical Africa, but also in Central and South
America.
A small focus if infection exists in Yamen and
South Arabia
It is the second major cause of blindness in
the world
Onchocerca volvulus
50. Geographical Range
• It occurs mainly in Africa with additional for us in
Latin America and the Middle East
51. Morphology
• Males range in length from 19-42 cm and range in width from 130-
210 micro metres
• Lacking alae, their tails are curled ventrally and bear 6 or 8 pairs of
postanal and 4 pairs of adanal papillae.
• Females are larger than males, ranging in length from 33.5-50 cm
and in width from 270-400 micrometers.
• The microfilariae released by adult females are 250-300
micrometres long, are unsheathed, and have sharply pointed and
curved tails
52. Epidemiology
• The people most at risk for acquiring onchocerciasis
are those who live or work near streams or rivers
where there are Simulium black flies.
• The habitat of Onchocerca volvulus is the body of its
host, in the black fly, microfilariae can be found in the
thoracic flight muscles
• In humans, microfilariae can be found in the skin,
lymph vessels, lymph nodes, and internal organs
53. Signs and Symptoms
• Infected people may show
symptoms such as severe itching
and various skin changes
• Infected people may also develop
eye lesions which can lead to visual
impairment and permanent
blindness.
55. Pathogenesis
• The infective larvae deposited in the skin by the bite of
the vector develop at the site to adult worms.
• Microfilariae cause lesions in the skin and eyes.
• The skin lesion is a dermatitis with pruritus,
pigmentation, atrophy and fibrosis.
• The subcutaneous nodule or onchocercoma is a
circumscribed, firm, non-tender tumor, formed as a result
of fibroblastic reaction around the worms.
57. Prevention, Control and
Treatment
• There are no programs to control
or eliminate loiasis in affected
areas.
• Your risk of infection may be less
in areas where communities
receive regular treatment for
onchocerciasis or lymphatic
filariasis.
• Aerial herbicide
• Chemotherapy
58. Mansonella Streptocerca
• Also known as
Acanthocheilonema,
Dipetalonema, or Tetrapetalonema
streptocerca, this worm is seen
only in West Africa.
• Streptocerciasis is form of human
filariasis caused by the nematode
Mansonella streptocerca
transmitted by Culicoides biting
midges.
59. Geographical Range
• M. streptocerca is an Old
World species that occurs in
tropical regions of West and
Central Africa.
• Generally, the transmission of
Mansonella spp. is highly
focal and local prevalence
varies widely within endemic
regions.
60. Morphology
• M. streptocerca adults have a
unique posterior end that is bent,
resembling the shape of a
shepherd’s crook.
• This feature makes it possible for
laboratory workers to distinguish M.
streptocerca from other species of
roundworms
• The adult worms live in the dermis,
just under the skin surface. The
unsheathed microfiliariae are found
in the skin.
61. Epidemiology
• It is a common parasite in the skin of
humans in the rain forests of Africa,
where it is thought to be a parasite
of chimpanzees, as well.
• The worm is distributed across West
and Central Africa. M. streptocerca
has reportedly been found in West
and Central Africa including Western
Uganda, the Uganda-Zaire border,
and the Bundibugyo district.
62. Signs and Symptoms
• Non-specific symptoms including
fever, fatigue, pruritus,
arthralgias, and abdominal pain
may occur.
• Headache and neuropsychiatric
symptoms also have been
reported.
• Signs may include
lymphadenopathy and
eosinophilia.
63. Diagnosis
• The infection of these roundworms
typically causes no symptoms but may
sometimes cause a mild dermatitis of
the thorax and shoulders.
• M. streptocerca infections fortunately
do not cause any nodules, skin disease,
or ocular infections like that of
Onchocerca volvulus.
• Due to the absence of nodules,
differentiating between M. streptocerca
and O. volvulvus infections are easier to
diagnose.
64. Treatment, Prevention and
Control
• Treatment of streptocerciasis
includes the use of
diethylcarbamazine (DEC) which is
reportedly effective against the
microfilarial and adult stage M.
streptocerca, but not proven as a
method of treatment
• Take preventative measures by
using DEET or other insect
repellents to ward off midges
when traveling into endemic areas.
68. Epidemiology
Tropical Africa
Central and Eastern
South America &
Caribbean.
Habitat: Adults- body
cavities(pleural cavity)
Microfilaris- Blood
Vector: Culicoides
speceis( midges)
69. Morphology
Adult
*white and thread-like
*cylindrical in shape
Male: 35–56 mm long and 45-60 μm; tail to full
coil
Female: 70–80 mm long and 80–120 μm wide
Microfilaria
*200 μm in length , and a width of 4.5
μm
*Unsheathed
*Head spot sometimes has a V-shaped
apparance
*Nuclei extend to the end of the tail
74. Epidemiology
• New World Filaroid Parasite:
subtropicial,tropical and
temperate regions of the Center
and South america ( Mexioco,
Panama, Brazil and Colmbia)
Habitat: Adults- body
cavities(pleural cavity)
Microfilaris- Blood
Vector: Culicoides speceis( midges)
Simulium (Black fly)
75. Morphology
Cylindrical and bilaterally
symmetrical worm
Females are much larger than than
the males and produce thousands of
offspring called microfilariae.
Microfilariae are 170- 240 μm long
and unsheathed.
Have a tapered tail without nuclei;
button hook
78. Signs and Symptoms
• The pathogenicity of M. ozzardi
needs further research. Although
the adult worms live in the body
cavities and the mesentery, they
do cause clinical manifestations
to their human hosts.
• Moderate fever
• Coldness in the legs
• Joint pains, like articular pain or
arthralgias
• Headaches
• Pruritus (itchiness)
• Skin eruptions
Wuchereria bancrofti is a filarial (arthropod-borne) nematode (roundworm) that is the major cause of lymphatic filariasis.
Habitat: The adult worms reside in the lymphatic system of man. The microfilariae are found in blood.
Morphology: As a dioecious worm, Wuchereria bancrofti exhibits sexual dimorphism. The adult worm is long, cylindrical, slender, and smooth with rounded ends. It is white in colour and almost transparent. The body is quite delicate, making removing it from tissues difficult. It has a short cephalic or head region connected to the main body by a short neck, which appears as a constriction. Dark spots are dispersed nuclei throughout the body cavity, with no nuclei at the tail tip.
Male is small with ventrally curved tail
Female is large and its tail gradually tapers and rounded at the tip.
The brighter the color; the higher the concentration of the disease.
W. bancrofti completes its life cycle in two hosts:
Definite host: Human
Intermediate host: mosquito, belonging to genus Culex, Aedes and Anopheles.
Life cycle in Human: Entrance in the human and development into adult worms
Infection is acquired by the bite of infected mosquito during which L3 larva are deposited on the skin.
The L3 larva are not directly injected into the blood stream.
The L3 larva are deposited on the skin near the site of the puncture.
Later attracted by the warmth of the skin, the larva enters through the puncture wound or penetrates through the skin on their own.
The L3 larva after penetrating the skin, reaches the lymphatic channels, settles down at some spot (inguinal, scrotal or abdominal lymphatics), metamorphose and becomes sexually mature.
The male fertilizes the female and the gravid females discharge microfilariae which usually appear in the peripheral blood in 8-12 month of infection.
These micro filariae circulate in the blood for 6 months to 2 years and then die if not taken by mosquito.
Life cycle in Mosquito: Stages in the development of micro filaria
Microfilaria ingested by the mosquito lose their sheath within 2 to 6 hours of their arrival in the stomach.
Then they penetrate the gut wall and migrate to the thoracic muscle, where they rest and begin to grow.
In the next 2 days, microfilaria become thick, short sausage shaped with a short spiky tail, measuring 124-200 mm in length 10-17 mm in breadth. This is the first stage larva L1.
The larvae possesses a rudimentary digestive tract.
During 3-7 days of time, the larva grows rapidly, moults once or twice and measures 225-330 mm in length by 15-30 mm in breadth. This is the second stage larva L2.
Metamorphosis completes by 10-11days with distinct features such as the tail atrophies to a mere stump and the digestive system, body cavity and genital organs are now fully developed. This is the third stage larva L3.
These L3 larva are the infective form which enters the proboscis sheath of the mosquito on or about the 14th day.
When the mosquito bites a man during the blood meal, the L3 larva are released from the tip of proboscis of mosquito and the cycle is repeated.
Development in mosquito takes place within 10-20 days.
The microfilaria is a miniature adult, and retains the egg membrane as a sheath, and is often considered an advanced embryo.
Peripheral blood is the specimen of choice. In India and other areas, where the prevalent filarial species is nocturnally periodic, it is best to collect "night blood" samples between 10 pm and 4 am. Microfilaria can be demonstrated in unstained as well as stained preparations and in thick as well as thin smears.
Treatments for lymphatic filariasis differ depending on the geographic location of the area of the world in which the disease was acquired. In sub-Saharan Africa, albendazole is being used with ivermectin to treat the disease, whereas elsewhere in the world, albendazole is used with diethylcarbamazine. Geo-targeting treatments is part of a larger strategy to eventually eliminate lymphatic filariasis by 2020.
Antibiotics[edit]
The antibiotic doxycycline is also effective in treating lymphatic filariasis.[28] Its drawbacks over anthelmintic drugs are that it requires 4 to 6 weeks of treatment, should not be used in young children and pregnant women, and is photosensitizing, which limits its use for mass prevention.[28] The parasites responsible for elephantiasis have a population of endosymbiotic bacteria, Wolbachia, that live inside the worm. When the symbiotic bacteria of the adult worms are killed by the antibiotic, they no longer provide chemicals which the nematode larvae need to develop, which either kills the larvae or prevents their normal development. This permanently sterilizes the adult worms, which also die within 1 to 2 years instead of their normal 10 to 14-year lifespan
Vaccine[edit]
A vaccine is not yet available, but in 2013, the University of Illinois College of Medicine was reporting 95% efficacy in testing against B. malayi in mice.
Supportive treatments[edit]
Additionally, surgical treatment may be helpful for issues related to scrotal elephantiasis and hydrocele. However, surgery is generally ineffective at correcting elephantiasis of the limbs.
