FINALS: INTESTINAL TREMATODES Flashcards
INTESTINAL TREMATODE
Phylum ?
Platyhelminthes
- Prevalent in Southeast Asia, lives in human and pigs’ intestine
- GIANT/LARGE INTESTINAL FLUKE
- Only member of its family (Fascioliidae) to invade the small
intestine - causes Fasciolopsiasis
Fasciolopsis buski
- Oval in shape
- Slightly yellow in color
- 20 – 75mm in length, and 8 – 20mm in width; the largest helminth
egg - Thinner shell with an operculum encloses an ovum and 20 – 40
yolk cells - UNEMBRYONATED when passed in feces
- Difficult to distinguish from Fasciola hepatica, although the abopercular end of the latter often has a roughened or irregular
area
Fasciolopsis buski EGG
- Measure 20 – 75mm long (look like a slice of raw meat)
- Hermaphroditic
- The ventral sucker is larger and near by the much smaller oral
sucker - Two coral-liked testes located in the posterior half of the body
- No seminal receptacle
Fasciolopsis buski ADULT
Fasciolopsis buski IH
o 1st intermediate host
▪ Snail
* Genus Segmentina or Hippeutis
o 2nd intermediate host
▪ Aquatic plants
* Trapa bicornis (water caltrop)
* Eliocharis tuberosa (water chestnut)
* Ipomea obscural (morning glory or
kangkong)
* Nymphaea latus (lotus)
Fasciolopsis buski DH
Humans and Pigs
PATHOGENESIS AND CLINICAL MANIFESTATION
- Fasciolopsiasis
o Pathological changes caused by the worms are ________, ________ and ________
traumatic, obstructive, and toxic.
Fasciolopsis buski
o Maximum worm burden report ______ worms
> 3,700 worms
Fasciolopsis buski DIAGNOSIS
- Stool examination
o Direct fecal smear
o Sedimentation Method
Fasciolopsis buski TREATMENT
- Praziaquantel
o Three doses of 25 mg/kg over 1 day
- Belongs to the family Echinomastidae
- Characterized by having a COLLAR OF SPINES behind the oral sucker
and encyst in mollusk or fishes
ECHINOSTOMIDS
ECHINOSTOMID 2 spp.
o Echinostoma ilocanum (Garrisoni’s fluke)
o Artyfechinostomum malayanum
- Straw-colored
- 83 – 116 um x 58 -69um
- Operculated
- Ovoid in shape
- Similar to Fasciolopsis buski ova but smaller
Echinostoma ilocanum EGG
- Reddish-gray
- 2.5 – 6.6mm x 1 – 1.33mm
- Horse-shoe shaped collar of spines (circumoral disc) around the
oral suckers - 49 – 51 collar spines
- Integument is covered by plaque -like scales
- Simple intestinal caeca
- Tapered at posterior end
- 2 bilobed testes
- Ovary at the front of testes
Echinostoma ilocanum ADULT
ECHINOSTOMID spp.?
- UNLOBED testes
- Cirrus sac NOT EXTENDING beyond
central sucke - Vitellaria confluent posttestically
Echinostoma ilocanum
ECHINOMASTIDS spp.?
- DEEPLY LOBED testes
- Cirrus sac EXTENDING beyond central sucker
- Vitellaria begging at level of central sucker, confluent posttestically
Artyfechinostomum malayanum
E. Ilocanum IH?
o 1st intermediate host
▪ Freshwater snails
* Gyraulus convexiusculus
* Hippeutis umbilicalis
o 2nd intermediate host
▪ Snail spp.
* Pila luzonica (kuhol)
* Vivipara angularis (susong pampang)
A. malayanum IH?
o 1st intermediate host
▪ Freshwater snails
* Indoplanorbis exustus
* Gyraulus convexiusculus
o 2nd intermediate host
▪ Snail spp.
* Lymnaea (Bullastra) cumingiana (bilabid)
* Ampularis cenaliculatus (golden apple
snail)
Definitive host
o Ducks
o rodents
Accidental host
Human
ECHINOSTOMID
FLUKES PATHOGENESIS AND CLINICAL MANIFESTATION
- INFLAMMATION develops AT THE SITE OF ATTACHMENT OF THE ADULT WORM to the intestinal wall
- ULCERATION
- DIARRHEA, which is sometimes bloody
- ABDOMINAL PAIN may also develop
- INTOXICATION
ECHINOSTOMID
FLUKES DIAGNOSIS
- Stool examination
o Direct Fecal Smear
o Sedimentation Method
ECHINOSTOMID
FLUKES TREATMENT
PRAZIQUANTEL is given in three doses of 25 mg/kg over 1 day
E. ilocanum infection is endemic in
- NORTHERN LUZON
- SAMAR
- LEYTE
- PROVINCES OF MINDANAO
ECHINOSTOMID
FLUKES PREVENTION AND CONTROL
Avoiding ingestion of raw or improperly cooked second intermediate snail hosts of these parasites
- Belongs to the HETEROPHYIDAE family
- are SMALL INTESTINAL TREMATODES (0.5 – 2mm in length)
- are capable of surviving and reproducing in a wide range of hosts
- Metagonimus, Heterophyes, and Haplorchis are the three most important genera
- Major endemic areas are located in SOUTHEAST ASIA
Heterophyids
- Formerly known as M. takahashii or M. miyatai
- SMALLEST HUMAN FLUKES
- Disease association: Metagonimiasis
- One of the 3 major species of Metagonimus generally humaninfecting species in Japan and Korea
- Endemic: Korea, Japan, China, Taiwan, Russia, India, Europe
Metagonimus yokogawai
- Ovoid, light brown
- Measures 30 by 15 um
- Have slight shoulders
- Lack of terminal knob
- Exhibit operculum
- Fully embryonated when laid
- Consist of miracidium
Metagonimus yokogawai EGG
- Measure 1.5 by 0.5mm size
- Tiny, TEARDROP-SHAPED flukes with tapering at the anterior end and
rounding at the posterior end - Color: Grayish
- Small laterally deviated ventral sucker
- No ventrogenital apparatus
- No genital sucker
- Medially-located ovary
- 2 testes (Side-by-side near the posterior end of body)
- Urine tubules: overlap or cross over the middle portion of the anterior testis
- Has COARSE VITELLARIA (FAN-SHAPE) in posterior lateral fields
Metagonimus yokogawai ADULT
Metagonimus yokogawai IH
o 1st intermediate host
▪ Freshwater snail
* Semisulcospra libertine
* s. coreana
o 2nd intermediate host
▪ Freshwater fish or brackish water fish
* Sweetfish (Plecoglossus altivelis): korea
and Japan
Metagonimus yokogawai DH
o Humans
o Dogs
o Rats
o Cats
o Foxes
o Boars
o Kites
- AKA VON SIEBOLD’S FLUKES
- Cobboled in 1866:
o Heterophyes aegyptiaca as the type; later this was
synonymized with H. heterophyes - SMALLEST TREMATODE parasite of man inhibit small intestine having
the life span about 2 MONTHS - Endemic: Nile Delta of Egypt and Sudan, Middle East, Southeastern
Europe, and India
Heterophyes heterophyes
- Pyriform and Grayish
- Measure 1.0 by 0.5mm in size
- The tegument has FINE, SCALE-LIKE SPINES
- Minute oral sucker, ventral sucker is thick walled
- Two side-by-side testes near the posterior extremity of the body
- Ovary – anterior to the testes
- Vitellaria – LARGE POLYGONAL FOLLICLES in the lateral posterior
- Medially large ventral sucker
- Large submedian genital sucker armed with 70-85 chitinous rodlets on the gonoty
Heterophyes heterophyes ADULT
Heterophyes heterophyes IH?
o 1st intermediate host
▪ Freshwater snails
* Pironela and cerithidea
* Pirenella corica, Cerithideopsila conica in
Egypt
* Certidia cingula in Japan
o 2nd intermediate host
▪ Freshwater fish or brackish water fish
* Mullet and Tilapia (tilapia nilotica and
Tilapia Zilli)
Heterophyes heterophyes DH?
o Humans
o Dogs
o Cats
o Wolves
o Bats
o Rats
o Foxes
o Seagulls
o Pelicans
- Species of Haplorchis predominate among fish borne zoonotic parasites
- Haplorchis = single testis
- Taichui = for Dr. Taichui
- original description of this species was based on specimens recovered from birds and mammals caught in the middle part of Taiwan
- Morphological feature for differentiation from other Haplorchis species is the size, shape, and number of spines on the ventral
sucker - Human infections with Haplorchis spp. are prevalent in Southeast
Asia, including countries located in Indo-China Peninsula, Taiwan, the Philippines, and also probably in Egypt
Haplorchis taichui
- Semi-lunar group of 12-16 long, crescentic, and HOLLOW SPINES
- Sinistral patch of very minute solid spines
- Minute and oval body with flattened dorsal and ventral sides
- Only ONE TESTIS
- A small armed ventral sucker lacking a gonotyl
- Lack the expulsor-style distal part of the seminal vesicle
Haplorchis taichui ADULT
Haplorchis taichui IH?
o 1st Intermediate host
▪ Freshwater snail
* Melania obliquegranosa in Taiwan
* Melanoides tuberculate and Melania
juncea in the Philippines
* Tarebia granifera in Hawaii
o 2nd intermediate host
▪ Freshwater fish or brackish water fish
* Barbodes gonionotus
* Cirrhinus molitorella
* Cyclocheilichthys spp.
* Hampala spp.
* Labiobarbus leptocheila
* Mystacoleucus marginatus
* Onychostoma elongatum
* Puntius spp.
* Rhodeus ocellatus
Haplorchis taichui DH?
o Humans
o Dogs
o Cats
DIAGNOSIS
Stool examination
o Modified kato thick method
o Polymerase chain reaction (PCR)
TREATMENT
Praziquantel is given in three doses of 25 mg/kg over 1 day
