Intro to Med Para

Symbiosis (living together) Symbiosis (living together) From the Latin word:

From the Latin word:symsym--_{living togetherliving together}

bio bio--_lifelife

An association between two different species of  An association between two different species of  organisms

organisms

Primarily aim for obtaining food or shelter from Primarily aim for obtaining food or shelter from one or both member of the relationship

one or both member of the relationship Has no overtones of benefit or harm Has no overtones of benefit or harm Includes a wide diversity of associations Includes a wide diversity of associations Most Important Symbiotic

Most Important Symbiotic Relationships:Relationships: y

y CC_{ommensalismommensalism}--_{one benefits from theone benefits from the} association while the other is unharmed association while the other is unharmed

Why study parasites? Why study parasites?

Parasites provide unique examples of biological Parasites provide unique examples of biological phenomena not found in free

phenomena not found in free--_{living organisms.living organisms.} Because of their medical importance

Because of their medical importance

Humans are hosts to many species of parasites. Humans are hosts to many species of parasites. M

M_{any of these parasites are causative agents of any of these parasites are causative agents of}  major public health problems of the world. major public health problems of the world. Recent estimates of the number of people Recent estimates of the number of people infected with parasites in the world a infected with parasites in the world are:re: Ascaris Ascaris 1.3 1.3 BB Hookworms Hookworms 1.3 1.3 BB Subject: Microbiology Subject: Microbiology Topic:

Topic:Introduction toIntroduction toMM_edicaledical Parasitology

Parasitology

Lecturer:

Lecturer: VV_{ictoria Basa-Dalay, MD, MScictoria Basa-Dalay, MD, MSc}

Da

Da_{te of Lecture:te of Lecture: June 28,2011June 28,2011}

Tr

Transans_{criptiocriptio}nn_iiss_t:t:

P Paa_gegess_{: 17: 17}    S    S    Y    Y    2    2    0    0    1    1    1    1  -   -   2    2    0    0    1    1    2    2



 CC_{ompetes for available nutrients since itompetes for available nutrients since it} absorbs sugars, proteins and fats from absorbs sugars, proteins and fats from the food

the food 

 OO_{bstructs the gut by bolus of wormsbstructs the gut by bolus of worms} 

 Damages vital organs during erraticDamages vital organs during erratic migration

migration

 A

 A_{csariscsariscan penetrate any hole (ears, anus,can penetrate any hole (ears, anus,}

mouth, common bile duct, appendix, etc) mouth, common bile duct, appendix, etc) SUR

SURVV_IIVALVAL_FFACTOACTO_RSRSOO_{F PF P}AA_RRAA_SISITTEE_SS

Parasites have successfully adapted to (all?) Parasites have successfully adapted to (all?) environmental niches in hosts

environmental niches in hosts

Parasites best adapted are least pathogenic Parasites best adapted are least pathogenic Not sensed by the body as foreign just like an Not sensed by the body as foreign just like an antigen but they will reside inside the body just antigen but they will reside inside the body just like a commensal initially and when they grow like a commensal initially and when they grow up they become a parasitic agent.

up they become a parasitic agent. Typically with long

Typically with long--_{term/chronic/intimateterm/chronic/intimate} parasite

parasite--_{host relationshipshost relationships} of

of Parasites Parasites

2.

2.MM_{eans of transmission from infected toeans of transmission from infected to} susceptible, new hosts

susceptible, new hosts

3. Ability to invade and successfully reside in 3. Ability to invade and successfully reside in new hosts new hosts 4. Ability to reproduce 4. Ability to reproduce Definition Definition Host Host

The bigger organism in which the parasite The bigger organism in which the parasite depends their survival

depends their survival

Provides the nourishment and protection in a Provides the nourishment and protection in a form of shelter whether inside or outside the form of shelter whether inside or outside the body

body M

M_{ay transferay transfer or harbor the organismor harbor the organism} temporarily or permanently

temporarily or permanently

Provide appropriate environment for growth Provide appropriate environment for growth and reproduction

and reproduction M

M_{aybe harmed, killed, not affected or they mayaybe harmed, killed, not affected or they may} even benefit in association with other organism even benefit in association with other organism

ypes of Host ypes of Host

y

y _{Pig  uncooked or not properly cookedPig  uncooked or not properly cooked} pork can cause Trichinellasis & Taeniasis pork can cause Trichinellasis & Taeniasis ((T T _{richinerichine}ll ll _aaandandT T _aeniaaenia))

y

y MM_anan--_PPl l _{asmodiumasmodium}

y

y CC_{rustaceans  cause Paragonimiasisrustaceans  cause Paragonimiasis} ((Paragonimus westemani Paragonimus westemani ))

In

InMM_{alaria:alaria:}

--_{Intermediate HostIntermediate Host  M}M_{an (harbors youngeran (harbors younger} forms: tropozoite, schizont, young gametocyte) forms: tropozoite, schizont, young gametocyte) --_{Definitive HostDefinitive Host M}M_{osquito (transformosquito (transform}

gametocyte to micro/macro gametocyte) gametocyte to micro/macro gametocyte)

Ex:

Ex:T T _{richomonas vaginarichomonas vagina}l l _{isis can be acquired can be acquired}

from toilet seats from toilet seats

II. Indirect

II. IndirectLL_{ife cycleife cycle}

At least one (1) intermediate host is needed or At least one (1) intermediate host is needed or a vector is required in transmitting the parasite a vector is required in transmitting the parasite from one host to another

from one host to another Eg.

Eg.F F _ascioasciol l _opsisopsis

P

Pl l _{asmodiumasmodium}

In Trematode: In Trematode:

1

1ststinetermediate Host: Snailinetermediate Host: Snail 2

2ndndIntermediate:Intermediate:

--_{if water plantif water plant}--F F _ascioasciol l _{a and a and}  F 

F _acioaciol l _opsisopsis

--_{if fish  liver fluke, intestinal flukeif fish  liver fluke, intestinal fluke}

I. Portal of exit I. Portal of exit

--_{opening opening where where the the parasite parasite leaves leaves thethe} host

host

S

S_{he used he used}  A A_scarisscarisl l _{umbricoidesumbricoides}l l _{ife cycife cyc}l l _{e as ane as an}

examp

exampl l _{e: portae: porta}l l _{of exit is through anus (feces)of exit is through anus (feces)}

II. Diagnostic stage

II. Diagnostic stage--_{stage that would help youstage that would help you} confirm the diagnosis

confirm the diagnosis

Presence of eggs in the feces Presence of eggs in the feces

--_{when the feces is lodged in the soil, thewhen the feces is lodged in the soil, the} fertilized and unfertilized egg can be found fertilized and unfertilized egg can be found (take note that before the disease

(take note that before the disease could becould be transmitted to another host, an embryonated transmitted to another host, an embryonated egg is needed)

egg is needed)

--_{unfertilized eggunfertilized egg}--_{could be diagnostic but couldcould be diagnostic but could} not be infective; will just die in the soil

not be infective; will just die in the soil --_{fertilized eggfertilized egg}-- _{means it is rapidlymeans it is rapidly}

differentiating; it can be infective if it develops differentiating; it can be infective if it develops to third stage larvae while inside the

to third stage larvae while inside the embyonated egg

(2)

(2) Trophozoite (Infective Trophozoite (Infective & Diagnost& Diagnostic)ic)

G

GEENNEE_RRALAL_IZIZEE_{D SPD SP}OO_RROO_ZZOANOAN LL_IFIFEECC_YYCLCLEE

Ex:

Ex: PPl l _{asmodium faasmodium fa}l l _{ciparumciparum}

y

y _{Infective stage: Infective stage: SporozoiteSporozoite} y

y _{Diagnostic Stage: TrophozoiteDiagnostic Stage: Trophozoite} Schizont Schizont y

y GG_{ametocytes found inside theametocytes found inside the} mosquito:

mosquito: GG_ametesametes y

L

L_ifeifeCC_{ycle of ycle of}  Ascaris lumbricoides Ascaris lumbricoides _{serves to transfer them to new hosts like inserves to transfer them to new hosts like in} mosquitoes.

mosquitoes.

T

T_{ypes of Parasitesypes of Parasites}

According to Taxonomic

According to TaxonomicGG_rouproup 1.

1. ProtozoansProtozoans 1.1.

1.1. Phylum sarcomastigophoraPhylum sarcomastigophora   reproduction: binary fission   reproduction: binary fission 1.1.1. Subphylum

1.1.1. SubphylumMM_{astigophoraastigophora} --_{moves by flagellamoves by flagella} Eg:

Eg:Giardia,Giardia,T T rypanosoma, Leishmania,rypanosoma, Leishmania,

T 

T _{richomonasrichomonas}

( 

( Please refer to Table 1 forPlease refer to Table 1 for characterization)

1.3.

1.3. PhylumPhylumMM_{icrosporaicrospora}

(according to Dr. Dalay, this phylum is not very (according to Dr. Dalay, this phylum is not very important medically)

important medically)

 classified under the Fungi kingdom by  classified under the Fungi kingdom by recent studies using DNA techniques

recent studies using DNA techniques

(http://www.stanford.edu/class/humbio103/Pa (http://www.stanford.edu/class/humbio103/Pa raSites2006/

raSites2006/MM_{icrosporidiosis/microsporidia1.hticrosporidiosis/microsporidia1.ht} ml)

ml)

--_{no locomotory organ; characterized byno locomotory organ; characterized by} a polar tube or polar filament found in the a polar tube or polar filament found in the spore used to infiltrate host cells

spore used to infiltrate host cells

--_{obligate, sporeobligate, spore}--_{forming, intracellularforming, intracellular} parasites; with alternating sexual and asexual parasites; with alternating sexual and asexual reproduction

reproduction ex:

products produce the episodic chills products produce the episodic chills and fever that characterize the disease) and fever that characterize the disease) y

y _{some merozoites form intosome merozoites form into} male/female gametocytes male/female gametocytes y

y _{Sporogonic cycle occurs in theSporogonic cycle occurs in the} mosquito (

mosquito (@@the mosquito serves as thethe mosquito serves as the

definitive host) definitive host) y

y _{the mosquito takes a blood meal andthe mosquito takes a blood meal and} ingests the gametocytes

ingests the gametocytes y

y _{in the mosquitos midgut, thein the mosquitos midgut, the}

gametocytes develop into gametes and gametocytes develop into gametes and fertilize each other (flagellated

fertilize each other (flagellated microgametes fertilize the microgametes fertilize the

macrogametocyte), forming motile macrogametocyte), forming motile zygotes called ookinetes

zygotes called ookinetes y

y _{the ookinete penetrates the gutthe ookinete penetrates the gut} epithelial cells and develops into an epithelial cells and develops into an oocyst

oocyst y

y _{the oocyst undergoes multiple roundsthe oocyst undergoes multiple rounds} of asexual reproduction, forming of asexual reproduction, forming

through the feces, or (b) a thin

through the feces, or (b) a thin--_walledwalled oocyst, which would autoinfect the host oocyst, which would autoinfect the host 1.4. Phylum

1.4. PhylumCC_{iliophorailiophora}

--_{locomotory organ = cilialocomotory organ = cilia}

--_{mostly includes a variety of freemostly includes a variety of free}--_livingliving and symbiotic species

and symbiotic species

--_{reproduce asexually by transversereproduce asexually by transverse} binary fission

binary fission ex.

ex.BB_aal l _{antidium coantidium co}l l 

( 

( Please refer to Table 3 for characterization)Please refer to Table 3 for characterization) 2.

2. HelminthsHelminths 

 worm  likworm  like organe organismism 

 multi cellular, multi cellular, metazoan (eukaryotmetazoan (eukaryoticic organisms of kingdom animalia)

organisms of kingdom animalia)

(Please refer to Table 4 for classification (Please refer to Table 4 for classification summary)

Table 6 summarizes Nematodes of 

Table 6 summarizes Nematodes of MM_edicaledical Importance

Importance

C

C_{omparison of nematode eggs. omparison of nematode eggs. EnterobiusEnterobiusisis} D

D--_{shaped;shaped;}T T _{richurisrichurisis bipolaris bipolar}

2.2. Phylum Platyhelminthes (flatworms) 2.2. Phylum Platyhelminthes (flatworms)

2.2.1.

2.2.1.CC_{lass Trematodalass Trematoda}

--_{flattened, leaf flattened, leaf} --_{shaped or cylindricalshaped or cylindrical} worms (

worms (SS_{chistosomachistosoma), unsegmented;), unsegmented;}

hermaphroditic hermaphroditic *

Red

Red--_{Redia (in snail)Redia (in snail)} C

C_{ertainlyertainly}-- CC_{ercaria (freeercaria (free}--_{living in water/snail)living in water/snail)} M

M_etet-- MM_{etacercaria (in 2nd intermediate host)etacercaria (in 2nd intermediate host)} Approval  Adult

Approval  Adult G

G_{eneralized schistosomal life cycle (bloodeneralized schistosomal life cycle (blood} flukes)

flukes)

Life cycle of a typical Fluke VS Life cycle of a typical Fluke VS

(unlike

(unlikeSS_{chistosoma,chistosoma,most trematodes aremost trematodes are}

hermaphrotidic and infect through hermaphrotidic and infect through metacercaria ingestion)

T

T_{rematoderematode}EE_ggsggs



CC_lasslassCC_estodaestoda

--_{leaf shape, ribbonleaf shape, ribbon}--_{like, elongated, flattenedlike, elongated, flattened} --_{sex: hermaphrodite or monoecioussex: hermaphrodite or monoecious}

Phylum

PhylumAA_{rthropodarthropoda}

 4 morphologic

 4 morphologicCC_{haracteristicsharacteristics}

--_{segmented body parts: head, thorax andsegmented body parts: head, thorax and} abdomen

abdomen

--_{3 to 4 pairs of jointed appendages3 to 4 pairs of jointed appendages} --_{covered by hard chitinous exoskeletoncovered by hard chitinous exoskeleton} --_{bilaterally symmetrical bodybilaterally symmetrical body}



MM_{edical significance of Arthropods toedical significance of Arthropods to}MM_anan

As direct agents of disease: As direct agents of disease:

O

O_{rder Anoplura : human licerder Anoplura : human lice} O

O_{rder Hemiptera: reduvild bugrder Hemiptera: reduvild bug} O

O_{rder Diptera : houseflyrder Diptera : housefly} O

O_{rder Hymenoptera : ants, bees, waspsrder Hymenoptera : ants, bees, wasps} O

O_{rder Siphonaptera : fleasrder Siphonaptera : fleas} O

O_{rder Diptera: mosquites, fliesrder Diptera: mosquites, flies} C

C_lasslassCC_{hilopoda (eg.hilopoda (eg.}CC_{entipedes)entipedes)}

Importance of studying Medical Parasitology Importance of studying Medical Parasitology  To know the different parasites affecting  To know the different parasites affecting M

P

Pl l _{asmodiumasmodium}

4. Snail Transmission 4. Snail Transmission

--_{parasitic infective stage develops in snailparasitic infective stage develops in snail} intermediate host or second

intermediate host or second intermediate host after partial intermediate host after partial development in the snail development in the snail e.g)

e.g)SS_{chistosoma sppchistosoma spp}..

5. Food/animal Transmission (food

5. Food/animal Transmission (food--_{born andborn and} animal born)

animal born)

--_{infective stage of parasite develops in aninfective stage of parasite develops in an} animal whose flesh is an important animal whose flesh is an important item for man

item for man e.g)

e.g)T T _{aenia soaenia so}l l _iumium

U

U_{seful sites:seful sites:}

http://www.dpd.cdc.gov/dpdx/Default.htm http://www.dpd.cdc.gov/dpdx/Default.htm http://www.udel.edu/medtech/dlehman/medt http://www.udel.edu/medtech/dlehman/medt 372/images.html 372/images.html

And please download the powerpoint And please download the powerpointMM_s.s. C

C_{hristel Pao has posted on FB for the photos.hristel Pao has posted on FB for the photos.} We try to make every tranx earth friendly. We try to make every tranx earth friendly.

No testing has undertaken you that is not No testing has undertaken you that is not common to everyone.

common to everyone.GG_{od is faithful, and Heod is faithful, and He} will not let you be tested beyond your streng will not let you be tested beyond your streng thth but with the testing He will also provide the way but with the testing He will also provide the way out so that

out so that you may be able you may be able to endure it.to endure it. 1

1.1.

1.1. Table 1.Table 1.CCharacterization of representative species of Phylum Sarcomastigophoraharacterization of representative species of Phylum Sarcomastigophora

..

Subphylum

SubphylumMMastigophora astigophora Subphylum Subphylum SarcodinaSarcodina

Giardia

Giardial l ambambl l iaia T T _{rypanosoma cruzi rypanosoma cruzi}  T T _{rypanosoma brucei rypanosoma brucei}  T T richomonasrichomonas

vagina

vaginal l isis Entamoeba histoEntamoeba histol l ytica ytica NaegNaegl l eria fow eria fow l l eri eri 

Disease Disease caused

caused GGiardiasisiardiasis

C

Chagas disease;hagas disease; American American trypanosomiasis trypanosomiasis African trypanosomiasis; African trypanosomiasis; sleeping sickness

sleeping sickness TrichomoniasisTrichomoniasis

Amoebic dysentery/ Amoebic dysentery/ colitis colitis Acute Amoebic Acute Amoebic M Meningoeningo --encephalitis in encephalitis in Normal Hosts Normal Hosts M Mode of ode of  transmission transmission Ingestion of  Ingestion of  cysts from cysts from contaminated contaminated water and food water and food

Bites of reduviid bug Bites of reduviid bug

((T T riatomariatoma)) Bites of infected tsetse flyBites of infected tsetse fly ((GGl l ossina)ossina)

Direct sexual Direct sexual contact contact

((T T richomonasrichomonas= only= only flagellate affecting flagellate affecting the genitals) the genitals)

ingestion of cysts from ingestion of cysts from contaminated food or contaminated food or water water Penetration of the Penetration of the nasal mucosa to the nasal mucosa to the brain

brain

Infective Infective stage

stage CCystsysts

M Metacyclicetacyclic trypomastigote

trypomastigote MMetacyclic etacyclic trypomastigote trypomastigote Trophozoite Trophozoite cysts cysts trophozoitetrophozoite

Diagnostic Diagnostic stage stage

C Cysts andysts and trophozoites trophozoites

Epimastigote Epimastigote----this isthis is accdg to docs ppt, but accdg to docs ppt, but accdg to the figure accdg to the figure below (which is also below (which is also found in docs ppt), it found in docs ppt), it should be the should be the trypomastigote trypomastigote Epimastigote

Epimastigote----this is accdgthis is accdg to docs ppt, but accdg to to docs ppt, but accdg to the figure below (which is the figure below (which is also found in docs ppt), it also found in docs ppt), it should be the

should be the trypomastigote trypomastigote

Trophozoite

Trophozoite cysts and trophozoitescysts and trophozoites trophozoitestrophozoites

Habitat

Habitat Small Small intestineintestine Skin, mucousSkin, mucous membrane, blood

membrane, blood Body Body fluids; fluids; blood blood Vagina Vagina and and prostateprostate CColonolon

brain brain Fx Fx Steatorheic Steatorheic diarrhea; diarrhea; dysentery dysentery C

Chagoma; Romanahagoma; Romana sign; megacolon; sign; megacolon; cardiomyopathy (most cardiomyopathy (most serious seriousCCx)x)

Somnolence; seizure; coma Somnolence; seizure; coma

Vaginal/ prostatic Vaginal/ prostatic discharge and discharge and itchiness itchiness

anchovy sauce; flask anchovy sauce; flask

--shaped ulcer shaped ulcer C Clinicallinical presentations like presentations like fatal meningitis fatal meningitis (rapid onset) (rapid onset) Diagnosis Diagnosis through through Fecalysis and Fecalysis and enterotest enterotest (string test) (string test)

Blood smear; body Blood smear; body fluids

fluids

Blood smear; body fluids; Blood smear; body fluids; NNN media

NNN media

Wet smear of  Wet smear of  vaginal discharge

vaginal discharge FecalysisFecalysis

Trophozoites in Trophozoites inCCSF/SF/ Brain tissue Brain tissue

Treatment

Treatment MMetronidazoleetronidazole Benznidazole orBenznidazole or nifurtimox nifurtimox

Pentamidine isethionate Pentamidine isethionate and sudamin

Table 2.

Table 2.CCharacterization of representative species of Phylum Apicomplexa.haracterization of representative species of Phylum Apicomplexa.

P

Pl l asmodium sppasmodium spp.. C C ryptosporidium sppryptosporidium spp..

Disease caused

Disease caused MMalaria; Blackwateralaria; Blackwater fever

fever

M

Malabsorption syndrome; cryptosporidiosisalabsorption syndrome; cryptosporidiosis**notenote the spelling

the spelling

M

Mode of transmissionode of transmission

Bites of infected Bites of infected female anopheline female anopheline mosquito mosquito

Drinking/contact with contaminated water Drinking/contact with contaminated water

Infective

Infective stage stage SporozoitesSporozoites

Small, sporulated oocyst with 4 sporozoites Small, sporulated oocyst with 4 sporozoites Diagnostic

Diagnostic stage stage Blood Blood stagesstages Habitat

Habitat Blood Blood Small Small intestineintestine Fx

Fx Tertian and quartanTertian and quartan periodicity

periodicity CCachexia and severe diarrheaachexia and severe diarrhea Diagnosis

Diagnosis through through Blood Blood smear smear FecalysisFecalysis Treatment

Treatment CChloroquine, quinine,hloroquine, quinine, quinghaosu

quinghaosu Nitazoxanide; fluid and electrolyte replacementNitazoxanide; fluid and electrolyte replacement

Table 3.

Table 3.CCharacterization of haracterization of BB_aal l antidium coantidium col l i,i,representative species of P.representative species of P.CCiliophorailiophora

B

Baal l antidium coantidium col l i i 

Disease caused

Disease caused Balantidiasis (common among slaughter houseBalantidiasis (common among slaughter house workers)

workers)

M

Mode ode of of transmission transmission Ingestion Ingestion of of contaminated contaminated water/foodwater/food Infective stage

Infective stage CCystyst Diagnostic stage

Diagnostic stage CCyst & Trophozoiteyst & Trophozoite Habitat

Habitat Large Large intestineintestine

Fx Diarrhea

Fx Diarrhea

Diagnosis

Diagnosis through through FecalysisFecalysis Treatment

Table 4.

Table 4.CClassification of Helminthslassification of Helminths Sub kingdom

Sub kingdom PhylumPhylum CClasslass Genus  eGenus  exxamplesamples Metazoa

Metazoa AAschelminthesschelminthes Round worms; Round worms;

possess a peculiar type of  possess a peculiar type of  body cavity called a body cavity called a pseudocoel pseudocoel

N

Nematodesematodes

Round worms; appear round in cross section, they have body Round worms; appear round in cross section, they have body cavities, a straight alimentary canal and an anus

cavities, a straight alimentary canal and an anus

Ascaris (roundworm) Ascaris (roundworm) Trichuris (whipworm) Trichuris (whipworm) Ancylostoma (hookworm) Ancylostoma (hookworm) Necator (hookworm) Necator (hookworm)

Enterobius (pinworm or threadworm) Enterobius (pinworm or threadworm) Strongyloides

Strongyloides Platyhelminthes

Platyhelminthes Flat worms; dorsoventrally Flat worms; dorsoventrally flattened, no body cavity flattened, no body cavity and, if present, the and, if present, the alimentary canal is blind alimentary canal is blind ending

ending

C Cestodesestodes

Adult tapeworms are found in the intestine of their host Adult tapeworms are found in the intestine of their host They have a head (scolex) with sucking organs, a segmented They have a head (scolex) with sucking organs, a segmented body but no alimentary canal

body but no alimentary canal Each body segment is hermaphrodite Each body segment is hermaphrodite

Taenia (tapeworm) Taenia (tapeworm)

T

Trematodesrematodes Non

Non--segmented, usually leaf segmented, usually leaf --shaped, with two suckers but noshaped, with two suckers but no distinct head

distinct head

They have an alimentary canal and are usually hermaphrodite They have an alimentary canal and are usually hermaphrodite and leaf shaped

and leaf shaped

Schistosomes are the exception. They are thread Schistosomes are the exception. They are thread--like, andlike, and have separate sexes

have separate sexes

Fasciolopsis

Fasciolopsis (liver fluke)(liver fluke) Schistosoma (not leaf shaped!) Schistosoma (not leaf shaped!)

Table 5. Summary of the distinctive features of worms Table 5. Summary of the distinctive features of worms

C

Cestodes (tapeworms)estodes (tapeworms) TTrematodes (flukes)rematodes (flukes) NNematodes (roundworms)ematodes (roundworms) Shape

Shape Segmented Segmented planeplane UUnsegmented planensegmented plane CCylindricalylindrical Body cavity

Body cavity No No No No PresentPresent

B

Booddy y ccoovveerriinng g TTeegguummeenntt TTeegguummeenntt CCuticleuticle S

Seex x HHeerrmmaapphhrrooddiittiicc HHeerrmmaapphhrrooddiittiicc, , eexxcceepptt schistosomes which are dioecious schistosomes which are dioecious

Dioecious Dioecious

Attachment

Attachment organs organs Sucker Sucker or or bothridia, bothridia, andand rostellum with hooks rostellum with hooks

O

Oral sucker and ventral sucker orral sucker and ventral sucker or acetabulum

acetabulum

Lips, teeth, filariform extremities, and dentary plates Lips, teeth, filariform extremities, and dentary plates

Example diseases Example diseases in humans in humans

Ta

Tapepewoworm rm ininfecfectitionon ScSchihiststososomomiaiasisis, s, swiswimmmmer'er's s ititch ch AscAscariariasasisis, , drdracacununcuculialiasisis, s, eleelephphanantitiasasisis, , enenteterorobibiasasis is (p(pininwowormrm),), filariasis, hookworm, onchocerciasis, trichinosis, trichuriasis filariasis, hookworm, onchocerciasis, trichinosis, trichuriasis (whipworm)

Table 6. Nematodes of medical importance. Table 6. Nematodes of medical importance. Habitat

Habitat GGeneraenera Small intestine

Small intestine  A Ascaris,scaris, A Ancy ncy l l ostoma, Necator,ostoma, Necator,T T richinerichinell ll a,a,C C api api ll ll ariaaria

Large intestine

Large intestine T T richiuris, Enterobiusrichiuris, Enterobius

Skin/Tissue

Skin/Tissue Onchocerca, Loa, Gnathostoma,Onchocerca, Loa, Gnathostoma,T T richinerichinell ll aa

Blood and Lymphatic system

Blood and Lymphatic system W W _{ucheria,ucheria,}BB_rugiarugia C

CNSNS  A Angiostrongy ngiostrongy l l usus

Table 7.

Table 7.CCharacterization of haracterization of  A A_ncy ncy l l ostoma spostoma sp..(hookworm), representative species of (hookworm), representative species of CClass Nematoda andlass Nematoda andW W _{uchereria bancrofti uchereria bancrofti} , a parasitic filarial nematode., a parasitic filarial nematode.

 A

 Ancy ncy l l ostomaostoma W W uchereria bancrofti uchereria bancrofti 

Disease

Disease caused caused Ancylostomiasis, Ancylostomiasis, Necatoriasis Necatoriasis Lymphatic Lymphatic filariasisfilariasis

M

Mode ode of of transmission transmission Skin Skin penetration penetration of of filariform filariform larvae larvae bites bites of of infected infected mosquitoesmosquitoes Infective

Infective stage stage Filariform Filariform larvae larvae Third Third stage stage larvae larvae (L3)(L3) Diagnostic stage

Diagnostic stage OOvava MMicrofilariaeicrofilariae Habitat

Habitat Small Small intestine intestine Lymphatic Lymphatic system; system; skin skin and and glandsglands Fx

Fx GGround round itch, itch, iron iron deficiency deficiency anemia anemia ElephantiasisElephantiasis Diagnosis

Diagnosis through through Fecalysis Fecalysis Blood Blood smearsmear Treatment