MT2 FUNGI/PARASITOLOGY Flashcards
(188 cards)
0
Q
How does YEAST divide?
A
by binary fission or budding
1
Q
This type of FUNGI is a single celled eukaryote:
A
YEASTS
2
Q
What do you call FUNGI that produce mycelia?
A
MOLDS
3
Q
Describe the composition of MOLDS:
A
multicellular;
composed of HYPHAE
4
Q
What is HYPHAE?
A
long, branching filament that, w/other hyphae, forms the feeding thallus of a fungus called the mycelium
5
Q
What are the 2 types of HYPHAE?
A
septate,
aseptate
6
Q
What is SEPTATE HYPHAE?
A
walls that divide hyphae into cells
7
Q
What is ASEPTATE HYPHAE?
A
no walls
8
Q
What are the 4 groups of FUNGUS?
A
PHYCOMYCETES,
ASCOMYCETES,
BASIDIOMYCETES,
DEUTEROMYCETES (FUNGI IMPERFECTI)
9
Q
Describe the SEXUAL STAGES of PHYCOMYCETES:
A
SEXUAL SPORES - free zygotes;
ASEXUAL SPORES - enclosed in sac-like structures called SPORANGIUM
10
Q
Describe the SEXUAL STAGES of ASCOMYCETES:
A
SEXUAL SPORES - enclosed in sacs called ASCI
ASEXUAL SPORES - exogenous, formed at the end of the hyphae
11
Q
Describe the SEXUAL STAGES of BASIDIOMYCETES:
A
SEXUAL SPORES - found on BASIDIA
12
Q
Describe the SEXUAL STAGES of DEUTEROMYCETES:
A
NO SEXUAL STAGE
13
Q
Name 3 types of SYSTEMIC MYCOSES:
A
HISTOPLASMOSIS (SPELUNKER’S DZ),
COCCIDIOMYCOSIS (VALLEY FEVER),
BLASTOMYCOSIS
14
Q
What causes HISTOPLASMOSIS?
A
HISTOPLASMA CAPSULATUM (ASCOMYCOTA)
15
Q
Where is HISTOPLASMOSIS found? Where is the fungus found?
A
worldwide, concentrated in US in MIDWEST & EASTERN US;
in soil contaminated w/BAT & BIRD FECES (frequently in caves)
16
Q
How is HISTOPLASMOSIS transmitted?
A
spores are inhaled
17
Q
What causes BLASTOMYCOSIS?
A
COCCIDIOIDES IMMITIS
18
Q
Where is COCCIDIOMYCOSIS found?
A
in SOUTHWESTERN US (NM/AZ)
19
Q
How is COCCIDIOMYCOSIS transmitted?
A
ARTHROSPORES are inhaled
= spores united in the form of a string of beads, formed by fission
20
Q
What symptoms present with COCCIDIOMYCOSIS?
A
most infections are ASYMPTOMATIC, maybe only a SLIGHT FEVER
21
Q
What causes BLASTOMYCOSIS?
A
BLASTOMYCES DERMATITIS
22
Q
How is BLASTOMYCOSIS transmitted?
A
spores are inhaled into lungs where they transform to a yeast form of the microbe
23
Q
What symptoms present with BLASTOMYCOSIS?
A
50% of individuals are SYMPTOMATIC, with flu-like illness w/productive cough
24
What is AMPHOTERICIN B used to treat?
SYSTEMIC FUNGI
25
How does AMPHOTERICIN B work?
binds to STEROLS, preferentially to the primary fungal cell membrane sterol (ERGOSTEROL); disrupts cell causing LYSIS
26
Name a SUBCUTANEOUS MYCOSIS:
SPOROTRICHOSIS (ROSE HANDLER'S DZ)
27
What causes SPOROTRICHOSIS?
SPOROTHRIX SCHENCKII
28
Where is SPOROTRICHOSIS found?
as an OCCUPATIONAL HAZARD for GREENHOUSE WORKERS/GARDENERS
29
How is SPOROTRICHOSIS transmitted?
fungi enter via SKIN LESION, transform to yeast form
30
What symptoms present with SPOROTRICHOSIS?
nodules & skin lesions appear along LYMPHATIC SYSTEM
31
What part of the body is affected by DERMATOPHYTOSES?
they invade dead keratinized tissue (HAIR, NAILS);
| aka SUPERFICIAL MYCOSES
32
What are 3 major genera of DERMATOPHYTOSES?
TRICHOPHYTON,
MICROSPORUM,
EPIDERMOPHYTON
33
What is a TINEA INFECTION? Is it CONTAGIOUS?
TINEA = name given to a fungal skin infection (synonymous w/DERMATOPHYTE);
YES
34
Define TINEA PEDIS:
ATHLETE'S FOOT
35
Where does TINEA CORPORIS present?
TRUNK, EXTREMITIES
36
Where does TINEA CAPITIS present? What does it cause?
HEAD;
| HAIR LOSS, RINGWORM
37
Where does TINEA UNGUIUM present?
NAILS
38
What causes TINEA VERSICOLOR?
YEAST (from normal flora)
39
What exacerbates T. VERSICOLOR?
heat, humidity, sweat (help it proliferate in some px)
40
Is TINEA VERSICOLOR contagious, like other TINEA INFECTIONS?
NO
41
How is T. VERSICOLOR diagnosed?
KOH wet mount (looking for yeast cells);
| WOOD'S LAMP (if infection present where illuminated, area will fluoresce; no fluorescence/shine w/o infection)
42
What is a WOOD'S LAMP? What is it used for?
a lamp that emits UV light;
| used to Dx TINEA VERSICOLOR
43
Name 2 conditions caused by PATHOGENIC YEAST:
CANDIDIASIS,
| CRYPTOCOCCOSIS
44
What causes CANDIDIASIS?
CANDIDA ALBICANS
45
Where is CANDIDA ALBICANS found?
part of normal flora in mouth, gut, vagina; pathogenic when normal conditions are altered (antibiotics, depressed immunity)
46
What symptoms present with CANDIDIASIS?
THRUSH, skin/vaginal infections
47
What causes CRYPTOCOCCOSIS?
CRYPTOCOCCUS NEOFORMANS (a large, encapsulated yeast)
48
How is CRYPTOCOCCUS NEOFORMANS transmitted?
enters the host via respiratory route; after some time in the LUNGS, C. NEOFORMANS spreads to extrapulmonary tissues
49
To what site will C. NEOFORMANS often spread? Causing what?
the BRAIN;
| infected px usually contract MENINGOENCEPHALITIS
50
What kind of organism is PNEUMOCYSTIS CARINII?
not yet established, bw FUNGUS (YEAST) or PROTOZOAN (antigenic differences have been found in strains derived from the various mammalian hosts)
51
Describe the PATHOGENESIS of PNEUMOCYSTIS CARINII:
in normal px, ASYMPTOMATIC infection of lungs occurs in early life --> organism persists in an INACTIVE/LATENT state unless the host becomes IMMUNOCOMPROMISED
52
What are the 3 life stages of a PARASITE?
EGG,
IMMATURE = LARVAE = NYMPH,
ADULTS
53
What is the surprising statistic about ASCARIS LUMBRICOIDES (a parasite/roundworm)?
>1.4 billion people are currently infected with roundworm Ascaris lumbricoides, 20%of world’s population infected with this one eukaryotic parasite
54
What is a DEFINITIVE HOST?
one in which parasite reproduces
55
What is an INTERMEDIATE HOST?
one in which development occurs, but w/NO REPRODUCTION
56
How are INTESTINAL PARASITES Dx'd?
fecal specimens
57
How are BLOOD PARASITES Dx'd? Explain the 2 types:
```
BLOOD FILMS (made from a drop of blood spread evenly on a slide and stained using Giemsa stain):
THICK FILMS (more sensitive for finding parasite in a thicker/more concentrated layer of blood);
THIN FILMS (more useful to ID parasites from a thin/monolayer blood specimen)
```
58
How are TISSUE PARASITES Dx'd?
biopsy, especially of muscle
59
What are PROTOZOA?
eukaryotic single celled parasites
60
Name an AMOEBA, & what it causes:
ENTAMOEBA HISTOLYTICA;
| causes AMEBIC DYSENTERY
61
What are the 2 life stages of ENTAMOEBA HISTOLYTICA? Explain them:
TROPHOZOITE (the active, motile feeding stage, characterized by PSEUDOPODS);
CYST (similar to an ENDOSPORE, resistant to env't, infective)
62
How is ENTAMOEBA HISTOLYTICA transmitted?
CYSTS ingested in contaminated water/food; use of NIGHTSOIL increases chance of contamination;
can be vectored by FLIES
63
Describe the pathogenesis of ENTAMOEBA HISTOLYTICA infection:
cysts EXCYST in intestine, causing bloody diarrhea; if TROPHOZOITES enter blood, they'll move to liver, causing HEPATIC AMEBIASIS (collection of PUS in LIVER)
64
Name 7 types of FLAGELLATED PROTOZOA:
GIARDIA LAMBLIA, TRICHOMONAS VAGINALIS, TRYPANOSOMA BRUCEI, TRYPANOSOMA CRUZI, LEISHMANIA DONOVANI, LEISHMANIA TROPICA, LEISHMANIA BRAZILIENSIS
65
What does GIARDIA LAMBLIA cause?
GIARDIASIS, aka BEAVER FEVER
66
What are 2 life stages of GIARDIA LAMBLIA?
TROPHOZOITE (active, motile feeding stage);
| CYST (similar to endospore, resistant to env't, infective)
67
How is GIARDIA LAMBLIA transmitted?
CYSTS ingested in contaminated water, particularly near beavers (reservoir)
68
Describe the pathogenesis of GIARDIA LAMBLIA:
CYSTS excyst in intestine, reproduce & cover intestinal wall;
this interferes w/FAT ABSORPTION, causing FATTY STOOLS/DIARRHEA
69
What causes TRICHOMONIASIS?
TRICHOMONAS VAGINALIS
70
What are the life stages of TRICHOMONAS VAGINALIS?
TROPHOZOITE (has 4 flagella);
| NO CYST form
71
How is TRICHOMONAS VAGINALIS transmitted?
TROPHOZOITES passed sexually, causing UROGENITAL infections
72
What symptoms present with TRICHOMONIASIS?
green discharge, itching in females;
| urethritis in males
73
What group of FLAGELLATED PROTOZOA cause TRYPANOSOMIASIS? Name 2 species:
TRYPANOSOMES;
| T BRUCEI, T CRUZI
74
What disease is caused by TRYPANOSOMA BRUCEI?
AFRICAN TRYPANOSOMIASIS, aka AFRICAN SLEEPING SICKNESS
75
What are the life stages of TRYPANOSOMA BRUCEI?
TRYPANOSOME (protozoa form);
| NO CYST form
76
How is TRYPANOSOMA BRUCEI transmitted?
vectored by TSE-TSE fly
77
Describe the pathogenesis of AFRICAN TRYPANOSOMIASIS:
(in VERTEBRATE hosts) trypanosomes live in BLOOD, LYMPH NODES, SPLEEN, CSF;
do NOT invade or LIVE IN cells, but rather in TISSUE SPACES (particularly in CNS);
within a few days animals become emaciated, uncoordinated, paralyzed --> death
78
What symptoms (in humans) present w/AFRICAN TRYPANOSOMIASIS?
normally experience mental dulness, tendency to sleep, finally COMA & DEATH
79
What disease is caused by TRYPANOSOMA CRUZI? Where is it seen?
CHAGAS' DZ;
| Mexico, South/Central America
80
What are the life stages of TRYPANOSOMA CRUZI?
TRYPANOSOME (protozoa form);
| NO CYST form
81
How is TRYPANOSOMA CRUZI transmitted?
vectored by the REDUVIID BUG (aka KISSING BUG) via defecation into a wound
82
What's the pathogenesis of ACUTE CHAGAS' Dz?
(from T. CRUZI) small red nodule (CHAGOMA) at bite site; heart, liver, spleen, lymph nodes are infected;
Sx include anemia, nervous disorders, muscle/bone pain, heart failure; death may ensue after 3-4 weeks;
most common in CHILDREN
83
What's the pathogenesis of CHRONIC CHAGAS' Dz?
(from T. CRUZI) Sx are primarily nervous dysfunction which may continue for years; px may be virtually ASYMPTOMATIC & suddenly die of heart failure
84
What disease is caused by LEISHMANIA DONOVANI?
VISCERAL LEISHMANIASIS, aka KALA-AZAR
85
What are the life stages for LEISHMANIA DONOVANI?
PROTOZOA form;
| NO CYST form
86
How is LEISHMANIA DONOVANI transmitted?
vectored by SANDFLY
87
What's the pathogenesis of VISCERAL LEISHMANIASIS?
L. DONOVANI invades liver, spleen, kidney; causes enlarged liver, spleen, wasting, finally death (if untreated) in 2-3 years;
2-3 yrs following treatment, a condition called POST-KALA-AZAR DERMAL LEISHMANOID may develop (this is a GRANULOMATIS REACTION on the SKIN)
88
What causes CUTANEOUS LEISHMANIASIS? What's another name for this Dz?
LEISHMANIA TROPICA;
| ORIENTAL SORE
89
What are the life stages of LEISHMANIA TROPICA?
PROTOZOA form;
| NO CYST form
90
What is unique about the LIFE STAGES of TRYPANOSOMA & LEISHMANIA species? What's a difference bw the 2?
NO CYST forms for either T or L species;
| T species life in TRYPANOSOME (which is a protozoa form), while L species live in PROTOZOA form
91
What species of FLAGELLATED PROTOZOA DOES have a CYST form?
only GIARDIA LAMBLIA
92
How is LEISHMANIA TROPICA transmitted?
vectored by the SANDFLY
93
Describe the pathogenesis of CUTANEOUS LEISHMANIASIS:
red papule from sandfly bite; slow to heal, scars
94
What causes MUCOCUTANEOUS LEISHMANIASIS? What's another name for this Dz?
LEISHMANIA BRAZILIENSIS;
| aka ESPUNDIA
95
What are the life stages of LEISHMANIA BRAZILIENSIS?
PROTOZOA form;
| NO CYST form
96
How is ESPUNDIA transmitted?
vectored by SANDFLY
| aka MUCOCUTANEOUS LEISHMANIASIS
97
Describe the pathogenesis of MUCOCUTANEOUS LEISHMANIASIS:
lesions in the junction of the PHARYNX result in the break down of the PALATE of the MOUTH & NOSE
98
Name a type of CILIATED PROTOZOA:
BALANTIDIUM COLI
99
What causes CILIARY DYSENTERY?
BALANTIDIUM COLI
100
What are the life stages of BALANTIDIUM COLI?
large, ciliated TROPHOZOITE form;
| CYST form
101
How is CILIARY DYSENTERY transmitted?
fecal-contaminated water, particularly ass'd w/infected PIG feces
102
What symptoms present w/BALANTIDIUM COLI infection?
abdominal pain; watery, bloody stools
103
What is the TREATMENT for all LEISHMANIASES?
antimony compounds like meglumine antimonate (Glucantime);
| also, more recently tx'd w/ORAL MILTEFOSINE
104
What are SPOROZOA? Name 2 genera:
eukaryotic single celled parasites;
characterized by complex life cycles;
Genera PLASMODIUM & TOXOPLASMA
105
Which GENUS causes MALARIA?
PLASMODIUM
106
What are the life stages of PLASMODIUM?
SPOROZOITES (released from MOSQUITO into human host, go to LIVER) --> undergo ASEXUAL reproduction (SCHIZOGONY) --> produce MEROZOITES (infect & destroy RBCs causing Sx of MALARIA) --> GAMETOCYTES (produced as result of erythrocytic stage in RBC, taken up by FEMALE MOSQUITO)
107
Describe the 2 cycles (within a vertebrate host) of PLASMODIUM:
EXOERYTHROCYTIC STAGE (in LIVER);
ERYTHROCYTIC STAGE (in RBCs) - MEROZOITES in RBCs produce waste product called MALARIAL PIGMENT; LYSIS of RBCs cause anemia & jaundice of malaria
108
How is PLASMODIUM transmitted?
vectored by ANOPHELES MOSQUITO
109
Name 4 species of PLASMODIUM:
P. VIVAX;
P. MALARIAE;
P. FALCIPARUM;
P. OVALE
110
Which PLASMODIUM species is most commonly the cause of MALARIA? Name the malaria type:
PLASMODIUM VIVAX;
| called BENIGN TERTIAN MALARIA
111
What symptoms present in BENIGN TERTIAN MALARIA?
SCHUFFNER'S DOTS (infected RBCs have unique PINK dots); fevers that typically occur every other day; relapse from LATENT LIVER INFECTION is common
112
What distinctive characteristic is seen in RBCs infected by PLASMODIUM VIVAX?
ring-shaped (referring to TROPHOZOITE stage within RBC); RBC is large when infected
113
What causes QUARTAN/MALARIAL MALARIA?
PLASMODIUM MALARIAE
114
What distinctive characteristics present with P. MALARIAE infections?
NO enlarged RBCs; a distinctive BANDING PATTERN; ASEXUAL forms in RBCs appear as ROSETTES; fever occurs in 72 hr pattern; no relapses occur
115
Which is more common bw P. VIVAX & P. MALARIAE?
P. VIVAX
116
What symptoms & pathologies result from PLASMODIUM FALCIPARUM infections?
daily fever, becoming TERTIAN (36 to 48 hours); chills, nausea;
```
BLACKWATER FEVER (characterized by intravascular hemolysis,
hemoglobin and kidney failure. When RBCs burst, hemoglobin leaks into blood plasma, damages the glomerulus in the kidney, begins to leak into the urine, causing further damage to kidney tubules);
```
CEREBRAL MALARIA can ensue (mental status changes, coma, death)
117
Where is PLASMODIUM FALCIPARUM common? How does it compare to the other PLASMODIUM infections?
common in the tropics;
| MOST serious dz
118
Describe the infection by PLASMODIUM FALCIPARUM:
multiple SPOROZOITES infect 1 RBC --> creates 'SIGNET RING' formation;
infection restricted to LIVER & SPLEEN
119
What are the similarities & differences bw P. VIVAX & P. OVALE?
(similarities) similar infection to P. VIVAX, common in AFRICA, commonly RELAPSE
(difference) produces FEWER MEROZOITES
120
What causes TOXOPLASMOSIS?
TOXOPLASMA
121
Name a species of TOXOPLASMA:
TOXOPLASMA GONDII
122
What animals are susceptible to TOXOPLASMA GONDII infection?
(very LOW host specificity) rodents, mammals, birds;
| DEFINITIVE HOST - domestic & wild CATS
123
What are the life stages of TOXOPLASMA GONDII?
SPOROZOITES are the INFECTIOUS form, they are within OOCYST that passes out in FECES
124
How is TOXOPLASMA GONDII transmitted?
ingestion of undercooked, infected meat, containing TOXOPLASMA OOCYSTS;
ingestion of OOCYST from fecally-contaminated HANDS/FOOD;
TRANSPLACENTAL TRANSMISSION
125
Describe the pathogenesis of TOXOPLASMOSIS in an IMMUNOCOMPETENT px:
(generally) cats shed OOCYSTS for only 1-2 weeks, but large #s may be shed; OOCYSTS can survive in env't for several months, are remarkably resistant to disinfectants, freezing, drying, but are killed by heating to 70°C for 10 min;
(immunocompetent px) generally an asymptomatic infection; ~10% experience acute dz w/flu-like Sx (self-limiting)
126
Describe TOXOPLASMOSIS in an IMMUNOCOMPROMISED px:
(generally) px often have CNS dz, may have RETINOCHOROIDITIS or PNEUMONITIS;
(in AIDS px) TOXOPLASMIC ENCEPHALITIS is the most common cause of INTRACEREBRAL MASS lesions, thought to be caused by reactivation of CHRONIC infection
127
Describe CONGENITAL TOXOPLASMOSIS:
results from an acute primary infection acquired by the mother during pregnancy; incidence/severity varies w/the trimester during which infection was acquired (1st trimester is most damaging); invades CNS, may cause blindness, encephalitis, mental retardation
128
What species of SPOROZOA resembles a GIARDIA LAMBLIA infection? Describe it:
CRYPTOSPORIDIUM PARVUM;
| difficult to detect in water (during water treatment); ingestion of CYSTS cause WATERY DIARRHEA
129
What are NEMATODES?
ROUNDWORMS; multicellular parasites
130
What are 3 broad categories of NEMATODES?
ROUNDWORMS transmitted by INGESTION of OVA;
ROUNDWORMS transmitted by DIRECT PENETRATION of INFECTIOUS LARVAE;
ROUNDWORM TISSUE PARASITES
131
Name 3 species of ROUNDWORMS transmitted by OVA INGESTION:
ASCARIS LUMBRICOIDES;
TRICHURIS TRICHIURA;
ENTEROBIUS VERMICULARIS
132
What's the largest species of NEMATODE to parasitize the human intestine?
ASCARIS LUMBRICOIDES (also the most COMMON helminthic infection)
133
Describe the life cycle of ASCARIS LUMBRICOIDES:
OVA are ingested --> LARVAE hatch in DUODENUM, move into BVs --> LARVAE move to LUNGS to molt & mature --> in 3 wks, LARVAE are coughed up & swallowed --> once in SMALL INTESTINE, develop into ADULT worms
FEMALES produce ~200,000 eggs DAILY; eggs pass out w/FECES; eggs in SOIL are viable for up to 3 yrs
134
What symptoms present w/ASCARIS LUMBRICOIDES infections?
may cause STUNTED GROWTH, but ADULT worms usually cause NO ACUTE Sx;
high worm burdens may cause ABDOMINAL PAIN & INTESTINAL OBSTRUCTION;
MIGRATING ADULT worms may block BILE DUCT;
during LUNG PHASE of larval migration, PULMONARY Sx possible
135
Which nematode is known as the WHIP WORM?
TRICHURIS TRICHIURA
136
Describe the life cycle of TRICHURIS TRICHIURA:
eggs ingested (oral-fecal route) --> hatch in SMALL INTESTINE --> LARVAE migrate to CECUM, mature into ADULTS --> ADULTS live in CECUM & ASC COLON (fixed in this location, w/anterior portions threaded into MUCOSA)
ADULT FEMALES produce up to 10,000 eggs daily; shed in FECES
137
What symptoms present w/TRICHURIS TRICHIURA infection?
ANEMIA (consume blood cells w/anterior end buried in mucosa), damage to epithelial layer (can lead to secondary bacterial infection), PROLAPSED RECTUM possible (in extreme cases)
138
What's a PINWORM, and what's its only HOST?
ENTEROBIUS VERMICULARIS;
| humans
139
Describe the life cycle of ENTEROBIUS VERMICULARIS:
GRAVID (pregnant) ADULT FEMALE worm (is NOCTURNAL) migrates out of INTESTINE to lay up to 20K eggs on PERIANAL skin at night --> eggs transferred to FINGERNAILS BY SCRATCHING --> eggs are ingested --> LARVAE hatch in SMALL INTESTINE, migrate to COLON where they mature into ADULTS
140
Where are PINWORMS found?
worldwide, more common in TEMPERATE (than tropical) climates;
most COMMON helminthic infection in the US (~40 mil px);
infections more frequent in SCHOOL/PRESCHOOL CHILDREN & in CROWDED conditions
141
What symptoms present w/ENTEROBIUS VERMICULARIS infections?
often ASYMPTOMATIC;
most typical Sx is PERIANAL ITCHING (esp @ night) which may lead to secondary infection;
occassionally, female genital tract invasion --> VULVOVAGINITIS
142
Name 4 nematodes transmitted by DIRECT PENETRATION of INFECTIOUS LARVAE:
ANCYLOSTOMA DUODENALE & NECATOR AMERICANUS;
ANCYLOSTOMA BRAZILIENSE;
STRONGYLOIDES STERCORALIS
143
What 2 species are nicknamed (together) as the AMERICAN HOOKWORM?
ANCYLOSTOMA DUODENALE & NECATOR AMERICANUS
144
Describe the life cycle of the AMERICAN HOOKWORM:
ADULT FEMALE in small intestine lays 10-20K eggs daily --> eggs in FECES --> LARVAE hatch, feed on bacteria --> RHABDITIFORM LARVA molts to FILARIFORM LARVA (infective) --> FILARIFORM LARVA penetrate bare skin --> moves to LUNG, are SWALLOWED
145
What symptoms present w/AMERICAN HOOKWORM infection?
larval penetration of skin usually does LITTLE damage, DERMATITIS possible;
LARVAE may cause PULMONARY Sx (rarely PNEUMONITIS);
ADULT worms in SM INT attach to MUCOSA w/strong cutting plates, begin feeding on BLOOD --> ANEMIA, MALNUTRITION
146
What's known as the DOG & CAT HOOKWORM?
ANCYLOSTOMA BRAZILIENSE
147
Describe the life cycle of ANCYLOSTOMA BRAZILIENSE:
LARVAE penetrate SKIN & wander --> (life cycle not complete in humans) continue to wander aimlessly --> CREEPING ERUPTION (VISCERAL LARVAL MIGRANS) in humans --> intense ITCHING & EOSINOPHILIA
148
Describe the life cycle of STRONGYLOIDES STERCORALIS:
(alternates bw FREE-LIVING & PARASITIC forms) --> FEMALE in SM INT is OVOVIVIPAROUS (eggs remain w/in mother up until they hatch), eggs are deposited in MUCOSA, hatch & move to LUMEN --> LARVAE excreted in FECES (or cause AUTO INFECTION) --> become FREE-LIVING ADULTS in SOIL, produce eggs that develop into infectious FILARIFORM LARVAE --> LARVAE penetrate skin --> thru BLOOD to LUNGS --> molt in LUNGS, are swallowed, become ADULTS in SM INT
149
Name 4 species of NEMATODE TISSUE PARASITES:
ANISAKA;
TRICHINELLA SPIRALIS;
WUCHERERIA BANCROFTI;
ONCHOCERCA VOLVULUS
150
What is ANISAKA?
they are parasites in the stomachs of MARINE FISH & BIRDS
151
Describe the life cycle of ANISAKA:
LARVAE ingested by humans (from raw fish) --> produce INTESTINAL OBSTRUCTION, PAIN, NAUSEA, VOMITING
152
Where is ANISAKA commonly seen? How is it TREATED?
```
where raw fish is eaten more commonly (Japan, Pacific coast of S Am., Netherlands);
SURGERY ONLY (no effective drug tx)
```
153
Describe the life cycle of TRICHINELLA SPIRALIS:
ENCYSTED LARVAE are ingested & during digestion reach SM INT where molt to become ADULTS --> ADULT FEMALES produce 100's of LARVAE --> just after copulation, MALE dies; following larval production FEMALE dies --> LARVAE carried via BLOOD to MUSCLE where they ENCYST --> if host is not consumed by another host, larvae calcify & die (humans are a dead end host)
154
What animals will TRICHINELLA SPIRALIS infect?
(low host specificity) bears, bigs, rats
155
What Sx present w/TRICHINELLA SPIRALIS infections?
LIGHT infections - may be ASYMPTOMATIC;
larval migration into muscle tissues can cause FACIAL EDEMA, CONJUNCTIVITIS, FEVER, MYALGIAS, RASHES, BLOOD EOSINOPHILIA;
occasional life-threatening manifestations - MYOCARDITIS, CNS involvement, PNEUMONITIS
156
What are 2 types of FILARIAL WORMS?
WUCHERERIA BANCROFTI;
| ONCHOCERCA VOLVULUS
157
What causes ELEPHANTIASIS & what is another name for this condition?
WUCHERERIA BANCROFTI;
| BANCROFTIAN FILARIASIS
158
How is BANCROFTIAN FILARIASIS transmitted?
vectored by MOSQUITO
159
Describe the life cycle of WUCHERERIA BANCROFTI:
females in LYMPH DUCT are OVOVIPAROUS, produce 1000s of immature LARVAE (aka MICROFILARIAE) --> MICROFILARIAE released into lymph, swept into blood thru THORACIC DUCT --> MOSQUITOES ingest MICROFILARIAE in BLOOD MEAL --> MICROFILARIAE mature in MOSQUITO to final infective LARVAL stage
160
What Sx present w/BANCROFTIAN FILARIASIS?
(when females release MICROFILARIAE) intense lymphatic inflammation occurs w/CHILLS & FEVER --> lymph nodes become obstructed --> SWEATING;
(M) SCROTUM/LEGS;
(F) LEGS;
161
How can a clinician Dx WUCHERERIA BANCROFTI infections?
MICROFILARIAE exhibit PERIODICITY in the blood (they can be demonstrated during certain times of the day, other times seem to disappear from peripheral circulation;
draw blood at NIGHT to observe MICROFILARIAE
162
What dz is caused by ONCHOCERCA VOLVULUS?
RIVER BLINDNESS
163
How is ONCHOCERCA VOLVULUS transmitted?
vectored by a BLACK FLY (SIMULIUM)
164
Describe the life cycle of ONCHOCERCA VOLVULUS:
ADULT worms locate under skin, become encapsulated by host reactions to form NODULES --> adult FEMALE releases MICROFILARIAE --> MF migrate thru skin to EYES
165
What Sx present w/RIVER BLINDNESS?
LIZARD SKIN - inflammation from larvae migrating thru skin;
| BLINDNESS - when larvae migrate to eyes from skin
166
PLATYHELMINTHES are also known as what? And what are 2 broad groups?
FLAT WORMS;
| TREMATODA (FLUKES), CESTODA (TAPEWORMS)
167
Name 6 types of FLUKES:
```
FASCIOLA HEPATICA (LIVER FLUKE);
CLONORCHIS SINENSIS (CHINESE LIVER FLUKE);
FASCIOLOPSIS BUSKI (GIANT INTESTINAL FLUKE);
SCHISTOSOMA MANSONI, S. HAEMATOBIUM, S. JAPONICUM (BLOOD FLUKES)
```
168
Describe a LIVER FLUKE:
large, leaf-shaped parasites of HERBIVORES, can infect humans accidentally
169
Describe the life cycle of a LIVER FLUKE:
(ADULTS live in BILE DUCT) eggs passed out of LIVER w/BILE, into INT to be voided w/FECES --> LARVAE penetrate SNAILS --> CERCARIAE (motile larvae) leave snail, ENCYST as METACERCARIAE on water plants --> METACERCARIAE ingested by animal, migrate to LIVER
170
What Sx present w/LIVER FLUKE infection?
LIVER is damaged (by fluke migration);
| worms in BILE DUCTS cause INFLAMMATION, PAIN, CHILLS, FEVER
171
Describe the life cycle of the CHINESE LIVER FLUKE:
eggs excreted in FECES --> eggs hatch in water, LARVAE penetrate snails --> larvae mature in snails, CERCARIAE leave snail to penetrate FISH --> METACERCARIAE encyst in fish flesh --> humans consume undercooked/raw fish --> worms mature in BILE DUCTS, produce up to 4K eggs/day for at least 6 months
172
Describe the life cycle of the GIANT INTESTINAL FLUKE:
eggs in FECES hatch in WATER --> LARVAE penetrate SNAILS --> CERCARIAE move to plants (usually WATER CHESTNUTS) --> METACERCARIAE encyst under leaves --> humans/pigs eat water chestnuts
173
What's unique about SCHISTOSOMES?
mature in blood stream of DEFINITIVE HOST;
| unlike other FLUKES) are DIOECIOUS (separate genders
174
What are the 3 SCHISTOSOMES & describe their similar life cycle:
SCHISTOSOMA MANSONI, S. HAEMATOBIUM, S. JAPONICUM;
M/F live in host BVs (each species prefer different vv.) --> F release 3K eggs/day --> eggs pass thru tissue to reach INT/BLADDER --> eggs reach fresh water in URINE/FECES --> eggs hatch in fresh water --> infective LARVAL stage penetrates snail --> snail excretes infective CERCARIAE form w/a FORKED TAIL --> CERCARIAE penetrate skin of a vertebrate host, mature into ADULTS, reside in vv. --> adults may live 20-30 years
175
What Sx present w/SCHISTOSOMA infections?
SWIMMER'S ITCH - dermatitis from penetration of skin by CERCARIA;
w/in 1-2 months, develop FEVER, CHILLS, COUGH;
(most serious damage done by EGGS) eggs lodged in VENULES & TISSUE cause immune system to respond --> as eggs accumulate --> SPLENOMEGALY, ASCITES (fluid in ABD cavity) --> high eosinophilia
176
Name 4 kinds of TAPEWORMS:
```
TAENIA SAGINATA (BEEF TAPEWORM);
TAENIA SOLIUM (PORK TAPEWORM);
DIPHYLLOBOTHRIUM LATUM (FISH TAPEWORM);
ECHINOCOCCUS GRANULOSUS
```
177
What is a SCOLEX?
the HEAD of an ADULT tapeworm, used to attach to human intestinal wall (SM INT)
178
What is a PROGLOTTID?
a segment of a tapeworm's body;
| each contains a set of M & F organs that produce eggs
179
Describe the life cycle of TAENIA SAGINATA:
cattle consume GRAVID PROGLOTTIDS or EGGS in contaminated feed --> eggs hatch & LARVAE migrate to muscle --> larvae encyst in muscle as CYSTICERCI
180
What Sx present w/TAENIA SAGINATA infection?
only produce MILD abdominal Sx; most striking feature is PASSAGE of PROGLOTTIDS
181
Describe the life cycle of the PORK TAPEWORM:
(morphology & life cycle similar to BEEF T.W.) proglottids & eggs eliminated in FECES --> PIGS consume gravid proglottids or eggs in contaminated feed --> eggs hatch & larvae migrate to muscle --> larvae encyst in muscle as CYSTICERCI
182
What is CYSTICERCUS?
consists of SCOLEX within a large BLADDER, so CYSTICERCI aka BLADDER WORMS
183
What conditions arise from TAENIA SOLIUM infection?
CYSTICERCOSIS - only occurs w/T. SOLIUM; infective larvae migrate into mm/tissue of human host & develop into CYSTICERCI (can develop in BRAIN or EYE --> MENINGITIS, VISUAL DISTURBANCE, ACUTE INFLAMMATION);
ADULT worms rarely cause Sx (main Sx often the PASSAGE of PROGLOTTIDS)
184
Describe the life cycle of the FISH TAPEWORM:
eggs eliminated in FECES --> eggs hatch in water, LARVAE called CORACIDIUM --> coracidium ingest by COPEPODS --> copepods eaten by FISH --> larvae mature to SPARGANUM, encyst in fish mm --> human infection from undercooked fish
185
What Sx present w/FISH TAPEWORM infection?
(infections can be long-lasting, like DECADES) most are ASYMPTOMATIC; may include abdominal discomfort, diarrhea, vomiting, weight loss; VIT B12 deficiency w/ANEMIA may occur (tapeworm absorbs large amounts of B12)
186
Describe the life cycle of ECHINOCOCCUS GRANULOSUS:
adult worms infect CANINES & release eggs in SM INT --> eggs eliminated in FECES, ingested by SHEEP/CATTLE/PIGS/etc --> humans are accidental hosts, transmission usually by contact w/infected DOG (dogs may be infected by eating VISCERA of LIVESTOCK) --> larvae move into LIVER/LUNG, form HYDATID CYST (contains infectious worms called HYDATID SAND)
187
What Sx present w/ECHINOCOCCUS GRANULOSUS infection?
can remain SILENT for years before enlarging cysts cause Sx in affected organs;
HEPATIC involvement can result in abdominal pain, a mass in the hepatic area, biliary duct obstruction;
PULMONARY involvement can produce chest pain & cough;
RUPTURE of cysts can produce fever, eosinophilia, anaphylactic shock, cyst dissemination;
other organs (BRAIN, BONE, HEART) can also be involved, w/resulting Sx
