parasites and vectors Flashcards
1
Q
Human African trypanosomiasis- in West Africa ?
A
- Trypanosoma brucei gambiense (gHAT)
- Exclusively human reservoir
2
Q
What is the causative agent of
Human African trypanosomiasis in East Africa ?
A
- ## Trypanosoma brucei rhodesiense (rHAT)
3
Q
What is the Vector for American Trypanosomiasis ?
A
Triatomine bugs
4
Q
whats the causative agent for american trypansomiasis?
A
Trypansoma Cruzii
5
Q
A
6
Q
Vector for gHAT?
A
Glossina palpalis group of Tsetse fly
7
Q
Vector of rHAT?
A
Glossina Morsitans group of Tsetse fly
8
Q
parasite cause Chagas disease ?
A
Trypanosoma cruzi
9
Q
Vector for Chagas ?
A
- Family : reduviid bug:
-Subfamily :Triatomine bugs : - In wild environment in Amazona region and central America:
1- Triatoma infestans
2- Triatoma braziliensis
3- Triatoma sordida
4- Panstrongylus megistus.
*In south cone - Brazil , Argentina , Peru , Bolivia
(in houses night biting) :
5- Rhodnius prolixus
10
Q
Infective stage of plasmodium to human?
A
Sporozoite
11
Q
plasmodium spp that has hypnozoite stage ?
A
p vivax
P ovale
12
Q
plasmodium that can cause band form in erythrocytic stage on microscopy?
A
P malariae
13
Q
Causes of tertian malaria ?
A
P vivax
p ovale ( but doesn’t sequestrate in microvasculature)
14
Q
quartan Malaria
A
p malariea
15
Q
plazmodium that cause enlarged RBC and classic comet form on micrscoy
A
p ovale
16
Q
How to differentiate b/w scoleces of Tania saginatum, Taenia solium , E chinococcus granulosus and diphyllobothrium latum?
A
1- Saginatum: not hooks
and has 4 sucking disks
2- Solium: Hooked 4 sucking disks
3- E granulosus: 30-36 hooks in 2 rows and 4 sucks
4- diphylobothrium latum: almond shape and with pair of suctorial grooves called bothria
16
Q
A
17
Q
Diseases caused by Taenia solium?
A
1- Taeniasis (Pork tape worm)
2- Cysticercosis
18
Q
T/F:
E granulosus can grow into adult form inside human body ?
A
F
E granulosus can only mature into an adult form and produce eggs in canine
19
Q
Mode of infection in Taeniasis and cysticercosis?
A
In Taeniasis : by ingestion of the larvae in pork flesh
In Cysticercoses: By ingestion of the embryonated eggs (oncospheres) from patients own stool or other human carrier
20
Q
What is the most common tape worm infection in human??
A
Hymenolepis nana
(Dwarf tapeworm)
21
Q
Mode of infection by Hymenolepis nana ?
A
1- ingestion of the eggs in contaminated food and water
2- accidentally ingest cysticercoid-infected arthropod
22
Q
Mode of infection of Hymenolepis diminuta (rat tapeworm) ?
A
By ingestion of intermediate host (Grain weevils and earwigs) containing larva stage
(mainly in precooked cereals)
23
Q
what is the infective stage of Diphyllobothrium latum to mammals??
A
Plerocercoid larvae in raw and undercooked fishes
24
Definitive host of Diphyllobothrium latum??
Human
bears
cats
dogs
(fish eaters)
25
what are the 2 required intermediate host for Diphyllobothrium latum lifecycle ?
1- the copepods
2- fish
26
what is the only cestode that have an operculated eggs ?
Diphyllobothrium latum
27
Mode of infection with dipylidium caninum?
what is the age group at risk ?
what is the diagnostic stage ?
- BY ingestion of Ctenocephalides fleas containing larvae
- Mainly affect infant and young kids with close relation with pets
- Diagnostic stage: Gravid proglottid in stool ( eggs are not seen in human stool)
28
Mode of infection of the liver fluke Fasciola hepatica?
and what is the intermediate ( secondary) host ?
What is the diagnostic stage in human?
Undercooked watercress which contain the encysted larval metacercaria
Intermediate host: water snails
diagnostic stage : operculated oval eggs in stool
29
T/F :
Fasciola hepatica eggs are operculated and identical to the eggs of Fasciolopsis buski ( giant intestinal fluke)
T
30
Opisthorcis sinensis (Chinese liver fluke ) mode of infection?
By Ingestion of undercooked / raw fish containing metacercaria
31
where is the anatomical journey of both Fasciola hepatica and Clonorchis sinensis in human body??
Fasciola hepatica:
larva penetrate intestinal wall then peritoneal cavity then penetrate liver capsule to reach bile duct where they mature
Clonorchis sinensis parasite pass from intestine via ampula of vater and then reach the liver by bile ducts
32
mode of human infection by giant intestinal fluke(fasciolopsis buski) ?
by ingestion of contaminated water chestnut
33
What is the mode of infection of paragonimus westermani?
by ingesting the undercooked crap meat containing metacercaria
34
which cancer can Opisthorchis sinensis infection causes??
Cholangiocarcinoma
35
what is the Size and shape of Paragonimus westermani adult worms ?
12 by 4 mm
resembles a coffee bean in size, shape, and color
36
T/F
Entamoeba histolytica can be zoonotic infection ?
F
37
38
what is the only protozoal diarrheal infection which can cause eosinophilia ??
Isospora belli
39
What are the CNS infections that can caused by Amoebiasis and Naegleria fowleri ?
1- Amoeba dysentery:
Amoebic brain abscess
2- Acanthamoeba spp: slowly progressive Amoebic granulomatous encephalitis - GAE
3- Naegleria fowleri :
Amoebic Meningoencephalitis
40
What are the spp that can cause GAE (Granulomatous amoebic encephalitis)
Free living amoeba spp:
1- Acanthamoeba
2- Balamuthia mandrillaris
3- Sappinia
41
What is the cause of scrup typhus (bush typhus) ? and what is the vector ? Reservoir ?
Orientia tsutsugamushi
The vector is the infected larval trombiculid mites, commonly known as chiggers
Wild rats are the natural reservoir
42
What is the cause and vector of African tick bite fever ?
Caused by: Rickettsia Africae
Vector is Amblyomma tick
43
What is the cause and vector of Queensland tick typhus
Rickettsia australis
Vector is Ixodes tick
44
What are the DEBONEL/TEBOLA?
What is the cause and vector?
TIBOLA is the tick‐born lymphadenitis
DEBONEL: Dermacentor‐borne necrosis, erythema, lymphadenopathy
-Caused by : Rickettsia slovaca is the causative agent
-Transmitted by ticks of the genus Dermacentor
45
What is the vector of Brugia timori?
Mansonia Mosquitoes
46
What are the diseases that can be transmitted by Aedes mosquitoes?
LF
YF
DHF
Zika
Chikungunya
47
what is the difference b/w Loaloa Encephalopathy and Mazotti reaction?
Loaloa Encephalopathy occues in Loa loa treatment with Ivermectin (commonest) and DEC (Less common)
Mazotti reaction occurs when Onchocerciasis treatment with DEC
48
Treatment of choice of Loa loa?
DEC
If no detectable microfilaremia :
9 mg/kg/day for 21 days
If detectable Microfilaremia : gradual increase dose of DEC from 1 mg/kg/day up to 9 mg/kg/day 21 days
49
Treatment of choice of LF?
DEC 6mg/kg/day for 1 or 12 days
If Tropical pulmonary eosinophilia for 14-21 days
50
Treatment of Oncocerca volvulus
1- To kill microfilariae:
ivermectin 150 mcg/kg orally in one dose
every 6 months
2- to kill macrofilariae:
doxycycline* 200 mg orally daily
for 6 weeks
51
Countries that have reported cases of Trypanosoma brucei gambiensis ?
DRC (Commonest)
Cameroon / Congo
Central Africa
S Sudan / Chad
E Guinea / Guinea/ Gabon
52
Countries that have reported cases of Trypanosoma brucei rhodesiense ?
Malawi
Zambia
Uganda
Tanzania
53
The vector of Trypanosoma brucei rhodesiense ?
Tsetse fly ( Glossina Morsitans )
54
The Vector of Trypanosoma brucei gambeinsis
Tsetse fly (Glossina palpalis)
55
(single genital ulcers)
1- Cause of Chancroids?
2- Lymphogranuloma venerum?
3- Granuloma inguinale ?
1- Haemophilus ducreyi
2- Chlamydia trachomatis (LGV serovar) L 1 ,L2 ,L3
3- Klebsiella granulomatis (donovanosis)
56
presentation and treatment of LGV?
(Chlamydia trachomatis)
1- Main presentation is Proctitis (bloody discharge, tenesmus, or ulceration)
2- inguinal lymphadenopathy with bubo formation
3- Single painless genital ulcer
Tx: Doxycycline 100 mg orally 2 times/day for 21 days or:
- Azithromycin 1 g once weekly for 3 weeks
Or:
Erythromycin base 500 mg orally 4 times/day for 21 days
57
What is the cause , Presentation and Tx of Granuloma Inguinale (Donovanosis)?
- Klebsiella granulomatis .
- slowly progressive Painless single genital ulcers Without regional LN
-subcutaneous granulomas (pseudobuboes) which are highly vascular (beefy red appearance) and can bleed.
Tx
First line:
Azithromycin 1 gm orally once weekly or 500 mg daily for > 3 weeks and until all lesions have completely healed
alternative :
Doxy , erythro ,cotrim
58
Causes of multiple , painful genital ulcers ?
1- HSV
2- Chancroids( Haemophilus ducreyi)
3- Scabies ( sarcoptes scapiei )
59
Tx of Chancroid?
1- Azithromycin single oral dose (1 gram)
2- single IM dose (250 mg) of ceftriaxone,
oral (500 mg) of
3- erythromycin three times a day for seven days
60
Diagnosis and treatment of Chlamydia trachomatis ?
NAAT testing ( always test LGV Serovar if MSM with suspected rectal Chlamydia as required longer treatment)
Treatment:
1- Doxy 100 mg BD x7 days or:
2- Azithro 1 grams stat then 500 mg OD x2 days
61
Diagnosis and Tx of Gonorrhea ?
Diagnosis:
Microscopy
NAAT
Culture for sensistivity testing
Tx:
Ceftriaxone
cefixim
Azithromycin
test for cure in 2 weeks time
62
Trichomonas vaginalis presentation, diagnosis and TX?
1- heavy frothy vaginal discharge
2- punctate haemorrahge in cervix(strawberry cervix)
Diagnosis :
1-Microscopy( only sens 7%)
2- PCR
3- POCT
4- Cultures (difficult)
Tx
Oral Metronidazole 500 mg bd x 7 days ( can increase dose to 2 grams bd)
Oral Tinidazole
63
Mode of transmission of Histoplasma?
1- mainly by inhalation of microconidia which transform into yeast phenotype at 37c and then phagocytosed by macrophages.
2- very rarely : primary cutaneous histoplasmosis
64
What is the cause and vector of Pappataci fever?
(AKA: sandfly fever or the 3 days fever)
Caused by : 3 different serotypes of phleboviruses:
T :Toscana
S :Sicillian
N :Naples
Vector:Phlebotomus sand flies
65
What is the vector of Chandipura viral encephalitis ?
Phlebotomus sand fly
66
What is the cause and vector of Oroya fever?
caused by Bartonella bacilliformis
Transmits by sandflies of the genus Lutzomyia.
67
The vector and causative agent of Trachoma ?
Chlamydia trachomatis serovar A B1 B2 C
eye seeking flies (Musca sorbens)
68
What are the 2 Clinical phases of Trachoma ?
1- Active Trachoma (Conjunctivitis)
2- Cicatricial disease (Corneal scarring)
69
What is the most sensitive and specific test for diagnosing Trachoma ?
NAAT
70
What is the medical Treatment of trachoma ?
Mass treatment if prevalence >10% , to be repeated annually for 3 years if (prevalence >10%) for 5 years of prevalence >30%)
Azithromycin 20mg/kg stat( max 1 grams po stat)
Topical tetracycline 1% eye ointment for 6 weeks
71
What are the diseases that can be caused by Bartonella bacilliformis?
What is the vector?
Carrion's disease :
1-Oroya fever
2- verruga Peruana
Transmission:
sandfly
72
What are the disease that can be transmitted by Lice
1-Bartonella Quintana(Trensh fever or the 5 days fever)
2- Borrelia recurrentes (relapsing fever)
3- Rickettsia prowazekii (Epidemic typhus)
73
What is the cause , vector and treatment of louse-borne relapsing fever?
caused by borrelia recurrentes
transmit by body louse
restricted to Ethiopian highland
Tx single dose doxycycline , tetracycline ,Erythromycin , penicillin G
74
What is the Vector , the cause and Treatment of Trench fever ?
Louse borne
Caused by Bartonella quintana
6 weeks of Doxycycline +2 weeks of Gentamycin
75
What is the cause and treatment of Brill-Zinsser disease?
It is the late relapse of Epidemic (louse-borne typhus)
Caused by Rickettsia Prowazekii
Tx :single dose Doxycycline
76
What is the cause of scabies ?
Caused by mite Sarcoptis scabei var hominis
77
What are the types of human louse?
1- Pediculus humanus capitis
2- Pediculus humanus corporis
3- Pthirus pubis
78
Name the diseases that can be transmitted by Sandfly?
1-Leishmaniasis
2-pappatachi fever (sandfly fever- 3 day fever) caused by 3 different viral serotypes
3- Carrion disease (Bartonella basilliformis )
4-Chandipura virus
79
What is the pappatachi fever ?
-It is the sandfly fever or three-day fever
-vector-borne febrile arboviral infection
- caused by three serotypes of Phlebovirus:
1- Naples virus
2- Sicilian virus
3- Toscana virus
80
Name the three pathogens of which the body louse (Pediculus humanus humanus) is a vector?
1- Rickettsia prowazekii (epidemic typhus)
2- Bartonella quintana(Trench fever)
3- Borrelia recurrentis (louse-borne relapsing fever)
81
Name the 5 medically important Fleas ?
1- pulex irritance
2- ctenocephalides felis and ctenocephalides canis (transmit Dipylidium caninum)
3-Xenopsylla cheopis- Oriental rat flea (transmit Yersinia pestis "Plague " and Rickettsia typhi "Endemic murine typhus"
4- Nosopsyllus fasciatus Northern rat fleas ( Transmit salmonella enteriditis and Francisella tularensis- rabbit fever)
5-Tunga penetrans (Jiggers or sandfleas)
82
What is the cause and vector for Scrub typhus ?
Caused by Oreintia tsutsugamushi
Transmit by Trombiculid mites (Chiggers)
83
What are the Chiggers and The Jiggers ?
Chiggers are the Trombculid mites that transmits orientia tsutsugamushi and causes scrub typhus
Jiggers are the fleas Tunga penetrans that's cause Tungiasis (Sandfleas)
84
What are the 2 viruses that can be transmitted by ixodid hard ticks ?
1- Tick borne encephalitis
2- Crimean Congo haemorrhagic fever
85
What are the 2 different classes of Sandfly?
1- Old world sandfly: Phlebotomus spp
2-New world Sandfly : Lutzomyia spp
86
What are the 2 different spp of Tsetse fly?
1- Glossina Morsitans
- Transmit Trypanosoma brucei rhodesiense
-Can cause east African trypanosomiasis
- Dry Savannah
2-Glossina palpalis
- Transmit Trypanosoma brucei gambiense
- Can cause west African Trypanosomiasis
- Wet vegetations and rivers and lakes
87
What is the mode of transmission of Lassa fever
1- via ingestion or inhalation of food contaminated with rodent urine or faeces
2- Human-to-human transmission can also occur via infected urine, feces, saliva, vomitus, or blood
88
What is the parasitic stage and mammalian stage of Leishmania species?
1- Insect stage:
Procyclic promastigote
2- Mammalian stage:
Amastigote
89
In diagnosing Leishmania under microscope , what other parasite can look similar to the intracellular amastigotes ?
Peniciilum marneffei
Histoplasma capsulatum
90
In Falciparum malaria what is commonest stage to see in BF?
Early Trophozoites (Ring stage)
91
What are the 2 stages that's least likely to be seen in thin blood film?
1- Late Trophozoite
2- Schizonts
92
What is the infectious stage of Malaria parasite ?
Sporozoite
93
What is the cause and vector of River blindness?
Caused by Onchocerca volvolus .
Transmit by Simulum fly (Black fly)
94
What is the vector of Loaiasis ?
Chrysops deer fly
95
T/F:
Onchocerca has sheathed microfilaria ?
F
96
List soil transmitted helminths of clinical importance?
1- Strongyloides stercoralis
2- Ascaris lumbricoides
3- Necator americanas and Ancylostomia duodenales
4- Trichuris trichuira
97
What is the mode of transmission of each human cestodial infection (tape worms)?
1- By ingestion of the encysted larvae stage (cysticercus) in undercooked meat:
= Taenia solium
=Taenia saginata
= Hymenolepsis diminuta ( by ingesting weevil grains contining larvae)
= Diphyllobothrium latum ( pleocercoid larva) in undercooked fish
= Dipyllidium caninum by ingestion of larvae within fleas (ctenocephalides canis and felis )
2- By ingestion of eggs ;
= Cysticercosis
= Hymenolepis nana
= Echinococcus granulosus
98
What is the diff b/w Taeniasis and cysticercosis ?
Cysticercosis is the condition where the human becomes infected by the adult worm by ingestion of eggs of taenia saginatum
In taeniasis , adult worms are never seen in human
only the larval stages located only in small intestine
99
What is the cause of alveococcosis ?
Echinococcus multilocularis (Fos tapeworms)
100
T/F';
The adult Echinococcus granulosus can be found in human ?
F
Only in Canine which get infected by eating the viscera of sheep containing hydatid cysts
101
Mode of infection of Hymenolepsis diminuta (Rat tapeworms) ?
By ingestion of larvae in intermediate host mainly the Grain weevils (Usually in pre-cooked cereals)
102
What are the 2 tapeworms with unhooked scolexes?
1- Taenia saginata
2- Hymenolepsis diminuta
103
What's the only tapeworm with operculated eggs?
Diphyllobothrium latum
104
What is the mode of infection of Diphylobothrium latum and dipyllidium caninum ?
Dyphylobothrium latum: ingestion of pleocercoid larvae in undercooked fish
Dipallydium caninum :
by ingestion of fleas conytaining larvae (Ctenovcephalides felis
105
Fasciola hepatica transmission ?
By ingestion of improperly cooked watercress containing larval Metacercaria
106
T/F
Fasciola hepatica eggs are identical to fasciolopsis buski and are 130-150 Micrometer in diameter ?
T
107
Fasciolopsis Buski mode of transmission ?
By ingestion of infected water chestnut containing Metacercaria
108
What is the adult Paragonimus westermani size?
And what is the egg size?
adult worm is 10 mm
weggs are 120 Micrometer
109
Paragonimus westermani mode of infection?
ingestion of infected crabmeat with Metacercaria
110
Mode of transmission of Chinese liver fluke (opisthorchis sinensis) ?
Ingestion of Metacercaria in undercooked fish meat
111
in Schistosomiasis:
What is
1- the human infective stage and
2- snail infective stage ?
1- Cercaria
2- Meracedia
112
What is Katayama syndrome ?
Acute toxaemic schistosomiasis
Caused by s mansoni and Japonicum
113
what is the cause of Loffler's syndrome?
Ascaris lumbricoides
114
what is the cause of larva currens ?
Strongyloidiasis s
115
what is the cause of cutaneous larva migrans?
Can or dogs hook worms e.g Ankylostoma braziliensis
116
what is the cause of Visceral larva migranse?
Toxocara catis and canis
117
What is the virus ass with Kaposi sarcoma
HHV8
118
What is the virus ass with PML (progressive multifocal leukoencephalopathy ?
JC Virus
119
What is the pathognomic histopathology feature of Toxoplasmosis ?
- Intracellular or intracellular Tachyzoite
120
What is the size and the shape of Paragonimus westernani eggs
# yellow-brown
#120 µm by 50 µm
# ovoid or elongate with a thick shell
#The are often asymmetrical with one end slightly flattened
#At the large end, the operculum is clearly visible
121
T/F
In paragonimiasis the eggs are unembryonated when passed in sputum or feces?
T
122
What is the most common cause of CLM (Cutaneous larva migrans or creeping eruption)?
Ancylostoma braziliense and A. caninum.
123
What are the features of Hymenolepis diminuta eggs ?
round or slightly oval # size 80 µm X 80 µm, # # has a striated outer membrane and a thin inner membrane
The space between the membranes is smooth or faintly granular
NO polar
filaments
124
Hymenolepis nana eggs ?
Size : 45 to 50 microns in diameter
exhibiting polar
filaments lying between the egg shell and the
hexacanth embryo.
125
What are the 2 cestodes that causes human hymenolepiasis ? and what is their size ?
1- Hymenolepis nana (the dwarf tapeworm, adults measuring 15 to 40 mm in length)
2- Hymenolepis diminuta (rat tapeworm, adults measuring 20 to 60 cm in length)
126
Diphylobothrium latum eggs size
30x60 micron
oval or ellipsoidal
operculated eggs
127
The only cestode that can cause vitamin B 12 deficiency
Diphylobothrium latum
128
T/F:
Dipylidium caninum and hymenolepis diminuta has same size adult worm ?
T
60-70 CM
129
what is the size of Giardia duodenalis cyst and trophozoites ?
10- 20 micrometre
130
Size and features of Entamoeba histolytica/ dispar cyst ?
size :15 mic
have 4 nuclei that
each have centrally-located karyosomes and peripheral chromatin
chromatoid body with blunt ends
131
Size and features of Entamoeba histolytica /dispar trophozoite?
#Size 20 mic
Has a single nucleus, which have a central karyosome and uniformly peripheral chromatin
The cytoplasm has a granular or “ground-glass” appearance
132
Characteristic feature of Iodamoeba butschilii
Glycogen vacuole and single nucleus
133
size of Cryptosporidium cysts?
5 micrometre
134
Which Nematode is commonly ass with Rectal prolapse ?
Trichuris trichura
135
what is the size and features of Trichuris trichiura eggs?
size :50 x 25 micrometers
barrel-shaped, thick-shelled and possess a pair of polar “plugs” at each end.
136
T/F:
Loffler syndrome ass with strongyloidiasis?
F
Ass with ascaris
hyperesinophilia , cough and urticaria)
137
T/F
larva currens is ass with ascaris?
F
Ass with strongyloidiasis
no eosinophilia
138
What is the size of adult ascaris worm?
35 cm female
30 cm male
139
what is the size of Ascaris eggs ?
#fertile eggs 70mic
elongated oval shape
has thinner outer layer with variable mammilation
infertile eggs: 90 mic
have a thick shell
less mammitation
more rounded
140
what is larva currens?
It is the subcutaneous migration of filariform larvae in the autoinfective cycle of strongyloidiasis
presents as a recurrent maculopapular or urticarial rash
due to repeated autoinfection. T
advances very rapidly (up to 10 cm/hr).
141
what is the infective and diagnostic stage of strongyloides stercoralis ?
infective: Filariform L3 larvae
Diagnostic : Rhabditiform L1 larvae
eggs never seen in stool
142
T/F:
The eggs of Ancylostoma and Necator cannot be differentiated microscopically.
T
143
What is the size of hook worm eggs ?
# measure 70 µm by 40 µm
#Thin-shelled and colorless
#smooth outer layer
#very lumpy interior
40-70 mic
144
What is the size and Identification feature of Simulum black flies?
0.5 cm
humped thorax
colourless wings
very large and compounded eyes
145
What are the identification features of Argasid ticks ?
oval or rounded
flat dorsoventrally
wrinkled and covered with tiny tubercles called mammillae
no scutum
146
Which disease can be transmitted by Soft tick Argasid of genus Ornithodoros.
TBRF - Borrelia hermsii
