Medically Important Mosquitoes & Flies 2012

7/28/2019 Medically Important Mosquitoes & Flies 2012

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Arthropods of Medical Importance

Identification

Medical Importance Mechanism of disease transmission

Control

(Practical only)

(Reading for oral)


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Medically Important Mosquitoes

Transmits (vector)Transmits (vector) Transmits (vector)

FemaleAedes FemaleAnophelesFemale Culex

Viral encephalitis

Rift valley fever

W.bancroftiYellow fever virus

Dengue fever virus

W.bancrofti

Rift valley fever Viral encephalitis

(occasionally)

W.bancrofti& B.malayi

Human malaria


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Mechanism ofW.bancrofti transmission by Culex

Proboscis

(mouth)Labium

Head

Thorax

Abdomen

Microfilaria

taken withblood meal

Mosquito gut

2 moults

Cyclodevelopmental

Numberof microfilariae that

enter the body of mosquitodevelop giving the same

numberof infective larvae

Infective larvae

This is called

Biological

transmission

Body of Mosquito

Lose the sheath


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AnophelesMalaria

transmitter

Mechanism ofPlasmodium transmission Anopheles

gametocytes taken

with blood meal

exflagellation

fusion

Zygote

to form gametes

Ookinete

Oocyst

Sporocyst

Sporozoites

in salivarygland

Reduction division

Alimentary canal of

Anopheles mosquito

Cyclopropagative

Biologicaltransmission


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Important Egyptian Mosquitoes

Anophelespharoensis

Anophelessergenti

Anopheles

multicolor

Anopheles

gambiae

Distributed all

over Egypt

especially inDeltaChief malaria

vector

Spread in oasis

in autumnA malaria

vector

Not widely distributed in Egypt

Suspected malaria vector

An efficient malaria vectorNot present in Egypt but

found in Sudan.

Anopheles species


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Anopheles gambiae

Is an efficient malaria vector because:

Anthropophilic.

Highly domesticated.

Highly Susceptible to infection.

Eggs resist desiccation.

Culex pipiensDistributed all over Egypt all the year round.

Breed in any type of water.

Aedes aegypti

Exterminated from Egypt.


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Phlebotomus papatasii(Sand fly)

Medical importance:

Protozoal:Cutaneous & visceral

Leishmaniasis.

Bacterial:Oroya fever or Carrionsdisease or Bartonellosis.

Viral:sand fly fever or papatasii

fever or 3-day fever.

Harara:

allergic reaction to bite of sand fly.

Transmission of diseases:


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Mechanism ofLeishmania transmission

Promastigotes

Biological

transmission

AmastigotePromastigotes

Block mouth & pharynx

In skin or blood

of patient

Multiply by

binary fission

Alimentary

canal of

sand fly

Cyclopropagative


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Simulium(Black or Coffee fly)

Mechanism of

transmission

The arthropod takes

microfilariae from infectedhuman through the bite

Inside the arthropod, the

microfiariae develop into

infective larvae to be

injected through the bite

Cyclodevelopmental

It transmits

Onchocerca volvulus

It transmits

M. perstans & M. ozzardi.

It transmits

Loa loa

Biological

transmission

Culicoides

Chrysops


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Glossina (Tse tse fly)

Medical Importance:

It transmits (vector):

T.b.gambiense:

causessleeping sickness in man(G. palpalis) in West Africa.

T.b.rhodesiense:

causes sleeping sickness in man

(G. morsitans) in East Africa.

G.palpalis

G.morsitans


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Mechanism of disease transmission by Glossina

Bite of

&Glossina

Trypomastigotes

12-42

Full of short

stumpy metacyclic

trypanosomes

3 weeks

Infective stage

Biological transmission

Salivary

gland

Epimastigote

(polymorphic trypanosomes)

cyclopropagative


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I- A patient presenting with dysentery

1- Which of the following

protozoa may cause

dysentery?

a b c

Cryptosporidium

parvum oocysts

Entamoeba

histolytica cyst

Trichomonas vaginalis

trophozoites


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2- The patient was infected by the following method:

ab c

Bite of female

sandfly

Contamination of

skin abrasions by

Triatoma faeces

Flies contaminatingfood by

quadrinucleate cyst


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ab c

3- If the patient was not properly treated, the

following complication may occur:

Haemoglobinuria Appendicitis Nephrotic syndrome


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1- Which of the following

protozoa may cause

dysentery?

a b c

Toxoplasma gondii

tachyzoites

Balantidiun coli

trophozoite

Giardia lamblia

trophozoites


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2- The patient was infected by the following method:

ab c

Bite of female

Phlebotomus

Bite of female

Anopheles

Flies contaminatingfood by

quadrinucleate cyst


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ab c

3- If the patient was not properly treated, the

following complication may occur:

Haemoglobinuria Appendicitis Nephrotic syndrome


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II- A patient presenting with haemolytic anaemia

ab c

1- Which of the following protozoamay cause haemolytic anaemia?

Leishmania

amastigotesGametocyte stage

ofP.falciparum

Polymorphic

trypanosomes


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a bc

2- the patient was infected by thefollowing method:

Bite of

Anopheles

Contamination by

Triatoma faeces

Bite of

sandfly


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a b c

3- Which of the following is thecause of anaemia?

Bone marrow

affection

Destruction

of RBCs

Decreased iron

intake in food


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II- A patient presenting with aplastic anaemia

ab c

1- Which of the following protozoamay cause aplastic anaemia?

Leishmania

amastigotesRing stage of

Babesia

Toxoplasma gondii

trophozoites


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a bc

2- the patient was infected by thefollowing method:

Bite of

Anopheles

Contamination by

Triatoma faeces

Bite of

sandfly


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a b c

3- Which of the following is thecause of anaemia?

Bone marrow

affection

Destruction

of RBCs

Decreased iron

intake in food


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III- A child presenting with hepatosplenomegaly

ab

c

1- Which of the following protozoamay cause hepatosplenomegaly?

G.lamblia

trophozoite

Leishmania

amastigotes

Balantidium

colicyst


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III- A patient presenting with hepatosplenomegaly

a b c

2- The patient was infected by thefollowing arthropod:

Bite ofGlossina

Contamination by

Triatoma faeces Bite of female

sandfly


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a b c

3- Diagnosis is confirmed by the

following method:

Detection of

parasite by

skin test

Detection of

parasite in

bone marrow

Detection of

parasite in

stool


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III- A child presenting with hepatosplenomegaly

a b c

1- Which of the following protozoamay cause hepatosplenomegaly?

G.lamblia

trophozoite

Polymorphic

trypanosomes

B.coli

cyst


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a b c

2- The patient was infected by thefollowing arthropod:

Bite ofGlossina

Contamination by

Triatoma faeces Bite of female

sandfly


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a b c

3- Diagnosis is confirmed by the

following method:

Detection of

parasite by

skin test

Detection of

parasite in

blood

Detection of

parasite in

stool


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IV- A patient presenting with appendicitis

ab

c

1- Which of the following protozoamay cause appendicitis?

G.lambliatrophozoite Balantidium coli

trophozoite

Entamoeba

colicyst


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a b c

2- The causative protozoa producesthe following lesion:

Ulcer with sharp-cut edge &

indurated margin

Flask-shaped

ulcer

Nodular

lesion


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b

3- The causative protozoa may

produces the following

complication:

Spread ofprotozoa to

liver or lungs

Perforation &

peritonitis

Steatorrhoea &

malabsorption

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Medically Important Mosquitoes & Flies 2012