MEDICAL ENTOMOLOGY
Subjects :
1. Medical Entomology (Introduction)
2. Mosquitoes and flies
3. Mites
ARTHROPODS
Compared to the number of species of mammals, protozoa and
helminthes, insect species outnumbers them all
MEDICAL ENTOMOLOGY
Introduction
Definition: entomology
 Science that study insects (Entomon =
Insecta) and other species belonging to
Phylum Arthropoda, in relation to
health, and its control
Introduction
Medical entomology
 Study of vector, vector borne diseases
and abnormalities caused by insects
Introduction
Vector
Medik
(Kedokteran)
 entomology
Vector are mostly
insects
which carry and
transmit
Ilmu yang
mempelajari
tentang
vector,
disease
agents from
patient
to
diseaseperson;
dan kelainan
disebabkan
healthy
or fromyang
disease
sources to
oleh insects
uninfected
food or drinks
ARTHROPODA
- Divided into 5 classes
I. Class Insecta --- Medically important insect :
* Order Diptera
* Order Anoplura
* Order Hemiptera
* Order Siphonaptera
II. Class Arachnida
III. Class Crustacea
IV. Class Chilopoda
V. Class Diplopoda
Characteristic
Phylum Arthropoda
 Multicellular animal (metazoa)
 Symmetric, bilateral
 Segmented body
 Possess an exoskeleton
 Appendages : antennae, palpa etc.
Metamorphosis
Metamorphosis
 Morphological changes and development
in the life cycle of Arthropods
Two type metamorphosis
 Complete metamorphosis
 Incomplete metamorphosis
Metamorphosis
Complete Metamorphosis
 Marked changes and development in the
morphology and biology (natural
habitat, types of food, etc)
 Eggs - Larva - Nymphs - Adults
Incomplete Metamorphosis

Eggs/ova - (Larva) - Pupa - Adults
ROLE OF ARTHROPODS
Role as vector
Insects may act as
Vector/transmitter of disease agents
As direct cause/etiology of disease or
injury
ROLE OF ARTHROPODS
Mode of transmission
Two modes of transmission
As mechanical vector
As biological vector
Role as mechanical vector
disease agents do not develop or multiply
inside the vector
Example : gastroenteritis agents in flies
and cockroach
Transmission occurs through the
proboscis, legs, body, wings
House flies
ROLE AS BIOLOGICAL VECTOR
- Disease agents develop or multiply inside the
vector
-
Example :Plasmodium sp. at Anopheles sp.
Transmission occurs through the proboscis
ROLE OF ARTHROPODS
Role as vector
Anopheles , vector of malaria
Aedes aegypti , vector of dengue
hemorrhagic fever
Role of Arthropods
Role as the cause of disease
Disease or injury may be caused by
insects through various means :
- Mechanical injury
- Injection of poisonous substances
- Allergies
- Psychosis
Role of Arthropods
Role as the cause of disease
Mechanical cause
Bites - sting - piercing and bloodsucking larval movement
Arthropods may act as :




Endoparasites : larva of flies causing myiasis
Ectoparasites: headlouse
Permanent parasites : fleas
Intermittent parasites: mosquito
Injection of Toxic substance
Poison enters through :
 Direct contact (caterpillars), bites (spider),
sting (scorpion), piercing (mosquito)
Common symptoms :
 Itching, swelling, urticaria (mosquito,
caterpillars)
 Hemolysis (scorpion)
 bleeding (bees)
 Nerve damage (scorpion)
Allergies
Dyspnea /asthma : caterpillar,
butterflies
Psychosis
A boy with allergy
Entomophobia from mosquito bite
Role of Arthropods
Insect as cause of injury and disease
Scorpion
Spider
(1)
(2)
(3)
Bedbugs: (1) female; (2) male; (3) bloodsucking activity
Centipedes
Mosquito
Life cycle
 Life span: 2 weeks
 Complete Metamorphosis (eggs - larva - pupa - adults).
 Eggs laid on water surface :
– White
1-2 hours
- Turns black
IV) 6-8 days - Pupa
1-3 day
2-4 days
- Larva ( stage I -
- Adults male and female
Medical importance
1. Mosquito bites may cause urticaria, and dermatitis
2. As vector transmitter of many diseases :
Example 1:
Malaria (Plasmodium)
 Main vectors of malaria in Jawa and Bali : Anopheles
sundaicus, A. aconitus, A. subpictus, A. maculatus, A.
balabacensis, A. sinensis.
Medical importance
 vector of disease : Example 3.
Dengue (by Dengue virus)
 Based on severity, clinical dengue may
manifest as Dengue Fever (DF), Dengue
Hemorrhagic Fever (DHF) or Dengue Shock
Syndrome (DSS).
 Vector: Aedes aegypti, Ae. albopictus, Ae.
scutelaris, Ae. togoi
Medical importance
 vector of disease : Example 4 & 5
Yellow fever - by Yellow Fever virus
 Primary vectors : Aedes aegypti, Ae. simpsoni
Japanese B. encephalitis and St. Louis
encephalitis (by JBE and SLE virus)
 Primary vectors : Culex pipiens, C. tarsalis, Ae. togoi
Medical importance
Aedes aegypti , vector of dengue fever
Flies
Bloodsucking Flies
1
2
3
Family Psychodidae
Genus Phlebotomus = Sandflies
Family Simuliidae
Genus Simulium = black fly = buffalo gnats
Family Ceratopogonidae/Heleidae
Genus Culicoides = midges = no-see-um =
punkies
Flies
Bloodsucking Flies
4
5
Sub ordo Brachycera
Family Tabanidae
Genus Tabanus = horse fly
Genus Chrysops = deer fly
Genus Hybomitra
Sub ordo Athericera = Cyclorrapha
Family Muscidae
Genus Glossina = Tsetse Flies
Genus Stomoxys = Stable Flies
Flies
Phlebotomus sp.
Medical importance
 The bites may cause dermal papules, intense pain,
itching, nausea, fever, malaise
 As vector of the following diseases :
Kala azar
Phlebotomus
Bartonellosis
= demam papataci

By Leishmaniafever
donovani
Disebabkan
Bartonella baciliformis
Oriental
sorevirus
Terdapat
di Pegunungan
lauttropica
Tengah, Arab,
AndesAsia selatan
By Leishmania
vectornya
Phlebotomus verrucosum
papataci
American Leishmaniasis
 By Leishmania braziliensis
Flies
Culicoides sp.
Medical importance
 Painful bite, causing itch and fever
 Act as vector of disease (as intermediate host of
Filarial worm) :
 Culicoides grahami, and C. austeni, as vector of
Acanthocheilonema perstans
 Culicoides grahami as vector of Dipetalonema
streptocerca
 Culicoides furens and C. paraensis as vector of
Mansonella ozzardi
Flies
Culicoides sp.
Adults Culicoides sp.
Source : Color Atlas of Medicine and parasitesology. 1977
W. Peters & H.M. Gillers
Flies
Glossina sp.
Medical importance
 vector Arfiican sleeping disease
 Trypanosoma gambiense, vector is Glossina
palpalis
 Trypanosoma rhodesiense, vector is Glossina
morsitans
Glossina sp.
Source : Atlas parasitesologi Kedokteran.
1994Juni Prianto, Tjahaya P.U., Darwanto
Source :A Colour Atlas of Clinical parasitesology.
Tomio Yamaguchi
Alih Bahasa : Lesmana Padmasutra, dkk.
Flies
Stomoxys sp.
Medical importance
 Painful bites; mostly on cattle and
horses which may cause anemia
 Mechanical vector of :
Trypanosoma evansi – which causes a
disease in animals called surra
- Example: Stomoxys calcitrans
Stomoxys sp.
Flies
Non-biting Flies
1
Family Muscidae
– Musca domestica = House flies
2
Family Sarcophagidae
– Meat flies
– Characteristic : viviparous
– Lay its larva on meat
Example :
– Genus Sarcophaga : myiasis semisystemic and accidental
– Genus Wohlfahrtia : specific
– myiasis
Flies
Non-biting Flies
3
Family Calliphoridae
– Blow flies
– Example : Chrysomyia bezziana
– Specific Myiasis on open wound,
nostril, ear holes (myiasis of the
skin and atrial openings)
4
Family Drosophilidae
– Species: Drosophila melanogaster
– Also called fruit flies, may cause
accidental intestinal myiasis
Flies
Musca domestica
Medical importance
 Adult flies may act as mechanical vector of
many disease agents : protozoa, worm eggs,
bacteria, virus.
 Larva stage may invade human tissue
causing a disease called myiasis
Flies
Musca domestica
Musca domestica (House flies )
Definition: Infestation of human or
animal tissue or organs by
maggot (larva stage) of certain
non-biting flies
This larva live from tissue, body liquid, or food from
the hospes
Myiasis
Larvae in necrotic tissue
TRANSMISSION
Infestations occur when the insects put their
eggs on the injury skin or open abscess.
 Species that cause myasis, for example
Passeromyia longicomis larvae.
 Species that cause myasis dermal only, for
example Cordylobia anthropophage and
Cordylobia hominis.

Diagnosis
For Ophtalmomyasis, irrigation of lacrimal
gland until the parasite come out.
 One drop of cocaine for paralyzing the
movement, then lifted by using tweezer (
forceps ). Same as dermal myasis.
 Myasis intestinal : feces examination.

MITES
Introduction

Classified under ordo Acarina
 Causing acariasis
 Medically most important mites :
Family Sarcoptidae (Scabies
mite)
Family Trombiculidae
MITES






Etiology : Sarcoptes
scabiei
Family Sarcoptidae
Order : Acarina
Disease : scabies,
sarcoptic mange
Ectoparasite, inhabit the
skin creating tunnels
under the stratum
corneum where female
lay eggs
Predilection sites : thin
skin folds (between
fingers, armpit, wrist,
genital fold)
Scabies , Sarcoptic mange
Source :A Colour Atlas of Clinical Parasitology. Tomio Yamaguchi.
Translation : Lesmana Padmasutra, dkk.

Common among children and
adults of poor personal hygiene
 Among inhabitants of prisons,
orphanages, boarding houses and
military barracks
Source :A Colour Atlas of Clinical Parasitology. Tomio Yamaguchi. Translation : Lesmana Padmasutra, dkk.
Scabies Mites
Clinical symptoms
 Night itch caused by :
 Female activity of tunnel burrowing
Host reaction against metabolic wastes
 Pruritus, vesicules and pustula along the
tunnel
 Pustula is the result of bacterial secondary
infection
Scabies Mites

Predilection sites of Scabies in man
Source : Basic Clinical Parasitology. 1994. Neva F.A. & Brown H.W.
Scabies Mites

Scabies of labia majora and the surrounding areas

Chronic Scabies of the scrotum
Source :A Colour Atlas of Clinical Parasitology. Tomio Yamaguchi.. Translation : Lesmana Padmasutra, dkk.
Scabies Mites
Diagnosis


Clinical D/
By finding specific skin infection in the area of
predilections
Observing patient scratching specific area of predilection
Laboratory D/
Potassium Hydroxide (KOH) Test : Skin scraping from
predilection area is placed on a glass slide, add one drop
of 10% KOH, warm the slide, cover with slide cover glass,
and examine under the microscope to find the adult mite
or the eggs.
Dark Ink Test : place a drop of ink on the suspected skin
surface, press slightly to allow ink to enter the tunnel,
rinse and observe the ink filled tunnels
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