WUCHURERIA BANCROFTI
Definitive Host: Human
Vector: Aedes poecilus, Culex, Anopheles
Diagnostic stage: Adult microfilaria in lymph nodes and
blood channels
Infective stage: Filariform Larva
Habitat: Lower lymph gland
Distinguishing characteristics:
Sheathed without caudal nuclei (nuclei are distinct
and arranged in 2-3 rows)
white in colour and almost transparent
short cephalic or head region
Adult:
Creamy white, long, and filiform in shape; found
tightly coiled un nodular dilations in lymph vessels
and sinuses of lymph glands.
Mode of transmission: Through vector
Pathology:
1. Asymptomatic
2. Inflammatory (acute) phase
a. lymphedema
b. orchitis (inflammation of the testes)
c. epididymitis (inflammation of the spermatic
cord)
3. Obstructive (chronic) phase
a. lymph varices
b. lymph scrotum
c. hydrocele
d. chyluria (lymph in urine)
e. elephantiasis
Diagnosis:
1. Blood smear- sample is taken during the period in
the day when the juveniles are in the peripheral
circulation
1
2. Examination of Giemsa stained blood. Filtering
using heparinized blood through a nucleopore filter,
Knott's technique (Nocturnal - 9pm-4am)
3. Ultrasonography - may be able to demonstrate live
worms in the lymphatics
4. Knott's method for concentration may be used.
Treatment: Diethylcarbamazine citrate (DEC) & Ivermectin
w/ Albendazole
Wuchereriabancrofti
Brugiamalayi(dread worm)
Size
M=2-4cm, F=8-10cm
M=13-23mm, F=43-55mm
Endemicity
Bicol,Palawan, Sorsogon
Palawan, East Samar, Sulu,
Agusan
Sheath
Description &
Nuclei
W/ hyaline sheath, dark
staining nuclei, arranged in
2-3 rows (conspicuous), no
terminal nuclei
Sheathed, 2 nuclei at the tip of
the tail which are indistinct or
confluent
Cephalic
Space
As long as wide
Longer than broad
Somatic cells
Discrete and separate
Big & overlapping
Vector
Aedes poecilus, Culex,
Anopheles
Mansonia bonnea/uniformis
Gen.
appearance of
microfilaria
Graceful curve
Secondary curve described as
kinky microfilaria
BRUGIA MALAYI
ONCHOCERCA VOLVULUS
River blindness
Definitive Host: Human
Vector: Mansonia Bonneae/uniformis
Diagnostic stage: Adult microfilaria in lymph nodes and
blood channels
Infective stage: Filariform larva
Habitat: Upper lymph gland
Distinguishing characteristics:
Sheathed; 2 nuclei at the tip of the tail which are
indistinct or confluent (Nocturnal/non-periodic)
Pink sheath in Giemsa stain
Microfilaria measure 177-230 um in length.
Male: 13-23mm in length
Female: 43-55mm; indistinguishable with W. Bancrofti
Mode of transmission: Through vector
Pathology:
1. Asymptomatic
2. Inflammatory (acute) phase
a. lymphedema
b. orchitis (inflammation of the testes)
c. epididymitis (inflammation of the spermatic
cord)
3. Obstructive (chronic) phase
a. lymph varices & scrotum
b. hydrocele
c. chyluria (lymph in urine)
d. elephantiasis
Diagnosis: Multiple Giemsa stained slides of tissue
biopsies; adult worm may be recovered in infected
nodules, opthalmogic using slit lamp
Treatment: Ivermectin
2
Definitive Host: Humans
Vector: Simulium damnosum (black fly)
Diagnostic stage: Adult microfilaria in subcutaneous
tissue
Infective stage: Filariform larva
Habitat: Subcutaneous tissue
Distinguishing characteristics:
No terminal nuclei, tail straight (unsheathed)
Non-periodic
Female: 50cm in length
Male: 5cm in length
Mode of transmission: Through vector
Pathology:
1. Disease. of subcutaneous tissue, skin and eyes.
2. Nodules (5-25mm); # nodules 3-6 up to 150
3. Africa – nodules in trunk, thigh and arms
4. America – nodules in head and shoulder
Diagnosis:
1. Microfilariae in “skin snip”
2. Ophthalmologic exam w/ slit lamp
3. Abs in ELISA test
4. Mazzotti test (not used in the eye)
Treatment:
1. Ivermectin
2. DEC - Diethylcarbamazine
3. Suramin - toxic drug, for heavy infection
LOALOA
DRACUNCULUS MEDINENSIS
Eye worm
Guinea worm disease
Definitive Host: Humans
Vector: Chrysops
Diagnostic stage: Adult found in spinal fluid, urine,
sputum, peripheral blood and in the lungs
Infective stage: Filariform larva
Habitat: Subcutaneous tissue
Distinguishing characteristics:
Continuous nuclei (sheathed)
Diurnal
Female: 6cm long and .5mm wide
Male: 3cm long and .4mm wide
Mode of transmission: Through vector
Pathology:
1. Eyes – irritation, pain, tumefaction of eyelids,
impaired vision
2. Swelling – painful, nonpitting subcutaneous
swelling, size of hen’s egg
3. Angioedema
4. Erythema
Diagnosis:
1. Giemsa/Hematoxylin
2. Antifilarial Abs
3. Knott and Nucleopore
4. Surgery
5. DEC/ + steroids
Treatment: Albendazole or Ivermectin
3
Definitive Host: Humans
Vector: Cyclops
Diagnostic stage: Adult microfilaria in subcutaneous
tissue
Infective stage: Filariform larva
Habitat: Subcutaneous tissue
Distinguishing characteristics:
Pair of uteri, oviducts, tubules and a single
unpaired vagina constitutes the female genital
tract
Unsheathed
Female: 80cm in length by 2mm in width; viviparous
Male: 2-4 cm in length with unequal spicules
Mode of transmission: Swallowing infected copepods
with drinking water
Pathology:
1. Blister – contains numerous larvae and
leukocytes
2. Urticaria, dyspnea, vomiting, mild fever, and
occasional fainting
3. Itchy rash
Diagnosis:
1. Parasitic diagnosis - Established by observation
of the typical ulcer and flooding ulcer with water
to recover the discharge of larvae
2. Serodiagnosis – IFA, IHA, ELISA, and western
blot
Treatment: No specific drug is used
to treat dracunculiasis. Metronidazole or thiabendazole
(in adults) is usually adjunctive to stick therapy and
somewhat facilitates the extraction process
MANZONELLA OZZARDI
MANSONELLA PERSTANS
New world filaria
Perstans Filaria
Definitive Host: Humans
Vector: Culicoides/midges or Black fly
Diagnostic stage: Adult in the bloodstream
Infective stage: Filariform larva
Habitat: Body cavities – visceral fat
Distinguishing characteristics: Continuous nuclei
(Unsheated)
Mode of transmission: Through vector
Pathology: Most infected people are completely
symptomless. However, joint pains, headaches, coldness
of the legs, inguinal adenitis, and itchy red spots have
been described in conjunction with infection.
Diagnosis:
1. Identification of microfilariae in the peripheral blood
2. Blood sample can be a thick smear, stained
with Giemsa or hematoxylin and eosin.
Treatment: Ivermectin
4
Definitive Host: Humans
Vector: Culicoides/midges or Black fly
Diagnostic stage:
Infective stage:
Habitat: Peritoneal and pleural cavities
Distinguishing characteristics:
measures about 200 um
unsheated
nuclei extend to the tip of the tail- rounded and
blunt (unsheathed)
blood is the specimen
non periodic
Mode of transmission: Through vector
Pathology: Often asymptomatic, can be associated with
angioedema, pruritus, fever, headaches, arthralgias,
and neurologic manifestations
Diagnosis:
1. Identification of microfilariae in the peripheral blood
2. Blood sample can be a thick smear, stained
with Giemsa or hematoxylin and eosin.
Treatment:
1. Doxycycline
2. Ivermectin
3. Mebendazole
4. Albendazole
MANSONELLA STREPTOCERCA
Definitive Host: Humans
Vector: Culicoides/midges or Black fly
Diagnostic stage: Adult in the bloodstream
Infective stage: Filariform larva
Habitat:
Distinguishing characteristics: No terminal
nuclei. Tail bent like fish (Unsheathed)
Mode of transmission: Through vector
Pathology:
1. can cause skin manifestations including
pruritus, papular eruptions and
pigmentation changes.
2. Eosinophilia is often prominent in filarial
infections.
Diagnosis:
1. Identification of microfilariae in the
peripheral blood
2. Blood sample can be a thick smear,
stained with Giemsa or hematoxylin and
eosin.
Treatment:
1. Doxycycline
2. Ivermectin
3. Mebendazole
4. Albendazole
Parasite
Vector
Periodi
city
Nuclei
Sheath
Peripher
al blood
Noctur
nal
dark staining
nuclei,
arranged in 23 rows
(conspicuous)
, no terminal
nuclei
Sheath
ed
2 nuclei at the
tip of the tail
which are
indistinct or
confluent
Sheath
ed
Lower
lymph
gland
B. malayi
Upper
lymph
gland
Mansoniabonne
a/uniformis
Peripher
al blood
Noctur
nal
Subper
iodic
Loa-loa
Subcuta
neous
tissue
Chrysops
Eye
tissue
Diurnal
Continuous
Sheath
ed
-do-
Simuliumdamno
sum or
Black fly
Skin
snips/
Nodule
aspirate
Nonperiodi
c
No terminal
nuclei, tail
straight
Unshe
athed
Culicoides/midg
es or Black fly
Peripher
al blood
Nonperiodi
c
Continuous
Unshe
athed
Culicoides/midg
es or Black fly
Peripher
al blood
Nonperiodi
c
No terminal
nuclei. Tail
bent like fish
Unshe
athed
Onchocerc
a volvulus
Dipetelone
maperstan
s
(Manzonell
aozzardi)
Body
cavities
–
visceral
fat
Body
cavities
–
visceral
fat
Aedespoecilus,
Culex,
Anopheles
Specim
en
W.
bancrofti
D.
streptocer
ca
5
Habitat