PREFI THE FILARIAE Flashcards
blood feeding arthropod vector-borne nematodes
FILARIAE
LYMPHATIC FILARIAE:
- Wuchereria bancrofti
- Brugia malayi
SUBCUTANEOUS FILARIAE:
- Loa loa
- Onchocerca volvulus
Filariae that causes infection in the
abdomen
SEROUS CAVITY
Considered one of the most delabilating
diseases that is known in the man
LYMPHATIC FILARIAE
“BANCROFT’S FILARIAL WORM”
Causative agent of BANCROFTIAN
FILARIASIS
Wuchereria bancrofti
INFECTIVE STAGE OF Wuchereria bancrofti
L3 larvae
DIAGNOSTIC STAGE OF Wuchereria bancrofti
SHEATHED microfilariae
MOT OF Wuchereria bancrofti
vector-borne by a mosquito bite
W. bancrofti DH (DEFINITIVE HOST)
HUMAN
W. bancrofti IH (INTERMEDIATE HOST)
genus CULEX, Aedes, and Anopheles
B. malayi IH
genus Aedes, Anopheles, MANSONIA
Motility: minute snake-like constantly
moving among the RBCs
* Development: 3-9 months
MICROFILARIAE
Both W. bancrofti and B. malayi are SHEATHED
W. bancrofti or B. malayi MICROFILARIAE
Mean length (um): 270-290 um
Cephalic space: breadth - 1:1
Tail: Single row of nuclei that DOES NOT REACH the tail’s end
TERMINAL NUCLEI: NONE
Sheath in Giemsa: unstained
- Blunt and round anterior end
Appearance in blood film: Smoothly curved
- Nuclei: conspicuous (dark staining nuclei); REGULARLY SPACED, separately situated
Innenkorper length (um): 34
W. bancrofti MICROFILARIAE
W. bancrofti or B. malayi MICROFILARIAE
Mean length (um): 111-222 um
Cephalic space: breadth - 2:1
Tail: Single row of nuclei that REACH the tail’s end
TERMINAL NUCLEI: 2 NUCLEI, which bulge the cuticle, conspicuously placed
Sheath in Giemsa: pink
- Rounded anterior end
Appearance in blood film: Kinky
- Nuclei: indistinct and confluent; IRREGULARLY SPACED, and overlapping
Innenkorper length (um): 30.7
B. malayi MICROFILARIAE
White and threadlike in appearance
Shape: filiform
MALE: 20-40 mm in length
FEMALE: 80-100 mm
ADULT WORMS
W. bancrofti PERIODICITY
- can see in peripheral blood during NIGHTTIME
NOCTURNAL PERIODICITY
“MALAYAN FILARIAL WORM”
Causes MALAYAN FILARIASIS
Brugia malayi
DEFINITIVE HOSTS OF Brugia malayi
HUMANS
PERIODICITY of Brugia malayi:
(microfilaria present in blood at all time
and the max. level is during afternoon)
NOCTURNAL and SUBPERIODIC
Pathogenesis
- lymph nodes of the LOWER extremities
W. bancroft
Pathogenesis
- lymph nodes of the UPPER extremities
B. malayi
Pathogenesis
- millions of vigorously motile microfilariae in the peripheral blood show no obvious signs
o “endemic normals
a. Asymptomatic microfilaremia
b. Acute dermatolymphangioadenitis
c. Acute filarial lymphangitis
d. Lymphedema and elephantiasis
a. Asymptomatic microfilaremia