Page 110 - Medical Parasitology_ A Textbook ( PDFDrive )

Filarial Worms Causing Lymphatic Filariasis 103

such as Knott’s concentration technique and nucleopore filtration can be used.
DEC provocation test is useful to bring out the microfilariae into peripheral cir-
culation for blood collection during day time.
2. Serodiagnosis
Immunochromatographic test (ICT). Blood samples can be collected at any
time of the day.
3. Molecular diagnosis
PCR on clinical samples.

Treatment
Diethylcarbamazine (DEC) (6 mg/kg/day orally either 1 day or 12 days. One day treat-
ment is generally as effective as the 12-day regimen) is the drug of choice. Ivermectin
(400 μg/kg single dose orally) can also be used. Tetracyclines have an effect in the
treatment of filariasis by inhibiting endosymbiotic bacteria (Wolbachia species).
In elephantiasis, it requires elevation of the affected limb, use of elastic bandage
and foot care to reduce symptoms. Surgery is required for hydrocele. Medical man-
agement of chyluria includes bed rest, high protein diet and treatment with DEC.

Prevention and Control
1. Control of the vector mosquito (anti-larval, anti-adult)
2. Using mosquito net and mosquito repellants
3. Detection and treatment of cases

Brugia malayi

Distribution
Brugia malayi occurs in India, Indonesia, Philippines, Malaysia, Thailand, Vietnam,
China, South Korea and Japan. Besides B. malayi, another species of this genus
includes Brugia timori which is found in Timor, Indonesia.

Habitat
The adult worms reside in the lymphatic system of human. The microfilariae are
found in blood.

Morphology
The adult worms of B. malayi are generally similar to those of W. bancrofti though
smaller in size.
The microfilaria of B. malayi is sheathed and it is stained with Giemsa. It is
kinky, cephalic space is longer (ratio is 2:1), overlapping body nucleus with 2 termi-
nal nuclei (terminal and subterminal) (Fig. 10.16).

Life Cycle
The life cycle of B. malayi is similar to that of W. bancrofti. However, the intermedi-
ate host of Brugia are vectors of genera Mansonia, Anopheles and Aedes.
Pathogenesis, clinical features, laboratory diagnosis and treatment are similar to W.
bancrofti.