2. • Lymphatic filariasis :infection with 3
nematode worm.
• W.bancrofti
• B.malayi
• B.timori
• Manifestation :acute and chronic.
• Lymphigitis,lymphadenitis,elephantiasis of
legs and arms, and tropical eosinophilia
3. • Endemic in 83 countries
• 1.2 billion at risk
• More than 120 million people infected
• More than 25 million men suffer from
genital symptoms
• More than 15 million people suffer from
lymphoedema or elephantiasis of the leg
4.
5. Agent factors
• Humans are the definitive host for the worms tha
• There are no known reservoirs for W.bancrofti.
• B.malayi has been found in monkeys, & cats.
• PERIODICITY :nocturnal periodicity.
6. Definitive Host
• Humans are the definitive host for the worms
that cause lymphatic filariasis
• There are no known reservoirs for W.bancrofti.
• B.malayi has been found in macaques, leaf
monkeys, and cats
7. • Intermediate Host
• W.bancrofti is transmitted by Culex .
• B.malayi and B.Timori is transmitted by Anopheles
and Mansonia species.
8. • W.bancrofti is a sexually dimorphic species.
• The adult male worm is long and slender,
between four and five centimeters in length, a
tenth of a centimeter in diameter, and has a
curved tail.
• The female is six to ten centimeters long, and
three times larger in diameter than the male.
• Microfilariae are sheathed, and approximately
245 to 300 µm in length.
11. • Man is natural host.
• All age are suseptible to infection.
• Filerial disease appears in a small percentage of
infected individuals.
• Mf is higher in men.
• Migration of people helps in spread of disease in
non endemic area.
• Man develop immunity after yrs of infection.
• Lymphatic fileriasis is associated with
urbanization, industrialisation ,poverty and poor
sanitation.
12. Enviromental factors
• 22-38 degreecent and relative humidity of
70% is favorable.
• Lymphatic fileriasis is associated with bad
drainage. vector breed profusely in
polluted water.
13. Vectors of lymphatic filariasis
• W.bancrofti, B.malayi and B.timori transmitted by
the bites of infective mosquito..
• Pre patent period: interval between inoculation
of infective larvae and the first appearance of
detectable mf .
• Clinical in cubation period :time interval from
invasion of infective larvae to the development
of clinical manifestation
• 8-16 mnths.
14. Clinical manifestations
• Asymptomatic amicrofilaraemia :exposed
people in endemic area do not show Mf or
clinical manifestation of disease.
• Asymptomatic microfilaraemia: blood is
positive for Mf, but no symptoms.
• carriers.
• Stage of acute manifestation: recurrent
episode of acute inflammation in lymph
gland and vessels.
• Filerial fever, lymphangitis, lymphadenitis,
lymphoedema and epididymoorchitis..
15. • Stage of chronic obstructive lesion:
develops 10- 15 yrs acute attack.
• Due to fibrosis and obstruction of
lymphatic vessel, causing permanent
structural change.
• Hydrocele, elephantiasis and chyluria.
18. Management of Acute
dermatolymphangioadinitis(ADLA)
• Analgesics.
• Antibiotic ,since majority of acute episodes
appears to be of bacterial etiology.
• local hygiene measures with or without
local antibiotic and antifungal agents to be
promoted to prevent ADL so as to permit
the reversal of lymph edema.
19. • home management includes drinking
plenty of water,rest,elevation of
limb,cooling the limb with cool water.
• Hydrocele Management :diagnosis and
surgery.
H
20. Filaria survey
• Mass blood survey :
• Thick film 20cc blood at midnight
Thick smear prepared
Dehaemoglobinised and stained
21. • Membrane filtration test:low density
microfileraemia.
• DEC provocation test
• Clinical survey.
• Xenodiagnosis
• Entomological survey
22. Control measure
• Chemotherapy :Diethylcarbamazine
• Vector control.
• Chemotherapy :DEC -6g/kg body wt per
day orally for 12 days.
• Effective in killing Mf.
• No effect in on adult worm and infective
larvae.
23. National Filaria Control Programme
launched in 1955 for the control of
bancroftian filariasis with the objectives of
undertaking
surveys in known endemic areas,
large scale control measures in selected
areas and
training of personnel required to man the
programme
24. • Antivector measures to continue in all the
NFCP towns as complimentary to
antiparasitic measures
• mf carriers detected in filaria clinics and
elsewhere to receive the standard dose of
6 mg/kg body wt. per day for 12 days
25. • mass drug administration with
diethylcarbamazine (DEC),
• The DEC dosage adopted in the
programme is 6mg/kg body wt. per day for
12 days
• DEC medicated salt project with 0.2%
concentration was concluded at Karaikal,
Pondicherry which gave significant
reduction in microfilaraemia
26. Vector control
• ANTI LARVAL MEASURE: ellimination of
breeding place
• Chemical control: larvicidal oil,pyrosene
oil,organophosporous larvicide.
• REMOVAL OF PISTIA PLANT.
• ENVIROMENTAL MEASURES.
• ANTI ADULT MEASURES:DDT,HCH
• PERSONAL PROPHYLAXIS.
27. Revised Strategy for the control
of Lymphatic Filariasis in India:
• Single day mass therapy at a dose of 6
mg/kg body wt. annually.
• Management of acute and chronic
filariasis through referral services at
selective centres.
• IEC for inculcating
individual/community based protective and
preventive measures for filaria control
28. ASSESSMENT OF FILARIA
CONTROL PROGRAMME
• CLINICAL PARAMETERS :incidence of acute
manifestations and prevalence of chronic
manifestation.
• PARASITOLOGICAL PARAMETERS :
• Microfilerae rates.
• Microfilerae density
• Average infestation rate
• ENTOMOLOGICAL PARAMETERS :vector
density,annual biting rate,larval breeding places.
