Epidemiology of Filariasis

1. Epidemiology of Filariasis

2. Epidemiology of Filariasis • Magnitude of the problem • Life cycle: Agent & Vector • Clinical features • Diagnosis • Treatment

3. introduction • Caused by the nematode worm either Wuchereriabancrofti or Brugiamalayi • Transmission: Culexquinquefasciatus & Mansoniaannulifera/uniformis • Lymphatic system is affected • The disease manifests often in bizarre swelling of legs and hydrocele • A great deal of social stigma

4. introduction • A major public health problem in India • Recorded in “Susruta Samhita” • Clarke called elephantoid legs in Cochin as Malabar legs

5. filariasis • Lymphatic filariasis • Wuchereriabancrofti, • Brugiamalayi • Brugiatimori • Lymphatic filariasis • O. Volvulus • M.Ozzardi etc

6. Magnitude of the problem: global • A major cause of clinical suffering, disability and handicap • Approximately 18% of the world's population — live in areas at risk of infection with lymphatic filarial parasites • Approximately one third of those at risk live in India, one third in Africa

7. Magnitude of the problem: global

8. Magnitude of the problem in India

11. Total DALYs lost

12. Socio - economic burden • Second leading cause of disability in the world. • Causes stigma, isolation, psychological stress and family discord among the affected individuals • Impairs educational and employment opportunities • Impedes domestic and occupational activities

13. Socio-economic burden • A male chronic patient on average losses as many as 69 working days/annum • The treatment costs incurred by patients range from RS 1 to 1000 per episode an • India loses also 1.2 billion man days due to LF

14. Epidemiology of Filariasis • Magnitude of the problem • Life cycle: Agent & Vector • Clinical features • Diagnosis • Treatment

16. Life cycle of Culex Mosquito

17. About the vectors • W. bancrofti : Culex mosquitoes in most urban and semi-urban areas • Anopheles in the more rural areas of Africa and • Aedes species in many of the endemic Pacific islands.

18. The vector • Brugian parasites : Mansonia species serve as the major vector • Brugian parasites are confined to areas of east and south Asia, especially China, India, Indonesia, Malaysia and the Philippines.

19. Epidemiology of Filariasis • Magnitude of the problem • Life cycle: Agent & Vector • Clinical features • Diagnosis • Treatment

20. Clinical features • Asymptomatic microfilarimia • Acute manifestations • Chronic obstructive lesions • Occult filariasis: Tropical Pulmonary eosinophilia

21. lymphoedema grading • Grade I : Mostly pitting oedema; spontaneously reversible on elevation. • Grade II: Mostly non-pitting oedema; not spontaneously reversible on elevation. • Grade III (elephantiasis): Gross increase in volume in a Grade II lymphoedema, with dermatosclerosis and papillomatous lesions.

22. elephantiasis

24. hydrocele

25. Bancroftian filariasis • Lymphatic vessels of the male genitalia are most commonly affected • Episodic funiculitis (inflammation of the spermatic cord) epididymitis and orchitis • Hydrocele is the most common sign of chronic bancroftianfilariasis, followed by lymphoedema & elephantiasis

26. Brugian filariasis • Lymphadenitis: one inguinal lymph node at a time • Lymphangitis • The infected lymph node may become an abscess, ulcerate, and heal with  fibrotic scarring • Characteristically, elephantiasis involves the leg below the knee but occasionally it affects the arm below the elbow

27. Epidemiology of Filariasis • Magnitude of the problem • Life cycle: Agent & Vector • Clinical features • Diagnosis • Treatment

28. Laboratory Diagnosis • Examining night blood collected by finger pricking • Og4C3  ELISA   Assay • ICT Card Test • Polycarbonate membrane filtration Test • Other tests • Serological techniques Indirect immuno fluorescent assay with mf and adult worm. • DNA based diagnostic tests

29. Wucheraria bancrofti

30. Epidemiology of Filariasis • Magnitude of the problem • Life cycle: Agent & Vector • Clinical features • Diagnosis • Treatment

31. Case treatment • Diethylcarbamazine (DEC): 6 mg/kg • For 12 days over 2 weeks • Toxic reactions • Ivermectin : 400 micro gm/kg single dose

32. lymphoedema management • Washing • Prevention and cure of entry lesions • Elevation of the foot • Exercise • Wearing proper footwear • Hydrocelectomy

33. Washing

34. Prevention and cure of entry lesions

35. Exercises

36. Mass Drug Regimen • 6 mg/kg diethylcarbamazine citrate (DEC) + 400 mg albendazole • 150 µg/kg ivermectin + 400 mg albendazole (in the case of co-endemicity with onchocerciasis) • A third option is to follow a treatment regimen using DEC-fortified cooking salt daily for a period of 12 months

37. questions • Clinical Spectrum of Filariasis • Treatment of Lymphatic Filariasis and Mass treatment regimen.

38. Next class • Filaria survey • Prevention & control strategies

39. Thank you!