LYMPHATIC FILARIASIS Community medicine.pptx

filariasis

1. LYMPHATIC FILARIASIS

2. Contents Introduction Problem statement Epidemiological Triad Lifecycle Clinical Manifestations Investigations ELF IVC National Filaria Day & IEC Assessment parameters

3. Introduction Latin origin: Filaria – Fil (um) – Slender or thread like Lymphatic Filariasis is caused by infection with parasites classified as nematodes ( roundworms ) of the family Filarioidea.

4. Lymphatic Filariasis (LF) is one of the oldest and most debilitating neglected tropical diseases (NTDs). Caused by three species of parasitic worms: Wuchereria bancrofti (90%) Brugia malayi (~10%) B. timori Transmitted to humans by mosquitoes.

5. Problem Statement Over 882 million people in 44 countries worldwide remain threatened by lymphatic filariasis and require preventive chemotherapy As of 2018, 51 million people were infected – a 74% decline since the start of WHO’s Global Programme to Eliminate Lymphatic Filariasis in 2000. Of which 65% live in WHO-SEAR, 30% live in WHO-African region

6. EPIDEMIOLOGICAL TRIAD

7. 1. Agent Adult worms lodge in the lymphatic vessels and disrupt the normal function of the lymphatic system. The worms can live for an average of 6–8 years and during their life time, produce millions of microfilariae (immature larvae) that circulate in the blood.

8. Agent Factors S.No Parasite Mosquito Disease 1. W.bancrofti Culex LF 2. B.malayi Mansonia LF 3. B.timori Anopheles/ Mansonia LF 4. O.volvulus Simulium flies River Blindness 5. L.loa Chrysops flies S/c swellings 6. M.perstans Culicoides Serous cavity 7. M. streptocerca Culicoides Serous cavity 8. M.ozzardi Culicoides Serous cavity

9. 2. Host Man – Natural Host Age – All age Sex – Higher in men Migration – leading to extension of infection to non-endemic areas Immunity – may develop after long year of exposure (Basis of immunity-not known)

10. 3. Environment Mosquitoes are infected with microfilariae by ingesting blood when biting an infected host. Major vectors of W. Bancrofti : Culex  mosquito in urban and semi-urban areas,  Rarely in Anopheles mainly found in rural areas, and  Also rarely in Aedes mainly in endemic islands in the Pacific Vector of B. Malayi : Mansonia (mostly) Anopheline (some areas)

11. Associated with Urbanization, Poverty, Industrialization, Illiteracy and Poor sanitation. Climate is an important factor which influences: The breeding of mosquito Longevity (Optimum temperature 20-30 C & Humidity 70%) The development of parasite in the vector Sanitation, Town planning, Sewage & Drainage.

12. Life cycle

13. Clinical Manifestations It is of 2 types: Lymphatic Filariasis (Presence of Adult worms) Occult Filariasis ( Immuno hyper responsiveness)

14. I. Lymphatic Filariasis 4 Clinical stages: Stage 1: Asymptomatic amicrofilariaemic stage Stage 2: Asymptomatic microfilariaemic stage Stage 3: Stage of Acute manifestation Stage 4: Stage of Obstructive (Chronic) lesions

15. A symptomatic a microfilariaemic stage Stage 1: In endemic areas, a proportion of population does not show microfilariae or clinical manifestation. Laboratory diagnostic techniques are not able to determine whether they are infected or free.

16. A symptomatic microfilariaemic stage Stage 2: Certain proportions are clinically asymptomatic (months and years) + circulating microfilariae present. Remain as an important source of infection . Night Blood Survey .

17. Stage of Acute manifestation Stage 3: Recurrent episodes of Acute inflammation in the lymph vessel/node of the limb & scrotum. Clinical manifestations are: Filarial fever (ADL-DLA) Adenolymphangitis-dermatotolymphangitis Lymphangitis Lymphadenitis Epididymo orchitis

18. Acute dermatolymphangioadenitis (ADLA) It's an inflammation of the skin, subcutaneous tissue, lymphatics, and lymph nodes in the affected area.  ADLA attacks are often associated with fever and chills, and usually occur in the limbs or scrotum, along with lymphedema

19. Stage of Obstructive ( Chronic ) lesions Stage 4: It is the permanent damage to the lymph vessels caused by the adult worms. Dilation of the lymph vessels occur due to recurrent inflammatory episodes ---> endothelial proliferation and granuloma formation around the parasite. It takes 10-15 years .

20. Pitting oedema ---> browny oedema ---> hardening of tissues ---> hyperpigmentation, keratosis , wart like lesions. Late stages- Non pitting edema Hydrocoele (40-60%). Elephantiasis of Legs , Scrotum, Arm, penis , Vulva, Breast and Chyluria.

21. Clinical stages of Lymphedema A total of 7 stages are present. Distinguished with presence or absence of: Oedema , Folds, Knobs, Mossy foot, Disability

22. Stage I Swelling reverses at night Skin folds - Absent Appearance of Skin – Smooth & Normal Stage II Swelling not reversible at night Skin folds - Absent Appearance of skin - Smooth, Normal

23. Stage III Swelling not reversible at night Skin folds - shallow Appearance of Skin – Smooth & Normal Stage IV Swelling not reversible at night Skin folds - shallow Appearance of Skin – Knobs & Nodules

24. Stage V Swelling not reversible at night Skin folds - deep Appearance of Skin – Smooth & Irregular Stage VI Swelling not reversible at night Skin folds – shallow or deep or irregular Appearance of Skin – Wart like like lesions on toe and foot

25. Stage VII Swelling not reversible at night Skin folds – shallow or deep or irregular Appearance of Skin – Irregular Needs help for daily activities - Walking, bathing, using bathrooms - Dependent on family or health care systems

26. Brugian filariasis : Rarely involves genitalia Differential diagnosis: Obstructions following Tumors Tuberculosis Surgery Irradiation Ethiopia: Endemic leg Elephantiasis is caused by silica deposition in iliac lymph nodes

27. II. Occult Filariasis Classical clinical manifestation will be absent . Hyper-responsiveness to filarial antigens derived from mf. Males > Females

28. Patients present with Paroxysmal cough Wheezing Low grade fever Scanty sputum with occasional haemoptysis Adenopathy Eosinophilia (high-grade) X-ray shows diffused nodular mottling and interstitial thickening.

29. Investigations Epidemiological screening: 20 cmm finger prick blood, dried flat on a slide, stained and examined for mf Xenomonitoring : (L3 larvae) Vector mosquitoes are collected and examined for the presence of parasite (dissection) or parasite material (Polymerase Chain Reaction) using molecular technique. Presence of infective stage larva of LF is considered as an indication of current risk of transmission and presence of microfilaria carriers in the community as well.

30. Management Treating the infection Treatment and prevention of Acute ADL A attacks Treatment and prevention of Lymphoedema

31. Chemotherapy Drugs effective against filariasis: Diethyl Car bamazine citrate (DEC) Ivermectin Albendazole

32. DEC Effective Microfilaricidal Effective against adult worms in 50% of patients Dose: 6mg/kg for 12 days Recent dosage: 6mg/kg single dose Adverse reactions are mostly due to the rapid destruction of mf which is characterized by fever, nausea, myalgia , sore throat, cough, headache. No effect : Treating ADLA

33. Ivermectin Effective microfilaricidal Dose: 150-200 µg/kg No action on adult worms Drug of choice in Co-endemic areas of Onchocerciasis with LF Adverse reactions are lesser but similar to that of DEC Mf reappears faster than DEC

34. Albendazole It is antihelmenthic and kills adult worms No action on microfilariae Dose: 400mg BD for 14 days With combination of DEC & Ivermectin , it enhances the action of the drugs. It induces severe adverse reactions in hydrocele cases due to the death of adult worms.

35. DEC fortified salt DEC medicated salt is also a form of Mass treatment using low dose of drug over a long period of time (1-2 gm /Kg of Salt).

36. Lymphedema Management Early detection of lymphoedema Skin care Washing and drying Preventing and treating entry lesions Providing lymph drainage by elevation and exercises Wearing proper foot-wear

37. Management of uncomplicated ADLA Analgesic: Tab Paracetamol 1g, TDS Antibiotic: Tab Amoxicillin 500 mg, TDS * 8days Clean the limb with antiseptic Check for wounds, cuts, abscess, interdigital infection and give appropriate antibiotic or antifungal No antifilarial medicine Follow-up after 2 days

38. Entry lesions & Ulcers

39. Management of severe ADLA Secondary to infections Inj Benzyl Penicillin i.v 3 million units 3 times a day or Inj Procaine Penicillin i.m 5 million units 2 times a day till fever subsides. Followed by, oral phenoxymethylpenicillin 750 mg – 1 g given 3 times a day. If penicillin allergy, give Inj Erythromycin iv 1 g 3 times a day until fever subsides followed by oral Erythromycin 1 g 3 times a day. Analgesic/ Antipyretic No anti-filarial medicine

40. Surgical Management Hydrocele : Excision Scrotal Flip: Surgical removal of Skin & Tissue, preserving penis and testicles. Lymphoedema (Elephantiasis): Excision of redundant tissue, Excision of subcutaneous and fatty tissues Postural drainage and physiotherapy

41. Control of LF NFCP launched in 1955 Strategies: Vector control Detection and treatment of filarial cases Delimitation of endemic areas. Control units, Night clinics and Survey teams

42. Global Programme to ELF

43. NHP 2002 Goal: To eliminate lymphatic filariasis (ELF) from India by the year 2015 Objectives: ( i ) To reduce and eliminate transmission of LF by Mass Drug Administration of anti-filarial drugs (DEC or DEC + Albendazole ) (ii) To reduce and prevent morbidity in affected persons

44. ELF LF ceases to be a public health problem, when The number of microfilaria carriers is less than one per cent and The children born after initiation of ELF are free from circulating antigenaemia . Absence of antigenaemia among children is considered as evidence for absence of transmission and new infection.

45. STRATEGY: Transmission control (prevent the occurrence of new infection and disease) by administration of annual single dose of anti-filarial drug i.e. DEC and/or coadministration of DEC+ Albendazole . Disability Prevention and Management – for those individuals who already have the disease Home based: Limb hygiene for lymphoedema Hospital based: Surgical Correction

46. Mass Drug Administration To approach every individual in the target community and administer annual single dose of anti-filarial drugs (DEC or DEC + Albendazole ). This annual dose is to be repeated every year for a period of 5 years or more aiming at minimum 85 % actual drug compliance.

47. “supervised drug administration by door to door visit supplemented with drug administration at booths and groups” Over 85% coverage of the population for at least 5 years could effectively interrupt transmission.

48. Effect OF MDA

49. Integrated Vector Control Vector control involves Anti larval measures Anti adult measures Personal prophylaxis An integrated method using all the vector control measures alone will bring about sustained vector control

50. I. Anti larval measures: 1. Chemical control Mosquito larvicidal oil Pyrosene oil Organo phosphorous compounds such as Temephos , Fenthion , 2. Removal of pistia plants 3. Minor environmental measures

51. II. Anti adult measures: Anti adult measures as indoor residual spray using DDT, HCH and Dieldrin. Pyrethrum as a space spray is also followed. III. Personal Prophylaxis: Reduction of man mosquito contact by using mosquito nets, screening of houses, etc.

52. National Filaria Day November 11 Mass Drug Administration is to be observed on a single day as National Filaria Day. Besides free drug distribution, there are additional inputs in the form of IEC, expenses, training, monitoring and evaluation of the project.

53. IEC

54. Assessment of Filaria control programmes FILARIAL INDICES Clinical Parameters Parasitological Parameters Entomological Parameters

55. 1. Clinical Parameters Incidence of acute manifestations Adeno-lymphangitis Epididymo-orchitis , etc Prevalence of chronic manifestations Lymphedema Elephantiasis Hydrocele Chyluria , etc

56. 2. Parasitological Parameters Microfilaria rate: Percentage of persons examined in the sample population showing Mf in their peripheral blood Filarial endemicity rate: Percentage of persons examined in the sample population showing Mf in the blood or disease manifestation or both

57. Microfilarial Density: It is the number of Mf per unit volume of blood in samples from individual persons ---> Intensity of infection Average Infestation Rate: It is the average number of Mf per positive slide ---> Prevalence of microfilaraemia

58. 3. Entomological parameters Vector density per 10 man-hour catch Percentage of mosquitoes positive for all stages of development Percentage of mosquitoes positive of infective larvae L3 (Mosquito infection rate) Annual biting rate- assessment of transmission

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