Communicable Diseases and Disease Surveillance

Filaria

National Filaria Control Programme In India and New Strategies for Its Control

Filariasis Control in India

      Pilot project in Orissa:  The first pilot project for the control of bancroftian filariasis was undertaken in a group of villages in Orissa from 1949 to 1954 through the conventional methods, namely

      mass drug administration with diethylcarbamazine (DEC),

     recurrent antilarval measures, and

      residual insecticidal spray as anti-adult measure.  The pilot study revealed that each of the above methods had its own drawback but a project using al the three methods concurrently was appropriate for the control of filariasis.

      National Filaria Control Programme: The National Filaria Control Programme (NFCP) was launched in 1955 for the control of bancroftian  filariasis with the objectives of undertaking

     delimitation surveys in known endemic areas,

     large scale control measures in selected areas and

     training of personnel required to man the programme.

The control activities included antiparasitic measures by instituting DEC administration to total population at a dose of 4 mg/kg body wt. per day for five consecutive days and antimosquito measures with three rounds of indoor dieldrin spray in rural areas and antilarval measures using mosquito larvicidal oil or BHC in urban areas. The NFCP set-up and population protected are given in Table 3

Table 3- Population protected under NFCP and the set-up as on 01-03-2002

     Assessment of NFCP:  The NFCP was independently assessed four times under the aegis of ICMR between 1960 and 1995 and each committee made the following recommendations:

     First ICMR Assessment Committee (1960): The results of the control measures executed from 1955 to 1960 were assessed by the ICMR Assessment  Committee.  The major recommendations were:

     Reorganisation of control units on the basis of population, instead of uniform 3 lakhs population (2:1 urban and surround rural areas respectively)

     Recurrent Antilarval measures.

Note: Coverage of mass DEC administration was 39.9% (5.62 million persons received DEC for one or more doses out of 14.1million target population) due to non-cooperation from the community to accept DEC on account of side effects (16.5% treated persons experienced side effects) and hence  antiparasitic measures were withdrawn). Similarly, the indoor insecticidal spray was also abandoned due to vector resistance.

     Establishment of new control units

     Prevention of filariogenic conditions in town extensions and new townships

     Adequate provision for disposal of sewage and sullage

     Second ICMR Assessment Committee (1970): It was appointed to assess the  progress made by NFCP till that time.  The salient recommendations were as follows:

     Selective mf carrier therapy as a compliment to antilarval measures

     Delimitation of the problem in unsurveyed districts

     Regionalisation of control measures in contiguous areas

     Third ICMR Assessment Committee (1982): It assessed the programme for the third time and recommended the following:

     NFCP should be made 100% centrally sponsored scheme.

     In order to cover rural population, the NFCP should be integrated with Primary Health Centres.

     The Village Health Guide (VHG) and Multipurpose Workers (MPW) may treat clinical cases of filariasis with DEC. In order to support, guide and monitor the above activities, a post of District Filaria Officer along with supporting staff be created in each endemic district.

     A filaria unit may be established in a town with minimum 20,000 people and 4% mf rate.

     Survey Unit should be engaged for resurvey of each old surveyed district, if routine survey has been completed.

     Pyrethrum extract can also be provided to NFCP towns by the Centre as per Urban Malaria Scheme to stop transmission.

     B.malayi Research Unit under NICD should be made permanent and a project on eradication of Brugia malayi  infection which is feasible may be launched in 1996.

     Medicated salt may be introduced in a phased manner.

     Fourth ICMR Assessment Committee (1995): It made the following recommendations:

     Project on eradication of Brugia malayi infection, which is feasible, may be launched in 1996.

     100% Central Assistance for material and equipment including vehicles be given.

     Integrated vectors control measures be undertaken for all vector borne diseases.

     Model bye-laws for effective control of vectors in domestic situation be adopted.

     Antigen and DNA based detection of microfilaria and operational research may be adopted.

     Fresh delimitation surveys in rural areas may be initiated.

     Community health education through intensified mass media be initiated.

     Training of different categories of workers and trainers training be organised.

     Transfer of programme component of NFCP from NICD to NAMP:  The programme component of NFCP was transferred from NICD to NAMP in June, 1978 while the research and training components were retained in NICD.

     Central Assistance: During Fourth Five Year Plan the NFCP was 100 per cent Centrally sponsored programme. But in Fifth Five Year Plan, only material and equipment were supplied by the Centre from its share and the entire operational cost was borne by the States. However, from 1978 onward the Central assistance was further reduced by sharing the cost of material and equipment on 50:50 basis. Up to Seventh Five Year Plan the NFCP budget was separate and the same was merged with budget of Urban Malaria Scheme during Eighth Five Year Plan continuing the sharing the cost of material and equipment on 50:50 basis. The organophosphorus compounds like temephos and fenthion and drugs are supplied by the Centre while MLO, etc. are procured by the States.

     DEC dosage schedule and larvicides currently in use:  The DEC dosage adopted in   the programme is 6mg/kg body wt. per day for 12 days.  Besides MLO as larvicide, organophosphorus larvicides namely fenthion and temephos have also been in use in the programme since 1975.

     Medicated salt regimens in India: Based on the encouraging results obtained in pilot trials in the Uttar Pradesh and Andhra Pradesh, the distribution of 0.1% DEC medicated salt to general public for one year was implemented in Lakshadweep, comprising a population of 25,000 during 1976-77 which reduced mf rate by 80% and circulating mf by about 90%.  The DEC medicated salt project with 0.2% concentration was concluded at Karaikal, Pondicherry which gave significant reduction in microfilaraemia. DEC pilot project was taken up during 1989 in selected villages of Kalakuchi Health District of Tamil Nadu.  The DEC medicated salt trials conducted in India are given in Table-4.

Table-4 DEC medicated salt trials in India

     B.malayi control: The pilot project under the auspices of NICD in Kerala has revealed that the vectors of B.malayi are amenable to indoor residual spray of HCH at a dose of 0.2 g/m2 per round, three rounds a year.  Integrated vector control approach for control of this infection was being implemented by VCRC Pondicherry in Shertally Taluk of Ernakulum district, Kerala.

     Revised Strategy for the control of Lymphatic Filariasis in India: The following new approaches have been recommended by WHO sponsored workshop held in January, 1996.

     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.

Antivector measures to continue in all the NFCP towns as complimentary to antiparasitic measures and mf carriers detected in filaria clinics and elsewhere to receive the standard dose of 6 mg/kg body wt. per day for 12 days