**2. Search methods**

We have searched MEDLINE (PubMed) and CAB Abstracts, checked the reference lists of all studies identified by the search, also performed Google Search on specific topics and examined references listed in review articles and previously compiled bibliographies.

## **3. Genesis and evolution of the elimination of lymphatic filariasis**

LF is responsible for deformities and disfigures of potential organs caused by this disease which make social stigma leading to hardship on normal life. Many marriageable persons undergo physical and psychological distress throughout their lives. LF is one of the six infectious diseases identified by the International Task Force for Disease Eradication of the WHO as 'eradicable' or 'potentially eradicable' in 1993 [6]. In 1997, the World Health Assembly resolved to eliminate LF as a public health problem globally [7]. In 2000, the WHO launched Global Programme to Eliminate Lymphatic Filariasis (GPELF). Following the London declaration on neglected tropical diseases (NTDs) in 2012, and consequent on several recent advances on the new knowledge of the pathogenesis, the biology of the parasite, development of better diagnostic tools and treatment strategies of LF, GPELF has an aim to eliminate this disease globally by 2020. India, a signatory to the World Health Assembly resolution, had initially set the target for elimination of filariasis by the year 2015 [4] but later aligned with global target of 2020 which is again to be reset. This programme is based on two components consisting of (i) interruption of transmission to prevent the disease by mass drug administration (MDA) and (ii) alleviation of the morbidity (lymphedema and hydrocele) associated with the disease [8]. Of the two strategies, preventive chemotherapy delivered through MDA has gained prominence as interruption of transmission after the implementation of the GPELF.

#### **4. Mass drug administration: scientific background**

Before the concept of MDA, the main strategy of LF management was selective treatment by identifying Mf carriers microscopically and/or clinically manifested cases and their treatment with diethylcarbamazine (DEC) for 12 days for individual cure. This strategy was focused on individual level where the people with

**325**

*A New Outlook in Lymphatic Filariasis Elimination in India*

low parasitaemia and asymptomatic were left and therefore infection persisted in the community. In the subsequent years, there were significant improvements of LF diagnosis and treatment. Combination of double to triple drugs in single doses has been found to be efficacious than monotherapy. Albendazole (ALB) and more recent ivermectin (IVM) have been added to DEC. Now DEC + ALB is used in the MDA programme, and additionally IVM has been advocated for treating the entire

Human pharmacokinetic studies on the two regimens of single-dose drugs have shown that all the three drugs when administered singly or as a partner were well tolerated and safe in both microfilaraemic and non-microfilaraemic cases. Efficacy studies of repeated annual MDAs on different combination drugs of ALB + DEC, ALB + IVM and DEC + IVM indicated significant reductions on Mf rate for long periods [9]. Microsimulation models based on drug coverage, its efficacy and endemicity level of LF have indicated the effectiveness of MDA on ELF. This enabled to assess the number of MDA rounds necessary to achieve

LF is considered one of the NTDs that cause huge deformities and disabilities on the society. India contributes the major burden globally. The initial effort was to establish the concept of controlling the disease. In the concept of its elimination on the line of global initiative, India has made significant progress. In India, LF is caused by two roundworm nematode parasites *W. bancrofti* and *B. malayi* and is transmitted by the mosquito vectors *Culex quinquefasciatus*, *Mansonia annulifera* and *M. uniformis. B. malayi* which contributes to a negligible proportion is present in Kerala, Andhra Pradesh, Odisha, Madhya Pradesh, Assam and West Bengal. In general, Bihar state has the highest endemicity while Goa the lowest [12]. Here a

After the pilot project in Orissa from 1949 to 1954 and based on its assessment, In India, the National Filaria Control Programme (NFCP) was launched in 1955. The main objective was to control the problem, have effective planning for control measures in endemic areas and also to train health personnel to strengthen the programme. The immediate control measures were mass drug administration of DEC, antilarval measures in urban areas and indoor residual spray in the rural areas. The programme was assessed four times by the assessment committees in 1961, 1971, 1982 and 1995, respectively. In 1961, the assessment revealed the failure of mass DEC administration due to community reluctance and ineffectiveness of insecticidal indoor spray due to the high resistance in the vector, and therefore as per recommendation of assessment committee, recurrent antilarval measures, establishment of new control units in endemic urban areas and provision of disposal of sewage and sullage were instituted. In 1971, the assessment committee recommended the detection and treatment of Mf cases with DEC at a dose of 6 mg/kg per day for 12 days and antilarval measures. Again in 1982, the assessment committee recommended extension of NFCP to rural areas through primary health-care system with 100% central assistance [5]. The fourth assessment in 1995 recommended to launch a project on the eradication of *B. malayi*, integrated vector control for all vector borne diseases, adoption of model bye-laws for effective control of vectors in

*DOI: http://dx.doi.org/10.5772/intechopen.92454*

**5. Filariasis control initiatives in India**

detailed recent account has been enumerated.

domestic situation and fresh delimitation survey in rural areas.

**5.1 National filaria control programme**

population at high risk [5].

elimination [10, 11].

*A New Outlook in Lymphatic Filariasis Elimination in India DOI: http://dx.doi.org/10.5772/intechopen.92454*

*Parasitology and Microbiology Research*

LF infection in the world [4].

in human blood [5].

**2. Search methods**

compiled bibliographies.

Bangladesh (all Asian countries) and Nigeria (Africa) contribute about 70% of the

LF is distributed in economically challenged countries. *W. bancrofti* is the most predominant species of human filariasis. It was recognized primarily as an urban disease which does not have animal reservoirs. Later it is reported from rural areas also. The parasites develop only in humans and in mosquitoes. But the adult worms may survive for 8–10 years and produce huge numbers of Mf from time to time.

We have searched MEDLINE (PubMed) and CAB Abstracts, checked the reference lists of all studies identified by the search, also performed Google Search on specific topics and examined references listed in review articles and previously

**3. Genesis and evolution of the elimination of lymphatic filariasis**

as interruption of transmission after the implementation of the GPELF.

Before the concept of MDA, the main strategy of LF management was selective treatment by identifying Mf carriers microscopically and/or clinically manifested cases and their treatment with diethylcarbamazine (DEC) for 12 days for individual cure. This strategy was focused on individual level where the people with

**4. Mass drug administration: scientific background**

disease which make social stigma leading to hardship on normal life. Many marriageable persons undergo physical and psychological distress throughout their lives. LF is one of the six infectious diseases identified by the International Task Force for Disease Eradication of the WHO as 'eradicable' or 'potentially eradicable' in 1993 [6]. In 1997, the World Health Assembly resolved to eliminate LF as a public health problem globally [7]. In 2000, the WHO launched Global Programme to Eliminate Lymphatic Filariasis (GPELF). Following the London declaration on neglected tropical diseases (NTDs) in 2012, and consequent on several recent advances on the new knowledge of the pathogenesis, the biology of the parasite, development of better diagnostic tools and treatment strategies of LF, GPELF has an aim to eliminate this disease globally by 2020. India, a signatory to the World Health Assembly resolution, had initially set the target for elimination of filariasis by the year 2015 [4] but later aligned with global target of 2020 which is again to be reset. This programme is based on two components consisting of (i) interruption of transmission to prevent the disease by mass drug administration (MDA) and (ii) alleviation of the morbidity (lymphedema and hydrocele) associated with the disease [8]. Of the two strategies, preventive chemotherapy delivered through MDA has gained prominence

LF is responsible for deformities and disfigures of potential organs caused by this

This is actually the real challenge in containing the disease.

In the sixth century BC in his book, *Susruta Samhita*, Susruta mentioned this disease. In the seventh century AD in his memoir, *Madhava Nidhana*, Madhavarakara first described the signs and symptoms of this disease. In 1709, Clarke described 'Malabar legs' from Cochin which is synonymous with elephantiasis. In 1872 in Calcutta (now Kolkata), Lewis first described the microfilariae (Mf)

**324**

low parasitaemia and asymptomatic were left and therefore infection persisted in the community. In the subsequent years, there were significant improvements of LF diagnosis and treatment. Combination of double to triple drugs in single doses has been found to be efficacious than monotherapy. Albendazole (ALB) and more recent ivermectin (IVM) have been added to DEC. Now DEC + ALB is used in the MDA programme, and additionally IVM has been advocated for treating the entire population at high risk [5].

Human pharmacokinetic studies on the two regimens of single-dose drugs have shown that all the three drugs when administered singly or as a partner were well tolerated and safe in both microfilaraemic and non-microfilaraemic cases. Efficacy studies of repeated annual MDAs on different combination drugs of ALB + DEC, ALB + IVM and DEC + IVM indicated significant reductions on Mf rate for long periods [9]. Microsimulation models based on drug coverage, its efficacy and endemicity level of LF have indicated the effectiveness of MDA on ELF. This enabled to assess the number of MDA rounds necessary to achieve elimination [10, 11].
