Impact of Mass Drug Administration on Elimination of Lymphatic Filariasis in Surat city, India

J. Commun. Dis. 44(4) 2012 : 251-259 Impact of Mass Drug Administration on Elimination of Lymphatic Filariasis in Surat city, India Vaishnav KG*, Desai HS*, Srivastava PK**, Joshi PT***, Kurian G***, Thakor HG** and Dhariwal AC** (Received for publication March 2011) Abstract Lymphatic filariasis (LF) is one of the major public health problems in some of the endemic districts in India including Surat city of Gujarat province. Historical data reveals that in 1960s, Surat city had infection rate of about 23% and infectivity rate of 1.6%. Since then, Surat city has been reporting the cases of Lymphoedema and hydrocele. Filaria Control Unit was established under National Filaria Control Programme to detect and provide treatment to the cases. Based on the reports of NFCP, Surat City has been considered as LF endemic. During 2004, the country launched campaign of Elimination of Lymphatic Filariasis through Mass Drug Administration (MDA) with annual single dose of 6mg/kg body weight of DEC tablets in all LF endemic districts including Surat city. Four rounds of MDA (2004-2007) had shown 41% reduction in mf rate, with drastic reduction in infection rate of 88% and 100% in infectivity th rate. Serious adverse effect (SAE) after 4 round of MDA was insignificant (<0.5%) during 2007. An assessment by surveying 5058 people in different parts of Surat city revealed the drug distribution coverage of more than 95% but actual drug compliance between 70-90%. Analysis of the data revealed that though the overall Microfilaria rate has been reduced due to MDA, higher Microfilaria rate was noticed in North zone of city where the migrant populations influx is higher. The observation and analysis of the data in Surat city towards elimination of Lymphatic filariasis has been discussed in this paper. * Surat Municipal Corporation, Surat, Gujarat ** Dte of National Vector Borne Disease Control Programme, Delhi-54. *** Dte of Health Service, Govt of Gujarat. Correspondence to: Dr. K. G. Vaishnav, Insecticide Officer, V.B.D.C. Department, Surat Municipal Corporation, Surat, Gujarat. E-mail: kgvaishnav@hotmail.com

252 Vaishnav KG et al INTRODUCTION Lymphatic filariasis (LF) is one of the public health problems in the world. It has been identified as one of the diseases to be eliminated globally and the target set for it is 1 to achieve elimination globally by 2020. In India, the National Health Policy -2002 has set the target of elimination of Lymphatic 2 filariasis by 2015. The Elimination is defined as Lymphatic Filariasis cases is to be a public health problem, when the number of microfilaria carriers is less than 1% and the children born after initiation of ELF are free from circulating antigenaemia (presence of 3 adult filaria worm in human body). In India, there are 250 Lymphatic filariasis endemic districts which are being covered under MDA and one of these is Surat city. Mass Drug Administration with single dose of Diethyl-carbamazine Citrate (DEC) is administered to the entire population of Surat city since 2004 excluding children below 2 year, pregnant women and seriously ill s. Various activities such as sensitization, training of medical, paramedicals and other stakeholders involved, microfilaria survey (during night time), supply of drugs to the periphery etc. are required to be completed prior to MDA programme. Massive IEC activities are carried out to sensitize the community, the health and non health workers involved in drug distribution during Mass Drug Administration. In spite of all the detailed microplanning, there are always gaps between the drug distribution and actual drug compliance mainly due to no signs and symptoms in apparently healthy looking s in most of the cases at early stages of infection and fear of side reactions. Non-compliance in drug consumption, delays in achieving the desired level of reduction in microfilaria rate for ultimate interruption of transmission. The study of these reasons in local situations and status of programme implementation is important (i) to identify weaknesses in programme implementation, (ii) to take corrective actions required to fill up the gaps (iii) to know the impact of MDA on the Mf rate and (iv) to facilitate in revising future policies based on the experience. MATERIALS AND METHODS Study design and sample size : The study was carried out in Surat City during December-2007. The urban area of Surat City is 326 sq. km with a population of about 4.5 million (2007 mid year population). Surat city is divided in to 7 zones viz. central, west, south-east, south-west, north and east. Two Urban Health Centres (UHCs) in each zone of Surat city were selected for assessment of coverage and compliance. For assessment 28 clusters in 14 UHCs in various zones were selected on the basis of highest and lowest coverage. Assessment was carried out in 30 houses in each cluster. Preliminary Filaria Surveys : The preliminary Filaria surveys were conducted during October-2007 to collect the baseline epidemiological data for later assessment of MDA. These surveys were confined to special study in routine sentinel and random spot-check areas, and covered 4.5 % of the total population (0.20/4.5million) of the Surat city. In each municipal zone, three areas were selected as routine sentinel sites (which are permanent for five years) and three random spot-check sites (which is changed every year) were selected for night

Impact of Mass Drug Administration on Elimination of Lymphatic Filariasis in Surat city, India 253 blood survey. The special survey was carried out by 300 night blood survey team (each team two health worker) after sufficient motivation and health education done by the survey team. During day time, house to house survey was done in selected sites, to search for filaria cases, like lymphadenitis, lymphangitis and chronic manifestation etc. The details including the length of stay at the present area, history of fever etc. were also recorded in the prescribed format. The residents were informed that blood samples will be collected at night. Blood smears were taken from all the members of the selected households during 9:00 p.m. to midnight and each team targeted about 75 NBS. Approximately 20 cmm blood was collected by hanging drop method in the centre of the slide and spread into oblong thick smear (3cm*2cm). The smear were dried first and numbered before transferring into slide box. The mosquitoes (Culex quinquefasciatus) were also collected and dissected to assess the infection and infectivity rate in the study area. 3460 parous C. quinquefasciatus species were dissected and analysis of entomological data was done to compare it with past data. The family members in study area were enquired through a questionnaire extracting the information on MDA compliance. Later the assessment was conducted from th th 17 to 27 December, 2007 in 7 zones of Surat city covering a total of 5058 members in 840 families. In each zone four clusters were selected and 120 families were selected for MDA assessment. Entomological analyses were also done and it was correlated with the presence of the disease. RESULTS The assessment of coverage and compliance in two Urban Health Centres (UHCs) in each zone of Surat city are indicated in Table 1. The data indicated that as per the reports submitted by the drug distributors, the coverage was between 91-100% and in some areas the per cent coverage has exceeded 100% which is mainly due to more population encountered at the time of MDA due to aggregation of labourers. However, according to the survey, the drug compliance was lower than the reported ones in all the UHC areas and was ranging from 69% (in Pune Urban Health Centre) to 97.78 % (in Fulpada Center). Certain people (2.0%) has not swallowed in presence of Drug Distributors as the medicines were handed over to family and 10.4% people either refused or were not present at the time of visit. These are usual phenomena during MDA, which have resulted in gap between the coverage of drug distribution and drug compliance. The center-wise analysis was done to assess the drug compliance. A total of 5058 members were interviewed and it was revealed that this population was comprising migrant, mix and indigenous population. The zone-wise breakup of the population as well as their compliance to drug administration during the MDA is given in Table 2. The total compliance was 87.6%, however, it was ranging from 83% to 93.8% in different zones. There was no marked difference in acceptance among the three groups of surveyed population. The data of last four years (2004 to 2007) on mf carriers, mf count and s with manifestations are indicated in Table-3. The mf carrier and mf count have declined after 4 rounds of MDA. Most of the MF carriers

254 Vaishnav KG et al Table 1 : Urban Health Centre (UHC) wise reported and assessed coverage Area/UHC Total Eligible No. of people % people % people Population population received received actually drug drug as per consumed records based on survey Variyali Bazar 12240 10404 10686 102.71 86.75 D.K. M. UHC 38250 32513 32108 98.76 93.38 Rander UHC 183600 156060 151246 96.92 90.24 Adajan UHC 253059 215100 197600 91.86 90.43 Udhna-UHC 183600 156060 184918 118.49 87.83 Pandesara 725957 617063 602170 97.59 75.92 Limbayat 237937 202246 205536 101.63 90.17 Navagam 119750 101788 102340 100.54 83.57 Althan UHC 132400 112540 110036 97.78 97.15 Panas UHC 246639 209643 212773 101.49 90.69 Singanpor 142700 121295 111036 91.54 83.47 Amroli UHC 150042 127536 128724 100.93 85.54 Fulpada UHC 129870 110390 109718 99.39 97.78 Puna UHC 348840 296514 318251 107.33 69.49 Note : The coverage of more than 100% is indicated because more than the assessed eligible population were found during MDA due to frequent migration. If it is added in targeted eligible population, it equals to 100% coverage. (Male+ female) have been found in age group of 15-39 (84.06% in 2004, 84.02% in 2005, 82.18% in 2006, 88.15% in 2007). No serious Adverse event (SAE) during mass drug administration (MDA) was recorded, however, some experiences viz., headache and nausea (less than 0.5%) were reported in 2007, which, however, subsided after 4-6 hours without treatment. It is worth mentioning that during MDA trial in fifties, a large number of unpleasant reactions were 4 recorded. The zone wise analysis for impact on microfilaria rate indicated (Figure 1 and 2) that in North zone, there was an increase noted in the mf rate, On further analysis, it was revealed that this is mainly because of influx of the significant number of migrant population in those zones from other LF endemic areas of the county. Though overall mf rate has declined in city, the migration from endemic states like Orissa, Bihar and Uttar Pradesh may increase the risk of transmission in the local areas. During 2007, total of 22071 s were screened through night blood smears, out of that 152 were positive for microfilaria (mf rate was 0.69%). After four round of MDA,

Impact of Mass Drug Administration on Elimination of Lymphatic Filariasis in Surat city, India 255 2.50 2.00 1.50 1.00 0.50 Vector Borne Diseases Control Department MF Rate & Disease Rate 0. 40 0. 35 0. 30 0. 25 0. 20 0. 15 0. 10 0. 05 0.00 0. 00 CZ SEZ SWZ NZ EZ SZ WZ Surat City 2004 Mf rate 2005 Mf rate 2006 Mf rate 2007 Mf rate 2004 Disease rate 2005 Disease rate 2006 Disease rate 2007 Disease rate Figure 1: Analysis of Disease rate and mf rate carriers in various zone of Surat city 0.80 0.70 0.60 Endemicity Rate 0.50 0.40 0.30 0.20 0.10 0.00 CZ SEZ SWZ NZ EZ SZ WZ Surat City 2004 2005 2006 2007 Figure 2: Endemicity rate from sentinel and spot-check sites on various Zone of Surat city (2004 to 2007) reductions observed were 41 percent in mf rate, and 33% in total mf count. It was also observed that the highest mf rate 1.55 and disease rate 0.06 was seen in North zone where the migrant populations mostly reside. The results also indicate that this MDA approach reduces not only the mf prevalence but also prevalence of infection and infectivity rate. In the fifties, natives of Surat city contributed 33.9% in microfilaria rate, 1.7% in disease rate and 33.60% endemicity rate.

256 Vaishnav KG et al Zone Table 2 : Community and Zone wise Distribution of Surveyed Sample Covered under MDA in Surat in 2007 Communities Migrant Mix Indigenous Total Total Y N Y N Y N Y N North 185 46 386 48 174 44 745 138 883 Per (%) 3.7 0.9 7.6 0.9 3.4 0.8 84.4 15.6 East 610 62 0 0 94 65 704 127 831 Per (%) 12.1 1.2 0 0 1.9 1.3 84.7 15.3 West 158 5 132 26 346 37 636 68 704 Per (%) 3.1 0.1 2.6 0.5 6.8 0.7 90.3 9.7 South 321 75 133 18 0 0 454 93 547 Per (%) 6.4 1.5 2.6 0.4 0 0 83.0 17 S-West 158 26 341 10 170 8 669 44 713 Per (%) 3.1 0.5 6.7 0.2 3.4 0.2 93.8 6.2 S-East 583 88 0 0 0 0 583 88 671 Per (%) 11.5 1.7 0 0 0 0 86.9 13.1 Central 0 0 0 0 641 68 641 68 709 Per (%) 0 0 0 0 12.7 1.3 90.4 9.6 Total 2015 302 992 102 1425 222 4432 626 5058 (100%) Per (%) 39.8 6 19.6 2 28.2 4.4 87.6 12.4 Y = DEC Acceptance, N =Non DEC Acceptance 9.6 9.6 13.1 9.6 3.8 21 46.7 Orissa Uttar Pradesh Bihar Other states Surat Maharashtra Gujarat Figure 3: Distribution of Filaria Carriers according to their original states as observed in Pre-MDA Data of Surat city (2004 to 2007)

Impact of Mass Drug Administration on Elimination of Lymphatic Filariasis in Surat city, India 257 Table 3 : Comparative status of Age / Sex wise MF carrier and Disease s in Surat city during 2004 to 2007 M F Age groups Year carrier & 1 to 4 5 to 14 15 to 39 40 above Total No. No. Disease Carrier Disease M F M F M F M F M F 2004 MF 0 0 7 2 139 14 15 5 161 21 182 0 carrier (56) (20) (781) (31) (130) (21) (967) (72) (1039) Disease 0 0 9 7 38 22 4 8 51 37 0 88 2005 MF 1(3) 0 3 2 134 8 20 1 158 11 169 0 carrier (31) (3) (554) (22) (60) (9) (648) (37) (685) Disease 0 0 1 1 88 9 25 14 114 24 0 138 2006 MF 0 0 8 3 133 10 15 5 156 18 174 0 carrier (34) (6) (630) (49) (61) (15) (725) (70) (795) Disease 0 1 1 1 61 11 36 15 98 28 0 126 2007 MF 0 0 2 2 122 12 11 3 135 17 152 0 carrier (5) (2) (574) (46) (28) (39) (607) (87) (694) Disease 0 0 1 0 48 1 13 5 62 6 0 68 Figure within parenthesis indicate mf density Table 4 : Trend of Entomological parameters (Ten-man hour density, infection and infectivity rate of C. quinquefasciatus) of Current and Past years Indicators/Year 1956 1957 1958 1959 2004 2005 2006 2007 Density10PMH 815 642 818 517 34 54 57 57 No. dissected 377 327 307 365 915 492 605 605 Infection rate 23.3 9.7 8.89 5.52 0.26 0.09 0.06 0.03 Infectivity rate 1.6 2.6 1.28 0.85 0.06 0.03 0.03 0.00 The impact of four round of MDA (2004-07) indicates that contribution of indigenous (Surat city) population in mf cases were 9.6% while the contribution of others (migrant population) was 46.7%, 21%, 9.6% and 13.1% respectively from migratory population of Orissa, Uttar Pradesh, Bihar and other states (Figure-3). Entomological data (Table-4) reveals that there is a reduction in both infection

258 Vaishnav KG et al and infectivity rate during the study. Comparison was done between the data of 1956-1959 and 2004-2007 to distinguish previous and existing density of C. quinquefasciatus, filarial infection and infectivity rate. All these indicators calculated 5,6 in Surat city are shown in Table-4. In 1956 mosquito infection rate was 23.3% and infectivity rate was 1.6% which showed remarkable reduction in 1959 after MDA trial and the infection rate came down to 5.52 (76.31% reduction) and infectivity rate to 7 0.85 (46.88% reduction) respectively. During the period of 2004 to 2007 also similar observations were made and there was marked reduction in Infection rate and Infectivity rate as evident from the figures shown in the Table 4. The reduction of 89% was observed in infection rate i.e. from 0.26% in 2004 to 0.03% in 2007. Similarly, the infectivity rate of 0.06% in 2004 was reduced to zero in 2007 (100% reduction). Among the zones, highest endemicity rate of 0.72% was observed in North Zone whereas overall endemicity rate of 0.24% was recorded in Surat city (Figure 2 & 3). However, from 2004 to 2007, the decline in endemicity rate has been noted e.g. in Surat city the endemicity rate reduced from 0.24% to 0.11% (reduction 54%) and in north zone it was reduced from 0.72% to 0.30% (reduction of 58%). DISCUSSION Over the past 50 years, since the first introduction of DEC in 1947, several endemic countries have used this drug towards control 7 of Lymphatic filariasis. In the year 1958, the mass course of treatment with Diethylcarbamazine (DEC) 4mg/kg/bw was given in the communities consecutively for five days, which reduced the infection load in the community and infection rate in the mosquitoes. However, due to high doses, many unpleasant reactions (in 23.9%) were observed which resulted in poor coverage subsequently and the DEC mass adminis- 6 tration was withdrawn in early 1960s. During the recent past the efforts towards elimination of Lymphatic filariasis with annual single dose of mass administration has generated new hopes of future generation becoming free from Lymphatic filariasis. The support towards preparatory activities, capacity building, assessment through micro filaria survey and independently through involvement of medical colleges/research institutions have made the local health authorities to implement the programme in massive way. This study has revealed that with well organised efforts, the coverage of about 90% can be achieved in urban areas like Surat city. The compliance also can be improved above 85% with massive social mobilization. However, there is a need to take care of the migratory population even if they enter the MDA covered areas after the MDA so that they also received a single dose of anti-filarial drugs. The above analysis reveals that though the overall Surat city has been showing the declining trend in microfilaria rate with increasing coverage & compliance of DEC but the group of the population migrating from endemic areas in a particular month harboring microfilaria can be a potential for transmission and therefore the timing for their migration and the area need to be kept under vigilance so the immediately after arrival their screening can be done for microfilaria and if they have not been given DEC in their respective areas, they should be immediately administered the tablet.

Impact of Mass Drug Administration on Elimination of Lymphatic Filariasis in Surat city, India 259 ACKNOWLEDGEMENTS The authors are thankful to J. Rawal, A. Thakar, R. Pandya and N. Mehta of Vector Borne Diseases Control Department, Surat Municipal Corporation for their valuable contributions in conducting the field survey along with Mr. Yogesh Patel and Mr. Arpit Joseph for helping for the computer data analysis. The co-operation of the community to furnish their views in the survey is appreciatively acknowledged. The authors deeply acknowledge the enthusiasm and encouragement provided by Late Dr. P. B. Prajapati, ex-joint Director (Mal. & Fil.), Govt. of Gujarat for improvement in the programme implementation. REFERENCES 1. World Health Assembly Resolution (1997): 50. 29. 2. Ministry of Health and Family Welfare, Govt. of India: National Health Policy 2002. 3. WHO, Report on Informal consultation on Epidemiological Approaches to Lymphatic Filariasis Elimination: Initial Assessment, Monitoring and Certification: WHO/FIL/ 99.195. 4. Patel TB and Paranjpey PD. Observations on mass therapy with diethylcarbamazine for Filaria Control in Bombay State. Indian J. Mal. 1958; 12 (3). 5. Das PK and Ramiah, KD. Entomological monitoring of annual mass drug administrations for the control or elimination of lymphatic filariasis. Annals of Tropical Medicin & Parasitol, 2002; 96, Suppl 2, S 142. 6. Vaishnav KG and Patel IC. Independent Assessment of Mass Drug Administration in filariasis affected Surat city. J. Commun. Dis. 2006; 38 (2): 149-154. 7. National Filaria Control Programme, GOI, A review of technical report (1955-1959).