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Field Station- Bangalore (Karnataka) |
Research Staff
Dr. S. K. Ghosh, Assistant Director and Officer-in-Charge
Dr. S.N. Tiwari, Research Officer (IDVC)
Dr. A.K. Kulshrestha, Research Scientist( IDVC)
Dr. T.R.R. Sampath, Research Scientist (IDVC)
Dr. T.S. Sathyanarayan, Assistant Research Scientist (IDVC)
A. About the station: The field station in Bangalore was the last one to be opened under the Integrated Disease Vector Control (IDVC) project of S&T in October 1992 with the active cooperation and participation of the State Health Department, Govt. of Karnataka. Staffs from different field stations were posted in Bangalore. Initially the field station was located in Jeevan Bima Nagar, Bangalore – 560 075. Since May 1996 the filed station is housed in the campus of Epidemic Disease Hospital, Old Madras Road, Bangalore – 560 038 about 4 km form the Bangalore Air Port and about 15 km from the Railway station. The National Highway no. 4 opposite to the T.B. Hospital is the landmark. This field station has 15 staff members with five scientists.
B. Local malaria problem: Malaria is one of the major public health problems in Karnataka and contributes about 7-10% of the total malaria in the country. Presently, districts Hassan, Tumkur, Chitradurga, Chickmagalur, Mandya, Raichur and Gulberga are most problematic. In these rural areas Anopheles culicifacies and An. fluviatilis are known vectors of malaria. Mangalore city on the western coast is also under the rage of malaria for the last one decade. Here An. stephensi is the main vector. Besides this, Bellary city also has problem for malaria and the district is under the threat of Japanese Encephalitis.
C. Major accomplishments, achievements: Following specific objectives were made for the field station. In general, the main objective was to transfer of technology on bioenvironmental control of malaria to the state health department, Government of Karnataka.
a. Identification of problems / location in high strata PHC where bio-environmental methods are required to be introduced.
i. Zero down to village level on the basis of API.
ii. Comprehensive longitudinal epidemiological and entomological studies (at least for one transmission season).
iii. Study of mosquito fauna.
iv. Dynamics of transmission, incrimination of vector(s) / sibling / resting / feeding behaviour / preferred breeding sties of vector mosquitoes (longitudinal study).
v. Extensive micro level Geographical reconnaissance (GR) in all the malaria problematic villages.
vi. To identify suitable bio-environmental intervention strategies including engineering methods.
vii. Preparation of action plan in all the problematic areas.
viii. To identify various collaborating agencies.
b. Transfer of Technology
i. Setting up of larvivorous fish hatcheries along with handling, transportation and its usage.
ii. To organize workshops / Training courses in various aspects of control of malaria from time to time to update knowledge and proper implementation of control strategy.
D. HIGHLIGHTS:
1. PHC KAMASAMUDRAM, DISRTICT KOLAR:The work on bioenvironmental control of malaria was first started in Kolar district where silk farmers resisted to the indoor residual insecticide spray for possible damage to the silk industry. In 1993 geographical reconnaissance (GR) for mosquito breeding habitats was carried out in four PHCs covering 222 problematic villages. GR revealed that irrigation tanks, wells and streams were the major breeding grounds for the vector mosquitoes Anopheles culicifacies and An. fluviatilis. Accordingly PHC Kamasamudram of this district was selected for demonstration of bioenvironmental control of malaria.
Demonstration of bioenvironmental control of malaria was first carried out in a silk producing area PHC Kamasamudram (93 villages, pop. 36,627) district Kolar. GR of larval breeding habitats in 1993 revealed that irrigation tanks, wells and streams are the major breeding habitats for the vector mosquitoes An. culicifacies and An. fluviatilis. Intervention with larvivorous fishes Guppy (Poecilia reticulata) in wells and streams in 1994 and Gambusia affinis in 1996 in tanks were found suitable. These fishes got wells established in these ecosystems. Entomological monitoring revealed that significant impact on the larval densities of all mosquitoes was observed (P<0.001). Larval emergence data revealed that significant impact was observed on the vector species in all the breeding habitats (P<0.001) while no impact was recorded on An. fluviatilis from streams (P<0.05). There was significant impact on MHD of An. culicifacies while no impact was observed on An. fluviatilis. Sibling species studies of the two vector species revealed that species A of An. culicifacies was prevalent in the villages having wells (~ 90%) while species B in steam influenced villages (~ 90%). All the An. fluviatilis were found to be species Impact on malaria incidence was highly significant. API was 41.8 in 1993, 15 in 1994, 11.1 in 1995, 12.3 in 1996, 4 in 1997, 1.2 in 1998, 0.1 in 1999, 0.05 in 2000 and 0.1 in 2001. Survival of fish was carried out and it was found that fishes were present in all the breeding habitats.
2. PHCs Banavara and Kanakatte, District Hassan: Selective vector control of malaria was carried out in PHCs Banavara and Kanakatte in district Hassan. In 1995 these PHCs were showing high incidence of malaria. In PHC Banavara (108 villages; pop. 55619) only larvivorous fishes were used as intervention measure. In PHC Kanakatte three sets of experimental villages were selected. a. Area with only fish (38 villages; pop. 20,546), b. area with only impregnated bed nets (7 villages; pop. 3448) and c. area with fish and impregnated bed nets (7 villages; pop. 4651). GR survey revealed that tanks and wells was the main contributors of vector mosquito An. culicifacies. Initially Guppy and Gambusia were released in all the breeding habitats in 1996. Gambusia could not sustain in tanks due to drying of tanks in the subsequent years. However Gambusia released in 1999 has been established in all the areas. Bed-nets were impregnated with Cyfluthrin @ 30mg /sq. mt. Entomological surveys carried out in these PHCs revealed that tanks (63.4 to 76%) and wells (8 to 32.1%) followed by stone quarries (3.6 to 20%) are the major breeding habitats of An. culicifacies. Larval and adult densities were significantly lower than the control ones. The best impact was observed in bed net plus fish area. In PHC Banavara the API came down from 154 in 1995 to 70 in 1996, 5 in 1997, 3.2 in 1998. 7.3 in 1999. In PHC Kanakatte in the bed net area API in 1995 was 77.63, 19.71 in 1996, 1.28 in 1997, 0.1 in 1998 and 0.2 in 1999. In the second area API came down from 86 in 1995 to 12.2 in 1996, 0.28 in 1997, 0 in 1998 and 0.2 in 1999. In the third area API came down from 187.17 in 1995 to 52.7 in 1996, 1.6 in 1997, 0.2 in 1998 and 0.2 in 1999. In 2000 an outbreak of malaria has occurred in all the neighbouring PHCs of districts Chickmagalur and Tumkur bordering PHC Kanakatte. As a result all the bordering villages of PHC Kanakatte have been affected. In 2001 the average API in PHCs Kanakatte and Banavara was <15.0. In the control PHC Belagur API in 1995 was 82 but it went up to 203 in 2001. This indicates that bio-environmantal control using larvivorous fish is highly effective in this area.
3. Malaria in Hosur Bande, Bangalore Urban district: Malaria was showing a great problem in a stone quarry area Hosur Bande approximately 20 km, from Bangalore city. Investigation was carried out from April 1998 in this area. A total of 560 blood smears were collected in 1998. All were found positive; 93 P. vivax, 455 P. falciparum and 12 mixed infection. An. culicifacies was the main vector. MHD varied from 8.5 to 124. Larvivorous fishes were used. Here fish could not sustain due to continuous quarry operations. Three rounds of Malathion were sprayed in 1999. As a result malaria cases came down drastically. A total of 70 blood smears were collected in 1999; 41 were positive for malaria - 6 P. vivax, 34 P. falciparum and 1 mix infection. In 2000, of the 20 blood samples collected all the 4 positives were P. falciparum. In 2001 only 2 Pv cases were reported. In all the wells Guppy was found and as a result no breeding of An. culicifacies was found in the subsequent years.
4. Outbreak investigation of malaria:
i. District Raichur: In November 1999 an investigation was carried out in PHCs Masarkal and Gabbur PHCs of Raichur district. Geographical Reconnaissance carried out in 10 villages revealed that streams (53.6%), wells (29%) and seepage (10.1%) are the major breeding sites for vector species An. culicifacies and An. stephensi. MHD of An. culicifacies varied from 0-20.1. At the time of survey two rounds DDT and four rounds Malathion fogging was covered in village Masarkal. As a result no adult vector mosquito species could be collected. Susceptibility status of An. culicifacies indicated that this species was resistant to DDT but susceptible to Malathion and Deltamethrin. A total of 341 blood smears were examined from two villages; 243 were positive for malaria - 12 Pv, 225 Pf and 6 mixed infection. Hence the SPR was 71.2% with Pf % of 95.1. An in vivo susceptibility study for P. falciparum to Chloroquine and SP compounds were also carried in two villages. Preliminary observation indicated that P. falciparum showed high degree of resistance to both the drugs 27/31 (87%) to Chloroquine and 22/28 (78.5%) to SP. All the cases were treated successfully with quinine after our findings. A follow-up study was conducted in March, 2000 in two villages Masarkal and Ramdurg under PHCs Masarkal and Gabbur, district Raichur. A total of 79 slides were collected from these two villages; 77 were positive for malaria; 12 P. vivax, 64 P. falciparum and 1 mixed infection. Two rounds Malathion and routine fogging were carried out in Masarkal. No anopheline was available in this village while 13 An. culicifacies (MHD 6.5) was collected from village Ramdurg. Malathion spray was under operation in this village. Sibling species studies of An. culicifacies revealed that species A, B and C were present in this area. Of the total 82 ovary samples processed 69 were species A, 7 species B and 6 species C.
ii. PHCs Singetegere and Panchnalli, district Chickmagalur: A total of 649 malaria cases were reported from PHC Panchnalli (pop. 30525) while 528 cases from PHC Singetegere (pop. 24,602) during 1999. These two PHCs are stretched along with the borders of PHCs Banavara and Kanakatte. In these areas Cyfluthrin was sprayed from 1996 to 1998. Here An. culicifacies is the main vector. MHD varied from 2 to 67. Emergence data revealed that tanks (90.4%), were the main contributors of An. culicifacies followed by wells (4.7%), bundh area (4.7%). 25 ovaries have processed for sibling species 21 were species A, 2 species B and 2 unidentified. Training on catching, handling, transportation and release of larvivorous fishes were rendered to 7 health staff of PHCs Panchnalli, Yagachi and Singetegere of district Chickmagalur. A total of 13, 000 Gambusia and 3.000 Guppy were released in all the 13 tanks and 42 wells in 6 villages.
iii. C.N. Halli Taluk, district Tumkur: In C.N. Halli taluk, district Tumkur an outbreak of malaria has occurred from April to August 2000. A total of 3319 malaria cases are reported as against 637 in 1999. An entomological survey was conducted in August. An. culicifacies was found to be the only vector for malaria. Adult emergence from larvae revealed that tanks (57.1%) were the main contributor of An. culicifacies followed by wells and bundh area (14.2% each). 48 ovaries were processed; of which 29 were species A, 6 species B and 13 unidentified. There was unpublished report in 1988 that An. culicifacies was resistant to Malathion in this area. Our study showed that this mosquito was highly susceptible to Malathion and resistant to DDT. Training on fish work was also rendered to 5 staff of C.N. Halli Taluk. After the training, the staffs of the C.N. Halli Taluk have released in the problematic PHCs. 13, 000 Gambusia in 13 tanks and 2750 Guppy in five wells in 13 villages. These fishes were taken from PHC Kanakatte.
iv. Tiptur Taluka, district Tumkur: An outbreak of malaria in PHC Halkurke, Tiptur Taluka, district Tumkur was investigated in July 2002. A sudden increase of malaria cases in this PHC was detected in June 2002. This PHC is adjacent to PHC Mathigatta of C.N. Halli taluka. A total of 777 malaria cases were reported (up to May 2002; of which 771 P. vivax and 66 were P. falciparum). Entomological investigation in two villages revealed that An. culicifacies is the only vector. PMHD of this mosquito varied from 14 to 47.1. Initially, indoor fogging with deltamethrin was carried out but was stopped afterwards as no effect on vector population was observed.
The second outbreak was reported in the first week of August, 2002 there was increasing trend of malaria in PHC Aaralguppe in Tiptur Taluka. Accordingly a team from MRC investigated the outbreak of malaria in this PHC. Of the total 245 blood smears examined on the spot, 127 were found positive for malaria; 123 P. falciparum and only 4 were P. vivax. In this area An culicifacies is the main vector and found to breed in tanks, wells and stone quarry pits. PMHD was 14.3. One An. culicifacies was found sporozoite positive of 13 dissected.
v. Karkal Taluk in Udupi district : In some stone quarry areas in district Udupi malaria is showing problem. A survey was conducted in village Jaladhar Nagar. An. culicifacies was found to breed in the stone quarry pits. A total of 16 blood smears were collected; all were found positive for P. falciparum. Report was given to the local health department and proper measures were undertaken. With the request of the DHO, Udupi 5000 Guppy fish were supplied to this district.
5. Mosquito Control in Bangalore City: Mosquito nuisance is one of the major problems in Bangalore city. Recently constituted Bangalore Agenda Task Force (BATF) has initiated `Swachha Bangalore' programme to keep Bangalore City clean and mosquito free. The mosquito control programme will be carried out with the help of Bangalore Mahanagara Palike (BMP) and BATF. As requested by BMP we have rendered training on different aspects of mosquito control to the health personnel engaged on mosquito control. A total number of 11 Insect collectors, 20 Head Gangmen and 234 Gangmen and ALOs have already undergone training on mosquito control in Malaria Research Centre. Study has shown that wells, small drains, cess pools, unused tyres, discarded materials are the major breeding habitats of mosquitoes. After Geographical Reconnaissance of mosquito breeding habitats in Lingarajpuram (Ward No. 87), monitoring of mosquitogenic situations and their control is being carried out. Monitoring of mosquitogenic situation is also carried out in other wards also. A total of 4 areas have been investigated for finding of mosquitogenic situation. It was revealed that drains, cess pools and wells are the major breeding habitats for mosquitoes. Culex quinquifasciatus, An. stephensi and Ae. aegypti are the major mosquito species recorded. It was revealed that there is a good impact on the larval density in the ward where the Medical Officer of Health is working as recommended by MRC.
6. Malaria control in Mangalore City : Malaria was showing a great problem in the coastal city of the western ghat. In 1994 there were 3149 malaria cases, 5222 cases in 1995; 9880 cases in 1996; 7872 cases in 1997; 6475 cases in 1998; 4598 cases in 1999 and 1572 cases in 2000. In 1996 four deaths due to malaria were reported. In such condition malaria control in this city was initiated in October 1998 with the request of a local NGO - Mangalore Parisara Sakta Ukuta. Training, workshops are being organised to have suitable control strategies. In 2001, 52, 000 Guppies have been supplied for release in wells and other breeding sites.
7. Geographical Information System (GIS) to identify mosquito breeding habitats in district Tumkur: A collaborative study has been started along with Regional Remote Sensing Centre (RRSC), Bangalore to find out the potential breeding grounds of vector mosquitoes. This will help in proper planning of malaria control.
8. Operational feasibility of use of larvivorous fish for control of malaria in a high risk areas of Karnataka State’
This project is funded under RBM WHOSEA, initially up to March 2003. The work is carried out in four talukas Arsikere of Hassan district, Kadur of Chickmagalur district, C.N. Halli of Tumkur district and Hosadurga of Chitradurga district. This work is being carried out with the active participation of the state health department. Assistant Entomologists of the respective district along with supportive staff are carrying out the work. Initially training was rendered to all the working staff. GR is also conducted along with. Details are given below:
Geographical Reconnaissance (GR) was first carried out all the problematic PHCs. Fishes were released after carrying out the GR. It was observed that around 80% of breeding sources are wells while the remaining breeding sources are irrigation tanks, ponds and streams. It is also observed that around 35% wells are dry in Kadur followed by Hosadurga and Arsikere. In C.N. Halli Taluka minimum number of wells found dry (6.7%). The local fisheries department is assisting in stocking the fish from long distance. Fishes were collected from the stocks already available in PHCs Banavara and Kanakatte of Arsikere Taluka in the morning hours with help of dragnets and strainers. These were transported in 100 lts. plastic drums.
I. Arsikere Taluka, district Hassan: Larvivorous fish were released in 324 draw wells, 266 irrigation wells, 63 step wells, 123 tanks, 119 ponds 4 streams and 20 other breeding sources in 171 villages. A total of 12290 Guppy and 87300 Gambusia were released.
II. C.N. Halli, district Tumkur: Fishes were released in 380 draw wells, 595 irrigation wells, 21 step wells, 151 tanks and 1 stream in 193 villages. A total of 180800 Guppy and 51500 Gambusia were released.
III. Kadur Taluk, district Chickmagalur: Fishes were released in 376 draw wells, 90 irrigation wells, 33 step wells and 165 tanks, 9 ponds in 293 villages. A total of 22270 Guppy and 99250 Gambusia were released.
IV. Hosadurga Taluk, district Chitradurga: Fishes were released in 358 draw wells, 747 irrigation wells, 43 step wells, 75 tanks, 196 ponds and 49 streams in 246 villages. A total of 161100 Guppy and 166250 Gambusia were released.
Entomological Monitoring : 12 villages were selected for entomological monitoring in the study areas. From each experimental taluka 2 villages (total 8) and 2 villages each from adjoining talukas Tiptur and Huliyar were selected as controls. An. culicifacies is the vector of malaria in this area. Its PMHDs varied from 09.0 to 53.0 while PSD varied from 4.0 to 118.0 Larval densities in wells varied from 1.00 to 5.66; in irrigation tank 1.56 to 31.33 and in streams 0.50 to 9.60. This is the base line data.
Tiptur Taluka : Taluka Tiptur of Tumkur district lies between C.N. Halli and Arsikere. This year an outbreak of malaria is observed in four PHCs of this Taluka. This taluka was not included in the project area. A special emphasis has been taken to control malaria in this area since this will influence the result of the intervention measures taken in the study area. The Taluka Health Officer is taking all measures to release fish with the help of MRC.
Involvement of Panchyati Raj Institution : It is essential to involve the local community for sustaining such programme. It has been decided to involve this institution in monitoring of the survival of fish with the help of local PHC Medical Officers. The Zilla Panchyat (ZP) is providing funding for fish release work in Tiptur Taluka. This will be precedence where ZP is coming forward to assist such programme. This will be a role model for other districts.
9. Evaluation of the impact of DDT indoor residual spraying being used in malaria control programme on the disease prevalence.
Evaluation of the impact of DDT was made in seven villages in sub-centre Mahadeshwarapura (Pop. 7665), PHC Pandavapura, district Mandya from July 2001 to February 2002. Studies were conducted in pre- and post-spray periods. Evaluation was made after 4,8,12 and 16 weeks after the spray. The percent room spray coverage was ~ 50%. An. culicifacies is the major vector of malaria in this region; species A is very less (3%) as compared to species B (97%). This species was 80% resistant to DDT and was susceptible to malathion (90%) and to Deltamethrin (100%). Bio-assays on sprayed wall surfaces revealed 20% (samples collected from un-sprayed villages) mortality though An. culicifacies in the sprayed villages were ~ 50% susceptible to DDT. This indicated the ineffectiveness of the DDT spray deposits in causing expected moralities. The density (PMHD) of An. culicifacies was 2-3 folds less during the post-spray evaluation period, but no impact on the proportions of the indoor resting stages. This suggests that the reduction in densities may not due to the insecticide spray. Two pre- and post-spray mass blood surveys conducted indicated very low very low incidence of malaria in the area. As a result, impact of the spray on the malaria incidence could not be ascertained.
10. Stratification of Karnataka based on An. culicifacies and An. fluviatilis sibling species prevalence.
i. By Polytene chromosome
This is an intramural project. This field station has carried out the role of sibling species of vector species Anopheles culicifacies and An. fluviatilis in different areas of Karnataka. The first study on sibling species in PHC Kamasamudram, district Kolar guided in formulating the intervention measure. This was the reason to have studies on sibling species of vector species in different ecological zones of Karnataka. It has been observed that in Southern Karnataka zone (districts Hassan, Kolar, Bangalore, Mandya, Tumkur, Chitradurga, Chickmagalur) sibling species A and of An. culicifacies are present while in Northern Karnataka zone (districts Raichur, Gulberga, Bijapur) species A, B, and C are present. Details are given below.
Southern Karnataka
a. District Kolar
· Villages having wells : species A 90.6%; species B 9.4%
· Villages situated on streams : species A 9.1%; species B 90.9%
b. District Mandya
· Dry land areas : species A 45.1%; species B 54.9%
· Wet land areas : species A 3%; species B 97%
c. District Tumkur : species A 71.5%; species B 28.5%
d. District Chitradurga : species A 59.5%; species B 40.5%
e. District Hassan : species A 70%; species B 30%
f. District Chickmagalur : species A 71.5%; species B 28.5%
g. District Bangalore Urban : species A 71.5%; species B 28.5%
Northern Karnataka
a. District Raichur : species A 84.1%; species B 8.5%; species C 7.3%
b. District Gulbarga : species A 33.3%; species B 50%; species C 16.7%
c. District Bijapur : species A 92.6%; species B 1.4%; species C 5.7%
Anopheles fluviatilis : All the An. fluviatilis species collected from district Kolar, Mandya and Belgaum are found to be species T.
ii. By PCR
Breeding site wise identification of An. culicifacies sibling species
In district Mandya, breeding site wise identification of An. culicifacies sibling species was identified following PCR technique. Adults emerged from field collected larvae of respective breeding habitats were utilized. It was revealed that species B was breeding 100% in tanks, canal, draw wells, seepage while in irrigation wells 20.7% species A and 79.3% species B; in streams 23.6% species A and 76.4% species B.
11. Workshops and training:
Several Workshops and training programmes are being organised by this field station to different health and non-health staff from time to time.
12. Work with NGOs and other sectors
Most of our work is carried out by the active cooperation and participation of the local NGOs
namely Community Health Cell, Bangalore, VHAK, Bangalore, CHAI, CMAI, Bangalore. Practically, the work in Mangalore City is being carried out with the local NGOs.
E. List of ongoing projects, collaborators and funding source
a. Mosquito control in Bangalore City.
Principal Investigator - Dr. S. K. Ghosh.
Co-investigator - Dr. S.N. Tiwari, Dr. T.R. R. Sampath, Dr. T.S. Sathyanarayan
Funded by - Bangalore Mahanagara Palike, Bangalore - March 2001 to March
2003.
b. Operational feasibility of use of larvivorous fishes for control of malaria in a
high risk area of Karnataka State, India.
PI - Dr. S. K. Ghosh, Co-investigator - Dr. S.N. Tiwari, Dr. T.R. R.Sampath,
Dr. T.S. Sathyanarayan
Funded by : WHO SEARO, New Delhi, 2002-2003
d. Malaria control in Mangalore City.
PI - Dr. S. K. Ghosh, Co-investigator - Dr. S.N. Tiwari, Dr. T.S. Sathyanarayan.
Funded by : Mangalore City Corporation and local NGO.
e. To develop strategies for integrated control of vectors of Malaria, JE and
Dengue in Karnataka.
PI - Dr. S. K. Ghosh, Co-investigator - Dr. S.N. Tiwari, Dr. T.R.R. Sampath
Dr. T.S. Sathyanarayan.
Funded by : WHO Biennium July 2002 to December 2003.
For further information, please contact:
Dr. SK Ghosh
Malaria Research Centre Field Station
Epidemic Disease Hospital, Old Madras Road, Bangalore- 560038, India
e mail: ghoshmrc@vsnl.net,
mrcbgl@vsnl.net
Phone:+91-80-5362115
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