ADAPTIVE DESIGN OF URBAN MALARIA CONTROL PROGRAMS Marcia Caldas de Castro Deo Mtasiwa
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ADAPTIVE DESIGN OF URBAN MALARIA CONTROL PROGRAMS Marcia Caldas de Castro Deo Mtasiwa 2 Burton Singer 1 Marcel Tanner 3 Juerg Utzinger 1 Yoichi Yamagata 4 1 Office of Population Research Princeton University 2 Dar es Salaam, Tanzania City Council 3 1 Swiss Tropical Institute 4 Japan International Cooperation Agency CHARACTERISTICS OF SUCCESSFUL MALARIA CONTROL PROGRAMS i. Environmental management is the central focus, with several interventions/surveillance methods acting simultaneously. ii. Tuning the package of interventions to minimize the number of malaria cases per year is an adaptive process involving ongoing performance evaluation of each of the tools and the outcome measure (interventions are adjusted over time in response to these evaluations). iii. 3-5 years were required before a given package of interventions exhibited high level performance. iv. Diagnosis of malaria cases, anti-malarial drugs, bed-nets, and the use of chemical insecticides (following the discovery of DDT) were necessary but not sufficient (for success) components of the program. v. Program staff contained people knowledgeable about entomology, hydrology, epidemiology/ecology, and clinical aspects of malaria. vi. The implementation strategy, including the mix of tools employed, was highly idiosyncratic to the particular locality. a) Roan Mine A.Gambie and A.Funestus larval habitats A.Gambie – Open and un-shaded natural or man-made pools of standing water, near rivers and tributaries – Open water tanks and nature wells loosely overgrown with grass A. Funestus – Shaded banks of rivers and tributaries – Swamps and flooded areas with partial shade Biting pattern Reduction of Average Monthly Malaria Rate and Total Malaria Cases after the Implementation of Malaria Control Program - (1930-1933) 34 475 32 450 30 425 400 28 375 26 350 24 325 22 300 20 275 18 250 16 225 14 200 175 12 150 10 125 8 100 6 75 4 50 2 25 0 0 1930 1931 Year 1932 1933 Average Monthly Malaria Rate (per 1,000 people) Annual Malaria Cases Average Monthly Malaria Incidence Rate and Annual Malaria Cases at the Roan Antelope Mine between 1944 and 1949 34 475 32 450 30 425 400 28 375 26 350 24 325 22 300 20 275 18 250 16 225 14 200 175 12 150 10 125 8 100 6 75 4 50 2 25 0 0 1944 1945 1946 1947 1948 Year Average Monthly Malaria Rate (per 1,000) Annual Malaria Cases 1949 b) Nkana Kitwe Mine Reduction of Malaria Incidence at Nkana-Kitwe Mine between 1935-1943 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Months Oct Mar Aug Jan-42 Jun Nov Apr Sep Feb Jul Dec May Oct Mar Aug Malaria Incidences per 1,000 per month Jan-35 Malaria Incidences (per 1,000 per month) Reduction of Malaria Incidences at Nkana-Kitwe Mine betwe Reduction of Malaria Incidence at Nkana Mine between 1944-1950 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Months Sep Apr Nov Jun Jan-49 Aug Mar Oct May Dec Jul Feb Sep Apr Nov Jun Malaria Incidences per 1,000 per month Jan-44 Malaria Incidences (per 1,000 per month) Reduction of Malaria Incidences at Nkana Mine between Malaria, Rainfall, and Anopheles Statistics at the Roan Antelope Mine between 1944-1949 Malaria, Rainfall, and Anopheles Statistics at the Roan Antelope Mine betw 1945 600 90 Malaria Cases Rainfall (Inches) A. Funestus A. Gambiae 80 70 500 400 60 50 300 40 200 30 20 100 10 0 Ja n- 44 M ay S Ja ep n45 M ay S Ja ep n46 M ay S Ja ep n47 M ay S Ja ep n48 M ay S Ja ep n49 M ay S ep 0 Year and Month Urban Malaria: Dar es Salaam, Tanzania Area Study Dar es Salaam N Africa Msasani Bay Oyster Bay Msimbazi Bay N 500 0 500 1000 Miles 1 0 1 2 Kilometers Roads and streets Rivers Railway Urbanization in Dar es Salaam Source: http://mshand.geog.gla.ac.uk/DAR/Tanzania.htm - Land Use Vegetable Production Source: http://www.cityfarmer.org/daressalaam.html History of Malaria Control in Dar es Salaam 1902 - 1961 • 1902-1912 – German Colonial Government Drainage, soil modification, bednets • 1912-1918 – German ordinances for controlling breeding sites; proscribed urban agriculture (potatoes and other ridge-and-furrow type cultivation • 1918-1961 – British Protectorate Continued drainage works, stronger legal measures 1920 – Sanitation Branch established East Africa Malaria Unit established 1951 – Tanganyika Malaria Service History of Malaria Control in Dar es Salaam Post colonial period • 1961+ – Urban mosquito control integrated into general health services • 1971 – Integrated malaria control experiment Dar es Salaam City Council & WHO East Africa Aedes Research Unit • 1980 – Reduction in size of central malaria control unit – Consequential to adverse economic conditions (1970s high inflation) • 1988-1996 – JICA – Malaria control initiative Japan-Tanzania bilateral project - Breeding Sites Aerial Observation Misimbazi Creek Breeding Sites - Aerial Observation Temeke - Breeding Sites Aerial Observation Regent State & Kijito-Nyama N Breeding Sites Msasani Bay fcfcf cfc f fc fcc f fc c fcfcfc fc Oyster Bay Malaria Risk Mapping Msimbazi Bay fc fcffcc fc ffcfcc 0 1 2 Kilometers fc fc ffcc fc fc Breeding places Ocean Dar es Salaam, 1993 fc fc fc fc fc 1 f f fcffccfccc fcfc fc fc Roads and streets Rivers Railway Breeding Sites Malaria Risk Mapping Msasani Bay 6 fc 9 fc 11 fc 10 fcfc 12 fcf 2 c fcf 4 3 43 c 5 fc 7fc fc 8 fc 1 ID 1 2 3 4 5 6 7 8 9 10 11 12 43 Type Pipe leakage Puddles Sand pits Sand pits Matuta Puddles Swamp Swamp Paddy Seepages Salt pans Breeding Sites Msimbazi Bay 22 fc 14 13 fc f c 18 f f f fc15ccc 17 16 20 fc fc 19 21 23 f c 24 fc 25 26 f c fc 29 fc Malaria Risk Mapping ID Type 13 14 Sand pits 15 Mangrove swamp 16 Matuta 17 Matuta 18 Sand pits 19 Marsh 20 Marsh 21 Marsh 22 Paddy 23 Matuta 24 Matuta 25 Marsh 26 Marsh 29 Matuta Breeding Sites Malaria Risk Mapping 28 27 fc fcfc 30 fc 31 35 f fcffcc 36 c 37 40 ID 27 28 30 31 35 36 37 40 Type Paddy Matuta Wells Pond Marsh Paddy Matuta Marsh Breeding Sites Malaria Risk Mapping 32 fc 33 fc 34 fc 38 fcfc 39 fc 41 fc 42 ID 32 33 34 38 39 41 42 Type Matuta Marsh Matuta Swamp Marsh Swamp Seepage Interventions Strategy Indoor Residual House Spraying (IRHS) and Larvicide Kisarawe Selected schools Pagu Kajungeni Se pN 88 ov Ja 88 nM 89 ar M -89 ay -8 Ju 9 l Se -89 pN 89 ov Ja 89 nM 90 ar M -90 ay -9 Ju 0 l Se -90 pN 90 ov Ja 90 nM 91 ar M -91 ay -9 Ju 1 l Se -91 pN 91 ov Ja 91 nM 92 ar M -92 ay -9 Ju 2 l Se -92 pN 92 ov Ja 92 nM 93 ar M -93 ay -9 Ju 3 l Se -93 pN 93 ov Ja 93 n94 Effect of Interventions - IRHS (%) 80 70 KIMARA KONGOWE 60 50 40 30 20 10 0 Month/Year Se pN 88 ov Ja 88 nM 89 ar M -89 ay -8 Ju 9 l Se -89 pN 89 ov Ja 89 nM 90 ar M -90 ay -9 Ju 0 l Se -90 pN 90 ov Ja 90 nM 91 ar M -91 ay -9 Ju 1 l Se -91 pN 91 ov Ja 91 nM 92 ar M -92 ay -9 Ju 2 l Se -92 pN 92 ov Ja 92 nM 93 ar M -93 ay -9 Ju 3 l Se -93 pN 93 ov Ja 93 n94 Effect of Interventions - Larvicide (%) 30 OYSTERBAY KISARAWE 25 20 15 10 5 0 Month/Year Se pN 88 ov Ja 88 nM 89 ar M -89 ay -8 Ju 9 lSe 89 pN 89 ov Ja 89 nM 90 ar M -90 ay -9 Ju 0 l Se -90 pN 90 ov Ja 90 nM 91 ar M -91 ay -9 Ju 1 l Se -91 pN 91 ov Ja 91 nM 92 ar M -92 ay -9 Ju 2 lSe 92 pN 92 ov Ja 92 nM 93 ar M -93 ay -9 Ju 3 l Se -93 pN 93 ov Ja 93 n94 (%) 80 Effect of Interventions Both IRHS and larvicide X no intervention 70 KIGAMBONI P.KAJIUNGENI 60 50 40 30 20 10 0 Month/Year Total Length of Drain Cleaned (cumulative - meters) Dar es Salaam Tanga YEAR ANTIMALARIA DRAIN STORM WATER DRAIN TOTAL 1990 1991 1992 1993 12,900 20,600 30,750 50,500 15,900 22,600 25,000 12,900 36,500 53,350 75,500 YEAR ANTIMALARIA DRAIN STORM WATER DRAIN TOTAL 1990 1991 1992 1993 24,119 31,670 38,100 38,200 38,450 25,300 43,860 33,800 62,569 56,970 81,960 72,000 - Program Implementation Based on successful programs in the past i. Environmental management is the central focus, with several interventions/surveillance methods acting simultaneously. ii. Tuning the package of interventions to minimize the number of malaria cases per year is an adaptive process involving ongoing performance evaluation of each of the tools and the outcome measure (interventions are adjusted over time in response to these evaluations). iii. 3-5 years were required before a given package of interventions exhibited high level performance. iv. Diagnosis of malaria cases, anti-malarial drugs, bed-nets, and the use of chemical insecticides (following the discovery of DDT) were necessary but not sufficient (for success) components of the program. v. Program staff contained people knowledgeable about entomology, hydrology, epidemiology/ecology, and clinical aspects of malaria. vi. The implementation strategy, including the mix of tools employed, was highly idiosyncratic to the particular locality.
