NATIONAL MALARIA CONTROL PROGRAMME An epidemiological profile of malaria and its control in Mainland Tanzania Report prepared by National Malaria Control Programme, Ministry of Health & Social Welfare, Dar es Salaam, Tanzania Ifakara Health Institute, Dar es Salaam, Tanzania World Health Organization, Country Office, Dar es Salaam, Tanzania The INFORM Project Department of Public Health Research Kenya Medical Research Institute - Wellcome Trust Progamme, Nairobi, Kenya July 2013 i Author details Fabrizio Molteni, Renata Mandike & Ally Mohammed National Malaria Control Programme, Ministry of Health & Social Welfare, P.O.Box 9083, Dar es Salaam, Tanzania email: [email protected]; [email protected] Prosper Chaki & Fredros Okumu Environmental Health and Ecological Sciences Thematic Group Ifakara Health Institute, P.O.Box 78373, Dar es Salaam, Tanzania email: [email protected] Ritha Njau WHO Country Office, P O Box 9292, Dar-es-Salaam, Tanzania email: [email protected] Abdisalan Mohamed Noor, Clara Mundia & Robert W Snow The INFORM Project, Department of Public Health Research, KEMRI-Wellcome Trust Programme, P.O.Box 43640-00100, Nairobi, Kenya email: [email protected] Suggested citation National Malaria Control Programme, WHO, Ifakara Health Institute and the INFORM Project (2013). An epidemiological profile of malaria and its control in mainland Tanzania. Report funded by Roll Back Malaria and Department for International Development-UK, July 2013. ii Table of Contents Executive Summary ................................................................................................................................ 1 Chapter 1: Introduction .......................................................................................................................... 2 Chapter 2: Country context, administration, population distribution & health service provision ........ 6 2.1 Country context ............................................................................................................................ 7 2.2 Economy & Poverty ....................................................................................................................... 8 2.3 Child survival ................................................................................................................................. 8 2.4 Defining health service administration-planning units ................................................................. 9 2.5 Population growth and distribution ............................................................................................ 12 2.6 Urbanization ................................................................................................................................ 15 2.7 Health facility mapping ............................................................................................................... 16 2.8 References................................................................................................................................... 21 Chapter 3: 100 years of malaria control in Tanzania ............................................................................ 25 3.1 Malaria control under the German administration: 1890-1914 ................................................. 26 3.2 British colonial malaria control: Between the wars .................................................................... 26 3.3 Malaria control post-second world war to independence: 1946-1961 ...................................... 30 3.4 Post-independence malaria control to the launch of RBM: assembling the evidence ............... 32 3.4.1 Changing antimalarial drug policies ................................................................................ 33 3.4.2 Establishing a national insecticide-treated bed net policy ............................................. 34 3.4.3 Urban malaria control revisited ...................................................................................... 35 3.4.4 Epidemics ........................................................................................................................ 36 3.4.5 The 1997-2000 National Malaria Strategy ...................................................................... 36 3.5 The decade of RBM 2000-2010 ................................................................................................... 37 3.5.1 The 2002-2007 National Malaria Strategy ...................................................................... 37 3.5.2 The 2008-2013 National Malaria Strategy ...................................................................... 39 3.6 The future.................................................................................................................................... 43 3.7 References................................................................................................................................... 44 Chapter 4: Mapping malaria transmission intensity............................................................................. 53 4.1 Previous malaria map use in Tanzania ........................................................................................ 54 4.1.1 Maps and malaria endemicity descriptions pre-independence ..................................... 54 4.1.2 Malaria maps used during National Strategic Plans 1997-200 ....................................... 55 4.1.3 Other mapped descriptions of malaria risk in Tanzania ................................................. 56 4.2 Malaria parasite prevalence data assembly, modelling and risk mapping ................................. 60 4.2.1 Parasite prevalence data search strategy ....................................................................... 60 4.2.2 Data abstraction .............................................................................................................. 61 4.2.3 Data geo-coding .............................................................................................................. 62 4.2.4 Database fidelity checks, exclusions and pre-processing ............................................... 63 4.2.5 Age standardization ........................................................................................................ 64 4.2.6 Parasite prevalence data summaries .............................................................................. 64 4.3 Model Based Geostatistical (MBG) modeling of age-corrected parasite prevalence ................ 68 4.3.1 Model form ..................................................................................................................... 68 4.3.2 Selection of covariates .................................................................................................... 68 4.4 Model predictions and populations at risk 2000 and 2010 ....................................................... 72 iii 4.5 Model uncertainty and validation statistics ............................................................................... 76 4.6 Malaria seasonality .................................................................................................................... 76 4.7 References.................................................................................................................................. 79 Chapter 5: Dominant malaria vectors in Tanzania .............................................................................. 84 5.1. Background ................................................................................................................................ 85 5.2 Data Assembly ............................................................................................................................. 85 5.3 Current geographical distribution of dominant vector species .................................................. 87 5.3.1 Anopheles arabiensis (Patton 1905) ............................................................................... 87 5.3.2 Anopheles funestus (Giles 1900) .................................................................................... 88 5.2.3 Anopheles gambiae sensu stricto (Giles 1900 ................................................................ 89 5.2.4 Anopheles merus (Donitz 1912) ...................................................................................... 90 5.4 Physiological insecticide resistance status of dominant vector species .................................... 90 5.5 Behavioural resilience and outdoor biting habits of malaria vector species in Tanzania ........... 92 5.6 References................................................................................................................................... 93 Chapter 6: Modelling the coverage of ITNs/IRS 2000, 2010 & 2012 .................................................... 99 6.1 ITN scale up in Tanzania ............................................................................................................ 100 6.2 Assembling ITN coverage data .................................................................................................. 103 6.3 Modelling spatial aggregates of ITN coverage using Small Area Estimation ............................ 103 6.4 Indoor Residual House-spraying coverage ................................................................................ 107 6.5 References................................................................................................................................. 108 Chapter 7: Summary, recommendations and actions points ............................................................