ADAPTIVE DESIGN OF URBAN ADAPTIVE DESIGN OF URBAN MALARIA CONTROL PROGRAMSMALARIA CONTROL PROGRAMS

Marcia Caldas de Castro 1

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 Swiss Tropical Institute 4 Japan InternationalCooperation Agency

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).

CHARACTERISTICS OF SUCCESSFUL MALARIA CONTROL PROGRAMS

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)

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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

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Average Monthly Malaria Rate (per 1,000)

Annual Malaria Cases

b) Nkana Kitwe Mine

Reduction of Malaria Incidence at Nkana-Kitwe Mine between 1935-1943

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Malaria Incidences per 1,000per month

Reduction of Malaria Incidence at Nkana Mine between 1944-1950

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Malaria, Rainfall, and Anopheles Statistics at the Roan Antelope Mine between 1944-1949

Malaria, Rainfall, and Anopheles Statistics at the Roan Antelope Mine between 1944-1945

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Year and Month

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Malaria CasesRainfall (Inches)A. FunestusA. Gambiae

Urban Malaria: Dar es Salaam, Tanzania

Dar es Salaam

500 0 500 1000 Miles

N

Africa

Area Study

OysterBay

MsasaniBay

Msimbazi Bay

RailwayRiversRoads and streets

N

1 0 1 2 Kilometers

Urbanizationin Dar esSalaam

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 Salaam1902 - 1961

• 1902-1912 – German Colonial GovernmentDrainage, 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 ProtectorateContinued drainage works, stronger legal measures1920 – Sanitation Branch established

East Africa Malaria Unit established1951 – Tanganyika Malaria Service

History of Malaria Control in Dar es SalaamPost colonial period

• 1961+ – Urban mosquito control integrated into general health services

• 1971 – Integrated malaria control experimentDar 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 initiativeJapan-Tanzania bilateral project

- Breeding Sites - Aerial Observation

Misimbazi Creek

Breeding Sites - Aerial Observation

Temeke

- Breeding Sites - Aerial Observation

Regent State & Kijito-Nyama

Breeding Sites

Malaria Risk Mapping

Dar es Salaam,1993

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fc fcfcfcfcfc fcfcfc fcfc

fc OysterBay

MsasaniBay

Msimbazi Bay

Breeding sites in Dar es Salaam

Ocean

fc Breeding places

RailwayRiversRoads and streets

N

1 0 1 2 Kilometers

Breeding SitesMalaria Risk Mapping

fcfcfcfc

fcfc fc

fcfc

fcfcfc

fc 12 3 4

56

7

89

1011

12

13

43

MsasaniBay

ID Type

1 Pipe leakage2 Puddles3 Sand pits4 Sand pits5 Matuta6 Puddles7 Swamp8 Swamp9 Paddy

10 Seepages11 -12 -43 Salt pans

Breeding SitesMalaria Risk Mapping

fcfcfcfcfcfcfcfc

fc

fcfc

fc

fcfc

fc

Msimbazi Bay

1314

15 16

18

2122

23

24

2526

29

17

1920

ID Type

13 -14 Sand pits15 Mangrove swamp16 Matuta17 Matuta18 Sand pits19 Marsh20 Marsh21 Marsh22 Paddy23 Matuta24 Matuta25 Marsh26 Marsh29 Matuta

Breeding SitesMalaria Risk Mapping

fc fcfcfc

fcfcfcfc

2728

3031

35

373640

ID Type

27 Paddy28 Matuta30 Wells31 Pond35 Marsh36 Paddy37 Matuta40 Marsh

Breeding SitesMalaria Risk Mapping

fc fc

fc

fcfcfc

fc

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34

3839

41

42 ID Type

32 Matuta33 Marsh34 Matuta38 Swamp39 Marsh41 Swamp42 Seepage

Interventions Strategy

Indoor Residual House Spraying

(IRHS) and Larvicide

Kisarawe

Pagu Kajungeni

Selected schools

Effect of Interventions - IRHS

0

10

20

30

40

50

60

70

80

Sep-8

8

Nov-8

8

Jan-

89

Mar-8

9

May-8

9

Jul-8

9

Sep-8

9

Nov-8

9

Jan-

90

Mar-9

0

May-9

0

Jul-9

0

Sep-9

0

Nov-9

0

Jan-

91

Mar-9

1

May-9

1

Jul-9

1

Sep-9

1

Nov-9

1

Jan-

92

Mar-9

2

May-9

2

Jul-9

2

Sep-9

2

Nov-9

2

Jan-

93

Mar-9

3

May-9

3

Jul-9

3

Sep-9

3

Nov-9

3

Jan-

94

Month/Year

(%)

KIMARA

KONGOWE

Effect of Interventions - Larvicide

0

5

10

15

20

25

30

Sep-8

8

Nov-8

8

Jan-

89

Mar-8

9

May-8

9

Jul-8

9

Sep-8

9

Nov-8

9

Jan-

90

Mar-9

0

May-9

0

Jul-9

0

Sep-9

0

Nov-9

0

Jan-

91

Mar-9

1

May-9

1

Jul-9

1

Sep-9

1

Nov-9

1

Jan-

92

Mar-9

2

May-9

2

Jul-9

2

Sep-9

2

Nov-9

2

Jan-

93

Mar-9

3

May-9

3

Jul-9

3

Sep-9

3

Nov-9

3

Jan-

94

Month/Year

(%)

OYSTERBAY

KISARAWE

Effect of InterventionsBoth IRHS and larvicide X no intervention

0

10

20

30

40

50

60

70

80

Sep-8

8

Nov-8

8

Jan-

89

Mar-8

9

May-8

9

Jul-8

9

Sep-8

9

Nov-8

9

Jan-

90

Mar-9

0

May-9

0

Jul-9

0

Sep-9

0

Nov-9

0

Jan-

91

Mar-9

1

May-9

1

Jul-9

1

Sep-9

1

Nov-9

1

Jan-

92

Mar-9

2

May-9

2

Jul-9

2

Sep-9

2

Nov-9

2

Jan-

93

Mar-9

3

May-9

3

Jul-9

3

Sep-9

3

Nov-9

3

Jan-

94

Month/Year

(%)

KIGAMBONI

P.KAJIUNGENI

Total Length of Drain Cleaned(cumulative - meters)

Dar es Salaam

Tanga

ANTIMALARIA STORM WATERDRAIN DRAIN

1990 12,900 - 12,9001991 20,600 15,900 36,5001992 30,750 22,600 53,3501993 50,500 25,000 75,500

YEAR TOTAL

ANTIMALARIA STORM WATERDRAIN DRAIN

1990 24,119 38,450 62,5691991 31,670 25,300 56,9701992 38,100 43,860 81,9601993 38,200 33,800 72,000

YEAR TOTAL

- 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.