EW112310H-0 1

Hydrometeorological, Entomological and Epidemiological Time Markers for

Urban Malaria in Niamey, Niger

Earle Williams

Session H36:  The Hydroclimatic Basis for Tropical Ecosystem Services

American Geophysical Union,  Fall Meeting

December 13-17, 2010

EW112310H-0 2

CERMES (Niamey, Niger)

Thierry Fandeur and Rabiou Labbo

Institut Pasteur (Paris, France)

Jean-Bernard Duchemin

Université des Antilles et de la Guyane (Guadeloupe, France)

Nathalie Nathou

AGRYMET (Niamey, Niger)

Abdou Ali and Adamou Mahamadou

DMN (Niamey, Niger)

Ousmane Allahi Daoura and Gaptia Lawan Katiellou

PNLP (Niamey, Niger)

Salissou Adamou and Abami Maazou

SPIS (Niamey, Niger)

Moussa Barké

Great Basin Unified Air Pollution Control District (Bishop, CA)

Brian Russell

Collaborators

EW112310H-0 3

Working Hypothesis:

• Hydrometeorological aspect:  The onset of sustained standing water is abrupt and synchronous

• Entomological aspect:  The onset of the mosquito population is abrupt and synchronous

• Epidemiological aspect:  The onset of malaria cases is abrupt and synchronous

The Nature of Malaria Development in Niamey, Niger

EW112310H-0 4

Time Line for Malaria Development

EW112310H-0 5

Map of Niamey, Niger Showing Locations of Public Clinics

EW112310H-0 6

0 50 100 150 200 250 300 3500

50

100

Gaweye

H.D.

Karadjé

Kirkissoye

Lamordé 1

Saguia

Lamordé 2

Zarmagandey

Julian Day

0

50

100

0

20

40

0

20

40

0100200

0

50

100

050

100150

050

100150200

Year 2005

Abrupt and Synchronous Increase in Malaria Cases

tMalaria

EW112310H-0 7

Evolution of Standing Water in One Niamey Street

15%

10%

5%

Rue Dallols – PlateauNiamey, Niger 2007

July August September

Sta

nd

ing

Wa

ter A

rea

(m2)

Fra

cti

on

al a

rea

(%)

2000

1500

1000

500

0

tWater

EW112310H-0 8

Standing Water in Niamey, Niger(Rue Dallols)

EW112310H-0 9

Climatology of Surface Relative Humidity Over Oceans

from Peixoto and Oort (1996)

80% is a common value

At night, a land surface with standing water behaves like the ocean

EW112310H-0 10

Daily Maximum Relative Humidity For 2004-2009 (Agrhymet Station, Niamey)

0 50 100 150 200 250 300 3500

20406080

100

Year 2009

Year 2008

Year 2007

Year 2006

Year 2005

Year 2004

JulianDay

Rel

ativ

e H

umid

ity (

%)

020406080

100

Rel

ativ

e H

umid

ity (

%)

020406080

100

Rel

ativ

e H

umid

ity (

%)

020406080

100

Rel

ativ

e H

umid

ity (

%)

020406080

100

R

elat

ive

Hum

idity

(%

)

020406080

100

Rel

ativ

e H

umid

ity (

%)

EW112310H-0 11

0 50 100 150 200 250 300 3500

20

40

60

80

100Year 2005

R

ela

tive

Hu

mid

ity (

%)

Julian Day

HRmax HRmin

Daily Max and Min Relative Humidity For 2005 (Agrhymet Station, Niamey)

tWater

EW112310H-0 12

Time Markers (tWater, tMalaria) for Seven Seasons

Year 80% RH 80% RH District I District II District III Difference (days)

(DMN) (AGRHYMET) tMalaria - tWater

2004 July 7 June 30 Aug 8 Aug 8 Aug 8 32, 39

2005 June 30 June25 Jul 24 Jul 24 Jul 24 25, 29

2006 July 15 July 9 Aug 6 Aug 6 Aug 6 21, 28

2007 July 22 July 22 Aug 21 Aug 21 Aug 21 28, 28

2008 June 25 June 25 Jul 27 Jul 27 Jul 20 25, 32

2009 July 27 July 27 Aug 15 Aug 15 Aug 15 20, 34

2010 July 28 July 30 Boukoki clinic max cases on Sept 2 36, 34

EW112310H-0 13

Abrupt and Synchronous Increases in Mosquito Counts

Light Trap Measurements

EW112310H-0 14

Evolution of Hydrometeorology and Mosquitoes   2010 Wet Season

tWater

tMosquito tMalaria

EW112310H-0 15

Value of Time Markers

Time Marker Value

tWater

Focused deployment of larvacides

tMosquito

Focused deployment of insecticides

tMalaria

Focused deployment of clinic personnel and supply of medication

EW112310H-0 16

• Consistent time markers have been identified in the development of urban malaria in Niamey, Niger

• Greater integration of expertise in hydrometeorology, entomology and epidemiology are needed to combat this disease

Conclusion

EW112310H-0 17

Annual Deaths Due to Malaria Versus Annual Rainfall Total in Niamey, Niger

300 400 500 600 700 800 900200

300

400

500

600

1998

20022003

2004

2005

2006

De

ath

s in

Nia

me

y d

ue

to m

ala

ria

Annual rainfall for Aéroport gauge

EW112310H-0 18

Standing Water in Niamey, Niger

EW112310H-0 19

Standing Water in Niamey, Niger

EW112310H-0 20

Abrupt and Synchronous Increase in Malaria Cases

20 30 40 50

0

50

100

Week

Goudel

0

100

200 G.R.

080

160 Boukoki

0

100

200 Lazaret

0

80

160 Maourey

0200400600 Tondibiah

0

50

100 F. Kouara

0

50

100 Yantala Haut

0

50

100 Recasement

20 30 40 50

0

200

400

Week

Goudel

0100200 G.R.

0

80

160 Boukoki

0100200 Lazaret

0

80

160 Maourey

0100200300 Tondibiah

0100200300 F. Kouara

050

100150 Yantala Haut

0

100

200 Recasement

20 30 40 50

04080

120

Week

Goudel

0204060 G.R.

0200400 Boukoki

0100200300 Lazaret

0

100

200 Maourey0

100200 Tondibiah

080

160 F. Kouara

0

80

160 Yantala Haut0

4080

120 Recasement

EW112310H-0 21

Evidence for Abrupt Increases in Mosquito Populations

EW112310H-0 22

Flooding in Taladje Quartier Due to a Blocked

Drain

EW112310H-0 23

Aircraft Surveillance of Boukoki Gouro