The KEMRI/CDC Health & Demographic Surveillance System

Kayla Laserson, ScDDirector, KEMRI/CDC Program

KEMRI/CDC Field Research StationKisumu, Kenya

Introduction

Timely and accurate population-based information is critical in the fight against disease and poverty

The Millennium Development Goals as a framework for poverty reduction and sustainable development comes with obligations to monitor progress

Global health initiatives like the Global Fund to combat AIDS, TB and Malaria, PEPFAR, or PMI require monitoring of progress and evaluation of impact

The KEMRI/CDC DSS

• Provides a platform for action-oriented research to test and evaluate public health interventions

• Provides a suitable sampling frame for clinical research, including vaccine trials

Provides timely information for policy formulation and rational resource allocation

Nyanza ProvinceMalaria – intense and holoendemic: highest incidence in country (EIR 100-300 annually)

HIV highest prevalence in country (15%, DHS)

TB – greatest burden in Kenya

Other infectious diseasesSchistosomiasis endemic Diarrhea (Shigellae including dysenteriae, cholera, rotavirus)

Demographic Surveillance System (DSS)

Launched in September 2001 • As a collaborative effort between the Kenya Medical Research

Institute (KEMRI) and the Centers for Disease Control and Prevention (CDC)

Continuous demographic monitoring of a geographically defined population in Bondo and Siaya districts, Nyanza province• 135,000 since 2001[Asembo and Gem]; 85,000 added in April

2007 [Karemo]• Birth rates• Mortality rates• Causes of death• Morbidity• Migration• Socio-economic indicators• EIR data since 1990’s• Includes Siaya District Hospital

q

q

q

q

q

0 10 20 Kilometers

Lwak H.

Asembo

GemKaremo

KombewaBondo D. H.

Kombewa Sub D.H.

Siaya D. H.

Yala Sub D.H.

*Kisian

*Kisumu

The Demographic Surveillance Area

Lake Victoria

DSS Methods

KEMRI/CDC DSS Study Area

Field Operations and Data Processing

Mapping of compounds and enumeration of households

Household surveillance and socio-economic surveys• Immunization survey• HIV status/ care-seeking survey• Marriage status form

Health facility surveillance

Entomology surveillance and insecticide treated bednets

Quality control

Data entry and management

Verbal Autopsy (VA)Indirect method of ascertaining cause of death from information about symptoms and signs obtained from bereaved relatives

Conducted for both children & adults• Child VA data (from 2001 to date)• Adult VA data (from 2003 to date)

Both questionnaires (child and adult) adopted from INDEPTH

Results

The Surveillance Population: Asembo and Gem

Population: 135,887 (2005 mid-year pop.)• 95% Luo ethnic group• 217 villages, 500 sq km• Males: 47%• Children <15 years: 44%• Children <5 years: 16%• Adults ≥65+: 7%• Total Fertility Rate = 5.2•• Rural subsistence Rural subsistence

agriculture, fishingagriculture, fishing

20.0 15.0 10.0 5.0 0.0 5.0 10.0 15.0 20.0

0-4

15-19

30-34

45-49

60-64

75-79

90-94

Age

Proportion (%)

Male Female

Age Specific Migration Rates by Year (Males)

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50

100

150

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300

350

0-4 10-14 20-24 30-34 40-44 50-54 60-64

Age group

Out

-mig

ratio

n ra

te (p

er 1

,000

pyo

) 2003 2004 2005 2006

0

50

100

150

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0-4 10-14 20-24 30-34 40-44 50-54 60-64

Age group

In-m

igra

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(per

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00 p

yo)

2003 2004 2005 2006

Out Migration

In Migration

Age Specific Migration Rates by Year (Females)

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50

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0-4 10-14 20-24 30-34 40-44 50-54 60-64

Age group

Out

-mig

ratio

n ra

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er1,

000

pyo)

2003 2004 2005 2006

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0-4 10-14 20-24 30-34 40-44 50-54 60-64

Age group

In-m

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2003 2004 2005 2006

Out Migration

In Migration

Causes of Clinic Attendance Among Children, 2003-2006

0

10

20

30

40

50

60

70

80

90

Malaria URTI Worms Gastroenteritis Pneumonia Diarrhea Anemia

Diagnosis

% o

f sic

k vi

sits

2003 2004 2005 2006

Life Expectancy at Birth for the Resident Population, 2002-2006

36.137.6 38.7

41.739.7 39.9

4344.8

0

10

20

30

40

50

2003 2004 2005 2006

Life

exp

ecta

ncy

at b

irth

(yrs

)

Males

Females

Age-specific Mortality Rates (2003-2006)

0

20

40

60

80

100

120

140

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180

0-4 10-14 20-24 30-34 40-44 50-54 60-64 70-74 80+

Age at Death

Mor

talit

y ra

te (p

er 1

,000

pyo

) Male Female

121/1000 live births – IMR (2005)241/1000 live births – U5MR (2005)

Causes of Death Among Infants and Children, 2003-2005

0

5

10

15

20

25

30

35

Malaria

Pneumonia

Anemia

Dehydratio

n

Diarrhoea/V

omiting

Malnutrition

Meningitis

HIV/TB

Undetermined

Others

Prop

ortio

n (%

) dea

ths

2003 2004 2005

Causes of Death Among Adults and Adolescents, 2003-2006

0

10

20

30

40

50

60

70

HIV/TB

Malaria

Pneumoni

a

Anemia

Dehyd

ratio

n/Diar

rhea

Stroke

/CCF

Menin

gitis

Injur

y

Other

s

Prop

ortio

n (%

) dea

ths

2003 2004 2005 2006

HIV Prevalence by Age & Sex, 2003/2004

1 1

10

18

3632

20

10

41

3033

0

10

20

30

40

50

13-14 15-19 20-24 25-29 30-34 All

Age group

Prev

alen

ce (%

)

Male Female

School Enrollment for Residents Aged 6-9, 2002-2006

0

20

40

60

80

100

Age 6 Age 7 Age 8 Age 9

Prro

port

ion

(%) e

nrol

led

2003200420052006

School Dropout

Approximately 9% of children aged 10-17 dropped out of school in 2003-2006

Reasons proffered for drop out include– Inability to pay fees– Ill health (of child or parent)– Poor performance– Early marriage and child bearing

Operational Research in the DSS

KEMRI/CDC DSS allows operational research where malaria transmission is intense, ITN coverage is high, and HIV prevalence is high

Expansion to include Siaya District Hospital will facilitate more clinic-based research– Siaya District Hospital Annex, with pharmacy, laboratory,

surgical suite, patient support center, and training/conference rooms, will allow rigorous clinical trial research

Malaria– Drug efficacy, including in pregnant and HIV(+) persons– Intermittent preventive treatment of malaria in infants/

pregnant mothers– Transmission reduction

• ITN coverage use, resistance• Larval breeding sites• Vector control interventions

Tuberculosis– TB prevalence survey

SchistosomiasisEmerging infections – Population-based morbidity surveillance– Diarrheal diseases surveillance: incidence and etiology– Expanded flu/respiratory surveillance

Operational Research in the DSS

Operational Research in the DSSHIV – Baseline cross-sectional surveys– Collection of self-reported status, care-seeking– Impact of ARVs at population level – Orphan prevalence/incidence – Planned comprehensive evaluation of HIV home-based

testing, community-based care and treatment service delivery, and circumcision uptake and feasibility

Vaccine trials• Rotavirus – Phase III• Malaria – Phase III• TB vaccine trial site development

Training and Collaborations in the DSS

Training– Provide data for MA theses & PhD dissertations– Data for epidemiological capacity building

Cross-site collaboration – Contributed data to the cross-site cause-specific

mortality analysis initiated by the INDEPTH and published in WHO Bulletin 84(3)

– Contributed data to the cross-site “Patterns of age-specific malaria mortality in children in endemic areas of sub-Saharan Africa” initiated by the INDEPTH and accepted for publication AJTMH

– Participating in the cross-site HIV research proposal initiated by INDEPTH

– Contributing a chapter to the INDEPTH monograph on Migration, Urbanization & Health

Concluding Remarks

The KEMRI/CDC DSS data have shown excessively high mortality and morbidity rates among the DSS residents– Resulting largely from infectious diseases (malaria &

HIV/AIDS)

The life expectancy at birth for the resident population is among the lowest in the world, but appears to be improving

The morbidity and mortality epidemiological profile in the KEMRI/CDC DSS is well-characterized; the DSS is well-positioned, and intends, to provide the platform to measure the impact of coming interventions (vaccines, scale up of HIV services, etc)

AcknowledgementsDr Adazu KubajeDSS staffKEMRI/CDC program, past and presentDr John Vulule, KEMRI

EXTRA SLIDES

Age Specific Migration Rates by Sex

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0-4 10-14 20-24 30-34 40-44 50-54 60-64

Age

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pyo

)Male_out Female_out

Male

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Out migration

In migration

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Num

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f vi

sits

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Mar Apr

May Jun

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12-59 mo 0-11 mo

Monthly Clinic Attendance Among Children, 2003-2006

Reasons for Dropping Out Among Children Aged 10-17 (KHDSS, 2003)

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10

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50

Death/si

ck Paren

tMarria

ge/p regnancy Fee

Poor perfo

rmance

Employment

Expelled

Il health

Reason

Pro

porti

on (%

) of d

ropo

uts

Male

Female

Age-specific Mortality Rates by Year (2003-2006)

0

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0-4 10-14 20-24 30-34 40-44 50-54 60-64 70-74 80+

Age at Death

Mor

talit

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er 1

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pyo

) 2003 2004 2005 2006

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Age at Death

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2003 2004 2005 2006

Males

Females

Literacy by Sex for Residents aged 10+, 2003-2006

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100

Male03 Female03 Male04 Female04 Male05 Female05 Male06 Female06

Prop

otio

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) of p

opul

atio

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Not at all With dif f iculty Easily