Lives at Risk: Malaria in pregnancy

Malaria Epidemiology Branch, Division of Parasitic DiseasesU.S. Centers for Disease Control and Prevention

The burden of malaria in pregnancy

45 million pregnancies in malarious areas; 23 million in sub-Saharan Africa

Estimated 200,000 Low Birth Weight pregnancies/year

Placental infection contributes to: 15% of maternal anemia 8-14% of all low birth weight 30% of preventable low birth weight 3-8% of infant mortality

Malaria in Pregnancy Malaria in Pregnancy High Transmission AreasHigh Transmission Areas

Altered Placental Integrity

Less Nutrient Transport

Placental Sequestration

Low Birth Weight Excess Infant Mortality

Asymptomatic infection

Anaemia

Acquired immunity - high

1st & 2nd pregnancies

HIV infection extends this to all pregnancies, and makes it worse

Neonatal Mortality Rates by BirthweightMangochi, Malawi -- September 1987 - June 1989

0

200

400

600

800

1000

<1500 1500-1999 200-2499 2500

Death

s p

er

1000 L

ive B

irth

s

800

300

49 26

31 11.7 2.4 1.0Relative Risk

Placental parasitemia by pregnancy number, Kisumu, Kenya, 1996-98

0

5

10

15

20

25

30

1st 2nd 3rd or greater

1-999 1000-9999 >10,000

Parasite density/mm3

% parasitemic

772 402 479

Pregnancy number

Placental parasitemia by HIV status and pregnancy number, Kisumu, Kenya, 1996-98

0

5

10

15

20

25

30

35

40

G1 G2 G3 G1 G2 G3

1-999 1000-9999 >10,000

Parasite density/mm3

% parasitemic

HIV (+) HIV (-)

231 159 197 772 402 479

Total n = 2263Summary RR = 1.63 (1.41-1.89), p<0.001

Low birth weight

Factors Contributing to Low Birth Weight - Developing Countries

Nonwhite race

Low caloric intake or wt gain

Low prepregnancy wt

Short stature

Malaria

Female sex

Primiparity

Maternal LBW/History LBW

General morbidity

Small paternal size/other

Factors Contributing to Low Birth Weight – that are amenable to intervention during pregnancy

Low caloric intake or wt gain

Malaria

General morbidity

Contribution of Prematurity and IUGR to Low Birth Weight

Mangochi, Malawi

Adapted from Steketee et al.

82%

8

18

Normal Birthweight

Low Birthweight

PrematurityNMR* 245/1000

IUGRNMR* 52/1000

18%

All InfantsN=1,618

Low BirthweightN=297

*Neonatal Mortality Rate

Frequency of Low Birth Weight by placental malaria infection,

Malawi 1988-91

0

5

10

15

20

25

30

35

Grav 1 Grav 2 Grav 3+

Placental +

Placental -

% Low Birth weight

Malaria in PregnancyMalaria in PregnancyOpportunities for InterventionOpportunities for Intervention

Program opportunity in areas of Africa with greatest LBW > 60% women

attend ANC Drugs

Intermittent Preventive Treatment (IPT)Case Management

Insecticide Treated Nets (ITN) Treatment of anemia

Iron/folateNutritional counseling

Antenatal care in AfricaAntenatal care in AfricaProportion of Pregnant Women Seeking Antenatal Clinic CareProportion of Pregnant Women Seeking Antenatal Clinic Care

0

10

20

30

40

50

60

70

80

90

100

Countries

Zambia-96Rwanda-92Zimbabwe-94Botswana-88Kenya-98Uganda-95Malawi-92Tanzania-96Ghana-98Namibia-92Comoros-96Cote d'Ivoire-94Senegal-97Liberia-86Togo-98Benin-96Cameroon-98Madagascar-97Guinea-99Sudan-90Mozambique-97CAR-94Burkina Faso-99Nigeria-90Eritrea-95Mali-96Niger-98Chad-97

Demographic and Health Surveys

• Preventive intermittent treatment (PIT)

• Insecticide treated nets (ITN)

• Treatment and Care of acute cases of malaria during pregnancy

Interventions to addressmalaria in pregnancy

Providing antimalarial treatment dose at scheduled antenatal clinic visits

• Shown to:

• Substantial improvement in maternal anemia

• >50% reduction in placental malaria rates

• 20-25% reduction in low birth weight rates

Preventive intermittent treatment (PIT)

Intermittent Preventive TherapyIntermittent Preventive Therapy- the monthly clinic dosing strategy-- the monthly clinic dosing strategy-

Weeks of gestationConception Birth

20 3010Quickening

Rx Rx Rx Rx

Insecticide Treated Materials

Bednets: Birth OutcomeBednets: Birth OutcomeGravidae 1-4

0

5

10

15

20

25

30

35

Stillb

irth/

aborti

on

Prete

rm d

eliv

ery

SGA

Low b

irth w

eigh

t

LBW o

r PTD o

r SG

A

Any ad

vers

e ou

tcom

e

Pre

vale

nce

(%

)

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Pre

vale

nce

rat

io

control

bednet

PR (95% CI)

ter Kuile 2001Kenya

Impact of ITNs on maternal and infant health, western Kenya

• During pregnancy 38% reduction in peripheral parasitemia 21% reduction in all cause anemia (Hb < 11 g/dl) 47% reduction in severe malarial anemia

At delivery 23% reduction in placental malaria 28% reduction in LBW 25% reduction in any adverse birth outcome

Interventions to address malaria in pregnancy

Intermittent preventive treatment

Insecticide-treated materials

Case management

UNICEF/C-55-10/Watson

Malaria in Mothers and Infants

Non-pregnantNon-pregnant PregnancyPregnancy Post-partumPost-partum

InfancyInfancy

Insecticide-treated nets

IPT

Case management

Malaria Control during PregnancyImplementation Package(s)

IPTIPT ITNsITNs

CMCM

ANCANCANCANCPrivatePrivateSectorSector

FacilitiesFacilitiesCommunityCommunity

Summary The effect of malaria during pregnancy on morbidity and mortality is: documented; consistent across

studies; amenable to interventions applied during the current pregnancy

The malaria effect is linked with anemia & HIV

Today, the tragedy rests in the failure to apply existing effective control measures