Open Access

Knowledge of malaria influences the use of insecticide treated nets but not intermittent presumptive treatment by pregnant women in Tanzania

  • Rhoida Y Nganda1,
  • Chris Drakeley2, 3Email author,
  • Hugh Reyburn2, 3 and
  • Tanya Marchant2
Malaria Journal20043:42

DOI: 10.1186/1475-2875-3-42

Received: 06 August 2004

Accepted: 12 November 2004

Published: 12 November 2004

Abstract

Background

To reduce the intolerable burden of malaria in pregnancy, the Ministry of Health in Tanzania has recently adopted a policy of intermittent presumptive treatment for pregnant women using sulphadoxine-pyrimethamine (IPTp-SP). In addition, there is strong national commitment to increase distribution of insecticide treated nets (ITNs) among pregnant women. This study explores the determinants of uptake for both ITNs and IPTp-SP by pregnant women and the role that individual knowledge and socio-economic status has to play for each.

Methods

293 women were recruited post-partum at Kibaha District Hospital on the East African coast. The haemoglobin level of each woman was measured and a questionnaire administered.

Results

Use of both interventions was associated with a reduced risk of severe anaemia (Hb<8 g/dL) compared to women who had used neither intervention (OR 0.31, 95% CI 0.14–0.67). In a logistic regression model it was found that attendance at MCH health education sessions was the only factor that predicted IPTp-SP use (OR 1.8, 95% CI 1.1–2.9) while high knowledge of malaria predicted use of ITNs (OR 2.3, 95% CI 1.1–4.9).

Conclusion

Individual knowledge of malaria was an important factor for ITN uptake, but not for IPTp-SP use, which was reliant on delivery of information by MCH systems. When both these interventions were used, severe anaemia postpartum was reduced by 69% compared to use of neither, thus providing evidence of effectiveness of these interventions when used in combination.

Background

Plasmodium falciparum malaria in pregnancy poses a substantial risk to pregnant women and their offspring: it has been estimated that malaria in pregnancy is the primary cause of up to 10,000 maternal anaemia-related deaths in sub-Saharan Africa annually [1]. Further, malaria in pregnancy increases the risk of an infant being born with low birth weight (LBW) and is responsible for up to 35% of preventable LBW in malaria-endemic areas[2].

Over the last decade a body of evidence has accumulated which supports the use of both ITNs and IPTp-SP to reduce the adverse effects of malaria during pregnancy [1, 3, 4] and both these interventions are currently recommended by WHO [5]. In Tanzania it is now national policy to offer IPT-p with sulfadoxine-pyrimethamine (SP) for every pregnant woman attending Maternal and Child Health services (MCH). There is strong commitment in Tanzania to achieve the targets agreed on by African countries at the Abuja Conference of 60% coverage of ITNs for pregnant women by 2005 using social marketing strategies and a national voucher scheme [6] to improve access for pregnant women and their children. However, there are currently no reliable data in Tanzania on current levels of use of these interventions.

Evidence suggests that malaria treatment choices are affected by knowledge of the problem [7, 8]. The success in implementing preventive interventions amongst pregnant women in Tanzania is thus likely to be determined in part by awareness of malaria and the strategies available to prevent it. This study set out to explore the determinants of uptake for both ITNs and IPTp-SP by pregnant women, with particular regard to knowledge of malaria and socio-economic status, and to estimate the impact that reported use of either of these interventions had on the prevalence of severe anaemia in the post-partum period.

Methods

Setting

This research was carried out at Kibaha District Hospital in the Coastal Region of Tanzania, an area with moderate to high malaria transmission. The area is predominantly rural, supported by a mixture of subsistence and cash crop farming, with a peri-urban belt along the main Tanzania/Zambia highway which crosses the district.

Study participants

All post-natal women who had delivered their baby in the hospital during April/May 2003, but had not been admitted to hospital during the pregnancy, were eligible for inclusion in the study.

Study tools

From studies elsewhere [9] it was estimated that a samples size of 293 women would give sufficient power to show a difference in uptake of malaria interventions by knowledge of malaria. On each working day of the study the first 13 women to come out of the labour ward and who gave informed consent to participate were registered and interviewed. Haemoglobin level was determined at the time of interview using a portable β-haemoglobin photometer (HemoCue©, HemoCue AB, Ängelholm, Sweden). Women with Hb<11 g/dL were referred within the hospital system.

Definitions

Knowledge of malaria score (KoM)

Participants were assigned a 'knowledge of malaria score' (KoM) according to their responses to a series of seven closed questions (Table 1).
Table 1

Components of the knowledge score

Malaria in pregnancy statement:

Agreement

  

n/293

%

Risk of infection

Increases in pregnancy

270

92

Consequences

Low birth weight

81

28

 

Pregnancy Loss

112

38

 

Maternal anaemia

150

51

Best Interventions*

ITN

266

91

 

SP

115

39

Transmission

Mosquitoes alone

102

35

*Women asked to state up to two malaria interventions

ITN users

Women who reported that during this pregnancy they had normally (i.e. >75% of the time) slept under a bednet which had been impregnated within the previous six months.

IPTp-SP users

Use of intermittent presumptive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine.

Severe anaemia

Severe anaemia post-partum was defined as Hb<8 g/dL.

Data analysis

Data were entered twice in Epi-Info version 6.04 and analysed in Stata version 7 (Stata Corporation, Texas USA). Evidence of an association was sought between the variables listed in Table 1 and the study outcomes (reported use of interventions or severe anaemia defined as Hb<8 g/dl). Variables found to have an association with each outcome (by χ2 P-value <0.10 or Mantel-Haenszel estimate of the rate ratio, P-value <0.10) were further analysed using multiple logistic regression. Significance in the multi-variate models was defined by a likelihood-ratio test (LRT) P-value <0.05.

Results

A completed questionnaire and measurement of haemoglobin level were available for 293 post-partum women whose characteristics are shown in Table 1. The group was predominantly made up of married women in the 20–29 years age-group, with primary level education only. Both urban and rural residents were represented. No women refused to participate.

Levels of knowledge

The KoM assessment consisted of four parts: knowledge of risk, consequences of risk, transmission and prevention, with seven questions in total (Table 1). Each question contributed one point to the overall KoM score (i.e. range of possible scores of 0–7) and overall the mean score was 3.7 (median 4). The KoM score was stratified into three groups: score 0–2 representing low (29% of respondents), score 3–4 representing median (38%) and score 5–7 representing high levels of knowledge (33% of respondents).

The lowest knowledge scores related to the impact of maternal malaria on the health of the foetus; only 28% (81/293) recognized low birth weight and 38% (112/293) pregnancy loss as a potential consequence of maternal malaria. There was also some confusion over the mode of transmission of malaria: 95% (279/293) agreed that mosquitoes could transmit malaria but only 35% thought that mosquitoes alone were responsible (excepting blood transfusion).

Having high KoM was strongly associated with education level (χ2 for linear trend 50.03, p < 0.0001). Because of colinearity between education level and high KoM, education was excluded from the logistic regression model used to identify determinants of high KoM. However, models for primary and secondary education respectively showed the same socio-economic effects as the data presented in Table 3. In the logistic regression model, only ages above teenage (LRT 9.8, p = 0.007), ownership of a radio (LRT 6.0, p = 0.01), ownership of a bicycle (LRT 4.8, p = 0.02) and citing the MCH rather than the community as the most important source of health information (LRT 7.5, p = 0.02) were significantly associated with a high KoM compared to low/median KoM.
Table 3

Unadjusted and adjusted OR's for characteristics of women with high knowledge of malaria1.

  

N

Unadjusted OR

Confidence Interval

Adjusted OR

Confidence Interval

LRT

P

Age

15–19

49

1.0

-

1.0

-

  
 

20–29

185

3.3

1.4–7.8

3.2

1.2–8.4

  
 

30+

59

4.4

1.7–11.4

4.6

1.6–13.3

9.8

<0.01

Radio

No

29

1.0

-

1.0

-

  
 

Yes

264

7.7

1.7–33.1

5.1

1.1–24.0

6.0

0.01

Bicycle

No

69

1.0

-

1.0

-

  
 

Yes

224

2.3

1.2–4.5

2.1

1.0–4.3

4.8

0.02

Source of health information

Community

36

1.0

-

1.0

-

  
 

MCH

83

5.8

11.8–18.0

4.3

1.3–14.0

  
 

Media

174

4.1

1.3–12.1

2.6

0.8–8.1

7.5

0.02

1All women with high malaria knowledge had formal schooling

Use of IPT-p or ITN

48% (141/293) of women were ITN users, 57% (166/293) had received IPTp-SP once and 12% (34/293) IPTp-SP twice. A multi-variate analysis of factors influencing the uptake of these two interventions is shown in Table 4. After adjustment, increasing age (LRT 10.3, P = < 0.01), owning a radio (LRT 4.0, P = 0.04) and having a high KoM, compared to a low/median KoM score (LRT 7.3, P = 0.02), were the only factors that independently predicted use of an ITN in pregnancy (table 4). By contrast, only a history of having received health education during the pregnancy significantly predicted uptake of any dose of IPTp-SP (LRT 5.6 p = 0.01).
Table 4

Factors associated with uptake of insecticide treated nets (ITNs) during pregnancy and at least one dose of sulphadoxine-pyrimethamine as part of intermittent presumptive treatment (IPTp-SP)

 

N

ITN users

Unadjusted OR

95% Confidence Interval

Adjusted OR

95% Confidence Interval

LRT

P

Health Education

       

No

160

      

Yes

133

      

Age

       

15–19

49

1.0

-

1.0

-

  

20–29

185

3.2

1.6–6.1

2.5

1.3–5.0

  

30+

59

4.2

1.8–10.3

3.8

1.5–9.4

10.3

<0.01

Knowledge

       

Low

86

1.0

-

1.0

-

  

Medium

110

1.3

0.7–2.3

1.0

0.5–1.8

  

High

97

3.6

1.7–7.1

2.3

1.1–4.9

7.3

0.02

Radio

       

No

29

1.0

-

1.0

-

  

Yes

264

2.9

1.3–6.3

2.3

1.0–5.5

4.0

0.04

  

Used IPTp-SP

     
  

Unadjusted OR

95% Confidence Interval

Adjusted OR

95% Confidence Interval

LRT

p

Health Education

       

No

160

1.0

-

1.0

-

  

Yes

133

1.8

1.1–2.9

1.8

1.1–2.8

5.6

0.01

Age

       

15–19

49

1.0

-

1.0

-

  

20–29

185

0.8

0.4–1.6

0.8

0.4–1.6

  

30+

59

0.9

0.4–2.0

0.7

0.3–1.7

0.4

0.8

Knowledge

       

Low

86

1.0

-

1.0

-

  

Medium

110

1.7

1.0–3.0

1.7

1.0–3.1

  

High

97

1.6

0.9–2.9

1.6

0.8–2.9

3.8

0.14

Radio

       

No

29

      

Yes

264

      

41% (120/293) of women had used both interventions. Women with a median KoM were twice as likely (OR 2.1 (95% CI 1.1–4.0) and women with a high KoM three times more likely (OR 3.2 (95% CI 1.7–6.0) to have used both IPT-p and an ITN than women with low KoM scores.

Timing of first MCH attendance

26% (76/293) of women had first attended the MCH during the first trimester, 65% (192/293) during the second trimester and 9% (25/293) during the third trimester of pregnancy. Predictably the median number of visits to MCH by women was correlated with the trimester of first visit: first trimester – median of 7.5 visits overall (mean 6.9 (s.d.2.2), second trimester – median of 5 visits overall (mean 5.4 (s.d.1.8) & third trimester – median of 2 visits overall (mean 2.4 (s.d.0.8). Women attending MCH for the first time during their first trimester were more than twice as likely to have attended health education sessions as women attending for the first time in their third trimester (χ2 test for trend 5.1, p = 0.02).

Risk factors for severe anaemia

Overall, 27% (80/293) of study participants had Hb<8 g/dL immediately post-partum. In the regression model, three factors were found to independently predict the risk of having severe anaemia in the post-partum period (Table 5). Firstly, with women using either an ITN or IPTp-SP alone, there was a reduced risk of severe anaemia, but it was not statistically significant (OR 0.77 (CI 0.36–1.65 and OR 0.70 (CI 0.34–1.41 respectively). However, the use of an ITN in conjunction with IPTp-SP was associated with a significant reduction in risk of being severely anaemic post partum compared to women not using any intervention (OR 0.31 (CI 0.14–0.67) LRT 10.1 p = 0.01). Secondly, having had any level of education (as compared to none) and, thirdly, attendance at the MCH clinic during the first rather than third trimester of pregnancy were both associated with a reduced risk of severe anaemia (OR 0.41, 95% CI 0.17–0.98) LRT 4.5 p = 0.03 and OR 0.31, 95%CI 0.11–0.83, LRT 5.3 p = 0.05 respectively).
Table 5

Risk factors for severe anaemia post partum.

 

% with severe anaemia

Unadjusted OR

95% confidence interval

Adjusted OR

95% confidence interval

LRT

P

Formal education

       

No

29

1.00

-

1.00

-

  

Yes

16

0.45

0.19–1.07

0.41

0.17–0.98

4.5

0.03

Time of first ANC use

       

3rd trimester

48

1.00

-

1.00

-

  

2nd trimester

26

0.39

0.16–0.91

0.41

0.17–1.0

  

1st trimester

22

0.31

0.12–0.80

0.31

0.11–0.83

5.3

0.05

Use of malaria intervention

       

None

37

1.00

-

1.00

-

  

ITN only

32

0.82

0.39–1.71

0.77

0.36–1.65

  

IPTp-SP only

27

0.64

0.32–1.28

0.70

0.34–1.41

  

ITN + IPTp-SP

16

0.34

0.16–0.72

0.31

0.14–0.67

10.1

0.01

Discussion

The key finding was that while knowledge, wealth and age were all found to be independently predictive of ITN use, only participation in health education was associated with use of IPTp-SP. That predictors of uptake for each of the two interventions were different was an interesting and unexpected finding. The data indicate that, while ITN use is driven by both access (i.e. wealth) as well as knowledge, use of IPTp is determined by its being offered in an MCH clinic. This is a positive finding that suggests the need to prioritise strategies for maximising early attendance to boost IPTp-SP uptake.

This finding is in contrast to research from Kenya which showed that uptake of IPTp-SP increased with higher levels of formal education [9]. The National Malaria Control Programme of Tanzania does not currently have any data on IPTp-SP uptake nationally, although it is planned for integration into routine surveillance next year. It is likely that distribution systems for this, as other clinic based interventions, will need more attention. It is possible that the new MCH clinic based voucher system for ITN will have an added benefit by increasing early attendance and therefore uptake of IPTp-SP.

These findings on knowledge and awareness suggest that the increased risk posed to pregnant women by malaria was almost universally recognized, but that knowledge of the health impact of that risk – especially to the health of the foetus – was very low. Over 90% of women thought that ITNs were a good intervention against malaria in pregnancy, but less than half thought the same about IPTp-SP. Knowledge of malaria in pregnancy was strongly associated with use of a combination of both ITN and IPTp. Although this was a small observational study where it was not possible to control for all likely confounding variables, there is evidence that the use of a combination of ITN use and IPT-p provides additive protection against severe anaemia, and that this effect is not confined to trial conditions. Use of an ITN or IPT-p alone was associated with a 23% and 30% reduction in the risk of severe anaemia post partum respectively, similar to estimates from other controlled trials [10, 11] The data suggest that MCH services are effective when used optimally. Women who accessed MCH services in their first trimester of pregnancy had a significantly lower risk of severe anaemia post-partum compared to women who first presented at MCH during their third trimester. Women attending MCH earlier were more likely to attend health education sessions, and women who attended health education sessions more likely to use IPTp-SP than women who did not attend. Women with high KoM were most likely to cite the MCH as their most important source of health information.

It must be noted that by recruiting only women who had uncomplicated pregnancies and who delivered in hospital this study had a selection bias towards the healthier and possibly wealthy members of the community. However, women from a considerable range of socio-economic situations are represented (no education vs. further education; mobile phone owners vs. not owning a radio) which probably reflects the rural/peri-urban catchment area of Kibaha and other newly urbanised areas. The data has shown that many of the factors indicative of relative wealth in a poor community were associated with increasing levels of knowledge – and that knowledge was positively associated with multiple intervention uptake and improved health outcome.

The importance of access to resources has been illustrated previously for both preventative interventions and treatment [12]. At the time of this study, IPTp-SP was offered free of charge to pregnant women via the antenatal clinics in Tanzania. There is social marketing of bednets (price approx $5) at the national level but not targeted at specific high risk groups. The newly initiated ITN voucher scheme for pregnant women is part of the Tanzanian commitment to improve access to ITNs for pregnant women as a whole. It is hoped that via mass health education and substantial price subsidy, some of these socio-economic inequities in access will also be addressed.
Table 2

Socio-economic breakdown of population.

  

n/293

%

Age

15–19

49

17

 

20–29

185

63

 

30+

59

20

Gravidity

Primigravidae

124

42

 

Mutigravidae

169

58

Residence

Urban

124

42

 

Rural

169

58

Education

None

44

15

 

Primary

217

74

 

Secondary +

32

11

Marital status

Married

207

71

 

Unmarried

86

29

Travel time to MCH

< 1 hour

252

86

 

1–2 hours

20

7

 

>2 hours

21

7

Household ownership

Radio

264

90

 

Bicycle

224

76

 

TV

16

5

 

M/phone

13

4

 

Bednet

245

83

Religion

Christian

104

35

 

Moslem

189

65

Main source of health information

Community

36

12

 

Health workers

83

28

 

Media

174

59

Used IPTp-SP

Once

166

57

 

Twice

34

12

Used bednet

Yes

207

71

Used ITN

Yes

141

48

Health education MCH

Yes

133

45

Knowledge score

Low

86

29

 

Medium

110

38

 

High

97

33

Conclusions

The findings highlight the importance of women's knowledge of malaria in pregnancy and of antenatal attendance for the uptake of preventative interventions. Now that effective malaria interventions are available and there is political will to implement them, to maximise the potential for health impact, it is essential to empower the intended recipients of interventions by providing the knowledge which can influence their health decisions.

Declarations

Acknowledgements

The authors thank the women who participated in the study and the staff of the maternity ward at Kibaha hospital for their cooperation. This research was conducted as partial fulfilment of the Degree of Master of Public Health of Tumaini University, Kilimanjaro Christian Medical Centre, and in collaboration with the Joint Malaria Programme, Tanzania. The Joint Malaria Programme is a collaboration between the National Institute for Medical Research (NIMR), Kilimanjaro Christian Medical College (KCMC), the London School of Hygiene and Tropical Medicine (LSHTM) and the Centre for Medical Parasitology, University of Copenhagen (CMP). During the period of study RN was jointly supported by United States Agency for International Development and the Ministry of Health, Tanzania.

Authors’ Affiliations

(1)
Kilimanjaro Christian Medical Centre
(2)
Joint Malaria Programme
(3)
London School of Hygiene and Tropical Medicine

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Copyright

© Nganda et al; licensee BioMed Central Ltd. 2004

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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