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Varying efficacy of intermittent preventive treatment for malaria in infants in two similar trials: public health implications.

Menendez C, Schellenberg D, Macete E, Aide P, Kahigwa E, Sanz S, Aponte JJ, Sacarlal J, Mshinda H, Tanner M, Alonso PL - Malar. J. (2007)

Bottom Line: The most relevant difference was in ITN's use ; 68% in Ifakara and zero in Manhiça.In Ifakara, IPTi was associated with a 53% (95% CI 14.0; 74.1) reduction in the risk of clinical malaria between the second and the third dose; during the same period there was no significant effect in Manhiça.Manhiça study registration number: NCT00209795Ifakara study registration number: NCT88523834.

View Article: PubMed Central - HTML - PubMed

Affiliation: Barcelona Center for International Health Research (CRESIB), Hospital Clinic, Institut d'Investigacions Biomedicas August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Spain. menendez@clinic.ub.es

ABSTRACT

Background: Intermittent preventive treatment (IPTi) with sulphadoxine-pyrimethamine (SP) in infants resulted in different estimates of clinical malaria protection in two trials that used the same protocol in Ifakara, Tanzania, and Manhiça, Mozambique. Understanding the reasons for the discrepant results will help to elucidate the action mechanism of this intervention, which is essential for rational policy formulation.

Methods: A comparative analysis of two IPTi trials that used the same study design, follow-up, intervention, procedures and assessment of outcomes, in Tanzania and Mozambique was undertaken. Children were randomised to receive either SP or placebo administered 3 times alongside routine vaccinations delivered through the Expanded Program on Immunisation (EPI). Characteristics of the two areas and efficacy on clinical malaria after each dose were compared.

Results: The most relevant difference was in ITN's use ; 68% in Ifakara and zero in Manhiça. In Ifakara, IPTi was associated with a 53% (95% CI 14.0; 74.1) reduction in the risk of clinical malaria between the second and the third dose; during the same period there was no significant effect in Manhiça. Similarly, protection against malaria episodes was maintained in Ifakara during 6 months after dose 3, but no effect of IPTi was observed in Manhiça.

Conclusion: The high ITN coverage in Ifakara is the most likely explanation for the difference in IPTi efficacy on clinical malaria. Combination of IPTi and ITNs may be the most cost-effective tool for malaria control currently available, and needs to be explored in current and future studies.

Trial registration: Manhiça study registration number: NCT00209795Ifakara study registration number: NCT88523834.

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a. Individual timeline Ifakara. b. Individual timeline Manhiça.
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Figure 1: a. Individual timeline Ifakara. b. Individual timeline Manhiça.

Mentions: Detailed descriptions of the Ifakara [4] and Manhica trials are provided elsewhere [6]. Briefly, in Ifakara infants were recruited at the MCH clinic immediately after receiving dose 2 of DTP/OPV between August 1999 and April 2000. IPTi was given at ages 2, 3, and 9 months alongside routine EPI vaccinations (Figure 1a). In Manhiça, children were recruited from those attending the EPI clinic to receive dose 2 of DTP/OPV/Hep B between September 2002 and February 2004 (Figure 1b). Identical randomization, blinding, treatment concealment and allocation procedures and inclusion and exclusion criteria were followed in each study. Tablets of SP and placebo (consisting of lactose and maize starch) were identical in shape and color and stored in bottles labeled only with a single treatment identification letter by investigators not involved in the studies. Placebo and SP tablets were provided by the same manufacturer (Hoffman La Roche, Basel, Switzerland). Doses of SP/placebo were administered by a health assistant according to body weight (< 5 kg-1/4 tablet, 5–10 kg-1/2 tablet, > 10 kg-1 tablet), crushed and mixed with water on a tablespoon.


Varying efficacy of intermittent preventive treatment for malaria in infants in two similar trials: public health implications.

Menendez C, Schellenberg D, Macete E, Aide P, Kahigwa E, Sanz S, Aponte JJ, Sacarlal J, Mshinda H, Tanner M, Alonso PL - Malar. J. (2007)

a. Individual timeline Ifakara. b. Individual timeline Manhiça.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2100068&req=5

Figure 1: a. Individual timeline Ifakara. b. Individual timeline Manhiça.
Mentions: Detailed descriptions of the Ifakara [4] and Manhica trials are provided elsewhere [6]. Briefly, in Ifakara infants were recruited at the MCH clinic immediately after receiving dose 2 of DTP/OPV between August 1999 and April 2000. IPTi was given at ages 2, 3, and 9 months alongside routine EPI vaccinations (Figure 1a). In Manhiça, children were recruited from those attending the EPI clinic to receive dose 2 of DTP/OPV/Hep B between September 2002 and February 2004 (Figure 1b). Identical randomization, blinding, treatment concealment and allocation procedures and inclusion and exclusion criteria were followed in each study. Tablets of SP and placebo (consisting of lactose and maize starch) were identical in shape and color and stored in bottles labeled only with a single treatment identification letter by investigators not involved in the studies. Placebo and SP tablets were provided by the same manufacturer (Hoffman La Roche, Basel, Switzerland). Doses of SP/placebo were administered by a health assistant according to body weight (< 5 kg-1/4 tablet, 5–10 kg-1/2 tablet, > 10 kg-1 tablet), crushed and mixed with water on a tablespoon.

Bottom Line: The most relevant difference was in ITN's use ; 68% in Ifakara and zero in Manhiça.In Ifakara, IPTi was associated with a 53% (95% CI 14.0; 74.1) reduction in the risk of clinical malaria between the second and the third dose; during the same period there was no significant effect in Manhiça.Manhiça study registration number: NCT00209795Ifakara study registration number: NCT88523834.

View Article: PubMed Central - HTML - PubMed

Affiliation: Barcelona Center for International Health Research (CRESIB), Hospital Clinic, Institut d'Investigacions Biomedicas August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Spain. menendez@clinic.ub.es

ABSTRACT

Background: Intermittent preventive treatment (IPTi) with sulphadoxine-pyrimethamine (SP) in infants resulted in different estimates of clinical malaria protection in two trials that used the same protocol in Ifakara, Tanzania, and Manhiça, Mozambique. Understanding the reasons for the discrepant results will help to elucidate the action mechanism of this intervention, which is essential for rational policy formulation.

Methods: A comparative analysis of two IPTi trials that used the same study design, follow-up, intervention, procedures and assessment of outcomes, in Tanzania and Mozambique was undertaken. Children were randomised to receive either SP or placebo administered 3 times alongside routine vaccinations delivered through the Expanded Program on Immunisation (EPI). Characteristics of the two areas and efficacy on clinical malaria after each dose were compared.

Results: The most relevant difference was in ITN's use ; 68% in Ifakara and zero in Manhiça. In Ifakara, IPTi was associated with a 53% (95% CI 14.0; 74.1) reduction in the risk of clinical malaria between the second and the third dose; during the same period there was no significant effect in Manhiça. Similarly, protection against malaria episodes was maintained in Ifakara during 6 months after dose 3, but no effect of IPTi was observed in Manhiça.

Conclusion: The high ITN coverage in Ifakara is the most likely explanation for the difference in IPTi efficacy on clinical malaria. Combination of IPTi and ITNs may be the most cost-effective tool for malaria control currently available, and needs to be explored in current and future studies.

Trial registration: Manhiça study registration number: NCT00209795Ifakara study registration number: NCT88523834.

Show MeSH
Related in: MedlinePlus