Research
Sub-microscopic infections and long-term recrudescence of Plasmodium falciparum in Mozambican pregnant women
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* Corresponding author: Alfredo Mayor agmayor@clinic.ub.es
1 Centre de Recerca en Salut Internacional de Barcelona, Hospital Clínic/Institut d'Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, Rosselló 132, E-08036 Barcelona, Spain
2 Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique
3 Direcção Nacional de Saúde/Instituto Nacional de Saúde, Ministerio de Saúde, Maputo, Mozambique
Malaria Journal 2009, 8:9 doi:10.1186/1475-2875-8-9
Published: 9 January 2009Abstract
Background
Control of malaria in pregnancy remains a public health challenge. Improvements in its correct diagnosis and the adequacy of protocols to evaluate anti-malarial drug efficacy in pregnancy, are essential to achieve this goal.
Methods
The presence of Plasmodium falciparum was assessed by real-time (RT) PCR in 284 blood samples from pregnant women with clinical complaints suggestive of malaria, attending the maternity clinic of a Mozambican rural hospital. Parasite recrudescences in 33 consecutive paired episodes during the same pregnancy were identified by msp1 and msp2 genotyping.
Results
Prevalence of parasitaemia by microscopy was 5.3% (15/284) and 23.2% (66/284) by RT-PCR. Sensitivity of microscopy, compared to RT-PCR detection, was 22.7%. Risk of maternal anaemia was higher in PCR-positive women than in PCR-negative women (odds ratio [OR] = 1.92, 95% confidence interval [CI] 1.09–3.36). Genotyping confirmed that recrudescence after malaria treatment occurred in 7 (21%) out of 33 pregnant women with consecutive episodes during the same pregnancy (time range between recrudescent episodes: 14 to 187 days).
Conclusion
More accurate and sensitive diagnostic indicators of malaria infection in pregnancy are needed to improve malaria control. Longer follow-up periods than the standard in vivo drug efficacy protocol should be used to assess anti-malarial drug efficacy in pregnancy.