Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.570229
Title: The burden of malaria in pregnancy in Madhya Pradesh, India
Author: Ahmed, Rukhsana
Awarding Body: University of Liverpool
Current Institution: University of Liverpool
Date of Award: 2011
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Abstract:
Introduction and Method: Malaria in pregnancy (MiP) can have devastating consequences for the mother and the newborn. An evidence based framework for the control of MiP has been developed by the World Health Organisation (WHO) for malaria endemic sub-Saharan Africa. In contrast, no such framework exists for areas with low malaria transmission, such as in Asia where both PJalciparum and P.vivax are the predominant species. There is relatively little information on the burden of MiP in this region, hampering the design of rational control strategies for this high risk group. The objective of my thesis was to better defIne the burden of MiP in the central Indian state of Madhya Pradesh and to evaluate the performance of new rapid diagnostic tests (RDTs) that are considered as part of the new antenatal malaria screening strategies for the control of MiP. Women attending antenatal clinics (ANC module) and delivery units (delivery module) in a primary, secondary and tertiary health facility in a rural, semi-rural and an urban town in 3 districts of Madhya Pradesh were enrolled in a series of cross-sectional surveys. Pregnant women, regardless of symptoms were screened for anaemia and maternal and placental malaria using RDTs and standard microscopy. An adjusted version of the MiP rapid assessment tools developed by the US-based Centres for Disease Control and Prevention was used. Results: 1817 and 2696 women were enrolled in the ANC and delivery modules conducted during two 6- week periods in the dry (April-May 2006) and the post-rainy season (October-November 2006). The delivery module was extended in two sites to provide year-round information. The overall malaria prevalence in antenatal women was low: 4.5% (1.9% in the dry season and 6.5% in post rainy season) with wide variation between the rural (20.7%) and urban (0.3%) sites. The prevalence of maternal and placental malaria in the delivery module, assessed by standard microscopy, was 2.0% and 1.0% respectively in the year-round survey. P Jalciparum was the predominant species (89%), with a seasonal peak between October and December. The prevalence of P.vivax infections was persistently low throughout the year «1%). Sixty-three percent of the microscopically detectable PJalciparum and 55% of the P.vivax infections were symptomatic. All gravidity and age groups were equally at risk. P Jalciparum was associated with moderate- severe anaemia and preterm low birth weight. Babies born to women with placental P Jalciparum malaria were approximately 20% lighter than women without malaria. Overall, 70% of the preterm births and 50% of the low birth weight in infected women were attributable to placental P Jalciparum malaria. The corresponding population attributable fractions were 6.6% and 4.6%. Mono-infections with P.vivax (pCR confirmed) were also associated with anaemia and preterm low birth weight. Studies using diagnostic PCR showed that in the peak transmission season, 1-in-5 smear and RDT negative women were PCR positive for malaria; these 'sub-patent' infections were associated with mild anaemia. Similarly, placental sub-patent infection was associated with reduced birth weight (207g). No PCR data was available at delivery. The P Jalciparum associated placental histopathological changes were mild and suggest most infections were acute, contrasting to findings in stable high transmission areas. P.vivax associated placental changes were negligible. Compared with microscopy, the new First Response= pLDH-based RDT had 94.7% sensitivity and 99.3% specificity for PJalciparum, and 85.7% and 99.5% for P.vivax. However, compared with PCR, the sensitivity was only 23.2% (99.4% specificity) and 4.7% (99.6% specificity) respectively. Conclusion: The overall prevalence of microscopically detectable malaria in Madhya Pradesh was low and markedly seasonal with a predominance of P Jalciparum. The persistence of P.vivax throughout the year probably reflects relapses of hypnozoites rather than year-round transmission. In contrast to malaria endemic Africa, many, but not all, infections were associated with fever. Maternal anaemia and LBW, primarily due to preterm births were the main adverse consequences. Severe placental sequestration or placental inflammation associated with P Jalciparum infections, were not seen. However, there was an unexpectedly high prevalence of sub-microscopic infections detected by PCR in antenatal women and this was associated with increased risk of anaemia. This suggests that the risk of exposure and the burden of MiP in this region of India may be much higher than previously appreciated and the presence of these sub-microscopic infections should be taken into account in planning appropriate control measures for pregnant women in this region.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.570229  DOI: Not available
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