Clinical course of malaria in pregnancy--a prospective controlled study from India

Malaria in pregnancy in India: a 50-year bird's eye

Introduction

In 2021, India contributed for ~79% of malaria cases and ~ 83% of deaths in the South East Asia region. Here, we systematically and critically analyzed data published on malaria in pregnancy (MiP) in India.

Methods

Epidemiological, clinical, parasitological, preventive and therapeutic aspects of MiP and its consequences on both mother and child were reviewed and critically analyzed. Knowledge gaps and solution ways are also presented and discussed. Several electronic databases including Google scholar, Google, PubMed, Scopus, Wiley Online library, the Malaria in Pregnancy Consortium library, the World Malaria Report, The WHO regional websites, and ClinicalTrials.gov were used to identify articles dealing with MiP in India. The archives of local scientific associations/journals and website of national programs were also consulted.

Results

Malaria in pregnancy is mainly due to Plasmodium falciparum (Pf) and P. vivax (Pv), and on rare occasions to P. ovale spp. and P. malariae too. The overall prevalence of MiP is ~0.1-57.7% for peripheral malaria and ~ 0-29.3% for placental malaria. Peripheral Pf infection at antenatal care (ANC) visits decreased from ~13% in 1991 to ~7% in 1995-1996 in Madhya Pradesh, while placental Pf infection at delivery unit slightly decreased from ~1.5% in 2006-2007 to ~1% in 2012-2015 in Jharkhand. In contrast, the prevalence of peripheral Pv infection at ANC increased from ~1% in 2006-2007 to ~5% in 2015 in Jharkhand, and from ~0.5% in 1984-1985 to ~1.5% in 2007-2008 in Chhattisgarh. Clinical presentation of MiP is diverse ranging from asymptomatic carriage of parasites to severe malaria, and associated with comorbidities and concurrent infections such as malnutrition, COVID-19, dengue, and cardiovascular disorders. Severe anemia, cerebral malaria, severe thrombocytopenia, and hypoglycemia are commonly seen in severe MiP, and are strongly associated with tragic consequences such as abortion and stillbirth. Congenital malaria is seen at prevalence of ~0-12.9%. Infected babies are generally small-for-gestational age, premature with low birthweight, and suffer mainly from anemia, thrombocytopenia, leucopenia and clinical jaundice. Main challenges and knowledge gaps to MiP control included diagnosis, relapsing malaria, mixed Plasmodium infection treatment, self-medication, low density infections and utility of artemisinin-based combination therapies.

Conclusion

All taken together, the findings could be immensely helpful to control MiP in malaria endemic areas.

Severe falciparum malaria in pregnancy in Southeast Asia: a multi-centre retrospective cohort study

BACKGROUND

Severe malaria in pregnancy causes maternal mortality, morbidity, and adverse foetal outcomes. The factors contributing to adverse maternal and foetal outcomes are not well defined. We aimed to identify the factors predicting higher maternal mortality and to describe the foetal mortality and morbidity associated with severe falciparum malaria in pregnancy.

METHODS

A retrospective cohort study was conducted of severe falciparum malaria in pregnancy, as defined by the World Health Organization severe malaria criteria. The patients were managed prospectively by the Shoklo Malaria Research Unit (SMRU) on the Thailand-Myanmar border or were included in hospital-based clinical trials in six Southeast Asian countries. Fixed-effects multivariable penalised logistic regression was used for analysing maternal mortality.

RESULTS

We included 213 (123 SMRU and 90 hospital-based) episodes of severe falciparum malaria in pregnancy managed between 1980 and 2020. The mean maternal age was 25.7 (SD 6.8) years, and the mean gestational age was 25.6 (SD 8.9) weeks. The overall maternal mortality was 12.2% (26/213). Coma (adjusted odds ratio [aOR], 7.18, 95% CI 2.01-25.57, p = 0.0002), hypotension (aOR 11.21, 95%CI 1.27-98.92, p = 0.03) and respiratory failure (aOR 4.98, 95%CI 1.13-22.01, p = 0.03) were associated with maternal mortality. Pregnant women with one or more of these three criteria had a mortality of 29.1% (25/86) (95%CI 19.5 to 38.7%) whereas there were no deaths in 88 pregnant women with hyperparasitaemia (> 10% parasitised erythrocytes) only or severe anaemia (haematocrit < 20%) only. In the SMRU prospective cohort, in which the pregnant women were followed up until delivery, the risks of foetal loss (23.3% by Kaplan-Meier estimator, 25/117) and small-for-gestational-age (38.3%, 23/60) after severe malaria were high. Maternal death, foetal loss and preterm birth occurred commonly within a week of diagnosis of severe malaria.

CONCLUSIONS

Vital organ dysfunction in pregnant women with severe malaria was associated with a very high maternal and foetal mortality whereas severe anaemia or hyperparasitaemia alone were not associated with poor prognosis, which may explain the variation of reported mortality from severe malaria in pregnancy. Access to antenatal care must be promoted to reduce barriers to early diagnosis and treatment of both malaria and anaemia.

Burden and impact of Plasmodium vivax in pregnancy: A multi-centre prospective observational study

Background

Despite that over 90 million pregnancies are at risk of Plasmodium vivax infection annually, little is known about the epidemiology and impact of the infection in pregnancy.

Methodology and principal findings

We undertook a health facility-based prospective observational study in pregnant women from Guatemala (GT), Colombia (CO), Brazil (BR), India (IN) and Papua New Guinea PNG). Malaria and anemia were determined during pregnancy and fetal outcomes assessed at delivery. A total of 9388 women were enrolled at antennal care (ANC), of whom 53% (4957) were followed until delivery. Prevalence of P. vivax monoinfection in maternal blood at delivery was 0.4% (20/4461) by microscopy [GT 0.1%, CO 0.5%, BR 0.1%, IN 0.2%, PNG 1.2%] and 7% (104/1488) by PCR. P. falciparum monoinfection was found in 0.5% (22/4463) of women by microscopy [GT 0%, CO 0.5%, BR 0%, IN 0%, PNG 2%]. P. vivax infection was observed in 0.4% (14/3725) of placentas examined by microscopy and in 3.7% (19/508) by PCR. P. vivax in newborn blood was detected in 0.02% (1/4302) of samples examined by microscopy [in cord blood; 0.05% (2/4040) by microscopy, and 2.6% (13/497) by PCR]. Clinical P. vivax infection was associated with increased risk of maternal anemia (Odds Ratio-OR, 5.48, [95% CI 1.83–16.41]; p = 0.009), while submicroscopic vivax infection was not associated with increased risk of moderate-severe anemia (Hb<8g/dL) (OR, 1.16, [95% CI 0.52–2.59]; p = 0.717), or low birth weight (<2500g) (OR, 0.52, [95% CI, 0.23–1.16]; p = 0.110).

Conclusions

In this multicenter study, the prevalence of P. vivax infection in pregnancy by microscopy was overall low across all endemic study sites; however, molecular methods revealed a significant number of submicroscopic infections. Clinical vivax infection in pregnancy was associated with maternal anemia, which may be deleterious for infant’s health. These results may help to guide maternal health programs in settings where vivax malaria is endemic; they also highlight the need of addressing a vulnerable population such as pregnant women while embracing malaria elimination in endemic countries.

More than 90 million pregnancies are exposed to P. vivax infection every year. While it is well known that pregnant women have an increased risk of P. falciparum infection and disease, much less is known on the epidemiology and the impact of P. vivax in pregnancy. A health-facility based observational study was conducted in pregnant women living in five vivax endemic countries aimed to determine the burden of the infection in pregnancy and its impact on the mother and the newborn health. We found that the prevalence of P. vivax malaria in pregnant women attending the routine antenatal clinic visits was overall low across all sites, however submicroscopic infections were unexpectedly high in some areas. Pregnant women with clinical malaria experienced an increased risk of anemia, which may have a deleterious impact on infant health. These findings may be useful for guiding maternal health programs in vivax endemic settings, as well as for malaria elimination activities.

Travel During Pregnancy: Considerations for the Obstetric Provider

Importance

Travel among US citizens is becoming increasingly common, and travel during pregnancy is also speculated to be increasingly common. During pregnancy, the obstetric provider may be the first or only clinician approached with questions regarding travel.

Objective

In this review, we discuss the reasons women travel during pregnancy, medical considerations for long-haul air travel, destination-specific medical complications, and precautions for pregnant women to take both before travel and while abroad. To improve the quality of pretravel counseling for patients before or during pregnancy, we have created 2 tools: a guide for assessing the pregnant patient's risk during travel and a pretravel checklist for the obstetric provider.

Evidence Acquisition

A PubMed search for English-language publications about travel during pregnancy was performed using the search terms "travel" and "pregnancy" and was limited to those published since the year 2000. Studies on subtopics were not limited by year of publication.

Results

Eight review articles were identified. Three additional studies that analyzed data from travel clinics were found, and 2 studies reported on the frequency of international travel during pregnancy. Additional publications addressed air travel during pregnancy (10 reviews, 16 studies), high-altitude travel during pregnancy (5 reviews, 5 studies), and destination-specific illnesses in pregnant travelers.

Conclusions and Relevance

Travel during pregnancy including international travel is common. Pregnant travelers have unique travel-related and destination-specific risks. We review those risks and provide tools for obstetric providers to use in counseling pregnant travelers.

Microsatellite Genotyping of Plasmodium vivax Isolates from Pregnant Women in Four Malaria Endemic Countries

Plasmodium vivax is the most widely distributed human parasite and the main cause of human malaria outside the African continent. However, the knowledge about the genetic variability of P. vivax is limited when compared to the information available for P. falciparum. We present the results of a study aimed at characterizing the genetic structure of P. vivax populations obtained from pregnant women from different malaria endemic settings. Between June 2008 and October 2011 nearly 2000 pregnant women were recruited during routine antenatal care at each site and followed up until delivery. A capillary blood sample from the study participants was collected for genotyping at different time points. Seven P. vivax microsatellite markers were used for genotypic characterization on a total of 229 P. vivax isolates obtained from Brazil, Colombia, India and Papua New Guinea. In each population, the number of alleles per locus, the expected heterozygosity and the levels of multilocus linkage disequilibrium were assessed. The extent of genetic differentiation among populations was also estimated. Six microsatellite loci on 137 P. falciparum isolates from three countries were screened for comparison. The mean value of expected heterozygosity per country ranged from 0.839 to 0.874 for P. vivax and from 0.578 to 0.758 for P. falciparum. P. vivax populations were more diverse than those of P. falciparum. In some of the studied countries, the diversity of P. vivax population was very high compared to the respective level of endemicity. The level of inter-population differentiation was moderate to high in all P. vivax and P. falciparum populations studied.

Treating severe malaria in pregnancy: a review of the evidence

Severe malaria in pregnancy is a large contributor to maternal morbidity and mortality. Intravenous quinine has traditionally been the treatment drug of choice for severe malaria in pregnancy. However, recent randomized clinical trials (RCTs) indicate that intravenous artesunate is more efficacious for treating severe malaria, resulting in changes to the World Health Organization (WHO) treatment guidelines. Artemisinins, including artesunate, are embryo-lethal in animal studies and there is limited experience with their use in the first trimester. This review summarizes the current literature supporting 2010 WHO treatment guidelines for severe malaria in pregnancy and the efficacy, pharmacokinetics, and adverse event data for currently used antimalarials available for severe malaria in pregnancy. We identified ten studies on the treatment of severe malaria in pregnancy that reported clinical outcomes. In two studies comparing intravenous quinine with intravenous artesunate, intravenous artesunate was more efficacious and safe for use in pregnant women. No studies detected an increased risk of miscarriage, stillbirth, or congenital anomalies associated with first trimester exposure to artesunate. Although the WHO recommends using either quinine or artesunate for the treatment of severe malaria in first trimester pregnancies, our findings suggest that artesunate should be the preferred treatment option for severe malaria in all trimesters.

Plasmodium knowlesi malaria during pregnancy

BACKGROUND

Plasmodium knowlesi is the commonest cause of malaria in Malaysia, but little is known regarding infection during pregnancy.

METHODS

To investigate comparative risk and consequences of knowlesi malaria during pregnancy, we reviewed (1) Sabah Health Department malaria-notification records created during 2012-2013, (2) prospectively collected data from all females with polymerase chain reaction (PCR)-confirmed malaria who were admitted to a Sabah tertiary care referral hospital during 2011-2014, and (3) malaria microscopy and clinical data recorded at a Sabah tertiary care women and children's hospital during 2010-2014.

RESULTS

During 2012-2013, 774 females with microscopy-diagnosed malaria were notified, including 252 (33%), 172 (20%), 333 (43%), and 17 (2%) with Plasmodium falciparum infection, Plasmodium vivax infection, Plasmodium malariae/Plasmodium knowlesi infection, and mixed infection, respectively. Among females aged 15-45 years, pregnancy was reported in 18 of 124 (14.5%), 9 of 93 (9.7%), and 4 of 151 (2.6%) P. falciparum, P. vivax, and P. malariae/P. knowlesi notifications respectively (P = .002). Three females with knowlesi malaria were confirmed as pregnant: 2 had moderate anemia, and 1 delivered a preterm low-birth-weight infant. There were 17, 7, and 0 pregnant women with falciparum, vivax, and knowlesi malaria, respectively, identified from the 2 referral hospitals.

CONCLUSIONS

Although P. knowlesi is the commonest malaria species among females in Sabah, P. knowlesi infection is relatively rare during pregnancy. It may however be associated with adverse maternal and pregnancy outcomes.

Malaria in pregnancy in the Asia-Pacific region

Most pregnant women at risk of for infection with Plasmodium vivax live in the Asia-Pacific region. However, malaria in pregnancy is not recognised as a priority by many governments, policy makers, and donors in this region. Robust data for the true burden of malaria throughout pregnancy are scarce. Nevertheless, when women have little immunity, each infection is potentially fatal to the mother, fetus, or both. WHO recommendations for the control of malaria in pregnancy are largely based on the situation in Africa, but strategies in the Asia-Pacific region are complicated by heterogeneous transmission settings, coexistence of multidrug-resistant Plasmodium falciparum and Plasmodium vivax parasites, and different vectors. Most knowledge of the epidemiology, effect, treatment, and prevention of malaria in pregnancy in the Asia-Pacific region comes from India, Papua New Guinea, and Thailand. Improved estimates of the morbidity and mortality of malaria in pregnancy are urgently needed. When malaria in pregnancy cannot be prevented, accurate diagnosis and prompt treatment are needed to avert dangerous symptomatic disease and to reduce effects on fetuses.

Maternal Deaths in a Tertiary Health Care Centre of Odisha: An In-depth Study Supplemented by Verbal Autopsy

BACKGROUND

Maternal mortality is a reflection of the care given to women by its society. It is tragic that deaths occur during the natural process of child birth and most of them are preventable.

OBJECTIVES

The present study was undertaken to find out the causes and contributing factors of maternal deaths.

MATERIALS AND METHODS

All maternal deaths occurring in a year in the medical college and hospital were traced and interviews were taken from the relatives as well as the health care providers who were present at the time of death of the woman.

RESULTS

Out of the total maternal deaths, 72% belonged to 20-30 yrs age group, also 46.5% were illiterate, and majority deaths (60.5%) were from low socio-economics status. Direct causes were responsible for 76.7% of maternal deaths. Hypertensive disorders of pregnancy were most common (32.6%) cause of direct deaths, while malaria (9.3%) and anemia (7%) were most common indirect causes. Most of the women had to use their own resources to travel to health care facilities. Delays at different levels, often in combination, contributed to the maternal deaths.

CONCLUSIONS

The study will serve as an eye-opener to the bottlenecks present in the community as well as in the health facility so as to take appropriate measures to prevent maternal deaths.

[Intrauterine growth retardation, low birth weight and prematurity in neonates of pregnant women with malaria in Colombia]

INTRODUCTION

Association between malaria and pregnancy complications, such as prematurity, intrauterine growth restriction, low birthweight and infant mortality has been reported. These effects have been studied widely in areas hyperendemic for malaria, but studies in low-endemic areas are scarce. The study investigated the relation between gestational malaria and low birthweight and intrauterine growth retardation in neonates of a malarial endemic region in Colombia, between 1993 and 2007.

METHODS

The pattern of development in 1,716 neonates of women with and without malaria infection during pregnancy was evaluated in a cohort study. A total of 394 infected (27% by P. falciparum and 73% by P. vivax) and 1,322 noninfected pregnant women were followed.

RESULTS

Exposure to gestational malaria was associated with increased risk of low birth weight (RR = 1.37; 1.03-1.83), short height (RR = 1.52; 1.25-1.85), intrauterine growth retardation (RR = 1.29; 1.0-1.66) and prematurity (RR = 1.68; 1.3-2.17). Prematurity was 77% higher in infants of mothers with malaria by P. falciparum than infants of mothers with malaria by P. vivax (RR = 1.77; 1.2-2.6).

CONCLUSIONS

Low birth weight and intrauterine growth retardation were associated with malaria during pregnancy. Infection with P. vivax was related with adverse effects on the newborn, similar to that reported for P. falciparum.

Availability and utilization of malaria prevention strategies in pregnancy in eastern India

Background

Malaria in pregnancy in India, as elsewhere, is responsible for maternal anemia and adverse pregnancy outcomes such as low birth weight and preterm birth.

It is not known whether prevention and treatment strategies for malaria in pregnancy (case management, insecticide-treated bednets, intermittent preventive therapy) are widely utilized in India.

Methods

This cross-sectional study was conducted during 2006-2008 in two states of India, Jharkhand and Chhattisgarh, at 7 facilities representing a range of rural and urban populations and areas of more versus less stable malaria transmission. 280 antenatal visits (40/site) were observed by study personnel coupled with exit interviews of pregnant women to assess emphasis upon, availability and utilization of malaria prevention practices by health workers and pregnant women. The facilities were assessed for the availability of antimalarials, lab supplies and bednets.

Results

All participating facilities were equipped to perform malaria blood smears; none used rapid diagnostic tests. Chloroquine, endorsed for chemoprophylaxis during pregnancy by the government at the time of the study, was stocked regularly at all facilities although the quantity stocked varied. Availability of alternative antimalarials for use in pregnancy was less consistent. In Jharkhand, no health worker recommended bednet use during the antenatal visit yet over 90% of pregnant women had bednets in their household. In Chhattisgarh, bednets were available at all facilities but only 14.4% of health workers recommended their use. 40% of the pregnant women interviewed had bednets in their household. Only 1.4% of all households owned an insecticide-treated bednet; yet 40% of all women reported their households had been sprayed with insecticide. Antimalarial chemoprophylaxis with chloroquine was prescribed in only 2 (0.7%) and intermittent preventive therapy prescribed in only one (0.4%) of the 280 observed visits.

Conclusions

A disconnect remains between routine antenatal practices in India and known strategies to prevent and treat malaria in pregnancy. Prevention strategies, in particular the use of insecticide-treated bednets, are underutilized. Gaps highlighted by this study combined with recent estimates of the prevalence of malaria during pregnancy in these areas should be used to revise governmental policy and target increased educational efforts among health care workers and pregnant women.

Attitudes, knowledge, and practices regarding malaria prevention and treatment among pregnant women in Eastern India

We explored views toward and use of malaria prevention and treatment measures among pregnant women in Jharkhand, India. We conducted 32 in-depth interviews and six focus group discussions (total = 73 respondents) with pregnant women in urban, semi-urban, and rural locations in a region with moderate intensity malaria transmission. Most respondents ranked malaria as an important health issue affecting pregnant women, had partially correct understanding of malaria transmission and prevention, and reported using potentially effective prevention methods, usually untreated bed nets. However, most conveyed misinformation and described using unproven prevention and/or treatment methods. Many described using different ineffective traditional malaria remedies. The majority also showed willingness to try new prevention methods and take medications if doctor-prescribed. Misconceptions and use of unproven prevention and treatment methods are common among pregnant women in eastern India. Policy makers should focus on improving knowledge and availability of effective malaria control strategies in this population.

Burden of malaria in pregnancy in Jharkhand State, India

Background

Past studies in India included only symptomatic pregnant women and thus may have overestimated the proportion of women with malaria. Given the large population at risk, a cross sectional study was conducted in order to better define the burden of malaria in pregnancy in Jharkhand, a malaria-endemic state in central-east India.

Methods

Cross-sectional surveys at antenatal clinics and delivery units were performed over a 12-month period at two district hospitals in urban and semi-urban areas, and a rural mission hospital. Malaria was diagnosed by Giemsa-stained blood smear and/or rapid diagnostic test using peripheral or placental blood.

Results

2,386 pregnant women were enrolled at the antenatal clinics and 718 at the delivery units. 1.8% (43/2382) of the antenatal clinic cohort had a positive diagnostic test for malaria (53.5% Plasmodium falciparum, 37.2% Plasmodium vivax, and 9.3% mixed infections). Peripheral parasitaemia was more common in pregnant women attending antenatal clinics in rural sites (adjusted relative risk [aRR] 4.31, 95%CI 1.84-10.11) and in those who were younger than 20 years (aRR 2.68, 95%CI 1.03-6.98). Among delivery unit participants, 1.7% (12/717) had peripheral parasitaemia and 2.4% (17/712) had placental parasitaemia. Women attending delivery units were more likely to be parasitaemic if they were in their first or second pregnancy (aRR 3.17, 95%CI 1.32-7.61), had fever in the last week (aRR 5.34, 95%CI 2.89-9.90), or had rural residence (aRR 3.10, 95%CI 1.66-5.79). Malaria control measures including indoor residual spraying (IRS) and untreated bed nets were common, whereas insecticide-treated bed nets (ITN) and malaria chemoprophylaxis were rarely used.

Conclusion

The prevalence of malaria among pregnant women was relatively low. However, given the large at-risk population in this malaria-endemic region of India, there is a need to enhance ITN availability and use for prevention of malaria in pregnancy, and to improve case management of symptomatic pregnant women.

Murine malaria infection induces fetal loss associated with accumulation of Plasmodium chabaudi AS-infected erythrocytes in the placenta

Malarial infection in nonimmune women is a risk factor for pregnancy loss, but the role that maternal antimalarial immune responses play in fetal compromise is not clear. We conducted longitudinal and serial sacrifice studies to examine the pathogenesis of malaria during pregnancy using the Plasmodium chabaudi AS/C57BL/6 mouse model. Peak parasitemia following inoculation with 1,000 parasite-infected murine erythrocytes and survival were similar in infected pregnant and nonpregnant mice, although development of parasitemia and anemia was slightly accelerated in pregnant mice. Importantly, pregnant mice failed to maintain viable pregnancies, most aborting before day 12 of gestation. At abortion, maternal placental blood parasitemia was statistically significantly higher than peripheral parasitemia. Infected mice had similar increases in spleen size and cellularity which were statistically significantly higher than in uninfected mice. In contrast, splenocyte proliferation in response to mitogenic stimulation around peak parasitemia was statistically significantly reduced in both groups of infected mice compared to uninfected, nonpregnant mice, suggesting that lymphoproliferation is not a good indicator of the antimalarial immune responses in pregnant or nonpregnant animals. This study suggests that while pregnant and nonpregnant C57BL/6 mice are equally capable of mounting an effective immune response to and surviving P. chabaudi AS infection, pregnant mice cannot produce viable pups. Fetal loss appears to be associated with placental accumulation of infected erythrocytes. Further study is required to determine to what extent maternal antimalarial immune responses, anemia, and placental accumulation of parasites contribute to compromised pregnancy in this model.

Studies on Plasmodium falciparum isotypic antibodies and numbers of IL-4 and IFN-gamma secreting cells in paired maternal cord blood from South West Cameroon

OBJECTIVES

In this study, the effect of maternal peripheral and placental Plasmodium falciparum parasitaemia on the level of antibody and cytokine immune responses in the neonate was investigated.

METHODS

Malaria parasites were detected by light microscopy. Levels of malaria-specific isotypic antibodies were measured in maternal and cord blood by indirect ELISA. The numbers of IFN-gamma and IL-4 cells produced by maternal/cord blood after in vitro stimulation were enumerated using the ELISPOT assay.

RESULTS

Malaria parasite rate of maternal, placental biopsy and cord blood was 32.8%, 33.7% and 7.8% respectively. Overall, ELISA seropositivity rates for P. falciparum-specific IgG, IgM, IgE and IgA in the maternal plasma samples were 71%, 85%, 29.3%, and 0% respectively, while those for the cord samples were 69%, 6.0%, 4.4% and 0% respectively. Mean IgM ELISA OD(405) values of neonates born from positive placentas, or whose mothers had peripheral malaria parasitaemia were higher than those who were parasite negative. The mean number of maternal cells producing IFN-gamma was higher (P=0.0001) than that of the paired cord samples. The mean number of IL-4 producing cells of neonates born of mothers who were positive (P<0.05) or from malaria-positive placentas (P<0.025) was higher than from those who were malaria negative. Neonates born of malaria-positive mothers or from parasitized placentas mounted predominantly Th2 type immune responses.

CONCLUSION

It appears from this study that neonates born from malaria-infected mothers or placentas may relatively be more susceptible to malaria attack during the first years of life.

Congenital malaria in a preterm infant

A case of congenital malaria in a preterm newborn infant is presented. The case illustrates the difficulty of early diagnosis, and the atypical nature of presentation in a preterm infant.

Malaria prevention strategies

Acute and severe consequences of pregnancy-associated malaria (PAM), such as materno-fetal death or cerebral malaria, seem limited to unstable malaria areas. In areas of stable endemicity, the main consequences are maternal anaemia and low birth weight (LBW) babies, particularly in primigravidae. Placental malaria seems more frequent and its consequences more severe in HIV-infected women. Since 1964, several chemoprophylaxis controlled trials have been undertaken, mainly in Tropical Africa where malaria is stable. Most showed an increase in mean birth weight in the prophylaxis group, especially among primigravidae. Similar findings were made with anaemia. Prophylaxis seems less effective in the case of HIV-malaria co-infection, which may require an increase in the number of doses. At present, intermittent treatment with sulfadoxine-pyrimethamine given twice or thrice during pregnancy in antenatal clinics seems the best policy for preventing PAM. Such effective prophylaxis should be integrated with other antenatal clinic services. Recently identified molecular receptors involved in cytoadherence of parasitized erythrocytes to placenta could yield new therapeutic or vaccine approaches, specifically targeted to pregnant women.

Malaria prevention during pregnancy in unstable transmission areas: the highlands of Madagascar

Malaria transmission in Madagascar is highly variable from one region to the next, and the consequences of the disease on pregnant women and their foetuses are not fully documented. In midwestern Madagascar, the high-transmission lowlands in the west of the country meet the central plateaux, where malaria is unstable because of the high altitude and annual indoor spraying of DDT since 1993. We studied five of the region's main maternity clinics. We began by interviewing sample groups of women of childbearing age living within the vicinity of each clinic. This enabled us to determine the extent to which they had accessed and made use of available maternal health services during pregnancy and delivery, and, hence, to estimate the feasibility of boosting the prophylaxis. We then spent a whole year (from June 1996 to May 1997) observing deliveries at the five clinics in order to gauge the prevalence of placental infection and its consequences on birthweight in various transmission situations. Although only between 2 and 15% of the women said that they had taken prophylaxis during their previous pregnancy, the vast majority had benefited from preventive care: 97% had attended an antenatal visit on at least one occasion and 84% had had the assistance of medical or paramedical staff during delivery, even when their homes were situated relatively far away from the clinic (76%). In total, we observed 1637 deliveries with a mean placental malaria prevalence rate of 8.1%. Individual prevalence rates, however, were found to differ significantly between the maternity clinics situated in the east (minimum 2.1%) and west (maximum 26.2%) of the region. There were also marked variations in line with the seasonal fluctuations in entomological transmission. On the whole, a greater percentage of low birthweights (LBWs) was recorded at the lowland clinics than at the highland ones (17.1% vs. 9.7%), possibly because of the higher malaria infection rate in low altitude areas. On the other hand, the relative risk of LBW linked to placental infection was far greater in the highlands [4.9 (3.3-7.3)] than in the lowlands [1.9 (1.2-3.0)]. Although the rate of placental malaria among women inhabiting the country's central plateaux may be low, it means that transmission--and, hence, the risk of LBW because of placental infection--still persists in spite of the indoor DDT spraying programme. For maximum efficacy, we recommend a combination of vector control (extended to lower altitude areas outside the current OPID zone) and preventive care--i.e. individual chemoprophylaxis--for all highland women during pregnancy.

Plasmodium falciparum infection in the pregnant patient

Malaria should be considered a risk factor in women who are pregnant, principally when the infection is Plasmodium falciparum. Moreover, the risk is greater if the woman is pregnant for the first time; if she has no immunity for malaria; if the diagnosis is made late; or if P. falciparum shows resistance to antimalarial drugs. This article presents the most significant aspects of P. falciparum malaria during pregnancy, including information about treatments and prophylaxis.

Malarial infection during pregnancy

This article reviews the parasitology of malaria, epidemiology in pregnancy, pathogenesis of increased susceptibility to infection in pregnancy, the effect of pregnancy on the clinical manifestations of malaria, the effect of malaria on perinatal outcomes, the safety of antimalarial agents during pregnancy, the role of chemoprophylaxis for inhabitants and travelers to endemic areas, and treatment of clinical malarial infections during pregnancy.

Antibodies to Pf155/RESA and circumsporozoite protein of Plasmodium falciparum in paired maternal-cord sera from Nigeria

Paired maternal-cord serum samples were analysed for antibodies to the Pf155/RESA and circumsporozoite protein (CSP) antigens of Plasmodium falciparum. Malaria parasites were found in 2.6% (3/117) of cord blood and 22.4% (26/116) of maternal samples. Immunofluorescence assays detected P. falciparum-specific IgG antibodies in all paired samples while P. falciparum-specific IgM was detected in 5.8% (7/121) of cord samples. The positivity rates for antibodies to Pf155/RESA and (NANP)6 but not (EENV)6, a C-terminal repeat sequence of Pf155/RESA, were significantly higher in maternal as compared with cord samples. Seropositivity rates to Pf155/RESA and (EENV)6 were not related to maternal parity group while positivity rates to the (NANP)6 peptide were higher in primiparae and multiparae of > or = 4 parity. These data confirm the transplacental transfer of P. falciparum-specific antibodies and the higher incidence of malaria parasitaemia in primiparae. The presence of P. falciparum-specific IgM in some cord samples suggests intrauterine sensitization of the foetus to malarial antigens.

Plasmodium falciparum-specific immunoglobulin G (IgG), IgM, and IgE antibodies in paired maternal-cord sera from east Sepik Province, Papua New Guinea

Enzyme-linked immunosorbent assay (ELISA) and Western blot (immunoblot) serological analyses for immunoglobulin G (IgG), IgM, and IgE antibodies to Plasmodium falciparum were made from 46 maternal-cord serum pairs obtained from parturient East Sepik (Papua New Guinea) women and their newborn. Concurrent study of these women had shown that placental parasitemia rates were related to parity with the highest rate (41%) in the primiparous group and the lowest rate (3%) in the women who had given birth more than three times (> 3 parity group). Overall ELISA positivity rates for antimalarial IgG, IgM, and IgE antibodies in the maternal sera were 54.3, 28.2, and 8.3%, respectively, while those for the cord sera were 36.9, 0, and 16.6% respectively. Seropositivity rates were not related to maternal parity group, except for maternal IgE, in which there was a higher rate, of borderline significance, in the > 3 parity group than in the primiparous group. Cord IgE positivity was largely independent of maternal positivity and vice versa. Cord and maternal IgG immunoblot pairs showed near homology. IgG antibodies to the P. falciparum antigens of sizes < 36 kDa were either weak or absent in parity group 1 and 2 maternal-cord serum pairs. Neither ELISA or immunoblot revealed IgM antibody in the cord serum samples. Maternal IgM antibodies showed a heterogeneity of responses both between paired IgG immunoblots and between different serum samples. The IgE immunoblots exhibited a similar diversity, albeit of less complexity. The presence of P. falciparum-specific IgE in the cord sera would indicate that prenatal immune hypersensitization of the fetus to malaria had occurred.

Placental Plasmodium falciparum parasitaemia in East Sepik (Papua New Guinea) women of different parity: the apparent absence of acute effects on mother and foetus

The effects of malaria were studied in a group of parturient women of East Sepik Province, Papua New Guinea. Further information was gathered from a search of hospital records and interviews with village aid post orderlies. Examination of placental blood revealed a Plasmodium falciparum parasitaemia rate of 41% of the primiparae, 23% in parous 2, 25% in parous 3, and 3% in multiparae greater than 3. Approximately one-half of those with placental parasitaemia had a concomitant detectable peripheral parasitaemia. Placental parasitaemias were of relatively low density, averaging 1.6%. There were no instances in the observed series of births, hospital records, or village studies of the occurrence of severe malaria in the mother or its acute effects on the foetus. Neither birthweight nor maternal or cord blood haematocrit was related to the presence or absence of placental parasitaemia. Neonatal birthweight and risk of delivering a low birthweight (less than 2.5 kg) baby was statistically associated only with maternal parity. The possible reasons for the relatively benign effect of malaria in the pregnant women of this population are discussed.