The effects of malaria in pregnancy on neurocognitive development in children at one and six years of age in Benin: a prospective mother-child cohort

Placental Malaria Induces a Unique Placental Methylation Profile Associated with Fetal Growth Restriction

Background

Fetal growth restriction (FGR) is associated with perinatal death and other adverse birth outcomes, as well as long term complications including increased childhood morbidity, abnormal neurodevelopment, and cardio-metabolic diseases in adulthood. FGR has been associated with placental epigenetic reprogramming, which may mediate these long term outcomes. Placental malaria (PM) is the leading cause of FGR globally, but the impact on placental epigenetics is unknown. We hypothesized that methylomic profiling of placentas from non-malarial and malarial FGR would reveal common and distinct mechanistic pathways associated with FGR.

Results

We used a methylation array to compare the CpG profiles between FGR from a cohort with no malaria exposure and a cohort of pregnancies complicated by both PM and FGR. Non-malarial FGR was associated with 65 differentially methylated CpGs, whereas PM-FGR was associated with 133 DMCs, compared to their corresponding controls. One DMC (cg16389901) was commonly hypomethylated in both groups, corresponding to the promoter region of BMP4 . Comparison of FGR vs. PM-FGR identified 522 DMCs between these two groups, which was not attributable to geographic location or different cellular compositions of these two groups.

Conclusion

Placentas from pregnancies with PM-associated FGR showed distinct methylation profiles as compared to non-malarial FGR, suggesting novel epigenetic reprogramming in response to malaria. There may be distinct long-term health outcomes in FGR pregnancies also complicated by PM.

Beyond TORCH: A narrative review of the impact of antenatal and perinatal infections on the risk of disability

Infections and inflammation during pregnancy or early life can alter child neurodevelopment and increase the risk for structural brain abnormalities and mental health disorders. There is strong evidence that TORCH infections (i.e., Treponema pallidum, Toxoplasma gondii, rubella virus, cytomegalovirus, herpes virus) alter fetal neurodevelopment across multiple developmental domains and contribute to motor and cognitive disabilities. However, the impact of a broader range of viral and bacterial infections on fetal development and disability is less well understood. We performed a literature review of human studies to identify gaps in the link between maternal infections, inflammation, and several neurodevelopmental domains. We found strong and moderate evidence respectively for a higher risk of motor and cognitive delays and disabilities in offspring exposed to a range of non-TORCH pathogens during fetal life. In contrast, there is little evidence for an increased risk of language and sensory disabilities. While guidelines for TORCH infection prevention during pregnancy are common, further consideration for prevention of non-TORCH infections during pregnancy for fetal neuroprotection may be warranted.

Trends of the Global, Regional and National Incidence, Mortality, and Disability-Adjusted Life Years of Malaria, 1990-2019: An Analysis of the Global Burden of Disease Study 2019

Background

Malaria remains a substantial concern in the realm of public health on a worldwide level. Using information from the global burden of disease (GBD) 2019 for 204 countries and territories between 1990 and 2019, we assessed the burden of malaria.

Methods

Data on malaria were derived from the GBD 2019 study between 1990 and 2019. We evaluated the number of incidence, deaths, disability-adjusted life years (DALYs), age-standardized incidence rates (ASIR), age-standardized mortality rates (ASMR), and age-standardized DALY rates (ASDR), examining them across variables such as age, year, gender, country, region, and socio-demographic index (SDI).

Results

The burden of malaria decreased globally between 1990 and 2019. There were 2313.57×10⁵ incident cases and 6.43×10⁵ deaths in 2019, contributing to 464.38×10⁵ DALYs. Largest incident cases were observed in Western Sub-Saharan Africa [1151.72 (95% UI: 890.01-1527.17)] ×10⁵ in 2019. The only region where deaths increased between 1990 and 2019 was Western Sub-Saharan Africa. ASRs of malaria are distributed heterogeneously in different regions. The highest ASIR was observed in Central Sub-Saharan Africa [21,557.65 (95% UI: 16,639.4-27,491.48)] in 2019. From 1990 to 2019, the ASMR of malaria declined. Compared to other age cohorts, the ASIR, ASMR, and ASDR for children aged between 1 to 4 years were found to be higher. Worst-affected regions by malaria infection were the low-middle SDI region and low SDI region.

Conclusion

Malaria threatens global public health, especially in Central Sub-Saharan Africa and Western Sub-Saharan Africa. Children 1-4 years old continue to bear the most significant burden of malaria. The study's results will guide efforts to reduce malaria's impact on the global population.

Effect of Malaria and Malaria Chemoprevention Regimens in Pregnancy and Childhood on Neurodevelopmental and Behavioral Outcomes in Children at 12, 24, and 36 Months: A Randomized Clinical Trial

BACKGROUND

Malaria in pregnancy has been associated with worse cognitive outcomes in children, but its association with behavioral outcomes and the effectiveness of malaria chemoprevention on child neurodevelopment are not well characterized.

METHODS

To determine if more effective malaria chemoprevention in mothers and their children results in better neurodevelopment, 305 pregnant women were randomly assigned to 3 doses of sulfadoxine-pyrimethamine, 3 doses of dihydroartemisinin-piperaquine (DP), or monthly DP during pregnancy, and their 293 children were assigned to DP every 3 months or monthly DP from 2 to 24 months of age. Cognition, language, and motor function were assessed at 12, 24. and 36 months of age, and attention, memory, behavior, and executive function were assessed at 24 and 36 months of age.

RESULTS

Children of mothers with versus without malaria in pregnancy had worse scores on cognitive, behavioral, and executive function outcomes at 24 months. Clinical malaria in children within the first 12 months was similarly associated with poorer scores in behavior and executive function at 24 months, language at 24 and 36 months, and motor function scores at 36 months. However, more effective malaria chemoprevention in the mothers and children was not associated with better outcomes.

CONCLUSIONS

Malaria in pregnancy was associated with worse cognitive, behavioral, and executive function scores in affected children, but more effective malaria chemoprevention measures did not result in better outcomes. Malaria chemoprevention prior to and early in gestation and with even higher efficacy in mothers and children may be required to prevent neurodevelopmental impairment in children. Clinical Trials Registration. NCT02557425.

Global estimates of the number of pregnancies at risk of malaria from 2007 to 2020: a demographic study

BACKGROUND

The most recent global estimates of the number of pregnancies at risk of Plasmodium falciparum and Plasmodium vivax malaria infection are from 2007. To inform global malaria prevention and control efforts, we aimed to estimate the global distribution of pregnancies at risk of malaria infection from 2007 to 2020.

METHODS

We used estimates from the Malaria Atlas Project on the total population living in areas of P falciparum and P vivax transmission, combined with country-specific demographic data on women of reproductive age, fertility rates, induced abortions, and stillbirths, to derive the annual number of pregnancies overall, by parasite species, and by endemicity strata from 2007 to 2020. The definition of endemicity strata was based on the parasite point prevalence in individuals aged 2-10 years for P falciparum and 1-99 years for P vivax. We also did a sensitivity analysis in which we considered most of sub-Saharan Africa endemic for P vivax.

FINDINGS

In 2020, 121·9 million pregnancies occurred in malaria transmission areas, resulting in an estimated 70·9 million (58·1%) livebirths. The total number of pregnancies at risk of malaria was 52·9 million in the WHO South-East Asia (SEARO) region, 5·1 million in the Western Pacific (WPRO) region, 46·1 million in the Africa (AFRO) region, 11·1 million in the Eastern Mediterranean (EMRO) region, and 6·7 million in the Americas (AMRO) region. Between 2007 and 2020, pregnancies in areas of P falciparum transmission declined by 11·4% globally, despite an overall 7·0% increase in pregnancies, representing a decrease of 100·0% in the WHO Europe (EURO) region, 52·6% in WPRO, 51·5% in AMRO, 23·9% in EMRO, and 17·2% in SEARO, and a 25·4% increase in AFRO. Pregnancies in P vivax transmission areas fell by 42·8%, representing a decrease of 100·0% in EURO, 89·8% in WPRO, 48·4% in AMRO, 32·4% in EMRO, and 10·0% in SEARO, and a 25·8% increase in AFRO. Our sensitivity analysis suggests that the number of pregnancies at risk of P vivax infection could be seven-fold higher for AFRO if the whole of sub-Saharan Africa was considered endemic for P vivax.

INTERPRETATION

Between 2007 and 2020, substantial declines in the number of pregnancies at risk of malaria were seen globally. However, in AFRO, 25·4% more pregnancies were at risk of P falciparum or P vivax malaria than in 2007. This increase in the number at risk in AFRO comes despite the decline in malaria rates due to the rapidly rising population and the corresponding number of pregnancies in endemic areas. These estimates should guide priority setting for resource allocation to control malaria in pregnancy.

FUNDING

Bill & Melinda Gates Foundation and Telethon Trust.

The Association among Malaria in Pregnancy, Neonatal inflammation, and Neurocognitive Development in a Cohort of Malawian Infants

Malaria in pregnancy (MIP) causes poor birth outcomes, but its impact on neurocognitive development has not been well characterized. Between 2012 and 2014, we enrolled 307 mother-infant pairs and monitored 286 infants for neurocognitive development using the Malawi Developmental Assessment Tool at 6, 12, and 24 months of age. MIP was diagnosed from peripheral blood and placental specimens. Cord blood cytokine levels were assessed for a subset of neonates. Predictors of neurodevelopment were examined using mixed-effect logistic regression for developmental delay. Among the participants, 78 mothers (25.4%) had MIP, and 45 infants (15.7%) experienced severe neurocognitive delay. MIP was not associated with differences in cord blood cytokine levels or neurocognitive development. Preterm birth, low birthweight, increasing maternal education level, and increasing interleukin 6 levels were associated significantly with delay. The results highlight the prevalence of severe delay and a need for broad access to early childhood support in this setting.

Pregnancy and malaria: the perfect storm

PURPOSE OF REVIEW

Malaria in pregnancy continues to exert a toll on pregnant women and their offspring.

RECENT FINDINGS

The burden of Plasmodium falciparum infection is especially large in Africa, and new data show lasting effects of maternal infection on the infant's neurocognitive development. Elsewhere, P. vivax infection causes relapsing infections that are challenging to prevent. Infection in first trimester of pregnancy is an area of increasing focus, and its adverse effects on pregnancy outcome are increasingly recognised. First-trimester infection is common and frequently acquired prior to conception. Although newer rapid diagnostic tests still have limited sensitivity, they may be useful in detection of early pregnancy malaria for treatment. Artemisinin-based combination therapies are efficacious in later pregnancy but have yet to be recommended in first trimester because of limited safety data. In Africa, intermittent preventive treatment in pregnancy (IPTp) with monthly sulfadoxine-pyrimethamine improves pregnancy outcomes, but sulfadoxine-pyrimethamine resistance is worsening. The alternative, IPTp with dihydroartemisinin-piperaquine, has greater antimalarial efficacy, but does not appear to improve pregnancy outcomes, because sulfadoxine-pyrimethamine has poorly understood nonmalarial benefits on birthweight.

SUMMARY

Novel IPTp regimens must be combined with interventions to strengthen protection from malaria infection acquired before and in early pregnancy.

Intermittent screening and treatment with artemisinin-combination therapy versus intermittent preventive treatment with sulphadoxine-pyrimethamine for malaria in pregnancy: a systematic review and individual participant data meta-analysis of randomised clinical trials

BACKGROUND

In sub-Saharan Africa, the efficacy of intermittent preventive therapy in pregnancy with sulphadoxine-pyrimethamine (IPTp-SP) for malaria in pregnancy is threatened by parasite resistance. We conducted an individual-participant data (IPD) meta-analysis to assess the efficacy of intermittent screening with malaria rapid diagnostic tests (RDTs) and treatment of RDT-positive women with artemisinin-based combination therapy (ISTp-ACT) compared to IPTp-SP, and understand the importance of subpatent infections.

METHODS

We searched MEDLINE and the Malaria-in-Pregnancy Library on May 6, 2021 for trials comparing ISTp-ACT and IPTp-SP. Generalised linear regression was used to compare adverse pregnancy outcomes (composite of small-for-gestational-age, low birthweight (LBW), or preterm delivery) and peripheral or placental Plasmodium falciparum at delivery. The effects of subpatent (PCR-positive, RDT/microscopy-negative) infections were assessed in both arms pooled using multi-variable fixed-effect models adjusting for the number of patent infections. PROSPERO registration: CRD42016043789.

FINDINGS

Five trials conducted between 2007 and 2014 contributed (10,821 pregnancies), two from high SP-resistance areas where dhfr/dhps quintuple mutant parasites are saturated, but sextuple mutants are still rare (Kenya and Malawi), and three from low-resistance areas (West-Africa). Four trials contributed IPD data (N=10,362). At delivery, the prevalence of any malaria infection (relative risk [RR]=1.08, 95% CI 1.00-1.16, I2=67.0 %) and patent infection (RR=1.02, 0.61-1.16, I2=0.0%) were similar. Subpatent infections were more common in ISTp recipients (RR=1.31, 1.05-1.62, I2=0.0%). There was no difference in adverse pregnancy outcome (RR=1.00, 0.96-1.05; studies=4, N=9,191, I2=54.5%). Subpatent infections were associated with LBW (adjusted RR=1.13, 1.07-1.19), lower mean birthweight (adjusted mean difference=32g, 15-49), and preterm delivery (aRR=1.35, 1.15-1.57).

INTERPRETATION

ISTp-ACT was not superior to IPTp-SP and may result in more subpatent infections than the existing IPTp-SP policy. Subpatent infections were associated with increased LBW and preterm delivery. More sensitive diagnostic tests are needed to detect and treat low-grade infections.

FUNDING

Centers for Disease Control and Prevention and Worldwide Antimalarial Resistance Network.