Helminth infection during pregnancy: insights from evolutionary ecology

Approaches to Address the Anemia Challenge

Anemia is a multifactorial condition; approaches to address it must recognize that the causal factors represent an ecology consisting of internal (biology, genetics, and health) and external (social/behavioral/demographic and physical) environments. In this paper, we present an approach for selecting interventions, followed by a description of key issues related to the multiple available interventions for prevention and reduction of anemia. We address interventions for anemia using the following 2 main categories: 1) those that address nutrients alone, and, 2) those that address nonnutritional causes of anemia. The emphasis will be on interventions of public health relevance, but we also consider the clinical context. We also focus on interventions at different stages of the life course, with a particular focus on women of reproductive age and preschool-age children, and present evidence on various factors to consider when selecting an intervention-inflammation, genetic mutations, nutrient delivery, bioavailability, and safety. Each section on an intervention domain concludes with a brief discussion of key research areas.

Malaria, Urogenital Schistosomiasis, and Anaemia in Pregnant Ghanaian Women

Background

Anaemia is common in sub-Saharan Africa, and parasitic infections could worsen its burden during pregnancy. Moreover, women become susceptible to malaria during pregnancy. We investigated Plasmodium falciparum (P. falciparum) and Schistosoma haematobium (S. haematobium) infections and determined their association with anaemia during pregnancy.

Methods

A cross-sectional study involving 707 pregnant women attending antenatal care visits (ANC) and 446 at delivery was conducted in Battor and Adidome hospitals. Pregnant women were screened by microscopy and qPCR for P. falciparum and S. haematobium infections. Haemoglobin (Hb) levels were determined, and most participants received intermittent preventive treatment during pregnancy (IPTp) during ANC till delivery. Regression analyses were performed for associations between parasite infection and anaemia.

Results

P. falciparum microscopy prevalence at ANC and delivery was 8% and 2%, respectively, and by PCR 24% at ANC and 12% at delivery. Anaemia prevalence at ANC was 52% and 49% at delivery. There was an increased risk of anaemia with P. falciparum infection (aOR = 1.92; p = 0.04). IPTp (p = 0.003) and age (p = 0.004) were associated with increased Hb levels at delivery. S. haematobium prevalence by microscopy was 4% at ANC and 2% at delivery. No significant correlation between S. haematobium and Hb levels was observed (coef. = -0.62 g/dl; p = 0.07).

Conclusion

High anaemia prevalence was observed during pregnancy, and P. falciparum infection was associated with anaemia at ANC. Low S. haematobium prevalence could be attributed to previous praziquantel treatment during mass drug administration. Routine diagnosis and treatment of S. haematobium infections in endemic areas could be initiated to reduce schistosomiasis during pregnancy.

Strongyloides stercoralis Hyperinfection Syndrome in Pregnancy

Strongyloidiasis is a parasitic infection with a high global burden of disease. Hyperinfection syndrome is a life-threatening complication that predominantly affects immunosuppressed individuals, such as those receiving corticosteroid treatment. Despite its worldwide prevalence, little is known about the clinical effects of this condition on the feto-maternal dyad during pregnancy. We present a case of placental abruption leading to preterm delivery in a pregnancy complicated by Strongyloides stercoralis hyperinfection syndrome following antenatal corticosteroid use. Although rare, this condition is associated with high mortality rates and adverse pregnancy outcomes. Therefore, screening at-risk individuals may be warranted in pregnancies where antenatal corticosteroid administration is considered.

Iron supplementation and deworming during pregnancy reduces the risk of anemia and stunting in infants less than 2 years of age: a study from Sub-Saharan Africa

BACKGROUND

In sub-Saharan Africa, infant anemia, stunting and low birth weight remains major public health problems. It is unclear whether prenatal iron supplementation and/or deworming can reduce the risk of infant stunting, anemia and low birth weight. The aim of this study was to investigate the relationship between iron supplementation and/or deworming and stunting, anemia, and low birth weight in infants under two years of age in sub-Saharan Africa.

METHODS

Our studies examined pooled data from Demographic and Health Surveys (DHS) in twenty-three African countries collected between 2014 and 2020. childhood anemia and stunting in infants under the age of two were the primary outcomes. Iron supplementation and deworming during prenatal visits were the main exposure variables. A multivariate logistic regression model was used to investigate these relationships.

RESULTS

The prevalence of stunting was 29.9%, severe stunting was 10.6%, childhood anemia was 74.3%, childhood severe anemia was 3.2%, and low birth weight was 16.4%, respectively. The use of prenatal iron supplementation alone was associated with a significant reduction of childhood anemia [aOR (95% CI) = 0.9 (0.8-1.0)]. Prenatal deworming alone was associated with a significantly reduced risk of stunting [aOR (95% CI) = 0.7 (0.8-1.0)], childhood anemia [aOR (95% CI) = 0.7 (0.8-0.9)], and low birth weight [aOR (95% CI) = 0.7 (0.8-1.0)]. Prenatal iron supplementation plus deworming or iron supplementation (with or without deworming) were not associated with childhood anemia, infant stunting and low birth weight.

CONCLUSIONS

In Sub-Saharan Africa, prenatal deworming alone has the potential to improve infants' outcomes. Childhood anemia was improved with prenatal iron supplementation alone. Our recent findings indicate the necessity for prospective studies on the association between prenatal iron supplementation plus deworming and childhood anemia, stunting and low birth weight.

Sex—the most underappreciated variable in research: insights from helminth-infected hosts

The sex of a host affects the intensity, prevalence, and severity of helminth infection. In many cases, one sex has been found to be more susceptible than the other, with the prevalence and intensity of helminth infections being generally higher among male than female hosts; however, many exceptions exist. This observed sex bias in parasitism results primarily from ecological, behavioural, and physiological differences between males and females. Complex interactions between these influences modulate the risk of infection. Indeed, an interplay among sex hormones, sex chromosomes, the microbiome and the immune system significantly contributes to the generation of sex bias among helminth-infected hosts. However, sex hormones not only can modulate the course of infection but also can be exploited by the parasites, and helminths appear to have developed molecules and pathways for this purpose. Furthermore, host sex may influence the efficacy of anti-helminth vaccines; however, although little data exist regarding this sex-dependent efficacy, host sex is known to influence the response to vaccines. Despite its importance, host sex is frequently overlooked in parasitological studies. This review focuses on the key contributors to sex bias in the case of helminth infection. The precise nature of the mechanisms/factors determining these sex-specific differences generally remains largely unknown, and this represents an obstacle in the development of control methods. There is an urgent need to identify any protective elements that could be targeted in future therapies to provide optimal disease management with regard to host sex. Hence, more research is needed into the impact of host sex on immunity and protection.

Prevalence of Intestinal Parasite Infections and Associated Factors among Pregnant Women in Northwest Ethiopia

Background

Intestinal parasite infections are among the most common infections worldwide. They pose a high burden in pregnant women in developing countries causing maternal anemia, low birth weight, and prenatal mortality. This study is aimed at assessing intestinal parasite infection prevalence, species diversity, and associated factors among pregnant women.

Methods

A community-based cross-sectional study was conducted among pregnant women in Debre Elias district from March 2021 to July 2021. Three hundred sixty-three study participants meeting the inclusion criteria were enrolled for the study, and all submitted the required amount and quality of stool specimen. Immediately after collection, macroscopic (gross) and microscopic (saline wet mount) examination of stool sample was performed to detect and identify intestinal parasites. The generated data were checked for completeness, coded, entered, and analyzed using SPSS version 20.0 (SPSS Inc., Chicago, 2011) software. Binary logistic regression was applied to show significant association between dependent and independent variables. Statistically significant association was declared at a P value of < 0.05.

Result

Of the study participants screened for intestinal parasite, 43.5% (158/363) were infected with at least one intestinal parasite. From the total positives, 40.5% (147/363) were mono and 3.0% (11/363) were double infections. Five intestinal parasite species were recorded, of which hookworm was the predominant, (65.2%, 103/158) followed by E. histolytica/dispar (12.7%, 20/158) and G. lamblia (11.4%, 18/158). Ascaris lumbricoides and Taenia species comprised the least percentage (1.9%, 3/158 each). Source of drinking water and occupation were identified as significant factors associated with intestinal parasite infection. Farmer pregnant women were 6.41 times (AOR = 6.41, 95% CI: 1.05-39.16; P = 0.034) more likely to be infected by intestinal parasites than their counterparts. Pregnant women who drank tape water were 0.52 times less (AOR = 0.52, 95% CI: 0.30-0.88; P = 0.017) likely to be infected by intestinal parasites.

Conclusion

Intestinal parasite infections remained a serious health burden to pregnant women in the study area with the dominance of a hematophagous worm (hookworm). Community-based intestinal parasite screening and treatment are essential to alleviate the burden caused by intestinal parasite infections.

Both the microbiome and the macrobiome can influence immune responsiveness in psoriasis

It is debatable whether intestinal dysbiosis in autoimmune disease is a cause or a consequence of chronic inflammation, but it is known that intestinal dysbiosis in the course of the disease is accompanied by an increased number of pro-inflammatory lymphocytes in the Th17 population. Yet, little is known about the systemic implications of skin and even the intestinal microbiome for skin immunity and pathogenesis in psoriasis, which the most prevalent autoimmune disease in the Caucasian population. The pathogenesis of psoriasis is multifactorial with notable contributions from genetics and environmental factors (e.g. diet, drugs and infection). This article describes alterations in the microbiome and macrobiome, which are involved in immune regulation. The composition of the gut microbiome can dramatically affect immune development and affect susceptibility to diseases, especially autoimmune disorders such as psoriasis. Understanding the mechanisms of pathogenesis induced by the micro- and macrobiome may prove crucial for innovative future solutions in skin disease treatment.

Global prevalence of intestinal parasitic infections and associated risk factors in pregnant women: a systematic review and meta-analysis

BACKGROUND

Intestinal parasitic infections (IPIs) during pregnancy, if left untreated, can cause adverse effects for the mothers, foetuses and newborns. However, limited information is available about the global status of IPIs in pregnant women. Here we undertook a meta-analysis to estimate the global prevalence of IPIs and associated risk factors in pregnant women.

METHODS

We searched the PubMed, Science Direct, Scopus, Web of Science and Google Scholar databases for relevant studies that were published between 1 January 1987 and 30 December 2019. A random effects meta-analysis model was used to estimate the pooled prevalence, odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A total of 114 studies comprising 98 342 pregnant women across 35 countries were included in the systematic review and meta-analysis. Among IPIs identified from pregnant women, three helminth infections (hookworm 19% [95% CI 15 to 23], Ascaris lumbricoides 17% [95% CI 13 to 21] and Trichuris trichiura 11% [95% CI 7 to 16]) and three protozoan infections (Blastocystis sp. 21% [95% CI 4 to 46], Entamoeba histolytica/dispar 9% [95% CI 3 to 19] and Giardia sp. 8% [95% CI 4 to 13]) were identified as the most prevalent intestinal parasites. Moreover, we found that there was a significant association between IPIs with increased risk of anaemia in pregnant women (OR 2.65 [95% CI 2.08 to 3.37]). The prevalence of IPIs was slightly higher in geophagic pregnant women compared with controls, but this was not significant (OR 1.22 [95% CI 0.87 to 1.71]). According to species, the pooled OR of A. lumbricoides infection had a significantly higher risk in geophagic pregnant women compared with controls (OR 2.66 [95% CI 1.37 to 5.16]). There was a positive relationship between the high prevalence of IPIs in pregnant women living in rural areas compared with urban residents (OR 3.36 [95% CI 1.57 to 7.19]).

CONCLUSIONS

The current review revealed a relatively high prevalence of IPIs in pregnant women, especially in some low- and middle-income countries. These results suggest a need for improved prevention and control efforts to reduce the health risks to pregnant women.

Burden of intestinal parasitic infections among pregnant women in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Comprehensive nationwide data on prevalence and distribution of intestinal parasites (IPIs) among pregnant women are lacking. Therefore, the aim of this study was to provide pooled prevalence estimate, prevalence in different regions and species-specific IPIs among pregnant women in Ethiopia.

METHODS

The search was carried out in Medline via PubMed, Scopus, Science Direct, Web of Science and Google Scholar on published and unpublished data between 2008 and Sep 2020 for studies describing rate of IPIs among pregnant women in Ethiopian. A random-effects model and forest plots to estimate pooled effect size and effect of each study with their confidence interval (CI) were used to provide a visual summary of the data. We conducted meta-regression to understand the source of heterogeneity and pooled the prevalence using 'metaprop' command using STATA software version 14.

RESULTS

A total of 3149 of the 9803 pregnant women were infected with one or more species of IPIs resulted in an overall prevalence of 29% (95% CI 22-37%). The prevalence estimate varied among studies with considerable heterogeneity (χ² = 2069.19, p < 0.001 I² = 98.84). The prevalence of IPIs was 36% (95% CI 22-50%) in Oromia region, 29% (95% CI 10-47%) in Amhara region, 24% (95% CI 17-32%) in southern nation, nationality and people region, 24% (95% CI 22-27%) in Tigray region and 24% (95% CI 20-29%) in Addis Ababa city. Hookworms with pooled prevalence estimate of 10% (95% CI 8-13%) followed by Ascaris lumbricoides 10% (95% CI 7-13%), and Entamoeba histolytica/dispar 6% (95% CI 4-8%) were the three common species of IPIs identified in this group of population.

CONCLUSION

The prevalence of IPIs among pregnant women is relatively high in comparison to other general population. Hookworms and Ascaris lumbricoides were the most dominant species of intestinal helminths, whereas Entamoeba histolytica/dispar was the dominant intestinal protozoa among pregnant women in Ethiopia.

Effect of Lymphatic Filariasis and Hookworm Infection on Pregnancy Course and Outcome in Women Living in the Democratic Republic of the Congo

Little is known about the effect of helminth infections on the natural gynecological and pregnancy course. Our goal was to assess the relationship between Wuchereria bancrofti and hookworm (HW) infections with pregnancy course and outcome in a group of 82 women living in a rural area of the Democratic Republic of the Congo. Demographics and information on gynecological and obstetrical histories were collected retrospectively with standardized questionnaires. Wuchereria bancrofti and HW infections were diagnosed using a filarial antigen-detection test and the Kato-Katz method, respectively. Analyses consisted of multivariable logistic regressions adjusting for age, number of deliveries, and history of anthelmintic treatment (HAHT). The median age of study participants was 35 (interquartile range [IQR]: 30-44) years, and the median number of deliveries was five (IQR: 3-7). Wuchereria bancrofti and HW infection rates were 44.5% and 43.3%, respectively. Filarial antigenemia and HW infection were not significantly associated with the number of deliveries. The proportions of women with a history of pregnancy resulting in neonatal death, miscarriage, premature birth, and postpartum hemorrhage were 56%, 44%, 23%, and 36%, respectively. History of pregnancy associated with neonatal death was less frequent in women with HAHT, tended to be more frequent in women with filarial antigenemia, and was not associated with HW infection. None of the three other pregnancy events studied (miscarriage, premature birth, and postpartum hemorrhage) were associated with filarial antigenemia or HW infection. The positive association found between HAHT and lower risk of neonatal death warrants investigation in larger groups of women.

Routine deworming during antenatal care decreases risk of neonatal mortality and low birthweight: A retrospective cohort of survey data

Background

Soil transmitted helminths (STH) are a common infection among pregnant women in areas with poor access to sanitation. Deworming medications are cheap and safe; however, the health benefit of deworming during pregnancy is not clear.

Methods / Principal findings

We created a retrospective cohort of more than 800,000 births from 95 Demographic and Health Survey datasets to estimate the impact of deworming medicine during routine antenatal care (ANC) on neonatal mortality and low birthweight. We first matched births on the probability of receiving deworming during ANC. We then modeled the birth outcomes with the matched group as a random intercept to estimate the effect of deworming during antenatal care after accounting for various risk factors. We also tested for effect modification of soil transmitted helminth prevalence on the impact of deworming during ANC. Receipt of deworming medication during ANC was associated with a 14% reduction in the risk of neonatal mortality (95% confidence interval = 10–17%, n = 797,772 births), with no difference between high and low transmission countries. In low transmission countries, we found an 11% reduction in the odds of low birth weight (95% confidence interval = 8–13%) for women receiving deworming medicine, and in high transmission countries, we found a 2% reduction in the odds of low birthweight (95% confidence interval = 0–5%).

Conclusions / Significance

These results suggest a substantial health benefit for deworming during ANC that may be even greater in countries with low STH transmission.

Soil-transmitted helminths cause a significant burden of disease throughout the world, particularly in communities with limited access to sanitation facilities and clean drinking water. Deworming medicines effectively clear these parasites, are inexpensive, and are well tolerated. However the effectiveness of deworming medicines, particularly for pregnant women, has not been clearly demonstrated. In this paper we analyze more than 800,000 births to measure the effect that deworming medicine during pregnancy has on birth outcomes. When women receive deworming medicine during pregnancy we saw two specific benefits for the baby: first the risk of neonatal mortality (a baby’s death within first 4 weeks of life) decreases by an estimated 14%, and second, the odds of low birthweight were 11% lower in countries with lower transmission of soil-transmitted helminths. In countries with higher transmission of soil-transmitted helminths we saw no effect of deworming medicine on the odds of low birthweight. Given the results, resources leading to widescale distribution of deworming during pregnancy would have a positive effect on child survival and health.

Protective Effect of Intestinal Helminthiasis Against Tuberculosis Progression Is Abrogated by Intermittent Food Deprivation

Background

Tuberculosis (TB) is still a major challenge for humankind. Because regions with the highest incidence also have a high prevalence of helminthiasis and nutritional scarcity, we wanted to understand the impact of these on TB progression.

Methods

We have developed an experimental murine model for active TB in C3HeB/FeJ, coinfected with Trichuris muris and Heligmosomoides polygyrus nematodes, and exposed to an environmental mycobacterium (M. manresensis) and intermittent fasting. Cause-effect relationships among these factors were explored with Partial Least Squares Path modelling (PLSPM).

Results

Previous parasitization had a major anti-inflammatory effect and reduced systemic levels of ADA, haptoglobin, local pulmonary levels of IL-1β, IL-6, TNF-α, CXCL-1, CXCL-5 and IL-10. Oral administration of heat-killed M. manresensis resulted in a similar outcome. Both interventions diminished pulmonary pathology and bacillary load, but intermittent food deprivation reduced this protective effect increasing stress and inflammation. The PLSPM revealed nematodes might have protective effects against TB progression.

Conclusions

Significantly higher cortisol levels in food-deprivation groups showed it is a stressful condition, which might explain its deleterious effect. This highlights the impact of food security on TB eradication policies and the need to prioritize food supply over deworming activities.

Burden of soil-transmitted helminth infection in pregnant refugees and migrants on the Thailand-Myanmar border: Results from a retrospective cohort

BACKGROUND

Soil-transmitted helminth (STH) infections are widespread in tropical and subtropical regions. While many STH infections are asymptomatic, vulnerable populations such as pregnant women face repercussions such as aggravation of maternal anaemia. However, data on prevalence and the effect of STH infections in pregnancy are limited. The aim of this analysis was to describe the burden of STH infections within and between populations of pregnant women from a local refugee camp to a mobile migrant population, and to explore possible associations between STH infection and pregnancy outcomes.

METHODOLOGY

This is a retrospective review of records from pregnant refugee and migrant women who attended Shoklo Malaria Research Unit antenatal care (ANC) clinics along the Thailand-Myanmar border between July 2013 and December 2017. Inclusion was based on provision of a stool sample during routine antenatal screening. A semi-quantitative formalin concentration method was employed for examination of faecal samples. The associations between STH mono-infections and maternal anaemia and pregnancy outcomes (i.e., miscarriage, stillbirth, preterm birth, and small for gestational age) were estimated using regression analysis.

PRINCIPAL FINDINGS

Overall, 12,742 pregnant women were included, of whom 2,702 (21.2%) had a confirmed infection with either Ascaris lumbricoides, hookworm, Trichuris trichiura, or a combination of these. The occurrence of STH infections in the refugee population (30.8%; 1,246/4,041) was higher than in the migrant population (16.7%; 1,456/8,701). A. lumbricoides was the predominant STH species in refugees and hookworm in migrants. A. lumbricoides and hookworm infection were associated with maternal anaemia at the first ANC consultation with adjusted odds ratios of 1.37 (95% confidence interval (CI) 1.08-1.72) and 1.65 (95% CI 1.19-2.24), respectively. Pregnant women with A. lumbricoides infection were less likely to miscarry when compared to women with negative stool samples (adjusted hazard ratio 0.63, 95% CI 0.48-0.84). STH infections were not significantly associated with stillbirth, preterm birth or being born too small for gestational age. One in five pregnant women in this cohort had STH infection. Association of STH infection with maternal anaemia, in particular in the event of late ANC enrolment, underlines the importance of early detection and treatment of STH infection. A potential protective effect of A. lumbricoides infection on miscarriage needs confirmation in prospective studies.

Maternal Hookworm Infection and Its Effects on Maternal Health: A Systematic Review and Meta-Analysis

Hookworm is an intestinal parasite that infects nearly 230 million people, with another 5.1 billion at risk, especially in poverty-stricken tropical and subtropical regions. Pregnancy is an especially vulnerable time for hookworm infection because of its effect on both maternal and subsequently fetal health. A systematic review and meta-analysis was conducted. The meta-analysis was performed on the association between maternal hookworm and maternal anemia, as well as maternal hookworm coinfection with malaria. The prevalence of hookworm ranged from 1% to 78% in pregnant women, whereas malaria prevalence ranged from 11% to 81%. Pregnant women with hookworm infection were more likely to have anemia (combined odds ratio [cOR] 2.55 [2.20, 2.96], P < 0.001). In addition, pregnant woman with hookworm were more likely to have malaria coinfection (cOR 1.60 [1.38, 1.86], P < 0.001). Other effects on maternal and child health were investigated and summarized without systematic review or meta-analysis because of the limited study numbers. Despite current deworming recommendations in pregnant women, heavy hookworm burden, coinfection with malaria, and subsequent anemia persist. Although this is likely due, in part, to a lack of implementation of preventive chemotherapy, additional interventions such as health education, proper waste management, or linking malaria and soil-transmitted helminth treatment and prevention programs may also be needed. Further investigations on maternal-child outcomes as a result of hookworm infection during pregnancy will highlight public health interventional targets to reduce morbidity in pregnant women and children globally.

The molecular tug of war between immunity and fertility: Emergence of conserved signaling pathways and regulatory mechanisms

Reproduction and immunity are energy intensive, intimately linked processes in most organisms. In women, pregnancy is associated with widespread immunological adaptations that alter immunity to many diseases, whereas, immune dysfunction has emerged as a major cause for infertility in both men and women. Deciphering the molecular bases of this dynamic association is inherently challenging in mammals. This relationship has been traditionally studied in fast-living, invertebrate species, often in the context of resource allocation between life history traits. More recently, these studies have advanced our understanding of the mechanistic underpinnings of the immunity-fertility dialogue. Here, we review the molecular connections between reproduction and immunity from the perspective of human pregnancy to mechanistic discoveries in laboratory organisms. We focus particularly on recent invertebrate studies identifying conserved signaling pathways and transcription factors that regulate resource allocation and shape the balance between reproductive status and immune health.

Parasite intensity drives fetal development and sex allocation in a wild ungulate

An understanding of the mechanisms influencing prenatal characteristics is fundamental to comprehend the role of ecological and evolutionary processes behind survival and reproductive success in animals. Although the negative influence of parasites on host fitness is undisputable, we know very little about how parasitic infection in reproductive females might influence prenatal factors such as fetal development and sex allocation. Using an archival collection of Dall’s sheep (Ovis dalli dalli), a capital breeder that depends on its body reserves to overcome the arctic winter, we investigated the direct and indirect impacts of the parasite community on fetal development and sex allocation. Using partial least squares modelling, we observed a negative effect of parasite community on fetal development, driven primarily by the nematode Marshallagia marshalli. Principal component analysis demonstrated that mothers with low parasite burden and in good body condition were more likely to have female versus male fetuses. This association was primarily driven by the indirect effect of M. marshalli on ewe body condition. Refining our knowledge of the direct and indirect impact that parasite communities can have on reproduction in mammals is critical for understanding the effects of infectious diseases on wildlife populations. This can be particularly relevant for species living in ecosystems sensitive to the effects of global climate change.

Placental gene expression and antibody levels of mother-neonate pairs reveal an enhanced risk for inflammation in a helminth endemic country

In utero exposure to environmental factors can modify the development of allergies later in life whereby the mechanisms of the feto-maternal crosstalk still remain largely unknown. Murine studies revealed that inflammatory maternal signals elicited by chronic helminth infection within the placenta imprint a distinct gene expression profile related to the Vitamin-D-receptor (VDR)-inflammation-axis. We thus investigated whether pro- or anti- inflammatory immune responses as well as VDR and related gene expression within the placenta differ between women from helminth-endemic and non-endemic areas. A prospective pilot study was conducted in Munich, Germany (helminth non-endemic) and Lambaréné, Gabon (helminth-endemic). At delivery, clinical information alongside placenta tissue samples and maternal and cord blood were obtained for further laboratory analysis. Schistosoma haematobium infection was detected in 13/54 (23%) Gabonese women. RT PCR revealed significantly lower gene expression of VDR, Cyp27b1, Foxp3 and IL10 in Gabonese compared to German placentae as well as significantly lower levels of plasma IgG4 in newborns resulting in a significantly higher IgE/IgG4 ratio. These findings demonstrate that exposure in utero to different environments alters placental gene expression and thus possibly plays a role in the development and modulation of the immune system of the offspring.

Old friends and friendly fire: Pregnancy, hookworm infection, and anemia among tropical horticulturalists

OBJECTIVES

Despite public health concerns about hookworm infection in pregnancy, little is known about immune profiles associated with hookworm (Necator americanus and Ancylostoma duodenale) infection during pregnancy. Fetal tolerance requirements may constrain maternal immune response to hookworm, thereby increasing susceptibility to new infections or increasing hemoglobin loss. To explore this possibility, we study systemic immune response and hemoglobin levels in a natural fertility population with endemic helminthic infection.

METHODS

We used Bayesian multilevel models to analyze mixed longitudinal data on hemoglobin, hookworm infection, reproductive state, eosinophils, and erythrocyte sedimentation rate (ESR) to examine the effects of pregnancy and hookworm infection on nonspecific inflammation, cellular parasite response, and hemoglobin among 612 Tsimane women aged 15-45 (1016 observations).

RESULTS

Pregnancy is associated with lower eosinophil counts and lower eosinophil response to hookworm, particularly during the second and third trimesters. Both hookworm and pregnancy are associated with higher ESR, with evidence for an interaction between the two causing further increases in the first trimester. Pregnancy is moderately associated with higher odds of hookworm infection (OR: 1.23, 95% CI: 0.83 to 1.83). Pregnancy and hookworm both decrease hemoglobin and may interact to accentuate this effect in the first-trimester of pregnancy (Interaction: β: -0.30 g/dL; CI: -0.870 to 0.24).

CONCLUSIONS

Our findings are consistent with a possible trade-off between hookworm immunity and successful pregnancy, and with the suggestion that hookworm and pregnancy may have synergistic effects, particularly in the first trimester.

Mass deworming for soil-transmitted helminths and schistosomiasis among pregnant women: A systematic review and individual participant data meta-analysis

The objective of the review is to use individual participant data (IPD) meta-analysis to explore the effect of mass deworming during pregnancy. We developed a search strategy and searched the databases till March 2018. We included individually randomised controlled trials; cluster randomised controlled trials and quasi randomised studies providing preventive or therapeutic deworming drugs for soil transmitted helminthiases and schistosomiasis during pregnancy. All IPD were assessed for completeness, compared to published reports and entered into a common data spreadsheet. Out of the seven trials elgible for IPD, we received data from three trials; out of 8,515 potential IPD participants; data were captured for 5,957 participants. Findings from this IPD suggest that mass deworming during pregnancy reduces maternal anaemia by 23% (Risk ratio [RR]: 0.77, 95% confidence intreval [CI]: 0.73-0.81; three trials; 5,216 participants; moderate quality evidence). We did not find any evidence of an effect of mass deworming during pregnancy on any of the other outcomes. There was no evidence of effect modification; however these findings should be interpreted with caution due to small sample sizes. The quality of evidence was rated as moderate for our findings. Our analyses suggest that mass deworming during pregnancy is associated with reducing anaemia with no evidence of impact on any other maternal or pregnancy outcomes. Our analyses were limited by the availability of data for the impact by subgroups and effect modification. There is also a need to support and promote open data for future IPDs.

Hymenolepiasis in a Pregnant Woman: A Case Report of Hymenolepis nana Infection

Hymenolepiasis is an infection caused by Hymenolepis nana (H. nana) and H. diminuta (H. diminuta). Hymenolepiasis is prevalent throughout the world with human infections with H. nana being frequently reported in the literature as compared to H. diminuta. Hymenolepiasis is more frequent among children, and most human infections remain asymptomatic and self-limited. Symptoms including abdominal pain, diarrhea, and vomiting are frequently noted in the cases of heavy infections. We report a case of hymenolepiasis caused by H. nana in a pregnant woman.

Immune response to asymptomatic infections by Entamoeba histolytica and other enteric pathogens in pregnant women and their infants in a high HIV burdened setting in Zimbabwe

BACKGROUND

Asymptomatic Entamoeba histolytica infections in pregnant women puts infants at risk of infection through vertical transmission or transmission during breastfeeding in high HIV prevalence areas. The study aimed at investigating the immune response to asymptomatic E.histolytica infection in pregnant women and their infants in a high HIV burdened setting in Harare, Zimbabwe.

METHODOLOGY

Serum samples from 39 predominantly breastfeeding mother-infant pairs were analyzed for inflammatory cytokine and immunoglobulin profiles using BIOPLEX. The infants' ages ranged from 10 days to 14 weeks.

RESULTS

IL-1r, IL-4, IL-9, IL-12p70, IL-17a, G-CSF and PDGF-BB were significantly raised in E. histolytica infected compared to non-infected lactating mothers (p < 0.05). Carriage of any form of enteric infection such as Non-lactose fermenters (NLFs) including E. histolytica significantly increased concentration levels of IL-1r, IL-4, IL-9, IL-10, IL-12p70, IL17a, G-CSF, GM-CSF, IFN-γ, PDGF-BB and TNF-α cytokines (p < 0.05) but no significant differences in immunoglobulin levels among the mothers. Anti-inflammatory cytokines (IL-1r, IL-2, IL-4, IL-5, IL-6), pro-inflammatory cytokines (IL-9, IL-12-p70, IL-15, IL-17a, TNF-α) and growth factors (FGF-β, G-CSF, GM-CSF, PDGF-bb) were significantly raised in HIV-uninfected mothers and not HIV-infected mothers during E. histolytica infection (p < 0.05). In infants, E. histolytica carriage and HIV exposure had no significant impact on the cytokine and immunoglobulin concentrations.

CONCLUSION

Pro-inflammatory cytokines and chemokines are highly raised in lactating mothers with asymptomatic enteric pathogens hence there is need to check cytokine profiles in pregnant women and their infants to assist in decision making linked to treatment and prevention in times of pandemics.

Malaria and Geohelminthiasis Coinfections in Expectant Women: Effect on Maternal Health and Birth Outcomes in a Malaria Endemic Region in Kenya

Geohelminthiasis and malaria coinfections in pregnancy are common in sub-Saharan Africa. The consequences of the disease combination on maternal health and birth outcomes are poorly understood. For a better understanding of this coinfection in expectant mothers, a cross-sectional study was carried out to evaluate the effect of the coinfection on maternal health and birth outcomes in expectant mothers in Bungoma County, Kenya. To collect data on malaria and maternal haematological parameters, blood samples were obtained from 750 participants aged 18-49 years and analyzed. Haemoglobin and eosinophils levels were determined by coulter counter while malaria parasitemia levels and red blood cell morphology were assessed by preparing and observing blood smears under the microscope. Fresh stool samples were collected and processed for identification and quantification of geohelminths species using Kato-Katz. Harada Mori technique was used to increase chances of detecting hookworms and Strongyloides infections. Neonate's health was evaluated based on the appearance, pulse, grimace, activity, and respiration (APGAR) scale. Parasites identified were Plasmodium falciparum, P. malariae, P. ovale, Ascaris lumbricoides, Necator americanus, Enterobius vermicularis, and Schistosoma mansoni. The prevalence of geohelminths, malaria parasites, and coinfection was 24.7%, 21.6%, and 6.8%, respectively. Those coinfected with geohelminths and malaria parasites were four times likely to have anaemia (OR 4.137; 95% CI 2.088-8.195; P=0.001) compared with those infected with geohelminths or malaria parasites alone (OR 0.505; 95% CI 0.360-0.709; P=0.001 and OR 0.274; 95%CI 0.187-0.402 P=0.001, respectively). The odds of having preterm deliveries (OR 6.896; 95% CI 1.755-27.101; P=0.006) and still births (OR 3.701; 95% CI 1.008-13.579 P< 0.048) were greater in those coinfected than in those infected with either geohelminths or malaria parasites. Geohelminths and malaria coinfections were prevalent among study participants; consequently the risk of maternal anaemia, preterm deliveries, and still births were high. Routine screening and prompt treatment during antenatal visits should be encouraged to mitigate the adverse consequences associated with the coinfections.

Travel-Related Infections Among Pregnant Travellers to the Tropics: An Overview

Infectious diseases acquired during travel pose a significant health risk to pregnant travellers, who are more susceptible to both acquiring certain infections and developing severe complications. A review of the literature focusing on recent evidence-based guidelines was conducted with attention to tropical infections in the pregnant patient. A summary meant to serve as a succinct reference for health care professionals caring for pregnant women is presented. Magnitude of risk, clinical features, management, and preventive strategies of major travel-acquired infections of pertinence to the pregnant traveller are summarized, including malaria, arboviral infections, foodborne infections, helminthic infections, and influenza. Tables with details on specific infections within each group and guidance for reducing travel-related health risks in the pregnant patient are presented.