Sulfadoxine/pyrimethamine intermittent preventive treatment for malaria during pregnancy

Direct therapeutic effect of sulfadoxine-pyrimethamine on nutritional deficiency-induced enteric dysfunction in a human Intestine Chip

BACKGROUND

Sulfadoxine-pyrimethamine (SP) antimalarial therapy has been suggested to potentially increase the birth weight of infants in pregnant women in sub-Saharan Africa, independently of malarial infection. Here, we utilized female intestinal organoid-derived cells cultured within microfluidic Organ Chips to investigate whether SP could directly impact intestinal function and thereby improve the absorption of essential fats and nutrients crucial for fetal growth.

METHODS

Using a human organ-on-a-chip model, we replicated the adult female intestine with patient organoid-derived duodenal epithelial cells interfaced with human intestinal endothelial cells. Nutrient-deficient (ND) medium was perfused to simulate malnutrition, resulting in the appearance of enteric dysfunction indicators such as villus blunting, reduced mucus production, impaired nutrient absorption, and increased inflammatory cytokine secretion. SP was administered to these chips in the presence or absence of human peripheral blood mononuclear cells (PBMCs).

FINDINGS

Our findings revealed that SP treatment effectively reversed multiple intestinal absorptive abnormalities observed in malnourished female Intestine Chips, as validated by transcriptomic and proteomic analyses. SP also reduced the production of inflammatory cytokines and suppressed the recruitment of PBMCs in ND chips.

INTERPRETATION

Our results indicate that SP could potentially increase birth weights by preventing enteric dysfunction and suppressing intestinal inflammation. This underscores the potential of SP as a targeted intervention to improve maternal absorption, subsequently contributing to healthier fetal growth. While SP treatment shows promise in addressing malabsorption issues that can influence infant birth weight, we did not model pregnancy in our chips, and thus its usefulness for treatment of malnourished pregnant women requires further investigation through clinical trials.

FUNDING

The Bill and Melinda Gates Foundation, and the Wyss Institute for Biologically Inspired Engineering at Harvard University, and the HDDC Organoid Core of the P30 DK034854.

The Impact of Patient Age and Corticosteroids in Patients With Sulfonamide Hepatotoxicity

INTRODUCTION

Sulfonamides are widely used to treat and prevent various bacterial and opportunistic infections. The aim of this study was to describe the clinical presentation and outcomes of a large cohort of patients with sulfonamide hepatotoxicity.

METHODS

Between 2004 and 2020, 105 patients with hepatotoxicity attributed to trimethoprim/sulfamethoxazole (TMP-SMZ) (n = 93) or other sulfonamides (n = 12) were enrolled. Available liver biopsies were reviewed by a single hepatopathologist.

RESULTS

Among the 93 TMP-SMZ cases, 52% were female, 7.5% younger than 20 years, and the median time to drug-induced liver injury (DILI) onset was 22 days (range: 3-157). Younger patients were significantly more likely to have rash, fever, eosinophilia, and a hepatocellular injury pattern at onset that persisted at the peak of liver injury compared with older patients ( P < 0.05). The 18 (19%) TMP-SMZ patients treated with corticosteroids had more severe liver injury and a higher mortality but a trend toward more rapid normalization of their laboratory abnormalities compared with untreated patients. During follow-up, 6.2% of the TMP-SMZ patients died or underwent liver transplantation. Chronic DILI developed in 20% and was associated with cholestatic injury at onset and higher peak total bilirubin levels.

DISCUSSION

Sulfonamide hepatotoxicity is characterized by a short drug latency with frequent hypersensitivity features at onset. Subject age is an important determinant of the laboratory profile at presentation, and patients with cholestasis and higher total bilirubin levels were at increased risk of developing chronic DILI. Corticosteroids may benefit a subgroup of patients with severe injury, but further studies are needed.

Drug Use Practices and Self-Treatment for Suspected Malaria in Ibadan, Nigeria

Antimalarial drug failures have been reported anecdotally in Nigeria, and malarial self-treatment practices could be a contributing factor. This study was designed to assess the pattern of drug use practices and self-treatment options among caregivers in Ibadan, Nigeria. We carried out a descriptive cross-sectional study among 283 study participant pairs (children under 5 years of age with suspected malaria and their caregivers). Structured questionnaires were used as research instruments. The results indicated that most caregivers were mothers (88.8%), 69% of caregivers self-prescribed and self-managed malaria for children under 5 years old without immediate hospital visits, and 76.4% of the caregivers believed most recommended and available antimalarial drugs were ineffective. Generally, 44.2% of respondents preferred and used antibiotics as a treatment strategy for malaria, 13.2% used agbo (a locally made liquid extract of plants and roots), 12.5% used prayers, and 19.6% used antimalarial drugs. Overall, only 57.1% of respondents stated that they always complete the standard antimalarial dosage regimen. The choice of malaria self-treatment options was significantly linked to the level of education. The findings identified antibiotics, agbo, and prayers as the immediate choices for self-treating malaria disease in Ibadan. Furthermore, incomplete adherence to antimalarial drugs is a general practice in Ibadan. Malaria self-treatment policy and continuous education on antimalarial drug use tailored to the different literacy and education levels of the general public is hereby recommended to reduce the risk of development of parasite resistance to effective anti-malarial drugs.

The prevalence of molecular markers of resistance to sulfadoxine-pyrimethamine among pregnant women at first antenatal clinic attendance and delivery in the forest-savannah area of Ghana

Intermittent preventive treatment during pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) is used to prevent malaria and associated unfavorable maternal and foetal outcomes in pregnancy in moderate to high malaria transmission areas. Effectiveness of IPTp-SP is, however, threatened by mutations in the Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps) genes which confer resistance to pyrimethamine and sulfadoxine, respectively. This study determined the prevalence of molecular markers of SP resistance among pregnant women in a high malaria transmission area in the forest-savannah area of Ghana. Genomic DNA was extracted from 286 P. falciparum-positive dried blood spots obtained from pregnant women aged ≥18 years (255 at first Antenatal Care (ANC) clinic visit and 31 at delivery from 2017 to 2019) using Chelex 100. Mutations in Pfdhfr and Pfdhps genes were detected using molecular inversion probes and next generation sequencing. In the Pfdhfr gene, single nucleotide polymorphisms (SNPs) were detected in 83.1% (157/189), 92.0% (173/188) and 91.0% (171/188) at codons 51, 59, and 108 respectively in samples collected at first ANC visit, while SNPs were detected in 96.6 (28/29), 96.6% (28/29) and 96.8% (30/31) in isolates collected at delivery. The Pfdhfr triple mutant N51I, C59R and S108N (IRN) was carried by 80.5% (128/159) and 96.5% (28/29) of the typed isolates collected at ANC visit and at delivery respectively. In the Pfdhps gene, SNPs were detected in 0.6% (1/174), 76.2% (138/181), 33.2% (60/181), 1.2% (2/174), 0% (0/183), and 16.6% (27/173) at codons 431, 436, 437, 540, 581 and 613 respectively in samples collected at ANC, and 0% (0/25), 72% (18/25), 40% (10/25), 3.6% (1/25), 0% (0/29) and 7.4% (2/27) in samples collected at delivery. Quadruple mutant Pfdhfr N51I, C59R, and S108N + Pfdhps A437G (IRN-GK) was present in 25.8% (33/128) and 34.8% (8/23) of isolates at ANC and at delivery respectively. Quintuple mutant alleles Pfdhfr N51I, C59R, and S108N + Pfdhps A437G and K540E (IRN-GE) were detected in 0.8% (1/128) and 4.4% (1/23) of samples collected at ANC and at delivery respectively. No mutations were identified at Pfdhfr codons 16 or 164 or Pfdhps 581. There is a high prevalence of Pfdhfr triple mutant P. falciparum infections among pregnant women in the study area. However, prevalence of the combined Pfdhfr/Pfdhps quadruple and quintuple mutants IRN-GK and IRN-GE respectively prior to commencement of IPTp-SP were low, and no Pfdhps A581G mutant was detected, indicating that SP is still likely to be efficacious for IPTp-SP in the forest-savannah area in the middle belt of Ghana.

Low birth weight and its associated risk factors in a rural health district of Burkina Faso: a cross sectional study

Background

Low birth weight (LBW) is a major factor of neonate mortality that particularly affects developing countries. However, the scarcity of data to support decision making to reduce LBW occurrence is a major obstacle in sub-Saharan Africa. The aim of this research was to determine the prevalence and associated factors of LBW at the Yako health district in a rural area of Burkina Faso.

Methods

A cross sectional survey was conducted at four peripheral health centers among mothers and their newly delivered babies. The mothers’ socio-demographic and obstetrical characteristics were collected by face-to-face interview or by review of antenatal care books. Maternal malaria was tested by standard microscopy and neonates’ birth weights were documented. Multivariate logistic regression was used to determine factors associated with LBW. A p-value < 0.05 was considered statistically significant.

Results

Of 600 neonates examined, the prevalence of low birth weight was 11.0%. Adjustment for socio-demographic characteristic, medical conditions, obstetrical history, malaria prevention measures by multivariate logistic regression found that being a primigravid mother (aOR = 1.8, [95% CI: 1.1–3.0]), the presence of malaria infection (aOR = 1.9, [95% CI: 1.1–3.5]), the uptake of less than three doses of sulfadoxine-pyrimethamine for the intermittent preventive treatment of malaria in pregnancy (IPTp-SP) (aOR = 2.2, [95% CI: 1.3–3.9]), the presence of maternal fever at the time of delivery (aOR = 2.8, [95% CI: 1.5–5.3]) and being a female neonate (aOR = 1.9, [95% CI: 1.1–3.3]) were independently associated with an increased risk of LBW occurrence. The number of antenatal visits performed by the mother during her pregnancy did not provide any direct protection for low birth weight.

Conclusion

The prevalence of LBW remained high in the study area. Maternal malaria, fever and low uptake of sulfadoxine-pyrimethamine doses were significantly associated with LBW and should be adequately addressed by public health interventions.

Impact of Drug Pressure versus Limited Access to Drug in Malaria Control: The Dilemma

Malaria burden has severe impact on the world. Several arsenals, including the use of antimalarials, are in place to curb the malaria burden. However, the application of these antimalarials has two extremes, limited access to drug and drug pressure, which may have similar impact on malaria control, leading to treatment failure through divergent mechanisms. Limited access to drugs ensures that patients do not get the right doses of the antimalarials in order to have an effective plasma concentration to kill the malaria parasites, which leads to treatment failure and overall reduction in malaria control via increased transmission rate. On the other hand, drug pressure can lead to the selection of drug resistance phenotypes in a subpopulation of the malaria parasites as they mutate in order to adapt. This also leads to a reduction in malaria control. Addressing these extremes in antimalarial application can be essential in maintaining the relevance of the conventional antimalarials in winning the war against malaria.

Synthesis and Antiparasitic Activity of New Conjugates—Organic Drugs Tethered to Trithiolato-Bridged Dinuclear Ruthenium(II)–Arene Complexes

Tethering known drugs to a metalorganic moiety is an efficient approach for modulating the anticancer, antibacterial, and antiparasitic activity of organometallic complexes. This study focused on the synthesis and evaluation of new dinuclear ruthenium(II)–arene compounds linked to several antimicrobial compounds such as dapsone, sulfamethoxazole, sulfadiazine, sulfadoxine, triclosan, metronidazole, ciprofloxacin, as well as menadione (a 1,4-naphtoquinone derivative). In a primary screen, 30 compounds (17 hybrid molecules, diruthenium intermediates, and antimicrobials) were assessed for in vitro activity against transgenic T. gondii tachyzoites constitutively expressing β-galactosidase (T. gondii β-gal) at 0.1 and 1 µM. In parallel, the cytotoxicity in noninfected host cells (human foreskin fibroblasts, HFF) was determined by an alamarBlue assay. When assessed at 1 µM, five compounds strongly impaired parasite proliferation by >90%, and HFF viability was retained at 50% or more, and they were further subjected to T. gondii β-gal dose-response studies. Two compounds, notably 11 and 13, amide and ester conjugates with sulfadoxine and metronidazole, exhibited low IC50 (half-maximal inhibitory concentration) values 0.063 and 0.152 µM, and low or intermediate impairment of HFF viability at 2.5 µM (83 and 64%). The nature of the anchored drug as well as that of the linking unit impacted the biological activity.

Evaluation of the usefulness of intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine in a context with increased resistance of Plasmodium falciparum in Kingasani Hospital, Kinshasa in the Democratic Republic of Congo

BACKGROUND

Increasing resistance of Plasmodium falciparum to sulfadoxine-pyrimethamine (SP) threatens its usefulness for intermittent preventive treatment in pregnancy (IPTp-SP). The prophylactic effects of IPTp-SP on maternal malaria and adverse pregnancy outcomes were evaluated in Kingasani Hospital, Kinshasa in the Democratic Republic of Congo (DRC).

METHODS

Laboring women (n = 844) and respective newborns were investigated. Blood samples collected from women were tested for malaria using rapid diagnostic test (RDT), blood smears examination, and real-time PCR. The hemoglobin level was measured by HemoCue© analyzer. A PCR-RFLP method was applied for detecting N51I, C59R, and S108N mutations on dhfr along with A437G and K540E mutations on dhps in P. falciparum positive samples. Logistic regression models assessed relationships between IPTp-SP uptake and pregnancy outcomes.

RESULTS

P. falciparum malaria was detected at delivery in 10.8% of women and was statistically associated with fever during the pregnancy (OR = 2.9 [1.5; 6.3]; p = 0.004) and maternal anemia (OR = 3.9 [2.4; 6.3]; p < 0.001). One out of five parasites was a quintuple mutant encoding dhfr mutations 51I, 59R, and 108 N along with dhps mutations 437G and 540E. The molecular profile of parasites (i.e., 32.6% of parasites carrying dhps K540E) was suitable with continued use of SP for IPTp. IPTp-SP uptake was not associated with reduced maternal malaria, fever reported in pregnancy, or fetal deaths (p > 0.05). Conversely, three or more doses of SP were associated with reduced maternal anemia at delivery (OR = 0.4 [0.2; 0.9]; p = 0.024), shortened gestation (OR = 0.4 [0.2; 0.8]; p = 0.009), and low-birth weights (OR = 0.2 [0.1; 0.5]; p < 0.001).

CONCLUSION

IPTp-SP was not associated with reduced maternal malaria in our study, but evidence was found of a prophylactic effect against adverse pregnancy outcomes. To counteract further loss of clinical effects of IPTp-SP in the study population, alternative strategies able to improve its anti-malarial efficacy such as combination of SP with partner molecules should be implemented.

Malaria in Pregnancy: What the Obstetric Provider in Nonendemic Areas Needs to Know

IMPORTANCE

Globally, more than 125 million women each year are at risk of malaria during pregnancy. Endemic regions carry the greatest burden; however, with globalization, providers in nonendemic regions are encountering increasing numbers of women exposed to or infected with malaria.

OBJECTIVES

The aim of this article is to provide obstetric providers in nonendemic areas with updated information on malaria infection in pregnancy focusing on pregnancy management and malaria prevention and treatment.

EVIDENCE ACQUISITION

This article is based on review of the most recent peer-reviewed articles and guidelines from the Centers for Disease Control and Prevention and the World Health Organization.

FINDINGS

Malaria infection in pregnancy causes maternal anemia, low birth weight, preterm birth, stillbirth, and miscarriages through placental malaria and severe infections. Pregnant women traveling to malaria-endemic areas should be advised against travel. If travel must occur, they should be provided with region-specific chemoprophylaxis and given methods for preventing infection. In the event that a pregnant patient has an acute malarial infection, prompt evaluation is needed to determine whether there are severe features. Medications for uncomplicated or severe malaria infection should be started as soon as the diagnosis is made.

CONCLUSIONS AND RELEVANCE

Malaria in pregnancy causes significant perinatal complications. Obstetric providers should be aware of the impact and how to prevent and treat malaria infection during pregnancy. Malaria infection should be suspected in women with concerning symptoms and recent travel to endemic areas. Providers should know the management of uncomplicated and severe malarial infection in pregnancy.

Intermittent Preventive Treatment (IPT): Its Role in Averting Disease-Induced Mortality in Children and in Promoting the Spread of Antimalarial Drug Resistance

We develop an age-structured ODE model to investigate the role of intermittent preventive treatment (IPT) in averting malaria-induced mortality in children, and its related cost in promoting the spread of antimalarial drug resistance. IPT, a malaria control strategy in which a full curative dose of an antimalarial medication is administered to vulnerable asymptomatic individuals at specified intervals, has been shown to reduce malaria transmission and deaths in children and pregnant women. However, it can also promote drug resistance spread. Our mathematical model is used to explore IPT effects on drug resistance and deaths averted in holoendemic malaria regions. The model includes drug-sensitive and drug-resistant strains as well as human hosts and mosquitoes. The basic reproduction, and invasion reproduction numbers for both strains are derived. Numerical simulations show the individual and combined effects of IPT and treatment of symptomatic infections on the prevalence of both strains and the number of lives saved. Our results suggest that while IPT can indeed save lives, particularly in high transmission regions, certain combinations of drugs used for IPT and to treat symptomatic infection may result in more deaths when resistant parasite strains are circulating. Moreover, the half-lives of the treatment and IPT drugs used play an important role in the extent to which IPT may influence spread of the resistant strain. A sensitivity analysis indicates the model outcomes are most sensitive to the reduction factor of transmission for the resistant strain, rate of immunity loss, and the natural clearance rate of sensitive infections.

The economic burden of malaria in pregnancy: a cross-sectional study

Background: Malaria in pregnancy carries a proven huge health burden; however, the economic challenges have not been properly evaluated in Nigeria.Methodology: The study was a descriptive cross-sectional hospital-based approach. A structured questionnaire was used to collect microeconomic data from pregnant women, on the medical and nonmedical cost of malaria to them.Results: A total of 371 questionnaires were analyzed (93%; 371/400), of 400 respondents interviewed. The average direct medical cost was N3581.78 naira (N) (US$11.86) with SD of N177.9 and mean direct nonmedical cost of N5741.5 (US$18.97). Of the patients, 86.8% received artemisinin-based combination therapy (ACTs) for the treatment of malaria. Nigeria has an estimated population of women of child-bearing age of 40 million and, the fertility rate of 124 per 1000. On the basis of estimation of 56.5% of pregnant women receiving at least one intermittent preventive therapy (IPT), will approximate to 22.8 billion naira (US$75.5 million) national annual expenditure for malaria in pregnancy. This approximates to 0.016% of the Nigerian gross domestic product of 481 billion USD of 2015. The major mechanism that was used to pay for treatment was out-of-pocket (OOP).Conclusions: Malaria carries high-economic burden both on individual and national levels, especially in Nigeria where OOPs is the major payment mechanism. Scaling up malaria control measures will not only improve the lives of pregnant women but will also improve the economy of the nation.

A brief review on features of falciparum malaria during pregnancy

Malaria in pregnancy is a serious public health problem in tropical areas. Frequently, the placenta is infected by accumulation of Plasmodium falciparum-infected erythrocytes in the intervillous space. Falciparum malaria acts during pregnancy by a range of mechanisms, and chronic or repeated infection and co-infections have insidious effects. The susceptibility of pregnant women to malaria is due to both immunological and humoral changes. Until a malaria vaccine becomes available, the deleterious effects of malaria in pregnancy can be avoided by protection against infection and prompt treatment with safe, effective antimalarial agents; however, concurrent infections such as with HIV and helminths during pregnancy are jeopardizing malaria control in sub-Saharan Africa.

Pharmaceutical Chaperones and Proteostasis Regulators in the Therapy of Lysosomal Storage Disorders: Current Perspective and Future Promises

Different approaches have been utilized or proposed for the treatment of lysosomal storage disorders (LSDs) including enzyme replacement and hematopoietic stem cell transplant therapies, both aiming to compensate for the enzymatic loss of the underlying mutated lysosomal enzymes. However, these approaches have their own limitations and therefore the vast majority of LSDs are either still untreatable or their treatments are inadequate. Missense mutations affecting enzyme stability, folding and cellular trafficking are common in LSDs resulting often in low protein half-life, premature degradation, aggregation and retention of the mutant proteins in the endoplasmic reticulum. Small molecular weight compounds such as pharmaceutical chaperones (PCs) and proteostasis regulators have been in recent years to be promising approaches for overcoming some of these protein processing defects. These compounds are thought to enhance lysosomal enzyme activity by specific binding to the mutated enzyme or by manipulating components of the proteostasis pathways promoting protein stability, folding and trafficking and thus enhancing and restoring some of the enzymatic activity of the mutated protein in lysosomes. Multiple compounds have already been approved for clinical use to treat multiple LSDs like migalastat in the treatment of Fabry disease and others are currently under research or in clinical trials such as Ambroxol hydrochloride and Pyrimethamine. In this review, we are presenting a general overview of LSDs, their molecular and cellular bases, and focusing on recent advances on targeting and manipulation proteostasis, including the use of PCs and proteostasis regulators, as therapeutic targets for some LSDs. In addition, we present the successes, limitations and future perspectives in this field.

Developing vaccines to prevent malaria in pregnant women

INTRODUCTION

Placental malaria (PM) is a major public health problem that constitutes a significant health concern for the mother, and especially for the developing fetus and offspring. Current means of prevention have limitations, including a restricted window of intervention that excludes the first trimester of pregnancy, and the fact that very few drugs can be used for this purpose. The identification of the VAR2CSA antigen, specific to PM parasites, offers an excellent opportunity to develop a vaccine against this disease. Proof of concept of a first-generation vaccine is nearing completion, and two clinical trials are underway.

AREAS COVERED

This review focuses on PM, which is mainly caused by Plasmodium falciparum. The review highlights recent advances and the key milestones that led to the identification of the optimal vaccine target within the large VAR2CSA protein. The paper also points out how future improvements can strengthen this process to achieve an effective vaccine in the field.

EXPERT OPINION

The approach taken to develop a P. falciparum erythrocyte membrane protein 1-based vaccine to protect pregnant women is very promising in view of the current difficulties of achieving a sterilizing vaccine against malaria parasite. This approach could help us to control the deleterious effect of malaria infections that characterize severe clinical forms.

Management of toxoplasmic retinochoroiditis during pregnancy, postpartum period and lactation: clinical observations

Background

During pregnancy and labor, the immune response is physiologically impaired and women are more susceptible to infections. Since many drugs may have potentially adverse effects on the fetus and newborn, less aggressive treatment regimens should be considered in pregnant and lactating patients. The aim of our study was to present the management of toxoplasmic retinochoroiditis during pregnancy, postpartum period, and lactation.

Material/Methods

A retrospective study was undertaken of the clinical records of 24 women during pregnancy, postpartum period, and lactation who were referred in the years 1994–2014 to the Department of Zoonoses and Tropical Diseases or the Department of Ophthalmology, Medical University of Warsaw for toxoplasmic retinochoroiditis. The diagnosis was based on the typical ophthalmoscopic picture, confirmed by serological testing using an ELISA method.

Results

A total of 28 attacks of toxoplasmic retinochoroiditis were observed in 24 patients during pregnancy, postpartum period, and lactation. The choice of treatment was guided by the character and location of the inflammatory lesion and the gestational age. Topical (steroidal/nonsteroidal eye drops) and systemic treatments with spiramycin or azithromycin, Fansidar (pyrimethamine 25 mg/sulfadoxine 500 mg), and prednisone were used.

Conclusions

Management of toxoplasmic retinochoroiditis during pregnancy, postpartum period, or lactation must be individualized and guided by the gestational age and location of the active lesion. Women of childbearing age with toxoplasma ocular lesions should be informed by their doctors about possible active recurrences during pregnancy and followed carefully by an ophthalmologist when pregnant.

High rates of parasite recrudescence following intermittent preventive treatment with sulphadoxine-pyrimethamine during pregnancy in Benin

BACKGROUND

Despite widespread parasite resistance to sulphadoxine-pyrimethamine (SP) its use for intermittent preventative treatment during pregnancy remains the policy in Benin and throughout most of sub-Saharan Africa.

METHODS

In a prospective study, 982 pregnant women were recruited in Benin and followed until delivery. The prevalence of point mutations in the pfdhfr and pfdhps genes associated with Plasmodium falciparum resistance to SP during consecutive antenatal visits was determined. Parasites clearance among women infected at SP intake was assessed by microscopy and PCR. Association between the persistence of parasites and malaria consequences, were investigated. Recurrent parasites were genotyped to identify recrudescences from re-infections.

RESULTS

The prevalence of pfdhfr/pfdhps quadruple mutants (triple pfdhfr + single pfdhps) was consistently above 80% while quintuple and sextuple mutants remained low. Importantly the higly mutated parasites apparently never included the two key mutations, pfdhfr 164 L or pfdhps 540E. Based on PCR results, SP failed to clear existing parasitaemia in half (48%) of the women who were infected at IPTp schedule. The frequency of recrudescence reached 76% after the second dose. Women with persistent parasitaemia had an increased prevalence of anaemia (P = 0.03).

CONCLUSION

The data presented here, highlight the inability of SP to ensure optimal antiplasmodial protection in late pregnancy, and invite urgent consideration of an alternative drug or strategy.

Comparative efficacy of uncontrolled and controlled intermittent preventive treatment during pregnancy (IPTp) with combined use of LLTNs in high resistance area to sulfadoxine-pyrimethamine in Côte d'Ivoire

Introduction

In recent years, intermittent preventive treatment for pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) has become policy in much of sub-Saharan Africa. But resistance to SP has been spreading across sub-Saharan Africa and thus the effectiveness of IPTp-SP has been questioned. The present study therefore sought to assess the incidence of placental malaria, low birth weight, and anemia of two IPTp-SP approaches (directly observed treatment scheme versus no directly observed treatment) in Anonkoua-Kouté and Samo, Côte d’Ivoire where the reported prevalence of dfr single mutant 108 was 62% and 52.2%, respectively.

Methods

The study was a longitudinal design involving pregnant women and was conducted in Anonkoua-Kouté, a suburban area, and Samo, a rural area, from January 2008 through March 2009. Women of a pregnancy less than 28 weeks duration were randomized to receive SP (1.5 g/0.075 g SP) in a single intake twice and were followed up monthly until delivery. Doses were administered under supervision in the controlled IPTp group, while SP was given free to women in the uncontrolled IPTp group with a recommendation to take it at home. The primary end point was the proportion of low birth weight infants (body weight < 2500 g) and the secondary end point was the rate of severe anemia and placental malaria detected at delivery.

Results

A total of 420 pregnant women were enrolled (212 and 208, respectively, in the controlled and uncontrolled groups). Delivery outcome was available for 378 women. In the modified intention-to-treat analysis, low birth weight infants were born from 15.5% of women of the uncontrolled IPTp group and from 11.9% of women in the controlled IPTp group (P = 0.31). The per-protocol population analysis showed consistent results. The proportion of women with placental malaria infection, moderate anemia (hemoglobin < 11 g/dL), and severe anemia (hemoglobin < 8 g/dL) at delivery were similar between the two groups (P > 0.05).

Conclusion

The study showed that the two approaches were equivalent, suggesting that unsupervised IPTp-SP free of charge should be used in areas where implementation of the directly observed treatment scheme suffers from many constraints.

Congenital parasitic infections: a review

This review defines the concepts of maternal-fetal (congenital) and vertical transmissions (mother-to-child) of pathogens and specifies the human parasites susceptible to be congenitally transferred. It highlights the epidemiological features of this transmission mode for the three main congenital parasitic infections due to Toxoplasma gondii, Trypanosoma cruzi and Plasmodium sp. Information on the possible maternal-fetal routes of transmission, the placental responses to infection and timing of parasite transmission are synthesized and compared. The factors susceptible to be involved in parasite transmission and development of congenital parasitic diseases, such as the parasite genotypes, the maternal co-infections and parasitic load, the immunological features of pregnant women and the capacity of some fetuses/neonates to overcome their immunological immaturity to mount an immune response against the transmitted parasites are also discussed and compared. Analysis of clinical data indicates that parasitic congenital infections are often asymptomatic, whereas symptomatic newborns generally display non-specific symptoms. The long-term consequences of congenital infections are also mentioned, such as the imprinting of neonatal immune system and the possible trans-generational transmission. The detection of infection in pregnant women is mainly based on standard serological or parasitological investigations. Amniocentesis and cordocentesis can be used for the detection of some fetal infections. The neonatal infection can be assessed using parasitological, molecular or immunological methods; the place of PCR in such neonatal diagnosis is discussed. When such laboratory diagnosis is not possible at birth or in the first weeks of life, standard serological investigations can also be performed 8-10 months after birth, to avoid detection of maternal transmitted antibodies. The specific aspects of treatment of T. gondii, T. cruzi and Plasmodium congenital infections are mentioned. The possibilities of primary and secondary prophylaxes, as well as the available WHO corresponding recommendations are also presented.

Molecular markers of resistance to sulphadoxine-pyrimethamine during intermittent preventive treatment of pregnant women in Benin

Background

The prevention of malaria faces with the repeated emergence of Plasmodium falciparum resistance to drugs, often involving point mutations of the target gene. In the pregnant woman, currently the WHO recommendation is the administration of an intermittent preventive treatment (IPTp) with sulphadoxine-pyrimethamine. Sulphadoxine-pyrimethamine (SP) resistance has increased for several years in Africa, stressing the need for alternative molecules. In this context, the first randomized clinical trial comparing the efficacy of SP and mefloquine for IPTp has been conducted recently in Benin. Using samples from this trial, the current study evaluated and quantified the prevalence of mutations on the pfdhfr and pfdhps genes as well as the copy number of the pfmdr1 gene in parasites from P. falciparum-infected pregnant women before first and second IPTp administration, and at delivery.

Methods

PCR-restriction fragment length polymorphism of polymorphic codons of the pfdhfr gene (51, 59, 108, and 164) was performed. The identification of mutations in three codons of the pfdhps gene (436, 437 and 540) was achieved by PCR and sequencing. Copy number quantification for pfmdr1 gene was performed using real-time PCR.

Results

Results show a high prevalence rate of mutant parasites in women taking IPTp with sulphadoxine-pyrimethamine or mefloquine. The prevalence of triple and quadruple mutants was high before first drug regimen administration (79/93, 85%), and remained similar until delivery. Infection with mutant parasites was not correlated with low birth weight nor placental infection. In all samples, the copy number of pfmdr1 gene was equal to one.

Conclusions

The clinical trial comparing SP and mefloquine efficacy during IPTp showed SP remained efficacious in preventing low birth weight. The present study shows a high prevalence of triple and quadruple mutations implicated in SP resistance. Although the pfdhfr/pfdhps triple and quadruple mutations were frequent, there was no evidence of correlation between these genotypes and the lack of efficacy of SP in the context of IPTp. Nevertheless, it is now obvious that SP will soon be compromised in whole Africa. Molecular markers have been recommended to monitor SP efficacy for IPTp, but given the current prevalence of mutant parasites their usefulness is questionable.