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van Eijk AM, Stepniewska K, Hill J, Taylor SM, Rogerson SJ, Cottrell G, Chico RM, Gutman JR, Tinto H, Unger HW, Yanow SK, Meshnick SR, Ter Kuile FO, Mayor A. Prevalence of and risk factors for microscopic and submicroscopic malaria infections in pregnancy: a systematic review and meta-analysis. Lancet Glob Health 2023; 11:e1061-e1074. [PMID: 37276878 PMCID: PMC10880462 DOI: 10.1016/s2214-109x(23)00194-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 04/05/2023] [Accepted: 04/11/2023] [Indexed: 06/07/2023]
Abstract
BACKGROUND Malaria infections during pregnancy can cause adverse birth outcomes, yet many infections are undetected by microscopy. We aimed to describe the epidemiology of submicroscopic malaria infections in pregnant women in Asia, the Americas, and Africa using aggregated and individual participant data (IPD). METHODS For this systematic review and meta-analysis, studies (published Jan 1, 1997 to Nov 10, 2021) with information on both microscopic and submicroscopic infections during pregnancy from Asia, the Americas, or Africa, identified in the Malaria-in-Pregnancy Library, were eligible. Studies (or subgroups or study groups) that selected participants on the basis of the presence of fever or a positive blood smear were excluded to avoid selection bias. We obtained IPD (when available) and aggregated data. Estimates of malaria transmission intensity and sulfadoxine-pyrimethamine resistance, matched by study location and year, were obtained using publicly available data. One-stage multivariable logit and multinomial models with random intercepts for study site were used in meta-analysis to assess prevalence of and risk factors for submicroscopic infections during pregnancy and at delivery. This study is registered with PROSPERO, number CRD42015027342. FINDINGS The search identified 87 eligible studies, 68 (78%) of which contributed to the analyses. Of these 68 studies, 45 (66%) studies contributed IPD (48 869 participants) and 23 (34%) studies contributed aggregated data (11 863 participants). During pregnancy, median prevalence estimates were 13·5% (range 0·0-55·9, 66 substudies) for submicroscopic and 8·0% (0·0-50·6, 66 substudies) for microscopic malaria. Among women with positive Plasmodium nucleic acid amplification tests (NAATs), the median proportion of submicroscopic infections was 58·7% (range 0·0-100); this proportion was highest in the Americas (73·3%, 0·0-100), followed by Asia (67·2%, 36·4-100) and Africa (56·5%, 20·5-97·7). In individual patient data analysis, compared with women with no malaria infections, those with submicroscopic infections were more likely to present with fever in Africa (adjusted odds ratio 1·32, 95% CI 1·02-1·72; p=0·038) but not in other regions. Among women with NAAT-positive infections in Asia and the Americas, Plasmodium vivax infections were more likely to be submicroscopic than Plasmodium falciparum infections (3·69, 2·45-5·54; p<0·0001). Risk factors for submicroscopic infections among women with NAAT-positive infections in Africa included older age (age ≥30 years), multigravidity, and no HIV infection. INTERPRETATION During pregnancy, submicroscopic infections are more common than microscopic infections and are associated with fever in Africa. Malaria control in pregnancy should target both microscopic and submicroscopic infections. FUNDING Bill & Melinda Gates Foundation through the Worldwide Antimalarial Resistance Network.
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Affiliation(s)
- Anna Maria van Eijk
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Kasia Stepniewska
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Jenny Hill
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Steve M Taylor
- Division of Infectious Diseases and Duke Global Health Institute, Duke University, Durham, NC, USA
| | - Stephen J Rogerson
- Department of Infectious Diseases, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
| | | | - R Matthew Chico
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Julie R Gutman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Halidou Tinto
- Institut de Recherche en Sciences de la Sant-Unité de Recherche Clinique de Nanoro, Ouagadougou, Burkina Faso
| | - Holger W Unger
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK; Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Stephanie K Yanow
- School of Public Health, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - Steven R Meshnick
- Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Feiko O Ter Kuile
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Alfredo Mayor
- ISGlobal, Barcelona Institute for Global Health, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
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Matambisso G, Brokhattingen N, Maculuve S, Cisteró P, Mbeve H, Escoda A, Miguel J, Buetas E, de Jong I, Cuna B, Melembe C, Ndimande N, Porras G, Chen H, Tetteh KKA, Drakeley C, Gamain B, Chitnis C, Chauhan V, Quintó L, Galatas B, Macete E, Mayor A. Gravidity and malaria trends interact to modify P. falciparum densities and detectability in pregnancy: a 3-year prospective multi-site observational study. BMC Med 2022; 20:396. [PMID: 36376866 PMCID: PMC9664815 DOI: 10.1186/s12916-022-02597-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 10/06/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Low-density Plasmodium falciparum infections prevail in low transmission settings, where immunity is expected to be minimal, suggesting an immune-independent effect on parasite densities. We aimed to describe parasite densities in pregnancy, and determine how gravidity and antibody-mediated immunity affect these, during a period of declining malaria transmission in southern Mozambique. METHODS We documented P. falciparum infections at first antenatal care visits (n = 6471) between November 2016 and October 2019 in Ilha Josina (high-to-moderate transmission area), Manhiça (low transmission area), and Magude (pre-elimination area). Two-way interactions in mixed-effects regression models were used to assess gravidity-dependent differences in quantitative PCR-determined P. falciparum positivity rates (PfPRqPCR) and densities, in the relative proportion of detectable infections (pDi) with current diagnostic tests (≥ 100 parasites/μL) and in antimalarial antibodies. RESULTS PfPRqPCR declined from 28 to 13% in Ilha Josina and from 5-7 to 2% in Magude and Manhiça. In primigravidae, pDi was highest in Ilha Josina at the first study year (p = 0.048), which declined with falling PfPRqPCR (relative change/year: 0.41, 95% CI [0.08; 0.73], p = 0.029), with no differences in antibody levels. Higher parasite densities in primigravidae from Ilha Josina during the first year were accompanied by a larger reduction of maternal hemoglobin levels (- 1.60, 95% CI [- 2.49; - 0.72; p < 0.001), than in Magude (- 0.76, 95% CI [- 1.51; - 0.01]; p = 0.047) and Manhiça (- 0.44, 95% CI [- 0.99; 0.10; p = 0.112). In contrast, multigravidae during the transmission peak in Ilha Josina carried the lowest pDi (p = 0.049). As PfPRqPCR declined, geometric mean of parasite densities increased (4.63, 95% CI [1.28; 16.82], p = 0.020), and antibody levels declined among secundigravidae from Ilha Josina. CONCLUSIONS The proportion of detectable and clinically relevant infections is the highest in primigravid women from high-to-moderate transmission settings and decreases with declining malaria. In contrast, the falling malaria trends are accompanied by increased parasite densities and reduced humoral immunity among secundigravidae. Factors other than acquired immunity thus emerge as potentially important for producing less detectable infections among primigravidae during marked declines in malaria transmission.
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Affiliation(s)
- Glória Matambisso
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | | | - Sónia Maculuve
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Pau Cisteró
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Henriques Mbeve
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Anna Escoda
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Judice Miguel
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Elena Buetas
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Ianthe de Jong
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Boaventura Cuna
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Cardoso Melembe
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Nelo Ndimande
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Gemma Porras
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Haily Chen
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Kevin K A Tetteh
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Benoit Gamain
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, Inserm, 75015, Paris, France
| | - Chetan Chitnis
- Department of Parasites & Insect Vectors, Malaria Parasite Biology and Vaccines, Institut Pasteur, Paris, France
| | - Virander Chauhan
- Malaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Llorenç Quintó
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Beatriz Galatas
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Eusébio Macete
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,National Directare of Health, Ministry of Health, Maputo, Mozambique
| | - Alfredo Mayor
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique. .,ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain. .,Spanish Consortium for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain. .,Department of Physiologic Sciences, Faculty of Medicine, Universidade Eduardo Mondlane, Maputo, Mozambique.
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Akinnawo A, Seyram K, Kaali EB, Harrison S, Dosoo D, Cairns M, Asante KP. Assessing the relationship between gravidity and placental malaria among pregnant women in a high transmission area in Ghana. Malar J 2022; 21:240. [PMID: 35987638 PMCID: PMC9392271 DOI: 10.1186/s12936-022-04252-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 07/28/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Malaria infection during pregnancy can cause significant morbidity and mortality to a pregnant woman, her fetus and newborn. In areas of high endemic transmission, gravidity is an important risk factor for infection, but there is a complex relationship with other exposure-related factors, and use of protective measures. This study investigated the association between gravidity and placental malaria (PM), among pregnant women aged 14-49 in Kintampo, a high transmission area of Ghana. METHODS Between 2008 and 2011, as part of a study investigating the association between PM and malaria in infancy, pregnant women attending antenatal care (ANC) clinics in the study area were enrolled and followed up until delivery. The outcome of PM was assessed at delivery by placental histopathology. Multivariable logistic regression analyses were used to investigate the association between gravidity and PM, identify other key risk factors, and control for potential confounders. Pre-specified effect modifiers including area of residence, socio-economic score (SES), ITN use and IPTp-SP use were explored. RESULTS The prevalence of PM was 65.9% in primigravidae, and 26.5% in multigravidae. After adjusting for age, SES and relationship status, primigravidae were shown to have over three times the odds of PM compared to multigravidae, defined as women with 2 or more previous pregnancies [adjusted OR = 3.36 (95% CI 2.39-4.71), N = 1808, P < 0.001]. The association appeared stronger in rural areas [OR for PG vs. MG was 3.79 (95% CI 3.61-5.51) in rural areas; 2.09 (95% CI 1.17-3.71) in urban areas; P for interaction = 0.07], and among women with lower socio-economic scores [OR for PG vs. MG was 4.73 (95% CI 3.08-7.25) amongst women with lower SES; OR = 2.14 (95% CI 1.38-3.35) among women with higher SES; P for interaction = 0.008]. There was also evidence of lower risk among primigravidae with better use of the current preventive measures IPTp and LLIN. CONCLUSIONS The burden of PM is most heavily focused on primigravidae of low SES living in rural areas of high transmission. Programmes should prioritize primigravidae and young women of child-bearing age for interventions such as LLIN distribution, educational initiatives and treatment to reduce the burden of malaria in first pregnancy.
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Affiliation(s)
- Ayodele Akinnawo
- grid.8991.90000 0004 0425 469XLondon School of Hygiene and Tropical Medicine, London, UK
| | - Kaali Seyram
- Research and Development Division, Kintampo Health Research Centre, Ghana Health Service, Kintampo North Municipality, Ghana
| | - Ellen Boamah Kaali
- Research and Development Division, Kintampo Health Research Centre, Ghana Health Service, Kintampo North Municipality, Ghana
| | - Samuel Harrison
- Research and Development Division, Kintampo Health Research Centre, Ghana Health Service, Kintampo North Municipality, Ghana
| | - David Dosoo
- Research and Development Division, Kintampo Health Research Centre, Ghana Health Service, Kintampo North Municipality, Ghana
| | - Matthew Cairns
- grid.8991.90000 0004 0425 469XLondon School of Hygiene and Tropical Medicine, London, UK
| | - Kwaku Poku Asante
- grid.8991.90000 0004 0425 469XLondon School of Hygiene and Tropical Medicine, London, UK
- Research and Development Division, Kintampo Health Research Centre, Ghana Health Service, Kintampo North Municipality, Ghana
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Naheda A, Aqeel S, Khan K, Khan W, Khan T. Immunohistopathological changes in the placenta of malaria-infected women in unstable transmission setting of Aligarh. Placenta 2022; 127:52-61. [PMID: 35970103 DOI: 10.1016/j.placenta.2022.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 07/16/2022] [Accepted: 07/24/2022] [Indexed: 10/15/2022]
Abstract
INTRODUCTION Pregnant women are more susceptible to malaria due to a combination of physiological and immunological changes. The infection may even affect the growth and survival of the foetus, which mainly occur when parasite enters the placenta. The sequestration of infected erythrocytes may trigger the host response, leading to placental inflammation and altered development, affecting the structure and nutrient transport of placenta. These factors collectively impair placental functions and affect foetal growth. METHODS Pregnant women with peripheral parasitaemia for P. falciparum and P. vivax (20 each) were included in the present study, along with 15 age-matched uninfected healthy pregnant women. Placentae were analysed for the presence of local parasitaemia along with pathological lesions caused due to the parasite. Immunohistochemical staining for CD20, CD45 and CD68 cells was performed for examining the specific leucocytes in the intervillous space of the placenta. RESULTS Of the 20 individuals with P. falciparum, only seven placentae showed parasitaemia, whereas individuals with P. vivax showed no placental infection. The pathological changes observed in the P. falciparum-infected placenta include syncytial knotting, excess fibrinoid deposition, syncytiotrophoblast necrosis, syncytial rupture, thickening of trophoblast basement membrane and increased collagen deposition. Immunohistochemical staining showed a significant increase in B cells (CD20), leucocytes (CD45) and monocytes and macrophages (CD68) in the P. falciparum-infected placenta (p < 0.0001). DISCUSSION The result implies that P. falciparum is responsible for pathological alterations in placenta, affecting the nutrient transport across placenta and foetal growth. The immune cells also migrate to the placenta and accumulate in the intervillous space to show humoral and cell-mediated immunity against the parasite.
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Affiliation(s)
- Ansari Naheda
- Section of Parasitology, Department of Zoology, Aligarh Muslim University, Aligarh, 202002, India.
| | - Sana Aqeel
- Section of Parasitology, Department of Zoology, Aligarh Muslim University, Aligarh, 202002, India
| | - Khadija Khan
- Section of Parasitology, Department of Zoology, Aligarh Muslim University, Aligarh, 202002, India
| | - Wajihullah Khan
- Section of Parasitology, Department of Zoology, Aligarh Muslim University, Aligarh, 202002, India.
| | - Tamkin Khan
- Department of Obstetrics & Gynaecology, Jawaharlal Nehru Medical College & Hospital, Aligarh Muslim University, Aligarh, 202002, India
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Bihoun B, Zango SH, Traoré-Coulibaly M, Valea I, Ravinetto R, Van Geertruyden JP, D'Alessandro U, Tinto H, Robert A. Age-modified factors associated with placental malaria in rural Burkina Faso. BMC Pregnancy Childbirth 2022; 22:248. [PMID: 35331181 PMCID: PMC8951713 DOI: 10.1186/s12884-022-04568-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/31/2022] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Malaria in pregnancy can result in placental infection with fetal implications. This study aimed at assessing placental malaria (PM) prevalence and its associated factors in a cohort of pregnant women with peripheral malaria and their offspring. METHOD The data were collected in the framework of a clinical trial on treatments for malaria in pregnant women . Placental malaria (PM) was diagnosed by histopathological detection of parasites and/or malaria pigment on placenta biopsies taken at delivery. Factors associated with PM were assessed using logistic regression. RESULTS Out of 745 biopsies examined, PM was diagnosed in 86.8 % of women. Acute, chronic and past PM were retrieved in 11 (1.5 %), 170 (22.8 %), and 466 (62.6 %) women, respectively. A modifying effect was observed in the association of gravidity or anemia at the study start with pooled PM (presence of parasites and/or malaria pigment). In women under 30, gravidity ≤ 2 was associated with an increased prevalence of pooled PM but in women aged 30 years or more, gravidity was no more associated with pooled PM (OR 6.81, 95 % CI 3.18 - 14.60; and OR 0.52, 95 % CI 0.10 - 2.76, respectively). Anemia was associated with pooled PM in women under 30 (OR 1.96, 95 % CI 1.03 - 3.72) but not in women aged 30 years or more (OR 0.68, 95 % CI 0.31 - 1.49). Similarly, the association of gravidity with past-chronic PM depended also on age. A higher prevalence of active PM was observed in women under 30 presenting with symptomatic malaria (OR 3.79, 95 % CI 1.55 - 9.27), while there was no significant increase in the prevalence of active PM (presence of parasites only) in women with symptomatic malaria when aged 30 years or more (OR 0.42, 95 % CI 0.10 - 1.75). In women with chronic PM, the prevalence of low birth weight or prematurity was the highest (31.2 %) as compared with past PM or no PM. CONCLUSION Despite the rapid diagnosis and efficacious treatment of peripheral infection, the prevalence of placental malaria remained high in women with P. falciparum peripheral infection in Nanoro, especially in younger women This underlines the importance of preventive measures in this specific group.
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Affiliation(s)
- Biébo Bihoun
- Unité de recherche clinique de Nanoro, Institut de recherche en science de la santé, Nanoro, Burkina Faso.
| | - Serge Henri Zango
- Unité de recherche clinique de Nanoro, Institut de recherche en science de la santé, Nanoro, Burkina Faso.,Pôle Epidémiologie et Biostatistiques, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Maminata Traoré-Coulibaly
- Unité de recherche clinique de Nanoro, Institut de recherche en science de la santé, Nanoro, Burkina Faso
| | - Innocent Valea
- Unité de recherche clinique de Nanoro, Institut de recherche en science de la santé, Nanoro, Burkina Faso
| | | | | | - Umberto D'Alessandro
- MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, Gambia
| | - Halidou Tinto
- Unité de recherche clinique de Nanoro, Institut de recherche en science de la santé, Nanoro, Burkina Faso
| | - Annie Robert
- Pôle Epidémiologie et Biostatistiques, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
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Leleu I, Alloo J, Cazenave PA, Roland J, Pied S. Autophagy Pathways in the Genesis of Plasmodium-Derived Microvesicles: A Double-Edged Sword? Life (Basel) 2022; 12:life12030415. [PMID: 35330166 PMCID: PMC8955828 DOI: 10.3390/life12030415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/02/2022] [Accepted: 03/08/2022] [Indexed: 11/16/2022] Open
Abstract
Malaria, caused by Plasmodium species (spp.), is a deadly parasitic disease that results in approximately 400,000 deaths per year globally. Autophagy pathways play a fundamental role in the developmental stages of the parasite within the mammalian host. They are also involved in the production of Plasmodium-derived extracellular vesicles (EVs), which play an important role in the infection process, either by providing nutrients for parasite growth or by contributing to the immunopathophysiology of the disease. For example, during the hepatic stage, Plasmodium-derived EVs contribute to parasite virulence by modulating the host immune response. EVs help in evading the different autophagy mechanisms deployed by the host for parasite clearance. During cerebral malaria, on the other hand, parasite-derived EVs promote an astrocyte-mediated inflammatory response, through the induction of a non-conventional host autophagy pathway. In this review, we will discuss the cross-talk between Plasmodium-derived microvesicles and autophagy, and how it influences the outcome of infection.
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Gore-Langton GR, Cano J, Simpson H, Tatem A, Tejedor-Garavito N, Wigley A, Carioli A, Gething P, Weiss DJ, Chandramohan D, Walker PGT, Cairns ME, Chico RM. Global estimates of pregnancies at risk of Plasmodium falciparum and Plasmodium vivax infection in 2020 and changes in risk patterns since 2000. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0001061. [PMID: 36962612 PMCID: PMC10022219 DOI: 10.1371/journal.pgph.0001061] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 10/03/2022] [Indexed: 11/11/2022]
Abstract
BACKGROUND Women are at risk of severe adverse pregnancy outcomes attributable to Plasmodium spp. infection in malaria-endemic areas. Malaria control efforts since 2000 have aimed to reduce this burden of disease. METHODS We used data from the Malaria Atlas Project and WorldPop to calculate global pregnancies at-risk of Plasmodium spp. infection. We categorised pregnancies as occurring in areas of stable and unstable P. falciparum and P. vivax transmission. We further stratified stable endemicity as hypo-endemic, meso-endemic, hyper-endemic, or holo-endemic, and estimated pregnancies at risk in 2000, 2005, 2010, 2015, 2017, and 2020. FINDINGS In 2020, globally 120.4M pregnancies were at risk of P. falciparum, two-thirds (81.0M, 67.3%) were in areas of stable transmission; 85 2M pregnancies were at risk of P. vivax, 93.9% (80.0M) were in areas of stable transmission. An estimated 64.6M pregnancies were in areas with both P. falciparum and P. vivax transmission. The number of pregnancies at risk of each of P. falciparum and P. vivax worldwide decreased between 2000 and 2020, with the exception of sub-Saharan Africa, where the total number of pregnancies at risk of P. falciparum increased from 37 3M in 2000 to 52 4M in 2020. INTERPRETATION Historic investments in malaria control have reduced the number of women at risk of malaria in pregnancy in all endemic regions except sub-Saharan Africa. Population growth in Africa has outpaced reductions in malaria prevalence. Interventions that reduce the risk of malaria in pregnancy are needed as much today as ever.
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Affiliation(s)
- Georgia R Gore-Langton
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Jorge Cano
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Expanded Special Project for Elimination of Neglected Tropical Diseases, WHO Regional Office for Africa, Brazzaville, Democratic Republic of the Congo
| | - Hope Simpson
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Andrew Tatem
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Natalia Tejedor-Garavito
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Adelle Wigley
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Alessandra Carioli
- WorldPop, Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Peter Gething
- Malaria Atlas Project, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Australia
- Faculty of Health Sciences, Curtin University, Bentley, Australia
| | - Daniel J Weiss
- Malaria Atlas Project, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Australia
- Faculty of Health Sciences, Curtin University, Bentley, Australia
| | - Daniel Chandramohan
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Patrick G T Walker
- Faculty of Medicine, School of Public Health, Imperial College London, London, United Kingdom
| | - Matthew E Cairns
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - R Matthew Chico
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Jafari-Guemouri S, Courtois L, Mama A, Rouas B, Neto Braga G, Accrombessi M, Massougbodji A, Ding XC, Tuikue Ndam N, Fievet N, Briand V. A Genotyping Study in Benin Comparing the Carriage of Plasmodium falciparum Infections Before Pregnancy and in Early Pregnancy: Story of a Persistent Infection. Clin Infect Dis 2021; 73:e355-e361. [PMID: 32569359 PMCID: PMC8282262 DOI: 10.1093/cid/ciaa841] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/17/2020] [Indexed: 12/16/2022] Open
Abstract
Background Malaria infections in the first trimester of pregnancy are frequent and deleterious for both mother and child health. To investigate if these early infections are newly acquired or already present in the host, we assessed whether parasites detected before pregnancy and those detected in early pregnancy are the same infection. Methods We used data from the preconceptional “RECIPAL” study (Benin, 2014–2017). Sixty-three pregnant women of 411 included who had a malaria infection detected by quantitative polymerase chain reaction both before pregnancy and at the first antenatal care (ANC) visit were selected for this study. Two highly polymorphic markers, msp-2 and glurp, and a fragment-analysis method were used to enumerate the Plasmodium falciparum genotypes and to quantify their proportions within isolates. An infection was considered as persistent when identical msp-2 and glurp genotypes were found in the corresponding prepregnancy and early-pregnancy samples. Results The median time between the 2 malaria screenings was 3 months. The median gestational age at the first ANC visit was 6.4 weeks. Most infections before pregnancy were submicroscopic infections. Based on both msp-2 and glurp genotyping, the infection was similar before and in early pregnancy in 46% (29/63) of cases. Conclusions Almost half of P. falciparum infections detected in the first trimester originate before pregnancy. Protecting young women from malaria infection before pregnancy might reduce the prevalence of malaria in early pregnancy and its related poor maternal and birth outcomes.
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Affiliation(s)
- Sayeh Jafari-Guemouri
- Université de Paris, UMR261-MERIT, Institut de Recherche pour le Développement, Paris, France
| | - Laura Courtois
- Université de Paris, UMR261-MERIT, Institut de Recherche pour le Développement, Paris, France
| | - Atika Mama
- Clinical Research Institute of Benin (IRCB), Abomey-Calavi, Benin
| | - Baptiste Rouas
- Université de Paris, UMR261-MERIT, Institut de Recherche pour le Développement, Paris, France
| | - Gabriel Neto Braga
- Université de Paris, UMR261-MERIT, Institut de Recherche pour le Développement, Paris, France
| | - Manfred Accrombessi
- Clinical Research Institute of Benin (IRCB), Abomey-Calavi, Benin.,Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | | | - Nicaise Tuikue Ndam
- Université de Paris, UMR261-MERIT, Institut de Recherche pour le Développement, Paris, France
| | - Nadine Fievet
- Université de Paris, UMR261-MERIT, Institut de Recherche pour le Développement, Paris, France
| | - Valérie Briand
- Université de Paris, UMR261-MERIT, Institut de Recherche pour le Développement, Paris, France.,University of Bordeaux, Inserm, Institut de Recherche pour le Développement, Inserm, University of Bordeaux, UMR, Bordeaux, France
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9
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Plant M, Armstrong C, Ruggiero A, Sherrill C, Uberseder B, Jeffries R, Nevarez J, Jorgensen MJ, Kavanagh K, Quinn MA. Advanced maternal age impacts physiologic adaptations to pregnancy in vervet monkeys. GeroScience 2020; 42:1649-1661. [PMID: 32588342 PMCID: PMC7732933 DOI: 10.1007/s11357-020-00219-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 06/15/2020] [Indexed: 12/17/2022] Open
Abstract
The trend to delay pregnancy in the USA has resulted in the number of advanced maternal age (AMA) pregnancies to also increase. In humans, AMA is associated with a variety of pregnancy-related pathologies such as preeclampsia (PE). While AMA is known to be a factor which contributes to the development of pregnancy-induced diseases, the molecular and cellular mechanisms giving rise to this phenomenon are still very limited. This is due in part to lack of a preclinical model which has physiologic relevance to human pregnancy while also allowing control of environmental and genetic variability inherent in human studies. To determine potential physiologic relevance of the vervet/African green monkey (Chlorocebus aethiops sabaeus) as a preclinical model to study the effects of AMA on adaptations to pregnancy, thirteen age-diverse pregnant vervet monkeys (3-16 years old) were utilized to measure third trimester blood pressure (BP), complete blood count, iron measurements, and hormone levels. Significant associations were observed between third trimester diastolic BP and maternal age. Furthermore, the presence of leukocytosis with enhanced circulating neutrophils was observed in AMA mothers compared to younger mothers. Moreover, we observed a negative relationship between maternal age and estradiol, progesterone, and cortisol levels. Finally, offspring born to AMA mothers displayed a postnatal growth retardation phenotype. These studies demonstrate physiologic impairment in the adaptation to pregnancy in AMA vervet/African green monkeys. Our data indicate that the vervet/African green monkey may serve as a useful preclinical model and tool for deciphering pathological mediators of maternal disease in AMA pregnancy.
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Affiliation(s)
- Maren Plant
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC, 27157, USA
| | - Cecilia Armstrong
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC, 27157, USA
| | - Alistaire Ruggiero
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC, 27157, USA
| | - Chrissy Sherrill
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC, 27157, USA
| | - Beth Uberseder
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC, 27157, USA
| | - Rachel Jeffries
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC, 27157, USA
| | - Justin Nevarez
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC, 27157, USA
| | - Matthew J Jorgensen
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC, 27157, USA
| | - Kylie Kavanagh
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC, 27157, USA
| | - Matthew A Quinn
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC, 27157, USA.
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10
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Kitojo C, Chacky F, Kigadye ES, Mugasa JP, Lusasi A, Mohamed A, Walker P, Reaves EJ, Gutman JR, Ishengoma DS. Evaluation of a single screen and treat strategy to detect asymptomatic malaria among pregnant women from selected health facilities in Lindi region, Tanzania. Malar J 2020; 19:438. [PMID: 33256758 PMCID: PMC7708125 DOI: 10.1186/s12936-020-03513-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/19/2020] [Indexed: 02/07/2023] Open
Abstract
Background In areas of high transmission, malaria in pregnancy (MiP) primarily causes asymptomatic infections; these infections nonetheless increase the risk of adverse maternal and fetal outcomes. In 2014, Tanzania initiated a single screening and treatment (SST) strategy for all pregnant women at their first antenatal care (ANC) visit using malaria rapid diagnostic tests (RDT) for surveillance purposes. However, there is paucity of data on the effectiveness of SST in the prevention of MiP. The objective of this study was to estimate the number of asymptomatic infections among pregnant women detected by SST, which would have been missed in the absence of the policy. Methods Data from pregnant women attending their first ANC visits between October 2017 and June 2018, including gestational age, history of fever, and RDT results, were abstracted from ANC registers in eight health centres in two randomly selected districts, Kilwa and Lindi, in Lindi Region. The proportion of symptomatic (with history of fever in the past 48 h) and asymptomatic pregnant women with positive RDTs were calculated and stratified by trimester (first, second and third). The study areas were categorized as low transmission with prevalence < 10% or moderate/high with ≥ 10%. Results Over the study period, 1,845 women attended their first ANC visits; 22.1% were in the first trimester (< 12 weeks gestation age). Overall 15.0% of the women had positive RDTs, and there was a trend towards higher malaria prevalence in the first (15.9%) and second (15.2%) trimesters, compared to the third (7.1%), although the differences were not statistically significant (p = 0.07). In total, 6.9% of women reported fever within the past 48 h and, of these, 96.1% were RDT positive. For every 100 pregnant women in the moderate/high and low transmission areas, SST identified 60 and 26 pregnant women, respectively, with asymptomatic infections that would have otherwise been missed. Among the 15.9% of women detected in the first trimester, 50.7% were asymptomatic. Conclusion In areas of moderate/high transmission, many infected women were asymptomatic, and would have been missed in the absence of SST. The benefits on maternal and fetal birth outcomes of identifying these infections depend heavily on the protection afforded by treatment, which is likely to be greatest for women presenting in the first trimester when intermittent preventive treatment (IPTp) with sulfadoxine-pyrimethamine (SP) is contraindicated, and in areas with high SP resistance, such as most parts of Tanzania. An evaluation of the impact and cost-effectiveness of SST across different transmission strata is warranted.
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Affiliation(s)
- Chonge Kitojo
- US President's Malaria Initiative, United States Agency for International Development, Dar es Salaam, United Republic of Tanzania. .,The Open University of Tanzania, Dar es Salaam, United Republic of Tanzania.
| | - Frank Chacky
- National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Emmanuel S Kigadye
- The Open University of Tanzania, Dar es Salaam, United Republic of Tanzania
| | - Joseph P Mugasa
- USAID Boresha Afya Southern Zone, FHI 360, Dar es Salaam, United Republic of Tanzania
| | - Abdallah Lusasi
- National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Ally Mohamed
- National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Patrick Walker
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Erik J Reaves
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention and US President's Malaria Initiative, Dar es Salaam, United Republic of Tanzania.,Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, USA
| | - Julie R Gutman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, USA
| | - Deus S Ishengoma
- National Institute for Medical Research, Dar Es Salaam, United Republic of Tanzania.,Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia.,Harvard T.H. Chan School of Public Health, Boston, MA, USA
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11
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Omer SA, Sulaiman SM. The Placenta and Plasmodium Infections: a Case Study from Blue Nile State, Sudan. CURRENT TROPICAL MEDICINE REPORTS 2020. [DOI: 10.1007/s40475-020-00214-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Walker PGT, Cairns M, Slater H, Gutman J, Kayentao K, Williams JE, Coulibaly SO, Khairallah C, Taylor S, Meshnick SR, Hill J, Mwapasa V, Kalilani-Phiri L, Bojang K, Kariuki S, Tagbor H, Griffin JT, Madanitsa M, Ghani ACH, Desai M, Ter Kuile FO. Modelling the incremental benefit of introducing malaria screening strategies to antenatal care in Africa. Nat Commun 2020; 11:3799. [PMID: 32732892 PMCID: PMC7393377 DOI: 10.1038/s41467-020-17528-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 06/29/2020] [Indexed: 12/01/2022] Open
Abstract
Plasmodium falciparum in pregnancy is a major cause of adverse pregnancy outcomes. We combine performance estimates of standard rapid diagnostic tests (RDT) from trials of intermittent screening and treatment in pregnancy (ISTp) with modelling to assess whether screening at antenatal visits improves upon current intermittent preventative therapy with sulphadoxine-pyrimethamine (IPTp-SP). We estimate that RDTs in primigravidae at first antenatal visit are substantially more sensitive than in non-pregnant adults (OR = 17.2, 95% Cr.I. 13.8-21.6), and that sensitivity declines in subsequent visits and with gravidity, likely driven by declining susceptibility to placental infection. Monthly ISTp with standard RDTs, even with highly effective drugs, is not superior to monthly IPTp-SP. However, a hybrid strategy, recently adopted in Tanzania, combining testing and treatment at first visit with IPTp-SP may offer benefit, especially in areas with high-grade SP resistance. Screening and treatment in the first trimester, when IPTp-SP is contraindicated, could substantially improve pregnancy outcomes.
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Affiliation(s)
- Patrick G T Walker
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
| | - Matt Cairns
- London School of Hygiene and Tropical Medicine, London, UK
| | - Hannah Slater
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
- PATH, Seattle, WA, USA
| | - Julie Gutman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Kassoum Kayentao
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine, Pharmacy, and Dentistry, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | | | - Sheick O Coulibaly
- Faculty of Health Sciences, University of Ouagadougou, Ouagadougou, Burkina Faso
| | - Carole Khairallah
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Steve Taylor
- Global Health Institute, Duke University, Durham, NC, USA
| | | | - Jenny Hill
- Faculty of Health Sciences, University of Ouagadougou, Ouagadougou, Burkina Faso
| | - Victor Mwapasa
- College of Medicine, University of Malawi, Blantyre, Malawi
| | | | - Kalifa Bojang
- Medical Research Council, London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Simon Kariuki
- Kenya Medical Research Institute/Centre for Global Health Research, Kisumu, Kenya
| | - Harry Tagbor
- University of Health and Allied Sciences, Ho, Ghana
| | - Jamie T Griffin
- School of Mathematical Sciences, Queen Mary University of London, Mile End Road, London, UK
| | | | - Azra C H Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Meghna Desai
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Feiko O Ter Kuile
- Faculty of Health Sciences, University of Ouagadougou, Ouagadougou, Burkina Faso
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13
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Karbwang J, Na‐Bangchang K. The Role of Clinical Pharmacology in Chemotherapy of Multidrug‐Resistant
Plasmodium falciparum. J Clin Pharmacol 2020; 60:830-847. [DOI: 10.1002/jcph.1589] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 01/21/2020] [Indexed: 01/02/2023]
Affiliation(s)
- Juntra Karbwang
- Graduate Program in Bioclinical SciencesChulabhorn International College of MedicineThammasat University (Rangsit Campus) Pathumthani Thailand
- Center of Excellence in Pharmacology and Molecular Biology of Malaria and CholangiocarcinomaThammasat University (Rangsit Campus) Pathumthani Thailand
- Drug Discovery and Development Center, Office of Advanced Science and TechnologyThammasat University (Rangsit Campus) Pathumthani Thailand
- Department of Clinical Product developmentNagasaki Institute of Tropical MedicineNagasaki University Nagasaki Japan
| | - Kesara Na‐Bangchang
- Graduate Program in Bioclinical SciencesChulabhorn International College of MedicineThammasat University (Rangsit Campus) Pathumthani Thailand
- Center of Excellence in Pharmacology and Molecular Biology of Malaria and CholangiocarcinomaThammasat University (Rangsit Campus) Pathumthani Thailand
- Drug Discovery and Development Center, Office of Advanced Science and TechnologyThammasat University (Rangsit Campus) Pathumthani Thailand
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14
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Tuikue Ndam N, Tornyigah B, Dossou AY, Escriou G, Nielsen MA, Salanti A, Issifou S, Massougbodji A, Chippaux JP, Deloron P. Persistent Plasmodium falciparum Infection in Women With an Intent to Become Pregnant as a Risk Factor for Pregnancy-associated Malaria. Clin Infect Dis 2019; 67:1890-1896. [PMID: 29733338 DOI: 10.1093/cid/ciy380] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 05/03/2018] [Indexed: 02/04/2023] Open
Abstract
Background Pregnant women are more susceptible to Plasmodium falciparum than before pregnancy, and infection has consequences for both mother and offspring. The World Health Organization recommends that pregnant woman in areas of transmission receive intermittent preventive treatment (IPTp) starting in the second trimester. Consequently, women are not protected during the first trimester, although P. falciparum infections are both frequent and harmful. Methods A cohort of nulligravid women was followed up during subsequent pregnancy. Malaria was diagnosed by means of microscopy and polymerase chain reaction. Parasites were genotyped at polymorphic loci. Results Among 275 nulligravidae enrolled, 68 women became pregnant and were followed up during pregnancy. Before pregnancy, P. falciparum prevalence rates were 15% by microscopy and 66% by polymerase chain reaction. Microscopic infection rates increased to 29% until IPTp administration, and their density increased by 20-fold. Conversely, submicroscopic infection rates decreased. After IPTp administration, all types of infections decreased, but they increased again late in pregnancy. The risk of infection during pregnancy was higher in women with a microscopic (odds ratio, 6.5; P = .047) or submicroscopic (3.06; P = .05) infection before pregnancy and was not related to the season of occurrence. Most infections during pregnancy were persistent infections acquired before pregnancy. Conclusions Microscopic and submicroscopic malaria infections were frequent in nulligravid women from south Benin. During the first trimester of pregnancy, microscopic infections were more frequent, with a higher parasite density, and mainly derived from parasites infecting the woman before conception. Preventive strategies targeting nonpregnant women with a desire for conception need to be designed.
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Affiliation(s)
- Nicaise Tuikue Ndam
- Mère et Enfant face aux Infections Tropicales, Institut de Recherche pour le Développement, Université Paris 5, Sorbonne Paris Cité, France.,Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon
| | - Bernard Tornyigah
- Mère et Enfant face aux Infections Tropicales, Institut de Recherche pour le Développement, Université Paris 5, Sorbonne Paris Cité, France.,Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon
| | | | - Guillaume Escriou
- Mère et Enfant face aux Infections Tropicales, Institut de Recherche pour le Développement, Université Paris 5, Sorbonne Paris Cité, France
| | - Morten A Nielsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Science, University of Copenhagen.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Denmark
| | - Ali Salanti
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Science, University of Copenhagen.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Denmark
| | - Saadou Issifou
- Centre de Recherche sur le Paludisme Associé à la Grossesse et l'Enfance, Cotonou, Benin
| | - Achille Massougbodji
- Centre de Recherche sur le Paludisme Associé à la Grossesse et l'Enfance, Cotonou, Benin
| | - Jean-Philippe Chippaux
- Mère et Enfant face aux Infections Tropicales, Institut de Recherche pour le Développement, Université Paris 5, Sorbonne Paris Cité, France.,Centre de Recherche sur le Paludisme Associé à la Grossesse et l'Enfance, Cotonou, Benin
| | - Philippe Deloron
- Mère et Enfant face aux Infections Tropicales, Institut de Recherche pour le Développement, Université Paris 5, Sorbonne Paris Cité, France
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15
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Feeney ME. The immune response to malaria in utero. Immunol Rev 2019; 293:216-229. [PMID: 31553066 DOI: 10.1111/imr.12806] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 09/03/2019] [Indexed: 12/13/2022]
Abstract
Malaria causes tremendous early childhood morbidity and mortality, providing an urgent impetus for the development of a vaccine that is effective in neonates. However, the infant immune response to malaria may be influenced by events that occur well before birth. Placental malaria infection complicates one quarter of all pregnancies in Africa and frequently results in exposure of the fetus to malaria antigens in utero, while the immune system is still developing. Some data suggest that in utero exposure to malaria may induce immunologic tolerance that interferes with the development of protective immunity during childhood. More recently, however, a growing body of evidence suggests that fetal malaria exposure can prime highly functional malaria-specific T- and B-cells, which may contribute to postnatal protection from malaria. In utero exposure to malaria also impacts the activation and maturation of fetal antigen presenting cells and innate lymphocytes, which could have implications for global immunity in the infant. Here, we review recent advances in our understanding of how various components of the fetal immune system are altered by in utero exposure to malaria, discuss factors that may tilt the critical balance between tolerance and adaptive immunity, and consider the implications of these findings for malaria prevention strategies.
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Affiliation(s)
- Margaret E Feeney
- Departments of Pediatrics and Medicine, University of California, San Francisco, San Francisco, CA, USA
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16
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Mayor A, Menéndez C, Walker PGT. Targeting Pregnant Women for Malaria Surveillance. Trends Parasitol 2019; 35:677-686. [PMID: 31395496 PMCID: PMC6708786 DOI: 10.1016/j.pt.2019.07.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 12/12/2022]
Abstract
Women attending antenatal care (ANC) are a generally healthy, easy-access population, contributing valuable data for infectious disease surveillance at the community level. ANC-based malaria surveillance would provide a routine measure of the malaria burden in pregnancy, which countries lack, whilst potentially improving pregnancy outcomes. It could also offer contemporary information on temporal trends and the geographic distribution of malaria burden as well as intervention coverage in the population to guide resource allocation and to assess progress towards elimination. Here, we review the factors underlying the relationship between Plasmodium falciparum in pregnancy and in the community, and outline strengths and limitations of an ANC-based surveillance in sub-Saharan Africa, its potential role within wider malaria surveillance systems, and subsequent programmatic applications.
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Affiliation(s)
- Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique.
| | - Clara Menéndez
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique
| | - Patrick G T Walker
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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17
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Accrombessi M, Fievet N, Yovo E, Cottrell G, Agbota G, Massougbodji A, Cot M, Briand V. Prevalence and Associated Risk Factors of Malaria in the First Trimester of Pregnancy: A Preconceptional Cohort Study in Benin. J Infect Dis 2019; 217:1309-1317. [PMID: 29325055 DOI: 10.1093/infdis/jiy009] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 01/05/2018] [Indexed: 02/06/2023] Open
Abstract
Background There is a lack of data on the burden of malaria in the first trimester of pregnancy in Africa, mainly because pregnant women generally attend the maternity clinic late. Bed nets are rarely provided to women before the second trimester of pregnancy and intermittent preventive treatment with sulfadoxine-pyrimethamine is not recommended before the second trimester, leaving women insufficiently or not protected in early pregnancy. Methods To assess the burden of first trimester malaria, 387 women were followed up monthly from preconception to delivery. They were screened for malaria monthly from early pregnancy until delivery. A logistic multilevel model was used to assess maternal factors associated with malaria during the first trimester. Results The proportion of women with at least 1 microscopic malaria infection during the first trimester of pregnancy was 20.8%. Women infected with malaria preconception were more likely to be infected during the first trimester (adjusted odds ratio: 2.68; 95% confidence interval, 1.24-5.78). Early gestational age was also positively correlated with malaria infection. Conclusions Using a preconceptional study design, we showed that malaria was highly prevalent in early pregnancy. This calls for the assessment of new strategies that could protect women as soon as the first trimester.
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Affiliation(s)
- Manfred Accrombessi
- Mère et Enfant Face aux Infections Tropicales, French National Research Institute for Sustainable Development, Paris Descartes University, France.,Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Nadine Fievet
- Mère et Enfant Face aux Infections Tropicales, French National Research Institute for Sustainable Development, Paris Descartes University, France
| | - Emmanuel Yovo
- Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Gilles Cottrell
- Mère et Enfant Face aux Infections Tropicales, French National Research Institute for Sustainable Development, Paris Descartes University, France
| | - Gino Agbota
- Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Achille Massougbodji
- Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Michel Cot
- Mère et Enfant Face aux Infections Tropicales, French National Research Institute for Sustainable Development, Paris Descartes University, France
| | - Valérie Briand
- Mère et Enfant Face aux Infections Tropicales, French National Research Institute for Sustainable Development, Paris Descartes University, France
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18
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Waltmann A, Patel JC, Thwai KL, Hathaway NJ, Parobek CM, Massougbodji A, Fievet N, Bailey JA, Deloron P, Juliano JJ, Ndam NT, Meshnick SR. Matched Placental and Circulating Plasmodium falciparum Parasites are Genetically Homologous at the var2csa ID1-DBL2X Locus by Deep Sequencing. Am J Trop Med Hyg 2018; 98:77-82. [PMID: 29342401 DOI: 10.4269/ajtmh.17-0529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In pregnancy-associated malaria, infected erythrocytes accumulate in the placenta. It is unclear if in polyclonal infections this results in distinct peripheral and placental parasite populations. We used long amplicon deep sequencing of Plasmodium falciparum var2csa ID1-DBL2X from 15 matched peripheral and placental samples collected at delivery from a high transmission area to determine genetic homology. Despite substantial sequence variation and detecting 23 haplotypes, the matched pairs mostly contained the same genetic variants, with 11 pairs sharing 100% of their variants, whereas others showed some heterogeneity. Thus, at delivery, peripheral and placental parasites appear to intermix and placental genotypes can be inferred through peripheral sampling.
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Affiliation(s)
- Andreea Waltmann
- Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Jaymin C Patel
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina
| | - Kyaw L Thwai
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina
| | - Nicholas J Hathaway
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, Massachusetts
| | - Christian M Parobek
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina
| | - Achille Massougbodji
- Centre d'Etude et de Recherche sur le paludisme associé à la Grossesse et à l'Enfance, Université d'Abomey-Calavi, Cotonou, Benin
| | - Nadine Fievet
- UMR216 - MERIT, Institut de Recherche pour le Développement, COMUE Sorbonne Paris Cité, Université Paris Descartes, Paris, France
| | - Jeffery A Bailey
- Division of Transfusion Medicine, Department of Medicine, University of Massachusetts, Worcester, Massachusetts.,Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, Massachusetts
| | - Philippe Deloron
- UMR216 - MERIT, Institut de Recherche pour le Développement, COMUE Sorbonne Paris Cité, Université Paris Descartes, Paris, France
| | - Jonathan J Juliano
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina.,Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina.,Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Nicaise Tuikue Ndam
- UMR216 - MERIT, Institut de Recherche pour le Développement, COMUE Sorbonne Paris Cité, Université Paris Descartes, Paris, France
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina.,Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
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19
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González R, Pons‐Duran C, Piqueras M, Aponte JJ, ter Kuile FO, Menéndez C. Mefloquine for preventing malaria in pregnant women. Cochrane Database Syst Rev 2018; 11:CD011444. [PMID: 30480761 PMCID: PMC6517148 DOI: 10.1002/14651858.cd011444.pub3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND The World Health Organization recommends intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine for malaria for all women who live in moderate to high malaria transmission areas in Africa. However, parasite resistance to sulfadoxine-pyrimethamine has been increasing steadily in some areas of the region. Moreover, HIV-infected women on cotrimoxazole prophylaxis cannot receive sulfadoxine-pyrimethamine because of potential drug interactions. Thus, there is an urgent need to identify alternative drugs for prevention of malaria in pregnancy. One such candidate is mefloquine. OBJECTIVES To assess the effects of mefloquine for preventing malaria in pregnant women, specifically, to evaluate:• the efficacy, safety, and tolerability of mefloquine for preventing malaria in pregnant women; and• the impact of HIV status, gravidity, and use of insecticide-treated nets on the effects of mefloquine. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE, Embase, Latin American Caribbean Health Sciences Literature (LILACS), the Malaria in Pregnancy Library, and two trial registers up to 31 January 2018. In addition, we checked references and contacted study authors to identify additional studies, unpublished data, confidential reports, and raw data from published trials. SELECTION CRITERIA Randomized and quasi-randomized controlled trials comparing mefloquine IPT or mefloquine prophylaxis against placebo, no treatment, or an alternative drug regimen. DATA COLLECTION AND ANALYSIS Two review authors independently screened all records identified by the search strategy, applied inclusion criteria, assessed risk of bias, and extracted data. We contacted trial authors to ask for additional information when required. Dichotomous outcomes were compared using risk ratios (RRs), count outcomes as incidence rate ratios (IRRs), and continuous outcomes using mean differences (MDs). We have presented all measures of effect with 95% confidence intervals (CIs). We assessed the certainty of evidence using the GRADE approach for the following main outcomes of analysis: maternal peripheral parasitaemia at delivery, clinical malaria episodes during pregnancy, placental malaria, maternal anaemia at delivery, low birth weight, spontaneous abortions and stillbirths, dizziness, and vomiting. MAIN RESULTS Six trials conducted between 1987 and 2013 from Thailand (1), Benin (3), Gabon (1), Tanzania (1), Mozambique (2), and Kenya (1) that included 8192 pregnant women met our inclusion criteria.Two trials (with 6350 HIV-uninfected pregnant women) compared two IPTp doses of mefloquine with two IPTp doses of sulfadoxine-pyrimethamine. Two other trials involving 1363 HIV-infected women compared three IPTp doses of mefloquine plus cotrimoxazole with cotrimoxazole. One trial in 140 HIV-infected women compared three doses of IPTp-mefloquine with cotrimoxazole. Finally, one trial enrolling 339 of unknown HIV status compared mefloquine prophylaxis with placebo.Study participants included women of all gravidities and of all ages (four trials) or > 18 years (two trials). Gestational age at recruitment was > 20 weeks (one trial), between 16 and 28 weeks (three trials), or ≤ 28 weeks (two trials). Two of the six trials blinded participants and personnel, and only one had low risk of detection bias for safety outcomes.When compared with sulfadoxine-pyrimethamine, IPTp-mefloquine results in a 35% reduction in maternal peripheral parasitaemia at delivery (RR 0.65, 95% CI 0.48 to 0.86; 5455 participants, 2 studies; high-certainty evidence) but may have little or no effect on placental malaria infections (RR 1.04, 95% CI 0.58 to 1.86; 4668 participants, 2 studies; low-certainty evidence). Mefloquine results in little or no difference in the incidence of clinical malaria episodes during pregnancy (incidence rate ratio (IRR) 0.83, 95% CI 0.65 to 1.05, 2 studies; high-certainty evidence). Mefloquine decreased maternal anaemia at delivery (RR 0.84, 95% CI 0.76 to 0.94; 5469 participants, 2 studies; moderate-certainty evidence). Data show little or no difference in the proportions of low birth weight infants (RR 0.95, 95% CI 0.78 to 1.17; 5641 participants, 2 studies; high-certainty evidence) and in stillbirth and spontaneous abortion rates (RR 1.20, 95% CI 0.91 to 1.58; 6219 participants, 2 studies; I2 statistic = 0%; moderate-certainty evidence). IPTp-mefloquine increased drug-related vomiting (RR 4.76, 95% CI 4.13 to 5.49; 6272 participants, 2 studies; high-certainty evidence) and dizziness (RR 4.21, 95% CI 3.36 to 5.27; participants = 6272, 2 studies; moderate-certainty evidence).When compared with cotrimoxazole, IPTp-mefloquine plus cotrimoxazole probably results in a 48% reduction in maternal peripheral parasitaemia at delivery (RR 0.52, 95% CI 0.30 to 0.93; 989 participants, 2 studies; moderate-certainty evidence) and a 72% reduction in placental malaria (RR 0.28, 95% CI 0.14 to 0.57; 977 participants, 2 studies; moderate-certainty evidence) but has little or no effect on the incidence of clinical malaria episodes during pregnancy (IRR 0.76, 95% CI 0.33 to 1.76, 1 study; high-certainty evidence) and probably no effect on maternal anaemia at delivery (RR 0.94, 95% CI 0.73 to 1.20; 1197 participants, 2 studies; moderate-certainty evidence), low birth weight rates (RR 1.20, 95% CI 0.89 to 1.60; 1220 participants, 2 studies; moderate-certainty evidence), and rates of spontaneous abortion and stillbirth (RR 1.12, 95% CI 0.42 to 2.98; 1347 participants, 2 studies; very low-certainty evidence). Mefloquine was associated with higher risks of drug-related vomiting (RR 7.95, 95% CI 4.79 to 13.18; 1055 participants, one study; high-certainty evidence) and dizziness (RR 3.94, 95% CI 2.85 to 5.46; 1055 participants, 1 study; high-certainty evidence). AUTHORS' CONCLUSIONS Mefloquine was more efficacious than sulfadoxine-pyrimethamine in HIV-uninfected women or daily cotrimoxazole prophylaxis in HIV-infected pregnant women for prevention of malaria infection and was associated with lower risk of maternal anaemia, no adverse effects on pregnancy outcomes (such as stillbirths and abortions), and no effects on low birth weight and prematurity. However, the high proportion of mefloquine-related adverse events constitutes an important barrier to its effectiveness for malaria preventive treatment in pregnant women.
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Affiliation(s)
- Raquel González
- Hospital Clínic ‐ Universitat de BarcelonaISGlobalBarcelonaSpain
| | - Clara Pons‐Duran
- Hospital Clínic ‐ Universitat de BarcelonaISGlobalBarcelonaSpain
| | - Mireia Piqueras
- Hospital Clínic ‐ Universitat de BarcelonaISGlobalBarcelonaSpain
| | - John J Aponte
- Hospital Clínic ‐ Universitat de BarcelonaISGlobalBarcelonaSpain
| | - Feiko O ter Kuile
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesPembroke PlaceLiverpoolMerseysideUKL3 5QA
| | - Clara Menéndez
- Hospital Clínic ‐ Universitat de BarcelonaISGlobalBarcelonaSpain
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20
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Hellewell J, Walker P, Ghani A, Rao B, Churcher TS. Using ante-natal clinic prevalence data to monitor temporal changes in malaria incidence in a humanitarian setting in the Democratic Republic of Congo. Malar J 2018; 17:312. [PMID: 30157850 PMCID: PMC6114784 DOI: 10.1186/s12936-018-2460-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/17/2018] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND The number of clinical cases of malaria is often recorded in resource constrained or conflict settings as a proxy for disease burden. Interpreting case count data in areas of humanitarian need is challenging due to uncertainties in population size caused by security concerns, resource constraints and population movement. Malaria prevalence in women visiting ante-natal care (ANC) clinics has the potential to be an easier and more accurate metric for malaria surveillance that is unbiased by population size if malaria testing is routinely conducted irrespective of symptoms. METHODS A suite of distributed lag non-linear models was fitted to clinical incidence time-series data in children under 5 years and ANC prevalence data from health centres run by Médecins Sans Frontières in the Democratic Republic of Congo, which implement routine intermittent screening and treatment alongside intermittent preventative treatment in pregnancy. These statistical models enable the temporal relationship between the two metrics to be disentangled. RESULTS There was a strong relationship between the ANC prevalence and clinical incidence suggesting that both can be used to describe current malaria endemicity. There was no evidence that ANC prevalence could predict future clinical incidence, though a change in clinical incidence was shown to influence ANC prevalence up to 3 months into the future. CONCLUSIONS The results indicate that ANC prevalence may be a suitable metric for retrospective evaluations of the impact of malaria interventions and is a useful method for evaluating long-term malaria trends in resource constrained settings.
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Affiliation(s)
- Joel Hellewell
- MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, UK.
| | - Patrick Walker
- MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, UK
| | - Azra Ghani
- MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, UK
| | - Bhargavi Rao
- Manson Unit, Médecins Sans Frontières (Operational Centre Amsterdam), London, UK
| | - Thomas S Churcher
- MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, UK
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21
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Harrington WE, Kakuru A, Jagannathan P. Malaria in pregnancy shapes the development of foetal and infant immunity. Parasite Immunol 2018; 41:e12573. [PMID: 30019470 DOI: 10.1111/pim.12573] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 05/21/2018] [Accepted: 07/10/2018] [Indexed: 12/11/2022]
Abstract
Malaria, particularly Plasmodium falciparum, continues to disproportionately affect pregnant women. In addition to the profoundly deleterious impact of maternal malaria on the health of the mother and foetus, malaria infection in pregnancy has been shown to affect the development of the foetal and infant immune system and may alter the risk of malaria and nonmalarial outcomes during infancy. This review summarizes our current understanding of how malaria infection in pregnancy shapes the protective components of the maternal immune system transferred to the foetus and how foetal exposure to parasite antigens impacts the development of foetal and infant immunity. It also reviews existing evidence linking malaria infection in pregnancy to malaria and nonmalarial outcomes in infancy and how preventing malaria in pregnancy may alter these outcomes. A better understanding of the consequences of malaria infection in pregnancy on the development of foetal and infant immunity will inform control strategies, including intermittent preventive treatment in pregnancy and vaccine development.
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Affiliation(s)
- Whitney E Harrington
- Department of Pediatrics, University of Washington/Seattle Children's Hospital, Seattle, Washington
| | - Abel Kakuru
- Infectious Diseases Research Collaboration, Kampala, Uganda
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22
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Ofori MF, Lamptey H, Dickson EK, Kyei-Baafour E, Hviid L. Etiology of Placental Plasmodium falciparum Malaria in African Women. J Infect Dis 2018; 218:277-281. [PMID: 29579263 PMCID: PMC6009667 DOI: 10.1093/infdis/jiy168] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 03/21/2018] [Indexed: 12/13/2022] Open
Abstract
Plasmodium falciparum parasites causing placental malaria express the VAR2CSA type of the clonally variant antigen family erythrocyte membrane protein 1 (PfEMP1). This enables evasion of preexisting immunity and results in placental accumulation of infected erythrocytes. We present data on seasonal variation in levels of VAR2CSA-specific immunoglobulin G (IgG) and IgG specific for a placental malaria-unrelated PfEMP1 protein among Ghanaian women at their first antenatal visit. Our results indicate that placental malaria does not require recent exposure to infected mosquitoes, in contrast to malaria in general. This has implications for the impact of insecticide-treated bed nets on placental malaria incidence and for antenatal care in woman with preexisting immunity.
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Affiliation(s)
- Michael F Ofori
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon
| | - Helena Lamptey
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon
| | - Emmanuel K Dickson
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon
| | - Eric Kyei-Baafour
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon
| | - Lars Hviid
- Center for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
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23
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Prevention of malaria in pregnancy. THE LANCET. INFECTIOUS DISEASES 2018; 18:e119-e132. [PMID: 29395997 DOI: 10.1016/s1473-3099(18)30064-1] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 10/23/2017] [Accepted: 10/27/2017] [Indexed: 12/15/2022]
Abstract
Malaria remains one of the most preventable causes of adverse birth outcomes. Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine is used to prevent malaria, but resistance to this drug combination has decreased its efficacy and new alternatives are needed. In Africa, a meta-analysis showed three-course or monthly IPTp with sulfadoxine-pyrimethamine to be safe and more effective than the original two-course sulfadoxine-pyrimethamine strategy, prompting WHO to update its policy in 2012. Although resistance to sulfadoxine-pyrimethamine reduces the parasitological efficacy of IPTp, this drug combination remains associated with reduced incidence of low birthweight in areas where prevalence of parasites with quintuple Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthetase (Pfdhps) mutations is greater than 90%. Nevertheless, its effectiveness is compromised in women infected with sextuple mutant parasites. Six trials of IPTp showed that neither amodiaquine, mefloquine, nor chloroquine-azithromycin are suitable replacements for sulfadoxine-pyrimethamine because of poor tolerability. Furthermore, four trials showed that intermittent screening and treatment with the current generation of malaria rapid diagnostic tests was not a suitable alternative strategy to IPTp with sulfadoxine-pyrimethamine, even in areas with high prevalence of quintuple mutations. Two trials showed that IPTp with dihydroartemisinin-piperaquine was well tolerated, effective, and acceptable for IPTp, with monthly regimens being the most effective. Coverage of IPTp and insecticide-treated nets continues to lag behind targets. The key barriers to uptake are well documented, and many are open to intervention. Outside of Africa, a single trial suggests a potential role for integrated approaches that combine sulfadoxine-pyrimethamine with azithromycin for IPTp in areas of Papua New Guinea where malaria transmission is high. Modelling analysis suggests the importance of the prevention of malaria early in pregnancy and the need to protect pregnant women declines more slowly than the rate at which transmission declines. Improved funding has led to an increase in the number of prevention trials in the past decade, showing the value of more sustained protection with monthly IPTp regimens. There is a need for confirmatory trials of the safety, efficacy, and feasibility of IPTp with dihydroartemisinin-piperaquine, for studies of intermittent screening and treatment with more sensitive rapid diagnostic tests, for studies of integrated strategies for malaria and other co-infections, and for studies of prevention strategies for malaria in pregnant women who are HIV-positive and living outside of Africa. Additional research is required on how to improve uptake of WHO's updated policy on IPTp with sulfadoxine-pyrimethamine and insecticide-treated nets.
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24
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González R, Pons‐Duran C, Piqueras M, Aponte JJ, ter Kuile FO, Menéndez C. Mefloquine for preventing malaria in pregnant women. Cochrane Database Syst Rev 2018; 3:CD011444. [PMID: 29561063 PMCID: PMC5875065 DOI: 10.1002/14651858.cd011444.pub2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The World Health Organization recommends intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine for malaria for all women who live in moderate to high malaria transmission areas in Africa. However, parasite resistance to sulfadoxine-pyrimethamine has been increasing steadily in some areas of the region. Moreover, HIV-infected women on cotrimoxazole prophylaxis cannot receive sulfadoxine-pyrimethamine because of potential drug interactions. Thus, there is an urgent need to identify alternative drugs for prevention of malaria in pregnancy. One such candidate is mefloquine. OBJECTIVES To assess the effects of mefloquine for preventing malaria in pregnant women, specifically, to evaluate:• the efficacy, safety, and tolerability of mefloquine for preventing malaria in pregnant women; and• the impact of HIV status, gravidity, and use of insecticide-treated nets on the effects of mefloquine. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE, Embase, Latin American Caribbean Health Sciences Literature (LILACS), the Malaria in Pregnancy Library, and two trial registers up to 31 January 2018. In addition, we checked references and contacted study authors to identify additional studies, unpublished data, confidential reports, and raw data from published trials. SELECTION CRITERIA Randomized and quasi-randomized controlled trials comparing mefloquine IPT or mefloquine prophylaxis against placebo, no treatment, or an alternative drug regimen. DATA COLLECTION AND ANALYSIS Two review authors independently screened all records identified by the search strategy, applied inclusion criteria, assessed risk of bias, and extracted data. We contacted trial authors to ask for additional information when required. Dichotomous outcomes were compared using risk ratios (RRs), count outcomes as incidence rate ratios (IRRs), and continuous outcomes using mean differences (MDs). We have presented all measures of effect with 95% confidence intervals (CIs). We assessed the certainty of evidence using the GRADE approach for the following main outcomes of analysis: maternal peripheral parasitaemia at delivery, clinical malaria episodes during pregnancy, placental malaria, maternal anaemia at delivery, low birth weight, spontaneous abortions and stillbirths, dizziness, and vomiting. MAIN RESULTS Six trials conducted between 1987 and 2013 from Thailand (1), Benin (3), Gabon (1), Tanzania (1), Mozambique (2), and Kenya (1) that included 8192 pregnant women met our inclusion criteria.Two trials (with 6350 HIV-uninfected pregnant women) compared two IPTp doses of mefloquine with two IPTp doses of sulfadoxine-pyrimethamine. Two other trials involving 1363 HIV-infected women compared three IPTp doses of mefloquine plus cotrimoxazole with cotrimoxazole. One trial in 140 HIV-infected women compared three doses of IPTp-mefloquine with cotrimoxazole. Finally, one trial enrolling 339 of unknown HIV status compared mefloquine prophylaxis with placebo.Study participants included women of all gravidities and of all ages (four trials) or > 18 years (two trials). Gestational age at recruitment was > 20 weeks (one trial), between 16 and 28 weeks (three trials), or ≤ 28 weeks (two trials). Two of the six trials blinded participants and personnel, and only one had low risk of detection bias for safety outcomes.When compared with sulfadoxine-pyrimethamine, IPTp-mefloquine results in a 35% reduction in maternal peripheral parasitaemia at delivery (RR 0.65, 95% CI 0.48 to 0.86; 5455 participants, 2 studies; high-certainty evidence) but may have little or no effect on placental malaria infections (RR 1.04, 95% CI 0.58 to 1.86; 4668 participants, 2 studies; low-certainty evidence). Mefloquine results in little or no difference in the incidence of clinical malaria episodes during pregnancy (incidence rate ratio (IRR) 0.83, 95% CI 0.65 to 1.05, 2 studies; high-certainty evidence). Mefloquine decreased maternal anaemia at delivery (RR 0.84, 95% CI 0.76 to 0.94; 5469 participants, 2 studies; moderate-certainty evidence). Data show little or no difference in the proportions of low birth weight infants (RR 0.95, 95% CI 0.78 to 1.17; 5641 participants, 2 studies; high-certainty evidence) and in stillbirth and spontaneous abortion rates (RR 1.20, 95% CI 0.91 to 1.58; 6219 participants, 2 studies; I2 statistic = 0%; high-certainty evidence). IPTp-mefloquine increased drug-related vomiting (RR 4.76, 95% CI 4.13 to 5.49; 6272 participants, 2 studies; high-certainty evidence) and dizziness (RR 4.21, 95% CI 3.36 to 5.27; participants = 6272, 2 studies; high-certainty evidence).When compared with cotrimoxazole, IPTp-mefloquine plus cotrimoxazole probably results in a 48% reduction in maternal peripheral parasitaemia at delivery (RR 0.52, 95% CI 0.30 to 0.93; 989 participants, 2 studies; moderate-certainty evidence) and a 72% reduction in placental malaria (RR 0.28, 95% CI 0.14 to 0.57; 977 participants, 2 studies; high-certainty evidence) but has little or no effect on the incidence of clinical malaria episodes during pregnancy (IRR 0.76, 95% CI 0.33 to 1.76, 1 study; high-certainty evidence) and probably no effect on maternal anaemia at delivery (RR 0.94, 95% CI 0.73 to 1.20; 1197 participants, 2 studies; moderate-certainty evidence), low birth weight rates (RR 1.20, 95% CI 0.89 to 1.60; 1220 participants, 2 studies; moderate-certainty evidence), and rates of spontaneous abortion and stillbirth (RR 1.12, 95% CI 0.42 to 2.98; 1347 participants, 2 studies; very low-certainty evidence). Mefloquine was associated with higher risks of drug-related vomiting (RR 7.95, 95% CI 4.79 to 13.18; 1055 participants, one study; high-certainty evidence) and dizziness (RR 3.94, 95% CI 2.85 to 5.46; 1055 participants, 1 study; high-certainty evidence). AUTHORS' CONCLUSIONS Mefloquine was more efficacious than sulfadoxine-pyrimethamine in HIV-uninfected women or daily cotrimoxazole prophylaxis in HIV-infected pregnant women for prevention of malaria infection and was associated with lower risk of maternal anaemia, no adverse effects on pregnancy outcomes (such as stillbirths and abortions), and no effects on low birth weight and prematurity. However, the high proportion of mefloquine-related adverse events constitutes an important barrier to its effectiveness for malaria preventive treatment in pregnant women.
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Key Words
- female
- humans
- pregnancy
- insecticide‐treated bednets
- abortion, spontaneous
- abortion, spontaneous/chemically induced
- abortion, spontaneous/epidemiology
- africa south of the sahara
- africa south of the sahara/epidemiology
- antimalarials
- antimalarials/adverse effects
- antimalarials/therapeutic use
- dizziness
- dizziness/chemically induced
- dizziness/epidemiology
- drug combinations
- drug therapy, combination
- hiv infections
- hiv infections/complications
- infant, low birth weight
- malaria
- malaria/epidemiology
- malaria/prevention & control
- mefloquine
- mefloquine/adverse effects
- mefloquine/therapeutic use
- parasitemia
- parasitemia/epidemiology
- pregnancy complications, parasitic
- pregnancy complications, parasitic/epidemiology
- pregnancy complications, parasitic/prevention & control
- pyrimethamine
- pyrimethamine/adverse effects
- pyrimethamine/therapeutic use
- randomized controlled trials as topic
- sulfadoxine
- sulfadoxine/adverse effects
- sulfadoxine/therapeutic use
- thailand
- thailand/epidemiology
- trimethoprim, sulfamethoxazole drug combination
- trimethoprim, sulfamethoxazole drug combination/therapeutic use
- vomiting
- vomiting/chemically induced
- vomiting/epidemiology
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Affiliation(s)
- Raquel González
- Hospital Clínic ‐ Universitat de BarcelonaISGlobalBarcelonaSpain
| | - Clara Pons‐Duran
- Hospital Clínic ‐ Universitat de BarcelonaISGlobalBarcelonaSpain
| | - Mireia Piqueras
- Hospital Clínic ‐ Universitat de BarcelonaISGlobalBarcelonaSpain
| | - John J Aponte
- Hospital Clínic ‐ Universitat de BarcelonaISGlobalBarcelonaSpain
| | - Feiko O ter Kuile
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesPembroke PlaceLiverpoolUKL3 5QA
| | - Clara Menéndez
- Hospital Clínic ‐ Universitat de BarcelonaISGlobalBarcelonaSpain
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25
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Rogerson SJ, Desai M, Mayor A, Sicuri E, Taylor SM, van Eijk AM. Burden, pathology, and costs of malaria in pregnancy: new developments for an old problem. THE LANCET. INFECTIOUS DISEASES 2018; 18:e107-e118. [PMID: 29396010 DOI: 10.1016/s1473-3099(18)30066-5] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 08/07/2017] [Accepted: 10/09/2017] [Indexed: 12/17/2022]
Abstract
Over the past 10 years, knowledge of the burden, economic costs, and consequences of malaria in pregnancy has improved, and the prevalence of malaria caused by Plasmodium falciparum has declined substantially in some geographical areas. In particular, studies outside of Africa have increased the evidence base of Plasmodium vivax in pregnancy. Rapid diagnostic tests have been poor at detecting malaria in pregnant women, while PCR has shown a high prevalence of low density infection, the clinical importance of which is unknown. Erythrocytes infected with P falciparum that express the surface protein VAR2CSA accumulate in the placenta, and VAR2CSA is an important target of protective immunity. Clinical trials for a VAR2CSA vaccine are ongoing, but sequence variation needs to be carefully studied. Health system and household costs still limit access to prevention and treatment services. Within the context of malaria elimination, pregnant women could be used to monitor malaria transmission. This Series paper summarises recent progress and highlights unresolved issues related to the burden of malaria in pregnancy.
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Affiliation(s)
- Stephen J Rogerson
- Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, Victoria, Australia.
| | - Meghna Desai
- Malaria Branch, Division of Parasitic Diseases and Malaria, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Alfredo Mayor
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique
| | - Elisa Sicuri
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; Health Economics Group, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College, London, UK
| | - Steve M Taylor
- Division of Infectious Diseases and Duke Global Health Institute, Duke University Medical Center, Durham, NC, USA
| | - Anna M van Eijk
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
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26
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Tassi Yunga S, Fouda GG, Sama G, Ngu JB, Leke RGF, Taylor DW. Increased Susceptibility to Plasmodium falciparum in Infants is associated with Low, not High, Placental Malaria Parasitemia. Sci Rep 2018; 8:169. [PMID: 29317740 PMCID: PMC5760570 DOI: 10.1038/s41598-017-18574-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/12/2017] [Indexed: 01/19/2023] Open
Abstract
Risk of malaria in infants can be influenced by prenatal factors. In this study, the potential for placental parasitemia at delivery in predicting susceptibility of infants to Plasmodium falciparum (Pf) infections was evaluated. Seventy-two newborns of mothers who were placental malaria negative (PM-) and of mothers who were PM+ with below (PM+ Lo) and above (PM + Hi) median placental parasitemia, were actively monitored during their first year of life. Median time to first PCR-detected Pf infection was shorter in PM + Lo infants (2.8 months) than in both PM- infants (4.0 months, p = 0.002) and PM + Hi infants (4.1 months, p = 0.01). Total number of new infections was also highest in the PM + Lo group. Only 24% of infants experienced clinical malaria episodes but these episodes occurred earlier in PM + Lo infants than in PM + Hi infants (p = 0.05). The adjusted hazard ratio (95% CI) of having Pf infection was 3.9 (1.8-8.4) and 1.5 (0.7-3.4) for infants in the PM + Lo and PM + Hi groups, respectively. Collectively, low placental parasitemia was associated with increased susceptibility to malaria during infancy. Therefore, malaria in pregnancy preventive regimens, such as sulfadoxine-pyremethamine, that reduce but do not eliminate placental Pf in areas of drug resistance may increase the risk of malaria in infants.
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Affiliation(s)
- Samuel Tassi Yunga
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo Street, BSB320, Honolulu, HI, 96813, USA
| | - Genevieve G Fouda
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, USA and Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Grace Sama
- The Biotechnology Center, University of Yaoundé 1, BP 3851 Messa, Yaoundé, Cameroon
| | - Julia B Ngu
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, BP 1364, Yaoundé, Cameroon
| | - Rose G F Leke
- The Biotechnology Center, University of Yaoundé 1, BP 3851 Messa, Yaoundé, Cameroon
| | - Diane W Taylor
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo Street, BSB320, Honolulu, HI, 96813, USA.
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Berry I, Walker P, Tagbor H, Bojang K, Coulibaly SO, Kayentao K, Williams J, Oduro A, Milligan P, Chandramohan D, Greenwood B, Cairns M. Seasonal Dynamics of Malaria in Pregnancy in West Africa: Evidence for Carriage of Infections Acquired Before Pregnancy Until First Contact with Antenatal Care. Am J Trop Med Hyg 2017; 98:534-542. [PMID: 29210351 PMCID: PMC5929207 DOI: 10.4269/ajtmh.17-0620] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In malaria-endemic areas, Plasmodium falciparum prevalence is often high in young women because of 1) low use of insecticide-treated nets before their first pregnancy and 2) acquired immunity, meaning infections are asymptomatic and thus untreated. Consequently, a common source of malaria in pregnancy (MiP) may be infected women becoming pregnant, rather than pregnant women becoming infected. In this study, prevalence of infection was determined by microscopy at first antenatal care (ANC) visit in primigravidae and secundigravidae in Ghana, Burkina Faso, Mali, and The Gambia, four countries with strong seasonal variations in transmission. Duration of pregnancy spent in the rainy season and other risk factors for infection were evaluated using multivariable Poisson regression. We found that the overall prevalence of malaria at first ANC was generally high and increased with time spent pregnant during the rainy season: prevalence among those with the longest exposure was 59.7% in Ghana, 56.7% in Burkina Faso, 42.2% in Mali, and 16.8% in Gambia. However, the prevalence was substantial even among women whose entire pregnancy before first ANC had occurred in the dry season: 41.3%, 34.4%, 11.5%, and 7.8%, respectively, in the four countries. In multivariable analysis, risk of infection was also higher among primigravidae, younger women, and those of lower socioeconomic status, independent of seasonality. High prevalence among women without exposure to high transmission during their pregnancy suggests that part of the MiP burden results from long-duration infections, including those acquired preconception. Prevention of malaria before pregnancy is needed to reduce the MiP burden.
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Affiliation(s)
- Isha Berry
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Harry Tagbor
- University of Health and Allied Sciences, Ho, Ghana
| | | | | | - Kassoum Kayentao
- Malaria Research and Training Center, Faculty of Medicine and Odontostomatology, University of Sciences, Techniques and Technologies, Bamako, Mali
| | | | | | - Paul Milligan
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Brian Greenwood
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Matthew Cairns
- London School of Hygiene and Tropical Medicine, London, United Kingdom
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McLean ARD, Stanisic D, McGready R, Chotivanich K, Clapham C, Baiwog F, Pimanpanarak M, Siba P, Mueller I, King CL, Nosten F, Beeson JG, Rogerson S, Simpson JA, Fowkes FJI. P. falciparum infection and maternofetal antibody transfer in malaria-endemic settings of varying transmission. PLoS One 2017; 12:e0186577. [PMID: 29028827 PMCID: PMC5640245 DOI: 10.1371/journal.pone.0186577] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/03/2017] [Indexed: 01/16/2023] Open
Abstract
Introduction During pregnancy, immunoglobulin G (IgG) is transferred from the mother to the fetus, providing protection from disease in early infancy. Plasmodium falciparum infections may reduce maternofetal antibody transfer efficiency, but mechanisms remain unclear. Methods Mother-cord paired serum samples collected at delivery from Papua New Guinea (PNG) and the Thailand-Myanmar Border Area (TMBA) were tested for IgG1 and IgG3 to four P. falciparum antigens and measles antigen, as well as total serum IgG. Multivariable linear regression was conducted to assess the association of peripheral P. falciparum infection during pregnancy or placental P. falciparum infection assessed at delivery with maternofetal antibody transfer efficiency. Path analysis assessed the extent to which associations between P. falciparum infection and antibody transfer were mediated by gestational age at delivery or levels of maternal total serum IgG. Results Maternofetal antibody transfer efficiency of IgG1 and IgG3 was lower in PNG compared to TMBA (mean difference in cord antibody levels (controlling for maternal antibody levels) ranged from -0.88 to 0.09, median of -0.20 log2 units). Placental P. falciparum infections were associated with substantially lower maternofetal antibody transfer efficiency in PNG primigravid women (mean difference in cord antibody levels (controlling for maternal antibody levels) ranged from -0.62 to -0.10, median of -0.36 log2 units), but not multigravid women. The lower antibody transfer efficiency amongst primigravid women with placental infection was only partially mediated by gestational age at delivery (proportion indirect effect ranged from 0% to 18%), whereas no mediation effects of maternal total serum IgG were observed. Discussion Primigravid women may be at risk of impaired maternofetal antibody transport with placental P. falciparum infection. Direct effects of P. falciparum on the placenta, rather than earlier gestational age and elevated serum IgG, are likely responsible for the majority of the reduction in maternofetal antibody transfer efficiency with placental infection.
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Affiliation(s)
- Alistair R. D. McLean
- Burnet Institute, Melbourne, Victoria, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
| | - Danielle Stanisic
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, Queensland, Australia
| | - Rose McGready
- Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Kesinee Chotivanich
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Caroline Clapham
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Francesca Baiwog
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Mupawjay Pimanpanarak
- Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Ivo Mueller
- Population Health & Immunity Division, WEHI, Parkville, Victoria, Australia
- Malaria: Parasites & Hosts Unit, Institut Pasteur, Paris, France
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Christopher L. King
- Center for Global Health and Diseases, Case Western Reserve University, and Veterans Affairs Medical Center, Cleveland, OH, United States of America
| | - François Nosten
- Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - James G. Beeson
- Burnet Institute, Melbourne, Victoria, Australia
- Department of Medicine, University of Melbourne, Melbourne, Australia
- Department of Microbiology and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Stephen Rogerson
- Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Julie A. Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Freya J. I. Fowkes
- Burnet Institute, Melbourne, Victoria, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
- Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Victoria, Australia
- * E-mail:
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Tassi Yunga S, Kayatani AK, Fogako J, Leke RJI, Leke RGF, Taylor DW. Timing of the human prenatal antibody response to Plasmodium falciparum antigens. PLoS One 2017; 12:e0184571. [PMID: 28950009 PMCID: PMC5614534 DOI: 10.1371/journal.pone.0184571] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 08/25/2017] [Indexed: 12/27/2022] Open
Abstract
Plasmodium falciparum (Pf)-specific T- and B-cell responses may be present at birth; however, when during fetal development antibodies are produced is unknown. Accordingly, cord blood samples from 232 preterm (20–37 weeks of gestation) and 450 term (≥37 weeks) babies were screened for IgM to Pf blood-stage antigens MSP1, MSP2, AMA1, EBA175 and RESA. Overall, 25% [95% CI = 22–28%] of the 682 newborns were positive for IgM to ≥1 Pf antigens with the earliest response occurring at 22 weeks. Interestingly, the odds of being positive for cord blood Pf IgM decreased with gestational age (adjusted OR [95% CI] at 20–31 weeks = 2.55 [1.14–5.85] and at 32–36 weeks = 1.97 [0.92–4.29], with ≥37 weeks as reference); however, preterm and term newborns had similar levels of Pf IgM and recognized a comparable breadth of antigens. Having cord blood Pf IgM was associated with placental malaria (adjusted OR [95% CI] = 2.37 [1.25–4.54]). To determine if in utero exposure occurred via transplacental transfer of Pf-IgG immune complexes (IC), IC containing MSP1 and MSP2 were measured in plasma of 242 mother-newborn pairs. Among newborns of IC-positive mothers (77/242), the proportion of cord samples with Pf IC increased with gestational age but was not associated with Pf IgM, suggesting that fetal B cells early in gestation had not been primed by IC. Finally, when cord mononuclear cells from 64 term newborns were cultured in vitro, only 11% (7/64) of supernatants had Pf IgM; whereas, 95% (61/64) contained secreted Pf IgG. These data suggest fetal B cells are capable of making Pf-specific IgM from early in the second trimester and undergo isotype switching to IgG towards term.
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Affiliation(s)
- Samuel Tassi Yunga
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America
| | - Alexander K. Kayatani
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America
| | - Josephine Fogako
- The Biotechnology Center, University of Yaoundé 1, Yaoundé, Cameroon
| | - Robert J. I. Leke
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
| | - Rose G. F. Leke
- The Biotechnology Center, University of Yaoundé 1, Yaoundé, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
| | - Diane W. Taylor
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America
- * E-mail:
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30
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Moore KA, Simpson JA, Wiladphaingern J, Min AM, Pimanpanarak M, Paw MK, Raksuansak J, Pukrittayakamee S, Fowkes FJI, White NJ, Nosten F, McGready R. Influence of the number and timing of malaria episodes during pregnancy on prematurity and small-for-gestational-age in an area of low transmission. BMC Med 2017; 15:117. [PMID: 28633672 PMCID: PMC5479010 DOI: 10.1186/s12916-017-0877-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Most evidence on the association between malaria in pregnancy and adverse pregnancy outcomes focuses on falciparum malaria detected at birth. We assessed the association between the number and timing of falciparum and vivax malaria episodes during pregnancy on small-for-gestational-age (SGA) and preterm birth. METHODS We analysed observational data collected from antenatal clinics on the Thailand-Myanmar border (1986-2015). We assessed the effects of the total number of malaria episodes in pregnancy on SGA and the effects of malaria in pregnancy on SGA, very preterm birth, and late preterm birth, by the gestational age at malaria detection and treatment using logistic regression models with time-dependent malaria variables (monthly intervals). World Health Organisation definitions of very preterm birth (≥28 and <32 weeks) and late preterm birth (≥32 and <37 weeks) and international SGA standards were used. RESULTS Of 50,060 pregnant women followed, 8221 (16%) had malaria during their pregnancy. Of the 50,060 newborns, 10,005 (21%) were SGA, 540 (1%) were very preterm, and 4331 (9%) were late preterm. The rates of falciparum and vivax malaria were highest at 6 and 5 weeks' gestation, respectively. The odds of SGA increased linearly by 1.13-fold (95% confidence interval: 1.09, 1.17) and 1.27-fold (1.21, 1.33) per episode of falciparum and vivax malaria, respectively. Falciparum malaria at any gestation period after 12-16 weeks and vivax malaria after 20-24 weeks were associated with SGA (falciparum odds ratio, OR range: 1.15-1.63 [p range: <0.001-0.094]; vivax OR range: 1.12-1.54 [p range: <0.001-0.138]). Falciparum malaria at any gestation period after 24-28 weeks was associated with either very or late preterm birth (OR range: 1.44-2.53; p range: <0.001-0.001). Vivax malaria at 24-28 weeks was associated with very preterm birth (OR: 1.79 [1.11, 2.90]), and vivax malaria at 28-32 weeks was associated with late preterm birth (OR: 1.23 [1.01, 1.50]). Many of these associations held for asymptomatic malaria. CONCLUSIONS Protection against malaria should be started as early as possible in pregnancy. Malaria control and elimination efforts in the general population can avert the adverse consequences associated with treated asymptomatic malaria in pregnancy.
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Affiliation(s)
- Kerryn A Moore
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia. .,Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia.
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Jacher Wiladphaingern
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Aung Myat Min
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Mupawjay Pimanpanarak
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Moo Kho Paw
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Jathee Raksuansak
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Sasithon Pukrittayakamee
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Freya J I Fowkes
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia.,Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia.,Department of Epidemiology and Preventive Medicine and Department of Infectious Diseases, Monash University, Melbourne, VIC, Australia
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - François Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Rose McGready
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Slater HC, Okell LC, Ghani AC. Mathematical Modelling to Guide Drug Development for Malaria Elimination. Trends Parasitol 2017; 33:175-184. [PMID: 27727128 PMCID: PMC5347022 DOI: 10.1016/j.pt.2016.09.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/05/2016] [Accepted: 09/12/2016] [Indexed: 11/16/2022]
Abstract
Mathematical models of the dynamics of a drug within the host are now frequently used to guide drug development. These generally focus on assessing the efficacy and duration of response to guide patient therapy. Increasingly, antimalarial drugs are used at the population level, to clear infections, provide chemoprevention, and to reduce onward transmission of infection. However, there is less clarity on the extent to which different drug properties are important for these different uses. In addition, the emergence of drug resistance poses new threats to longer-term use and highlights the need for rational drug development. Here, we argue that integrating within-host pharmacokinetic and pharmacodynamic (PK/PD) models with mathematical models for the population-level transmission of malaria is key to guiding optimal drug design to aid malaria elimination.
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Affiliation(s)
- Hannah C Slater
- MRC Centre for Outbreak Analysis & Modelling, Department of Infectious Disease Epidemiology, Imperial College London, UK
| | - Lucy C Okell
- MRC Centre for Outbreak Analysis & Modelling, Department of Infectious Disease Epidemiology, Imperial College London, UK
| | - Azra C Ghani
- MRC Centre for Outbreak Analysis & Modelling, Department of Infectious Disease Epidemiology, Imperial College London, UK.
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32
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Estimated impact on birth weight of scaling up intermittent preventive treatment of malaria in pregnancy given sulphadoxine-pyrimethamine resistance in Africa: A mathematical model. PLoS Med 2017; 14:e1002243. [PMID: 28245259 PMCID: PMC5330448 DOI: 10.1371/journal.pmed.1002243] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/23/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Malaria transmission has declined substantially in the 21st century, but pregnant women in areas of sustained transmission still require protection to prevent the adverse pregnancy and birth outcomes associated with malaria in pregnancy (MiP). A recent call to action has been issued to address the continuing low coverage of intermittent preventive treatment of malaria in pregnancy (IPTp). This call has, however, been questioned by some, in part due to concerns about resistance to sulphadoxine-pyrimethamine (SP), the only drug currently recommended for IPTp. METHODS AND FINDINGS Using an existing mathematical model of MiP, we combined estimates of the changing endemicity of malaria across Africa with maps of SP resistance mutations and current coverage of antenatal access and IPTp with SP (IPTp-SP) across Africa. Using estimates of the relationship between SP resistance mutations and the parasitological efficacy of SP during pregnancy, we estimated the varying impact of IPTp-SP across Africa and the incremental value of enhancing IPTp-SP uptake to match current antenatal care (ANC) coverage. The risks of MiP and malaria-attributable low birthweight (mLBW) in unprotected pregnancies (i.e., those not using insecticide-treated nets [ITNs]) leading to live births fell by 37% (33%-41% 95% credible interval [crI]) and 31% (27%-34% 95% crI), respectively, from 2000 to 2015 across endemic areas in sub-Saharan Africa. However, these gains are fragile, and coverage is far from optimal. In 2015, 9.5 million (8.3 million-10.4 million 95% crI) of 30.6 million pregnancies in these areas would still have been infected with Plasmodium falciparum without intervention, leading to 750,000 (390,000-1.1 million 95% crI) mLBW deliveries. In all, 6.6 million (5.6 million-7.3 million 95% crI) of these 9.5 million (69.3%) pregnancies at risk of infection (and 53.4% [16.3 million/30.6 million] of all pregnancies) occurred in settings with near-perfect SP curative efficacy (>99%) based on the most recent estimates of resistance. Forty-four percent of these pregnancies (23% of all pregnancies) were not receiving any IPTp-SP despite making ≥3 ANC visits, representing 160,000 (94,000-236,000 95% crI) preventable low birthweight (LBW) deliveries. Only 4% (1.4 million) of pregnancies occurred in settings with >10% prevalence of the sextuple haplotype associated with compromised SP effectiveness. Forty-two percent of all pregnancies occurred in settings where the quintuple dhfr/dhps haplotype had become established but where in vivo efficacy data suggest SP maintains the majority of its effectiveness in clearing infections. Not accounting for protection from the use of ITNs during pregnancy, expanding IPTp-SP to all women with ≥3 ANC visits in Africa could prevent an additional 215,000 (128,000-318,000 95% crI) LBW deliveries. In 26 countries with sufficient recent data to estimate ITN impact (population-based ITN usage data that can be stratified by gravidity), we estimate that, due primarily to low ITN use by primigravidae, only 16.5% of the potential LBW births prevented by scaling up IPTp-SP would in fact have already have been prevented through ITN use. Our analysis also highlights the difficulties associated with estimating the relationship between the effectiveness of interventions against parasitological endpoints such as placental infection at delivery and health outcomes including birthweight, which is also determined by a wide range of unrelated factors. We also did not capture other aspects of malaria burden such as clinical malaria, maternal and neonatal anaemia, and miscarriage, all of which increase the overall importance of effective preventative strategies but have their own relationship with transmission intensity, parity, and SP resistance. CONCLUSIONS Despite recent declines in malaria transmission in Africa, the burden of MiP in the absence of adequate prevention remains substantial. Even accounting for SP resistance, extending IPTp-SP to all women attending ANC, as well as long-lasting insecticidal net distribution targeted towards first-time mothers, would have a sizeable impact upon maternal and infant health in almost all malaria-endemic settings in sub-Saharan Africa.
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Moore KA, Simpson JA, Paw MK, Pimanpanarak M, Wiladphaingern J, Rijken MJ, Jittamala P, White NJ, Fowkes FJI, Nosten F, McGready R. Safety of artemisinins in first trimester of prospectively followed pregnancies: an observational study. THE LANCET. INFECTIOUS DISEASES 2016; 16:576-583. [PMID: 26869377 PMCID: PMC4835584 DOI: 10.1016/s1473-3099(15)00547-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 12/14/2015] [Accepted: 12/15/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND Artemisinins, the most effective antimalarials available, are not recommended for falciparum malaria during the first trimester of pregnancy because of safety concerns. Therefore, quinine is used despite its poor effectiveness. Assessing artemisinin safety requires weighing the risks of malaria and its treatment. We aimed to assess the effect of first-trimester malaria and artemisinin treatment on miscarriage and major congenital malformations. METHODS In this observational study, we assessed data from antenatal clinics on the Thai-Myanmar border between Jan 1, 1994, and Dec 31, 2013. We included women who presented to antenatal clinics during their first trimester with a viable fetus. Women were screened for malaria, and data on malaria, antimalarial treatment, and birth outcomes were collected. The relationship between artemisinin treatments (artesunate, dihydroartemisinin, or artemether) and miscarriage or malformation was assessed using Cox regression with left-truncation and time-varying exposures. FINDINGS Of 55 636 pregnancies registered between 1994 and 2013, 25 485 pregnancies were analysed for first-trimester malaria and miscarriage, in which 2558 (10%) had first-trimester malaria. The hazard of miscarriage increased 1·61-fold after an initial first-trimester falciparum episode (95% CI 1·32-1·97; p<0·0001), 3·24-fold following falciparum recurrence (2·24-4·68; p<0·0001), and 2·44-fold (1·01-5·88; p=0·0473) following recurrent symptomatic vivax malaria. No difference was noted in miscarriage in first-line falciparum treatments with artemisinin (n=183) versus quinine (n=842; HR 0·78 [95% CI 0·45-1·34]; p=0·3645) or in risk of major congenital malformations (two [2%] of 109 [95% CI 0·22-6·47] versus eight (1%) of 641 [0·54-2·44], respectively). INTERPRETATION First-trimester falciparum and vivax malaria both increase the risk of miscarriage. We noted no evidence of an increased risk of miscarriage or of major congenital malformations associated with first-line treatment with an artemisinin derivative compared with quinine. In view of the low efficacy of quinine and wide availability of highly effective artemisinin-based combination therapies, it is time to reconsider first-trimester antimalarial treatment recommendations. FUNDING The Wellcome Trust and The Bill & Melinda Gates Foundation.
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Affiliation(s)
- Kerryn A Moore
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia; Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia.
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Moo Kho Paw
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - MuPawJay Pimanpanarak
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Jacher Wiladphaingern
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Marcus J Rijken
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Podjanee Jittamala
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Freya J I Fowkes
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia; Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia; Department of Epidemiology and Preventive Medicine and Department of Infectious Diseases, Monash University, Melbourne, VIC, Australia
| | - François Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Rose McGready
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Boudová S, Divala T, Mawindo P, Cohee L, Kalilani-Phiri L, Thesing P, Taylor TE, Laufer MK. The prevalence of malaria at first antenatal visit in Blantyre, Malawi declined following a universal bed net campaign. Malar J 2015; 14:422. [PMID: 26510414 PMCID: PMC4625940 DOI: 10.1186/s12936-015-0945-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 10/21/2015] [Indexed: 11/30/2022] Open
Abstract
Background Preventing malaria during pregnancy is important for the health of mothers and newborns. Interventions, which include distribution of bed nets and administration of intermittent preventive treatment (IPT), typically occur at the first antenatal visit, usually in the second or third trimester of pregnancy. In 2012, during the course of ongoing clinical studies of malaria among pregnant women in Malawi, a universal bed net campaign was implemented by the Government. This study tested the hypothesis that a universal bed net campaign would decrease the prevalence of malaria among pregnant women at their first antenatal visit. Methods Some 1661 women were recruited for two studies from 2009 to 2014. Quantitative PCR (qPCR) was conducted from dried blood spots collected at the first antenatal care visit (prior to administration of IPT or any study interventions) from women who were in their first or second pregnancy and less than 28 weeks gestation by clinical assessment. Results Overall, 320 of 1629 (19.6 %) women tested for malaria at their first antenatal visit were infected. Malaria infection rates declined from 28.4 % before the universal bed net campaign, to 18.5 % in 2012, to 15.0 % in the years following the universal bed net campaign. The odds of malaria infection at the time of first antenatal visit in 2012 and the years following the bed net campaign were significantly lower than in the years prior to the intervention (OR 0.6, 95 % CI 0.4–0.8; and OR 0.4, 95 % CI 0.3–0.6, respectively). A similar pattern was observed for the prevalence of clinical malaria. The inverse trend was observed for reported bed net use. However bed net use and malaria infection were not significantly associated on the individual level. Conclusions Malaria infection in pregnant women is common even after a bed net campaign in Malawi, though prevalence rates declined. These early infections may cause maternal anaemia and placental malaria resulting in adverse maternal and fetal outcomes. Infection early in pregnancy may also contribute to malaria transmission as pregnant women represent a significant untreated reservoir of parasites. Universal bed net distribution appears to have moderate success in preventing malaria early in pregnancy and these findings support continued efforts to target women early in pregnancy and all women of childbearing age.
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Affiliation(s)
- Sarah Boudová
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Titus Divala
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi.
| | - Patricia Mawindo
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi.
| | - Lauren Cohee
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
| | | | - Phillip Thesing
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi.
| | - Terrie E Taylor
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi. .,Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA.
| | - Miriam K Laufer
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
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From within host dynamics to the epidemiology of infectious disease: Scientific overview and challenges. Math Biosci 2015; 270:143-55. [PMID: 26474512 DOI: 10.1016/j.mbs.2015.10.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Since their earliest days, humans have been struggling with infectious diseases. Caused by viruses, bacteria, protozoa, or even higher organisms like worms, these diseases depend critically on numerous intricate interactions between parasites and hosts, and while we have learned much about these interactions, many details are still obscure. It is evident that the combined host-parasite dynamics constitutes a complex system that involves components and processes at multiple scales of time, space, and biological organization. At one end of this hierarchy we know of individual molecules that play crucial roles for the survival of a parasite or for the response and survival of its host. At the other end, one realizes that the spread of infectious diseases by far exceeds specific locales and, due to today's easy travel of hosts carrying a multitude of organisms, can quickly reach global proportions. The community of mathematical modelers has been addressing specific aspects of infectious diseases for a long time. Most of these efforts have focused on one or two select scales of a multi-level disease and used quite different computational approaches. This restriction to a molecular, physiological, or epidemiological level was prudent, as it has produced solid pillars of a foundation from which it might eventually be possible to launch comprehensive, multi-scale modeling efforts that make full use of the recent advances in biology and, in particular, the various high-throughput methodologies accompanying the emerging -omics revolution. This special issue contains contributions from biologists and modelers, most of whom presented and discussed their work at the workshop From within Host Dynamics to the Epidemiology of Infectious Disease, which was held at the Mathematical Biosciences Institute at Ohio State University in April 2014. These contributions highlight some of the forays into a deeper understanding of the dynamics between parasites and their hosts, and the consequences of this dynamics for the spread and treatment of infectious diseases.
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Gutierrez JB, Galinski MR, Cantrell S, Voit EO. WITHDRAWN: From within host dynamics to the epidemiology of infectious disease: Scientific overview and challenges. Math Biosci 2015:S0025-5564(15)00085-1. [PMID: 25890102 DOI: 10.1016/j.mbs.2015.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Juan B Gutierrez
- Department of Mathematics, Institute of Bioinformatics, University of Georgia, Athens, GA 30602, United States .
| | - Mary R Galinski
- Emory University School of Medicine, Division of Infectious Diseases, Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, United States .
| | - Stephen Cantrell
- Department of Mathematics, University of Miami, Coral Gables, FL 33124, United States .
| | - Eberhard O Voit
- Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive, Suite 4103, Atlanta, GA 30332-0535, United States .
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González R, Boerma RS, Sinclair D, Aponte JJ, ter Kuile FO, Menéndez C. Mefloquine for preventing malaria in pregnant women. Hippokratia 2015. [DOI: 10.1002/14651858.cd011444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Raquel González
- Barcelona Institute for Global Health, ISGlobal, Barcelona Ctr. Int. Heath Res. (CRESIB), Hospital Clínic-Universitat de Barcelona; Barcelona Spain
| | - Ragna S Boerma
- Barcelona Institute for Global Health, ISGlobal, Barcelona Ctr. Int. Heath Res. (CRESIB), Hospital Clínic-Universitat de Barcelona; Barcelona Spain
| | - David Sinclair
- Liverpool School of Tropical Medicine; Department of Clinical Sciences; Pembroke Place Liverpool UK L3 5QA
| | - John J Aponte
- Barcelona Institute for Global Health, ISGlobal, Barcelona Ctr. Int. Heath Res. (CRESIB), Hospital Clínic-Universitat de Barcelona; Barcelona Spain
| | - Feiko O ter Kuile
- Liverpool School of Tropical Medicine; Child & Reproductive Health Group; Pembroke Place Liverpool Merseyside UK L3 5QA
| | - Clara Menéndez
- Barcelona Institute for Global Health, ISGlobal, Barcelona Ctr. Int. Heath Res. (CRESIB), Hospital Clínic-Universitat de Barcelona; Barcelona Spain
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Huynh BT, Cottrell G, Cot M, Briand V. Burden of malaria in early pregnancy: a neglected problem? Clin Infect Dis 2014; 60:598-604. [PMID: 25362205 DOI: 10.1093/cid/ciu848] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
According to the current World Health Organization guidelines, the drug prevention of malaria during pregnancy does not adequately cover the first trimester of gestation in high-transmission areas. Although the pathophysiological mechanisms of early infections are not completely understood yet, a review of the most recent studies on the topic suggests that their consequences are serious in terms of maternal anemia and low birth weight. Consequently, there is a need to focus on the awareness of women in a period hard to access, to develop safe drugs to be used in the first trimester, and to consider preconceptional interventions in teenage girls, such as a new malaria vaccine to be used in pregnancy.
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Affiliation(s)
- Bich-Tram Huynh
- Research Institute for Development Université Paris Descartes, Sorbonne Paris Cité, UMR 216, Paris, France
| | - Gilles Cottrell
- Research Institute for Development Université Paris Descartes, Sorbonne Paris Cité, UMR 216, Paris, France
| | - Michel Cot
- Research Institute for Development Université Paris Descartes, Sorbonne Paris Cité, UMR 216, Paris, France
| | - Valérie Briand
- Research Institute for Development Université Paris Descartes, Sorbonne Paris Cité, UMR 216, Paris, France
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Estimated risk of placental infection and low birthweight attributable to Plasmodium falciparum malaria in Africa in 2010: a modelling study. LANCET GLOBAL HEALTH 2014; 2:e460-7. [PMID: 25103519 DOI: 10.1016/s2214-109x(14)70256-6] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Plasmodium falciparum infection during pregnancy leads to adverse outcomes including low birthweight; however, contemporary estimates of the potential burden of malaria in pregnancy in Africa (in the absence of interventions) are poor. We aimed to estimate the need to protect pregnant women from malaria across Africa. METHODS Using a mathematical model applied to estimates of the geographical distribution of P falciparum across Africa in 2010, we estimated the number of pregnant women who would have been exposed to infection that year in the absence of pregnancy-specific intervention. We then used estimates of the parity-dependent acquisition of immunity to placental infection and associated risk of low birthweight to estimate the number of women who would have been affected. FINDINGS We estimate that, without pregnancy-specific protection, 12·4 million pregnant women (44·9% of all 27·6 million livebirths in malaria endemic areas in Africa in 2010) would have been exposed to infection, with 11·4 million having placental infection (41·2% of all livebirths). This infection leads to an estimated 900,000 (95% credible interval [CrI] 530,000-1,240,000) low birthweight deliveries per year. Around the end of the first trimester, when the placenta becomes susceptible to infection, is a key period during which we estimate that 65·2% (95% CrI 60·9-70·0) of placental infections first occur. INTERPRETATION Our calculations are the only contemporary estimates of the geographical distribution of placental infection and associated low birthweight. The risk of placental infection across Africa in unprotected women is high. Prevention of malaria before conception or very early in pregnancy is predicted to greatly reduce incidence of low birthweight, especially in primigravidae. The underlying lifetime risk of low birthweight changes slowly with decreasing transmission, drawing attention to the need to maintain protection as transmission falls. FUNDING Malaria in Pregnancy Consortium and the Bill & Melinda Gates Foundation.
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