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Cellich P, Unger HW, Rogerson SJ, Mola GDL. Impact on pregnancy outcomes of intermittent preventive treatment with sulfadoxine-pyrimethamine in urban and peri-urban Papua New Guinea: a retrospective cohort study. Malar J 2024; 23:201. [PMID: 38970076 PMCID: PMC11225125 DOI: 10.1186/s12936-024-05010-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 06/04/2024] [Indexed: 07/07/2024] Open
Abstract
BACKGROUND Intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) reduces malaria-attributable adverse pregnancy outcomes and may also prevent low birth weight (< 2,500 g) through mechanisms independent of malaria. Malaria transmission in Papua New Guinea (PNG) is highly heterogeneous. The impact of IPTp-SP on adverse birth outcomes in settings with little or no malaria transmission, such as PNG's capital city Port Moresby, is unknown. METHODS A retrospective cohort study was conducted amongst HIV-negative women with a singleton pregnancy who delivered at Port Moresby General Hospital between 18 July and 21 August 2022. The impact of IPTp-SP doses on adverse birth outcomes and anaemia was assessed using logistic and linear regression models, as appropriate. RESULTS Of 1,140 eligible women amongst 1,228 consecutive births, 1,110 had a live birth with a documented birth weight. A total of 156 women (13.7%) did not receive any IPTp-SP, 347 women (30.4%) received one, 333 (29.2%) received two, and 304 (26.7%) received the recommended ≥ 3 doses of IPTp-SP. A total of 65 of 1,110 liveborn babies (5.9%) had low birth weight and there were 34 perinatal deaths (3.0%). Anaemia (haemoglobin < 100 g/L) was observed in 30.6% (243/793) of women, and 14 (1.2%) had clinical malaria in pregnancy. Compared to women receiving 0-1 dose of IPTp-SP, women receiving ≥ 2 doses had lower odds of LBW (adjusted odds ratio [aOR] 0.50; 95% confidence interval [CI] 0.26, 0.96), preterm birth (aOR 0.58; 95% CI 0.32, 1.04), perinatal death (aOR 0.49; 95% CI 0.18, 1.38), LBW/perinatal death (aOR 0.55; 95% CI 0.27, 1.12), and anaemia (OR 0.50; 95% CI 0.36, 0.69). Women who received 2 doses versus 0-1 had 45% lower odds of LBW (aOR 0.55, 95% CI 0.27, 1.10), and a 16% further (total 61%) reduction with ≥ 3 doses (aOR 0.39, 95% CI 0.14, 1.05). Birth weights for women who received 2 or ≥ 3 doses versus 0-1 were 81 g (95% CI -3, 166) higher, and 151 g (58, 246) higher, respectively. CONCLUSIONS Provision of IPTp-SP in a low malaria-transmission setting in PNG appears to translate into substantial health benefits, in a dose-response manner, supporting the strengthening IPTp-SP uptake across all transmission settings in PNG.
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Affiliation(s)
- Philip Cellich
- Division of Obstetrics and Gynaecology, School of Medicine and Health Sciences, Port Moresby General Hospital, University of Papua New Guinea, Port Moresby, Papua New Guinea.
- Department of Obstetrics and Gynaecology, Canterbury Hospital, 575 Canterbury Road, Campsie 2194, NSW, Australia.
| | - Holger W Unger
- Menzies School of Health Research, Charles Darwin University, PO Box 41096, Casuarina 0810, NT, Australia.
- Department of Obstetrics and Gynaecology, Royal Darwin Hospital, Darwin, NT, Australia.
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK.
- Department of Infectious Diseases, University of Melbourne, The Doherty Institute, Melbourne, VIC, Australia.
| | - Stephen J Rogerson
- Department of Infectious Diseases, University of Melbourne, The Doherty Institute, Melbourne, VIC, Australia
- Department of Medicine, University of Melbourne, The Doherty Institute, Melbourne, VIC, Australia
| | - Glen D L Mola
- Division of Obstetrics and Gynaecology, School of Medicine and Health Sciences, Port Moresby General Hospital, University of Papua New Guinea, Port Moresby, Papua New Guinea
- School of Medicine and Health Sciences, University of Papua New Guinea, Port Moresby, Papua New Guinea
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Mukala J, Mogere D, Kirira P, Kanoi BN, Akisa V, Kobia F, Waweru H, Gitaka J. Predictors of birth weight in pregnant women with malaria: a prospective cohort facility-based study in Webuye-Kenya. BMC Pregnancy Childbirth 2024; 24:187. [PMID: 38459499 PMCID: PMC10921604 DOI: 10.1186/s12884-024-06355-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 02/18/2024] [Indexed: 03/10/2024] Open
Abstract
In sub-Saharan Africa, malaria, which remains a major public health burden, has a prevalence of 9 to 28% and malaria in pregnancy is associated with severe adverse outcomes for the mother and her baby. Here, we sought to determine the predictors of birth weight in a cohort of 140 women with malaria in pregnancy, who were recruited at the Webuye County hospital in Western Kenya. All study participants underwent malaria diagnosis through microscopic examination of blood smear samples and were grouped into the malaria-positive and malaria-negative groups. Both groups were followed up beginning at the first antenatal visit (March 2022) until delivery (December 2022) and various data, including demographic, parity, gravidity, socioeconomic, maternal and fetal outcomes were collected. Data analyses were done using SPSS version 27. Chi-square and Fisher's Exact tests were used for bivariate and relative risk analyses at a p-value of ≤0.05 (95%) confidence level. Most of the participants were aged 18-25 years, were primigravidas and married, had secondary school-level education, earned 20-30 thousand Kenya shillings, resided in rural areas, and were in the second trimester. There were 6 (4.6%) cases of low birth weight, 3 (4.5%) in the malaria-negative group and 3 (4.7%) in the malaria-positive group. During pregnancy, 41 (31.5%) were anaemic, 5 (3.8%) were HIV-positive, 5 (3.8%) had preeclampsia, and 2 (1.5%) had gestational diabetes. Our analyses show that confounding factors like anaemia, HIV, pre-eclampsia and gestational diabetes did not influence birthweight (p ≥ 0.923). The malaria-positive and malaria-negative groups did not differ significantly with regard to the low birth weight (relative risk: 0.999, 95% confidence interval: 0.926-1.077). Marital status, gestational age, and area of residence were associated with malaria p ≤ 0.001, ≤ 0.001 and 0.028 respectively. In both groups, 124 of the 140 deliveries had normal birth weights and of these 63 (95.4%, n = 70) were in the malaria-negative group, whereas 61 (95.3%, n = 70) belonged to the malaria-positive group.
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Affiliation(s)
- Joseph Mukala
- School of Public Health, Mount Kenya University, P.O. Box 342-01000, Thika, Kenya.
| | - Dominic Mogere
- School of Public Health, Mount Kenya University, P.O. Box 342-01000, Thika, Kenya
| | - Peter Kirira
- School of Applied Sciences, Mount Kenya University, Thika, Kenya
| | - Bernard N Kanoi
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
- Centre for Malaria Elimination, Mount Kenya University, Thika, Kenya
| | | | - Francis Kobia
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
- Centre for Malaria Elimination, Mount Kenya University, Thika, Kenya
| | - Harrison Waweru
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
- Centre for Malaria Elimination, Mount Kenya University, Thika, Kenya
| | - Jesse Gitaka
- Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
- Centre for Malaria Elimination, Mount Kenya University, Thika, Kenya
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Carrasco-Escobar G, Rosado J, Nolasco O, White MT, Mueller I, Castro MC, Rodriguez-Ferruci H, Gamboa D, Llanos-Cuentas A, Vinetz JM, Benmarhnia T. Effect of out-of-village working activities on recent malaria exposure in the Peruvian Amazon using parametric g-formula. Sci Rep 2022; 12:19144. [PMID: 36351988 PMCID: PMC9645738 DOI: 10.1038/s41598-022-23528-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 11/01/2022] [Indexed: 11/11/2022] Open
Abstract
In the Amazon Region of Peru, occupational activities are important drivers of human mobility and may increase the individual risk of being infected while contributing to increasing malaria community-level transmission. Even though out-of-village working activities and other mobility patterns have been identified as determinants of malaria transmission, no studies have quantified the effect of out-of-village working activities on recent malaria exposure and proposed plausible intervention scenarios. Using two population-based cross-sectional studies in the Loreto Department in Peru, and the parametric g-formula method, we simulated various hypothetical scenarios intervening in out-of-village working activities to reflect their potential health benefits. This study estimated that the standardized mean outcome (malaria seroprevalence) in the unexposed population (no out-of-village workers) was 44.6% (95% CI: 41.7%-47.5%) and 66.7% (95% CI: 61.6%-71.8%) in the exposed population resulting in a risk difference of 22.1% (95% CI: 16.3%-27.9%). However, heterogeneous patterns in the effects of interest were observed between peri-urban and rural areas (Cochran's Q test = 15.5, p < 0.001). Heterogeneous patterns were also observed in scenarios of increased prevalence of out-of-village working activities and restriction scenarios by gender (male vs. female) and age (18 and under vs. 19 and older) that inform possible occupational interventions targetting population subgroups. The findings of this study support the hypothesis that targeting out-of-village workers will considerably benefit current malaria elimination strategies in the Amazon Region. Particularly, males and adult populations that carried out out-of-village working activities in rural areas contribute the most to the malaria seropositivity (recent exposure to the parasite) in the Peruvian Amazon.
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Affiliation(s)
- Gabriel Carrasco-Escobar
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California San Diego, La Jolla, CA, USA.
- Health Innovation Lab, Institute of Tropical Medicine "Alexander Von Humboldt", Universidad Peruana Cayetano Heredia, Lima, Peru.
| | - Jason Rosado
- G5 Épidémiologie Et Analyse Des Maladies Infectieuses, Département de Santé Globale, Institut Pasteur, 75015, Paris, France
| | - Oscar Nolasco
- Instituto de Medicina Tropical Alexander Von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación Y Desarrollo, Facultad de Ciencias Y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Michael T White
- G5 Épidémiologie Et Analyse Des Maladies Infectieuses, Département de Santé Globale, Institut Pasteur, 75015, Paris, France
| | - Ivo Mueller
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Marcia C Castro
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | - Dionicia Gamboa
- Instituto de Medicina Tropical Alexander Von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación Y Desarrollo, Facultad de Ciencias Y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Departamento de Ciencias Celulares Y Moleculares, Facultad de Ciencias Y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Alejandro Llanos-Cuentas
- Instituto de Medicina Tropical Alexander Von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joseph M Vinetz
- Instituto de Medicina Tropical Alexander Von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación Y Desarrollo, Facultad de Ciencias Y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Tarik Benmarhnia
- Scripps Institution of Oceanography, University of California, San Diego, CA, 92037, USA
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Roh ME, Mpimbaza A, Oundo B, Irish A, Murphy M, Wu SL, White JS, Shiboski S, Glymour MM, Gosling R, Dorsey G, Sturrock H. Association between indoor residual spraying and pregnancy outcomes: a quasi-experimental study from Uganda. Int J Epidemiol 2022; 51:1489-1501. [PMID: 35301532 PMCID: PMC9557839 DOI: 10.1093/ije/dyac043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Malaria is a risk factor for adverse pregnancy outcomes. Indoor residual spraying with insecticide (IRS) reduces malaria infections, yet the effects of IRS on pregnancy outcomes are not well established. We evaluated the impact of a large-scale IRS campaign on pregnancy outcomes in Eastern Uganda. METHODS Birth records (n = 59 992) were obtained from routine surveillance data at 25 health facilities from five districts that were part of the IRS campaign and six neighbouring control districts ∼27 months before and ∼24 months after the start of the campaign (January 2013-May 2017). Campaign effects on low birthweight (LBW) and stillbirth incidence were estimated using the matrix completion method (MC-NNM), a machine-learning approach to estimating potential outcomes, and compared with the difference-in-differences (DiD) estimator. Subgroup analyses were conducted by HIV and gravidity. RESULTS MC-NNM estimates indicated that the campaign was associated with a 33% reduction in LBW incidence: incidence rate ratio (IRR) = 0.67 [95% confidence interval (CI): 0.49-0.93)]. DiD estimates were similar to MC-NNM [IRR = 0.69 (0.47-1.01)], despite a parallel trends violation during the pre-IRS period. The campaign was not associated with substantial reductions in stillbirth incidence [IRRMC-NNM = 0.94 (0.50-1.77)]. HIV status modified the effects of the IRS campaign on LBW [βIRSxHIV = 0.42 (0.05-0.78)], whereby HIV-negative women appeared to benefit from the campaign [IRR = 0.70 (0.61-0.81)], but not HIV-positive women [IRR = 1.12 (0.59-2.12)]. CONCLUSIONS Our results support the effectiveness of the campaign in Eastern Uganda based on its benefit to LBW prevention, though HIV-positive women may require additional interventions. The IRS campaign was not associated with a substantively lower stillbirth incidence, warranting further research.
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Affiliation(s)
- Michelle E Roh
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA.,Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, CA, USA
| | - Arthur Mpimbaza
- Child Health and Development Centre, Makerere University, College of Health Sciences, Kampala, Uganda
| | - Brenda Oundo
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Amanda Irish
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA.,Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, CA, USA
| | - Maxwell Murphy
- Department of Biostatistics, University of California, Berkeley, CA, USA
| | - Sean L Wu
- Department of Biostatistics, University of California, Berkeley, CA, USA
| | - Justin S White
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA.,Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco, CA, USA
| | - Stephen Shiboski
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
| | - M Maria Glymour
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
| | - Roly Gosling
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA.,Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, CA, USA
| | - Grant Dorsey
- Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Hugh Sturrock
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA.,Malaria Elimination Initiative, Institute of Global Health Sciences, University of California, San Francisco, CA, USA
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Waltmann A, McQuade ETR, Chinkhumba J, Operario DJ, Mzembe E, Itoh M, Kayange M, Puerto-Meredith SM, Mathanga DP, Juliano JJ, Carroll I, Bartelt LA, Gutman JR, Meshnick SR. The positive effect of malaria IPTp-SP on birthweight is mediated by gestational weight gain but modifiable by maternal carriage of enteric pathogens. EBioMedicine 2022; 77:103871. [PMID: 35217408 PMCID: PMC8866062 DOI: 10.1016/j.ebiom.2022.103871] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 01/24/2022] [Accepted: 01/24/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Poor pregnancy and birth outcomes are common in sub-Saharan Africa and have complex aetiologies. Sulfadoxine-pyrimethamine (SP), given for intermittent preventive therapy of malaria in pregnancy (IPTp), is one of few existing interventions that improves outcomes of both mother and baby despite widespread SP-resistant malaria. Compelling evidence exists that malaria-independent pathways contribute to this protective effect, but the exact sources of non anti-malarial protection remained unknown. We hypothesized that the beneficial effect of SP on birthweight is mediated by SP activity on maternal factors, including increased gestational weight gain and antibiotic activity on pathogens in the maternal gut. METHODS Expectant mothers from a larger randomized control trial comparing the efficacy of IPTp-SP to IPTp with dihydroartemisinin-piperaquine (DP) were also enrolled in this sub-study study at their first antenatal care visit before commencement of IPTp (n = 105). Participants were followed monthly until delivery. Weights and mid-to-upper-arm circumferences (MUAC) were recorded. Monthly stool samples were collected and screened for five Escherichia coli pathotypes, Shigella spp., Vibrio cholerae, Salmonella, Campylobacter coli/jejuni, and three protozoa (Giardia spp., Entameba histolytica, and Cryptosporidium spp.) using previously validated molecular assays. FINDINGS IPTp-SP vs. IPTP-DP was associated with higher maternal gestational weight gain (GWG) and nutritional indicators (MUAC and body-mass index, BMI). GWG was found to be a mediator of the birthweight and IPTp-SP relationship, as the birthweight of SP infants, but not DP infants, varied according to maternal GWG. The burden of maternal enteric infections was high. The three most commonly observed pathogens were enteroaggregative E. coli (EAEC), atypical enteropathogenic E.coli/enterohaemorrhagic E. coli (aEPEC/EHEC), and typical enteropathogenic E.coli (tEPEC). We found that SP reduced the prevalence of EAEC in a dose-dependent manner. After 3 or more doses, SP-recipients were 90% less likely to be infected with EAEC compared to DP-recipients (ORadj = 0.07, CI95 = 0.12, 0.39, p = 0.002). Compared to DP, this coincided with higher maternal gestational weight gain (GWG) and nutritional indicators (MUAC and body-mass index, BMI). The beneficial effect of SP on maternal GWG, MUAC and BMI, was lower if SP mothers had detectable EAEC, aEPEC/EHEC, tEPEC, and LT-ETEC at baseline. Maternal EAEC and tEPEC at baseline associated with lower birthweight for babies of both SP mothers and DP mothers. When comparing IPTp regimens, the positive effect of SP on birthweight compared to DP was only observed for infants of women who did not test positive for EAEC at baseline (adjusted mean birthweight difference SP vs. DP = 156.0 g, CI95 = -18.0 g, 336.9 g, p = 0.087), though confidence intervals crossed the null. INTERPRETATION Our findings indicate that in pregnant Malawian women, IPTp-SP vs. IPTp-DP is consistently associated with higher MUAC, BMI, and GWG following the WHO-recommended regimen of at least 3 doses, but carriage of maternal gut pathogens before initiation of IPTp lessens this effect. Because GWG was a mediator of the association between birthweight and SP, we show that SP's previously proven positive effect on birthweight is by promoting maternal weight gain. Overall, our results present one plausible pathway SP exerts malaria-independent protection against poor birth outcomes in the context of its waning antimalarial activity and warrants further investigation. FUNDING A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.
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Affiliation(s)
- Andreea Waltmann
- Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, USA.
| | | | - Jobiba Chinkhumba
- Malaria Alert Centre (MAC), University of Malawi College of Medicine, Blantyre, Malawi
| | - Darwin J Operario
- Division of Infectious Diseases & International Health, Department of Medicine, University of Virginia, VA, USA
| | - Enala Mzembe
- Malaria Alert Centre (MAC), University of Malawi College of Medicine, Blantyre, Malawi
| | - Megumi Itoh
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | | | - Don P Mathanga
- Malaria Alert Centre (MAC), University of Malawi College of Medicine, Blantyre, Malawi
| | - Jonathan J Juliano
- Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, USA; Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - Ian Carroll
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - Luther A Bartelt
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - Julie R Gutman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Steven R Meshnick
- Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, USA; Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
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Unger HW, Laurita Longo V, Bleicher A, Ome-Kaius M, Karl S, Simpson JA, Karahalios A, Aitken EH, Rogerson SJ. The relationship between markers of antenatal iron stores and birth outcomes differs by malaria prevention regimen-a prospective cohort study. BMC Med 2021; 19:236. [PMID: 34607575 PMCID: PMC8491429 DOI: 10.1186/s12916-021-02114-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/31/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Iron deficiency (ID) has been associated with adverse pregnancy outcomes, maternal anaemia, and altered susceptibility to infection. In Papua New Guinea (PNG), monthly treatment with sulphadoxine-pyrimethamine plus azithromycin (SPAZ) prevented low birthweight (LBW; <2500 g) through a combination of anti-malarial and non-malarial effects when compared to a single treatment with SP plus chloroquine (SPCQ) at first antenatal visit. We assessed the relationship between ID and adverse birth outcomes in women receiving SPAZ or SPCQ, and the mediating effects of malaria infection and haemoglobin levels during pregnancy. METHODS Plasma ferritin levels measured at antenatal enrolment in a cohort of 1892 women were adjusted for concomitant inflammation using C-reactive protein and α-1-acid glycoprotein. Associations of ID (defined as ferritin <15 μg/L) or ferritin levels with birth outcomes (birthweight, LBW, preterm birth, small-for-gestational-age birthweight [SGA]) were determined using linear or logistic regression analysis, as appropriate. Mediation analysis assessed the degree of mediation of ID-birth outcome relationships by malaria infection or haemoglobin levels. RESULTS At first antenatal visit (median gestational age, 22 weeks), 1256 women (66.4%) had ID. Overall, ID or ferritin levels at first antenatal visit were not associated with birth outcomes. There was effect modification by treatment arm. Amongst SPCQ recipients, ID was associated with a 81-g higher mean birthweight (95% confidence interval [CI] 10, 152; P = 0.025), and a twofold increase in ferritin levels was associated with increased odds of SGA (adjusted odds ratio [aOR] 1.25; 95% CI 1.06, 1.46; P = 0.007). By contrast, amongst SPAZ recipients, a twofold increase in ferritin was associated with reduced odds of LBW (aOR 0.80; 95% CI 0.67, 0.94; P = 0.009). Mediation analyses suggested that malaria infection or haemoglobin levels during pregnancy do not substantially mediate the association of ID with birth outcomes amongst SPCQ recipients. CONCLUSIONS Improved antenatal iron stores do not confer a benefit for the prevention of adverse birth outcomes in the context of malaria chemoprevention strategies that lack the non-malarial properties of monthly SPAZ. Research to determine the mechanisms by which ID protects from suboptimal foetal growth is needed to guide the design of new malaria prevention strategies and to inform iron supplementation policy in malaria-endemic settings. TRIAL REGISTRATION ClinicalTrials.gov NCT01136850 .
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Affiliation(s)
- Holger W Unger
- Department of Obstetrics and Gynaecology, Royal Darwin Hospital, Darwin, Northern Territory, Australia.,Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia.,Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Valentina Laurita Longo
- Catholic University of Sacred Heart, Rome, Italy.,Department of Obstetrics and Gynaecology, San Pietro-Fatebenefratelli Hospital, Rome, Italy
| | - Andie Bleicher
- Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Maria Ome-Kaius
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Stephan Karl
- Australian Institute of Tropical Health & Medicine, James Cook University, Cairns, Australia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Amalia Karahalios
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Elizabeth H Aitken
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia.,Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Stephen J Rogerson
- Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia. .,Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia.
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Chua CLL, Hasang W, Rogerson SJ, Teo A. Poor Birth Outcomes in Malaria in Pregnancy: Recent Insights Into Mechanisms and Prevention Approaches. Front Immunol 2021; 12:621382. [PMID: 33790894 PMCID: PMC8005559 DOI: 10.3389/fimmu.2021.621382] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 02/23/2021] [Indexed: 12/13/2022] Open
Abstract
Pregnant women in malaria-endemic regions are susceptible to malaria in pregnancy, which has adverse consequences on birth outcomes, including having small for gestational age and preterm babies. These babies are likely to have low birthweights, which predisposes to infant mortality and lifelong morbidities. During malaria in pregnancy, Plasmodium falciparum-infected erythrocytes express a unique variant surface antigen, VAR2CSA, that mediates sequestration in the placenta. This process may initiate a range of host responses that contribute to placental inflammation and dysregulated placental development, which affects placental vasculogenesis, angiogenesis and nutrient transport. Collectively, these result in the impairment of placental functions, affecting fetal development. In this review, we provide an overview of malaria in pregnancy and the different pathological pathways leading to malaria in pregnancy-associated low birthweight. We also discuss current prevention and management strategies for malaria in pregnancy, and some potential therapeutic interventions that may improve birth outcomes. Lastly, we outline some priorities for future research that could bring us one step closer to reducing this health burden.
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Affiliation(s)
| | - Wina Hasang
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Stephen J Rogerson
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Andrew Teo
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
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Nkoka O, Chuang TW, Chen YH. Effects of Malaria Interventions During Pregnancy on Low Birth Weight in Malawi. Am J Prev Med 2020; 59:904-913. [PMID: 33220759 DOI: 10.1016/j.amepre.2020.05.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 11/29/2022]
Abstract
INTRODUCTION In malaria-endemic countries, malaria during pregnancy is associated with adverse birth outcomes, including low birth weight (i.e., <2.5 kg). However, the effects of the widely promoted and recommended approaches of intermittent preventive treatment for malaria in pregnancy and insecticide-treated nets for pregnant women on low birth weight have been insufficiently examined. This analysis investigates the independent and combined effects of intermittent preventive treatment for malaria in pregnancy and insecticide-treated nets on low birth weight among Malawian children. METHODS Using pooled data sets from 2004, 2010, and 2015-2016 Malawi Demographic and Health Surveys, a total of 18,285 births were analyzed between August and December 2019. Binomial generalized linear regression models with a log-link function explored the associations under consideration. RESULTS The overall low birth weight prevalence was 10.3%. Prevalence was lower in children whose mothers used adequate intermittent preventive treatment for malaria in pregnancy (adjusted prevalence ratio=0.88, 95% CI=0.79, 0.99) or used insecticide-treated nets (adjusted prevalence ratio=0.89, 95% CI=0.79, 0.99) than their respective counterparts. Low birth weight was 20.0% lower among children whose mothers adequately used both intermittent preventive treatment for malaria in pregnancy and insecticide-treated nets than those without these approaches (adjusted prevalence ratio=0.80, 95% CI=0.68, 0.93). Iron supplement consumption and survey year were significant effect modifiers on the relationship between intermittent preventive treatment for malaria in pregnancy and low birth weight. CONCLUSIONS There were evident benefits of independent and combined use of intermittent preventive treatment for malaria in pregnancy and insecticide-treated nets on low birth weight, thereby supporting the use of these interventions during pregnancy. The reduced protective effects of intermittent preventive treatment for malaria in pregnancy over time highlight the need for innovative preventive methods against malaria in pregnancy.
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Affiliation(s)
- Owen Nkoka
- School of Public Health, College of Public Health, Taipei Medical University, Taipei, Taiwan
| | - Ting-Wu Chuang
- Department of Molecular Parasitology and Tropical Diseases, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yi-Hua Chen
- School of Public Health, College of Public Health, Taipei Medical University, Taipei, Taiwan.
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Breger TL, Edwards JK, Cole SR, Westreich D, Pence BW, Adimora AA. Two-stage g-computation: Evaluating Treatment and Intervention Impacts in Observational Cohorts When Exposure Information Is Partly Missing. Epidemiology 2020; 31:695-703. [PMID: 32657953 PMCID: PMC8725064 DOI: 10.1097/ede.0000000000001233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Illustrations of the g-computation algorithm to evaluate population average treatment and intervention effects have been predominantly implemented in settings with complete exposure information. Thus, worked examples of approaches to handle missing data in this causal framework are needed to facilitate wider use of these estimators. We illustrate two-stage g-computation estimators that leverage partially observed information on the full study sample and complete exposure information on a subset to estimate causal effects. In a hypothetical cohort of 1,623 human immunodeficiency virus (HIV)-positive women with 30% complete opioid prescription information, we illustrate a two-stage extrapolation g-computation estimator for the average treatment effect of shorter or longer duration opioid prescriptions; we further illustrate two-stage inverse probability weighting and imputation g-computation estimators for the average intervention effect of shortening the duration of prescriptions relative to the status quo. Two-stage g-computation estimators approximated the true risk differences for the population average treatment and intervention effects while g-computation fit to the subset of complete cases was biased. In 10,000 Monte Carlo simulations, two-stage approaches considerably reduced bias and mean squared error and improved the coverage of 95% confidence limits. Although missing data threaten validity and precision, two-stage g-computation designs offer principled approaches to handling missing information.
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Affiliation(s)
- Tiffany L. Breger
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Jessie K. Edwards
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Stephen R. Cole
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Daniel Westreich
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Brian W. Pence
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Adaora A. Adimora
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
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Malaria-Associated Factors among Pregnant Women in Guinea. J Trop Med 2019; 2019:3925094. [PMID: 31885633 PMCID: PMC6925697 DOI: 10.1155/2019/3925094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 10/10/2019] [Accepted: 10/23/2019] [Indexed: 11/17/2022] Open
Abstract
Introduction Malaria is the leading cause of consultation in Guinea health facilities. During pregnancy, it remains a major health concern causing considerable risks for mother, fetus, and newborn. However, little is known about the epidemiology of malaria among pregnant women in Guinea. We aimed to provide information on malaria-associated factors in parturients. Methods It was a cross-sectional survey in two regional hospitals and two district hospitals. 1000 parturients and their newborns were surveyed. All patients were interviewed, and thick and thin blood smears were examined. To determine the predictive factors of malaria in parturients, the Classification and Regression Tree (CART) was first performed by using peripheral and placental malaria as dependent variables and sociodemographic and antenatal characteristics as independent variables; then, explanatory profile variables or clusters from these trees were included in the logistic regression models. Results We found 157 (15.8%) and 148 (14.8%) cases of peripheral and placental malaria, respectively. The regular use of long-lasting insecticide-treated nets (LLINs) before delivery was 53.8%, and only 35.5% used sulfadoxine-pyrimethamine doses ≥3. Factors significantly associated with malaria were as follows: women from Forécariah and Guéckédou who did not regularly use LLINs and accomplished less than four antenatal care visits (ANC <4) and primigravid and paucigravid women who did not regularly use LLINs. Similarly, the odds of having malaria infection were significantly higher among women who had not regularly used LLINs and among primigravid and paucigravid women who had regularly used LLINs compared to multigravida women who had regularly used LLINs. Conclusion This study showed that pregnant women remain particularly vulnerable to malaria; therefore, strengthening antenatal care visit strategies by emphasizing on promoting the use of LLINs and sulfadoxine-pyrimethamine, sexual education about early pregnancies, and family or community support during first pregnancies might be helpful.
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