TY - JOUR
T1 - Prevalence of and risk factors for microscopic and submicroscopic malaria infections in pregnancy
T2 - a systematic review and meta-analysis
AU - Subpatent Malaria in Pregnancy Group
AU - van Eijk, Anna Maria
AU - Stepniewska, Kasia
AU - Hill, Jenny
AU - Taylor, Steve M.
AU - Rogerson, Stephen J.
AU - Cottrell, Gilles
AU - Chico, R. Matthew
AU - Gutman, Julie R.
AU - Tinto, Halidou
AU - Unger, Holger W.
AU - Yanow, Stephanie K.
AU - Meshnick, Steven R.
AU - ter Kuile, Feiko O.
AU - Mayor, Alfredo
AU - Taylor, Steve M.
AU - Rogerson, Stephen J.
AU - Chico, R. Matthew
AU - Gutman, Julie R.
AU - Tinto, Hallidou
AU - Unger, Holger W.
AU - Yanow, Stephanie K.
AU - Accrombessi, Manfred
AU - Adegnika, Ayola A.
AU - Ahmed, Rukhsana
AU - Arango-Flórez, Eliana María
AU - Arevalo-Herrera, Myriam
AU - Arinaitwe, Emmanual
AU - Arnaldo, Paulo
AU - Ashorn, Per
AU - Ashorn, Ulla
AU - Bardaji, Azucena
AU - Betuela, Inoni
AU - Bharti, Praveen K.
AU - Bohissou, Francis
AU - Bôtto-Menezes, Camila
AU - Braun, Vera
AU - Briand, Valerie
AU - Briggs, Jessica
AU - Castellanos, María Eugenia
AU - Chandramohan, Daniel
AU - Chaponda, Enesia Banda
AU - Chitnis, Chetan
AU - Cohee, Lauren M.
AU - Cot, Michel
AU - d'Alessandro, Umberto
AU - Denoeud-Ndam, Lise
AU - Desai, Meghna
AU - Dicko, Alassane
AU - Ding, Xavier
AU - Okech, Bernard A.
N1 - Publisher Copyright:
© 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license
PY - 2023/7
Y1 - 2023/7
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85162159317&partnerID=8YFLogxK
U2 - 10.1016/S2214-109X(23)00194-8
DO - 10.1016/S2214-109X(23)00194-8
M3 - Article
C2 - 37276878
AN - SCOPUS:85162159317
SN - 2214-109X
VL - 11
SP - e1061-e1074
JO - The Lancet Global Health
JF - The Lancet Global Health
IS - 7
ER -