Determinants of Infant Susceptibility to Malaria During the First Year of Life in South Western Cameroon

Apinjoh, Tobias O.; Anchang-Kimbi, Judith Kuoh; Mugri, Regina N.; Njua-Yafi, Clarisse; Tata, Rolland Bantar; Hanesh, F.; Tangoh, Delphine A.; Loh, Beatrice T.; Achidi, Eric A.

doi:10.1093/ofid/ofv012

Cited by 24 publications

(36 citation statements)

References 40 publications

(67 reference statements)

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“…These studies detected more infections in the rainy than in the dry season but unexpectedly higher MSP diversity in the dry season than in the rainy season [41] and lowered MOI in the rainy season with higher polyclonal infections in the dry seasons [42] . In South-Western Cameroon where malaria transmission is perennial, a similar paradox was observed where infants born during the wet season were more susceptible to malaria infection while children born in the dry season were protected [43]. MOIs for residents of Kintampo coincided with the lowest entomological inoculation rates (EIR), at the end of the dry season, while the lowest MOIs coincided with the highest EIR at the end of the wet season [4, 35].…”

Section: Discussionmentioning

confidence: 97%

Dynamics in multiplicity of Plasmodium falciparum infection among children with asymptomatic malaria in central Ghana

et al. 2017

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BackgroundThe determinants of malaria parasite virulence is not entirely known, but the outcome of malaria infection (asymptomatic or symptomatic) has been associated with carriage of distinct parasite genotypes. Alleles considered important for erythrocyte invasion and selected as candidate targets for malaria vaccine development are increasingly being shown to have distinct characteristics in infection outcomes. Any unique/distinct patterns or alleles linked to infection outcome should be reproducible for a given malaria-cohort regardless of location, time or intervention. This study compared merozoite surface protein 2 (MSP2) genotypes from children with asymptomatic malaria at same geographical location, from two time periods.ResultsAs the prevalence and incidence of malaria (measured for other studies) significantly reduced between 2004 (time point one) and 2009 (time point two), MSP2 multiplicity of infections (MOI) also reduced significantly from 2.3 at time point (TP) one to 1.9 at TP two. IC/3D7 genotypes out-numbered FC27 genotypes at both time points. At TP2 however, FC27 allele diversity was more than the IC/3D7 allele diversity. A decrease in the IC/3D7:FC27 genotype proportions from 2:1 at TP1 to 1:1 at TP2, seemed to be driven mainly by a decrease in carriage of IC/3D7 alleles. MOI was higher in the dry season than in the subsequent wet season, but the decrease was not significant at TP2.ConclusionMSP2 MOI was higher in the dry season than in the subsequent wet season, while the carriage of IC/3D7 alleles decreased over this time period. It may be that decreases in transmission are related specifically to the IC/3D7 allelic family. The influence of transmission on MSP2 allele diversity needs to be clearly deciphered in studies which should include the use of sensitive methods for the detection of polymorphic parasite markers for both symptomatic and asymptomatic malaria. Such studies will enable better understanding of associations between allelic variants, MOI, transmission, malaria infection and disease.

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Section: Discussionmentioning

confidence: 97%

Dynamics in multiplicity of Plasmodium falciparum infection among children with asymptomatic malaria in central Ghana

et al. 2017

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“…Interestingly, one recent study also found that infants were specifically at increased risk of parasites that carried a matching glurp allele as those that infected their mothers’ placentas . However, these associations are not universal, as in additional studies conducted in Ghana, Cameroon and Benin, PM was not associated with an increased risk of malaria infection or clinical malaria in infants (Table ) …”

Section: Maternal Malaria Predicts An Increased Risk Of Malaria Durinmentioning

confidence: 98%

Malaria in pregnancy shapes the development of foetal and infant immunity

Harrington

Kakuru

Jagannathan

2018

Parasite Immunology

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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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“…124 Consistent with this model, several studies have reported that infants born to women with PM are themselves at higher risk of malaria during early life. [8][9][10][11]125,126 However, this association has not been observed in all cohorts, [127][128][129] and indeed one study found that infants of primagravidas with PM actually have a lower risk of parasitemia during infancy. 7 A parsimonious explanation for the repeated observation of higher infant malaria risk following in utero exposure is that these studies are confounded by variability in exposure.…”

Section: Doe S In Utero Anti G En E Xp Osure Impac T the De Velopmementioning

confidence: 99%

The immune response to malaria in utero

Feeney

2019

Immunological Reviews

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Malaria caused by Plasmodium falciparum is a leading killer of infants and children. Efforts to develop a protective vaccine have been hindered by the parasite's numerous evasion strategies, which include the induction of immunoregulatory mechanisms in the human host.Indeed, several promising vaccine candidates that induce robust protection in malaria-naive populations have been shown to have much lower efficacy when administered to individuals residing in endemic settings, 1,2 suggesting that immunomodulatory mechanisms induced by prior malaria exposure may pose a critical barrier to vaccine-mediated protection. In endemic regions, many individuals are first exposed to malaria in utero, when P. falciparum-infected red blood cells sequester in the placenta and parasite antigens cross the syncytiotrophoblast barrier, gaining entry into the fetal circulation.Therefore, even during the neonatal period, vaccination may be influenced by prior malaria exposure. Here, we examine the consequences of in utero antigen exposure for fetal immune development and postnatal immunity. The worldwide burden posed by malaria-related complications of pregnancy is profound. More than 125 million pregnancies occur annually in regions at risk for malaria transmission, 3 and one in four pregnant women in sub-Saharan Africa have evidence of infection with malaria at parturition. 4 Although most placental malaria (PM) infections are attributable to P. falciparum, recent evidence indicates that P.vivax is also associated with poor pregnancy outcomes, and some data suggest that it too may sequester in the placenta. 5,6 Pregnancy-associated malaria results in tremendous obstetrical and pediatric morbidity, AbstractMalaria 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 malariaspecific 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 strateg...

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Determinants of Infant Susceptibility to Malaria During the First Year of Life in South Western Cameroon

Cited by 24 publications

References 40 publications

Dynamics in multiplicity of Plasmodium falciparum infection among children with asymptomatic malaria in central Ghana

Dynamics in multiplicity of Plasmodium falciparum infection among children with asymptomatic malaria in central Ghana

Malaria in pregnancy shapes the development of foetal and infant immunity

The immune response to malaria in utero

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