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1.
medRxiv ; 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38746440

RESUMO

In Africa, the first Plasmodium falciparum Kelch13 (K13) artemisinin partial resistance mutation 561H was first detected and validated in Rwanda. Surveillance to better define the extent of the emergence in Rwanda and neighboring countries as other mutations arise in East Africa is critical. We employ a novel scheme of liquid blood drop preservation combined with pooled sequencing to provide a cost-effective rapid assessment of resistance mutation frequencies at multiple collection sites across Rwanda and neighboring countries. Malaria-positive samples (n=5,465) were collected from 39 health facilities in Rwanda, Uganda, Tanzania, and the Democratic Republic of the Congo (DRC) between May 2022 and March 2023 and sequenced in 199 pools. In Rwanda, K13 561H and 675V were detected in 90% and 65% of sites with an average frequency of 19.0% (0-54.5%) and 5.0% (0-35.5%), respectively. In Tanzania, 561H had high frequency in multiple sites while it was absent from the DRC although 675V was seen at low frequency. Conceringly candidate mutations were observed: 441L, 449A, and 469F co-occurred with validated mutations suggesting they are arising under the same pressures. Other resistance markers associated with artemether-lumefantrine are common: P. falciparum multidrug resistance protein 1 N86 at 98.0% and 184F at 47.0% (0-94.3%) and P. falciparum chloroquine resistance transporter 76T at 14.7% (0-58.6%). Additionally, sulfadoxine-pyrimethamine-associated mutations show high frequencies. Overall, K13 mutations are rapidly expanding in the region further endangering control efforts with the potential of engendering partner drug resistance.

2.
Evol Med Public Health ; 11(1): 251-261, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37485054

RESUMO

Background and objectives: The Developmental Origins of Health and Disease hypothesis posits that early life adversity is associated with poor adult health outcomes. Epidemiological evidence has supported this framework by linking low birthweight with adult health and mortality, but the mechanisms remain unclear. Accelerated epigenetic aging may be a pathway to connect early life experiences with adult health outcomes, based on associations of accelerated epigenetic aging with increased morbidity and mortality. Methodology: Sixty-seven mother-infant dyads were recruited in the eastern Democratic Republic of Congo. Birthweight data were collected at birth, and blood samples were collected at birth and follow-up visits up to age 3. DNA methylation data were generated with the Illumina MethylationEPIC array and used to estimate epigenetic age. A multilevel model was used to test for associations between birthweight and epigenetic age acceleration. Results: Chronological age was highly correlated with epigenetic age from birth to age 3 (r = 0.95, p < 2.2 × 10-16). Variation in epigenetic age acceleration increased over time. Birthweight, dichotomized around 2500 g, predicted epigenetic age acceleration over the first 3 years of life (b = -0.39, p = 0.005). Conclusions and implications: Our longitudinal analysis provides the first evidence for accelerated epigenetic aging that emerges between birth and age 3 and associates with low birthweight. These results suggest that early life experiences, such as low birthweight, may shape the trajectory of epigenetic aging in early childhood. Furthermore, accelerated epigenetic aging may be a pathway that links low birthweight and poor adult health outcomes.

3.
Epigenetics ; 18(1): 2222473, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37300821

RESUMO

Prenatal maternal stress has a negative impact on child health but the mechanisms through which maternal stress affects child health are unclear. Epigenetic variation, such as DNA methylation, is a likely mechanistic candidate as DNA methylation is sensitive to environmental insults and can regulate long-term changes in gene expression. We recruited 155 mother-newborn dyads in the Democratic Republic of Congo to investigate the effects of maternal stress on DNA methylation in mothers and newborns. We used four measures of maternal stress to capture a range of stressful experiences: general trauma, sexual trauma, war trauma, and chronic stress. We identified differentially methylated positions (DMPs) associated with general trauma, sexual trauma, and war trauma in both mothers and newborns. No DMPs were associated with chronic stress. Sexual trauma was positively associated with epigenetic age acceleration across several epigenetic clocks in mothers. General trauma and war trauma were positively associated with newborn epigenetic age acceleration using the extrinsic epigenetic age clock. We tested the top DMPs for enrichment of DNase I hypersensitive sites (DHS) and found no enrichment in mothers. In newborns, top DMPs associated with war trauma were enriched for DHS in embryonic and foetal cell types. Finally, one of the top DMPs associated with war trauma in newborns also predicted birthweight, completing the cycle from maternal stress to DNA methylation to newborn health outcome. Our results indicate that maternal stress is associated with site-specific changes in DNAm and epigenetic age acceleration in both mothers and newborns.


Assuntos
Metilação de DNA , Mães , Gravidez , Feminino , Criança , Humanos , Recém-Nascido , Peso ao Nascer/genética , Cuidado Pré-Natal , Epigênese Genética
4.
Microorganisms ; 11(4)2023 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-37110398

RESUMO

The developing infant gut microbiome is highly sensitive to environmental exposures, enabling its evolution into an organ that supports the immune system, confers protection from infection, and facilitates optimal gut and central nervous system function. In this study, we focus on the impact of maternal psychosocial stress on the infant gut microbiome. Forty-seven mother-infant dyads were recruited at the HEAL Africa Hospital in Goma, Democratic Republic of Congo. Extensive medical, demographic, and psychosocial stress data were collected at birth, and infant stool samples were collected at six weeks, three months, and six months. A composite maternal psychosocial stress score was created, based on eight questionnaires to capture a diverse range of stress exposures. Full-length 16S rRNA gene sequences were generated. Infants of mothers with high composite stress scores showed lower levels of gut microbiome beta diversity at six weeks and three months, as well as higher levels of alpha diversity at six months compared to infants of low stress mothers. Longitudinal analyses showed that infants of high stress mothers had lower levels of health-promoting Lactobacillus gasseri and Bifidobacterium pseudocatenulatum at six weeks compared to infants of low stress mothers, but the differences largely disappeared by three to six months. Previous research has shown that L. gasseri can be used as a probiotic to reduce inflammation, stress, and fatigue, as well as to improve mental state, while B. pseudocatenulatum is important in modulating the gut-brain axis in early development and in preventing mood disorders. Our finding of reduced levels of these health-promoting bacteria in infants of high stress mothers suggests that the infant gut microbiome may help mediate the effect of maternal stress on infant health and development.

5.
Emerg Infect Dis ; 28(12): 2482-2490, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36417939

RESUMO

Cholera causes substantial illness and death in Africa. We analyzed 24 toxigenic Vibrio cholerae O1 strains isolated in 2015-2017 from patients in the Great Lakes region of the Democratic Republic of the Congo. Strains originating in southern Asia appeared to be part of the T10 introduction event in eastern Africa. We identified 2 main strain lineages, most recently a lineage corresponding to sequence type 515, a V. cholerae cluster previously reported in the Lake Kivu region. In 41% of fecal samples from cholera patients, we also identified a novel ICP1 (Bangladesh cholera phage 1) bacteriophage, genetically distinct from ICP1 isolates previously detected in Asia. Bacteriophage resistance occurred in distinct clades along both internal and external branches of the cholera phylogeny. This bacteriophage appears to have served as a major driver for cholera evolution and spread, and its appearance highlights the complex evolutionary dynamic that occurs between predatory phage and bacterial host.


Assuntos
Bacteriófagos , Cólera , Vibrio cholerae O1 , Humanos , Cólera/epidemiologia , Cólera/microbiologia , Bacteriófagos/genética , República Democrática do Congo/epidemiologia , Filogenia
6.
Trop Med Infect Dis ; 7(10)2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36287998

RESUMO

In this paper, we provide an overview of how spatial video data collection enriched with contextual mapping can be used as a universal tool to investigate sub-neighborhood scale health risks, including cholera, in challenging environments. To illustrate the method's flexibility, we consider the life cycle of the Mujoga relief camp set up after the Nyiragongo volcanic eruption in the Democratic Republic of Congo on 22 May 2021. More specifically we investigate how these methods have captured the deteriorating conditions in a camp which is also experiencing lab-confirmed cholera cases. Spatial video data are collected every month from June 2021 to March 2022. These coordinate-tagged images are used to make monthly camp maps, which are then returned to the field teams for added contextual insights. At the same time, a zoom-based geonarrative is used to discuss the camp's changes, including the cessation of free water supplies and the visible deterioration of toilet facilities. The paper concludes by highlighting the next data science advances to be made with SV mapping, including machine learning to automatically identify and map risks, and how these are already being applied in Mujoga.

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