A5041875705- Malaria Research and Control
- Mosquito-borne diseases and control
- Complement system in diseases
- Parasites and Host Interactions
- HIV Research and Treatment
- Global Maternal and Child Health
- Reproductive System and Pregnancy
- Computational Drug Discovery Methods
- HIV/AIDS drug development and treatment
- Immune Cell Function and Interaction
- Drug-Induced Hepatotoxicity and Protection
- Trypanosoma species research and implications
- HIV/AIDS Research and Interventions
- Pregnancy and preeclampsia studies
- Drug Transport and Resistance Mechanisms
- Monoclonal and Polyclonal Antibodies Research
- vaccines and immunoinformatics approaches
- Hepatitis C virus research
- Pneumocystis jirovecii pneumonia detection and treatment
- Viral Infections and Vectors
- Iron Metabolism and Disorders
- Hemoglobinopathies and Related Disorders
- Vector-borne infectious diseases
- Research on Leishmaniasis Studies
- Invertebrate Immune Response Mechanisms
Centers for Disease Control and Prevention
2013-2022
Division of Parasitic Diseases and Malaria
2013-2022
Center for Global Health
2012-2022
Emory University
2022
Tiangong University
2021
National Center for Emerging and Zoonotic Infectious Diseases
2008-2010
Kenya Medical Research Institute
1996-2009
Centers for Disease Control and Prevention
2003-2009
University of Toronto
2009
Toronto General Hospital
2009
The impact of insecticide (permethrin)-treated bed nets (ITNs) on malaria in pregnancy was studied a rural area western Kenya with intense perennial transmission. All households 40 79 villages were randomized to receive ITNs by January 1997. distributed control two years later. Complete data birth outcome available 2,754 (89.6%) 3,072 deliveries. Women (n = 780) followed monthly throughout 19 villages. Among gravidae 1-4, associated reductions 38% (95% confidence interval [CI] 17-54%) the...
Background. Owing to increasing sulfadoxine-pyrimethamine (SP) resistance in sub-Saharan Africa, monitoring the effectiveness of intermittent preventive therapy pregnancy (IPTp) with SP is crucial. Methods. Between 2009 and 2013, both efficacy IPTp-SP at clearing existing peripheral malaria infections reducing low birth weight (LBW) were assessed among human immunodeficiency virus–uninfected participants 8 sites 6 countries. Sites classified as high, medium, or after measuring parasite...
Background. The A581G mutation in the gene encoding Plasmodium falciparum dihydropteroate synthase (dhps), combination with quintuple mutant involving mutations both dhps and dihydrofolate reductase (dhfr), so-called sextuple mutant, has been associated increased placental inflammation decreased infant birth weight among women receiving intermittent preventive treatment sulfadoxine-pyrimethamine (IPTp-SP) during pregnancy.
As part of a community-based, group-randomized, controlled trial insecticide-treated bed nets (ITNs) in an area with intense malaria transmission western Kenya, birth cohort (n = 833) was followed monthly until the age 24 months to determine potential beneficial and adverse effects reduced exposure during pregnancy infancy. Malaria morbidity were comparable pre-intervention. The ITNs attack rates (force infection) infancy by 74%, delayed median time-to-first parasitemia (4.5 10.7 months; P <...
Information on the impact of insecticide (permethrin)-treated bed nets (ITNs) from randomized controlled trials in areas intense perennial malaria transmission is limited. As part a large-scale, community-based, group-randomized trial effect ITNs childhood mortality holoendemic area western Kenya, we conducted three cross-sectional surveys 60 villages to assess morbidity 1,890 children less than years old. Children ITN and control were comparable pre-intervention, but after introduction...
Sulfadoxine-pyrimethamine has been widely used as first-line therapy for uncomplicated malaria throughout sub-Saharan Africa. Recent studies conducted in Asia and Africa suggest the triple-mutant dhfr genotype (51I/59R/108N) may have generated a single event Southeast Asia, with subsequent spread of lineage to African continent, but this hypothesis needs further validation.Direct sequencing polymerase chain reaction (PCR) products, pyrosequencing, cloning PCR products were utilized identify...
Protein-energy malnutrition (PEM) affects millions of children in the developing world. The relationship between malaria and PEM is controversial. goal this study was to evaluate whether undernutrition associated with increased or decreased attributable morbidity. Three cross-sectional surveys were conducted using insecticide-treated bed nets (ITNs) among aged 0-36 months living an area intense transmission. Data collected on nutritional status, recent history clinical illness, socioeconomic...
Recent efforts in malaria control have resulted great gains reducing the burden of Plasmodium falciparum, but P. vivax has been more refractory. Its ability to form dormant liver stages confounds and elimination efforts. To compare efficacy safety primaquine regimens for radical cure, we undertook a randomized controlled trial Ethiopia.Patients with normal glucose-6-phosphate dehydrogenase status symptomatic mono-infection were enrolled randomly assigned receive either chloroquine (CQ) or...
Monitoring local malaria transmission intensity is essential for planning evidence-based control strategies and evaluating their impact over time. Anti-malarial antibodies provide information on cumulative exposure have proven useful, in areas where has dropped to low sustained levels, retrospectively reconstructing the timing magnitude of reduction. It unclear whether serological markers are also informative high settings, interventions may reduce transmission, but a level considerable...
We have characterized the natural immune responses to 19-kDa domain of merozoite surface protein 1 in individuals from an area western Kenya which malaria is holoendemic. used three known variant forms yeast-expressed recombinant fragment that are referred as E-KNG, Q-KNG, and E-TSR antigens. T-cell proliferative older than 15 years profile immunoglobulin G (IgG) antibody isotypes 2 74 old were determined. Positive Q-KNG antigen observed for 54% individuals, 37 35% responded E-KNG...
The 42-kDa, C-terminal region of the merozoite surface protein-1 (MSP-1) Plasmodium falciparum is a putative malaria vaccine candidate Ag. Nine synthetic peptides corresponding to predicted T cell sites MSP-1 in blocks 15 and 16 eight overlapping representing conserved block 17 were used identify naturally immunogenic epitopes. These tested for their ability induce proliferation PBMC from residents western Kenya, where transmission holoendemic. Six (PL145, PL146, PL147, PL148, PL149, PL150)...
Abstract To determine whether maternal placental malaria is associated with an increased risk for perinatal mother-to-child HIV transmission (MTCT), we studied HIV-positive women in western Kenya. We enrolled 512 mother-infant pairs; 128 (25.0%) had malaria, and 102 (19.9%) infants acquired perinatally. Log10 viral load episiotomy or perineal tear were transmission, whereas low-density (<10,000 parasites/μL) was reduced (adjusted relative [ARR] 0.4). Among dually infected HIV, high-density...
Background Geohelminth infections are common in rural western Kenya, but risk factors and effects among pregnant women not clear. Methodology During a community-based cross-sectional survey, were interviewed asked to provide blood sample single fecal sample. Hemoglobin was measured slide examined for malaria. identified using the concentration Kato-Katz method. Results Among 390 participants who provided stool sample, 76.2% infected with at least one geohelminth: 52.3% Ascaris lumbricoides,...
Abstract Background Resistance to sulphadoxine-pyrimethamine (SP) in Plasmodium falciparum parasites is associated with mutations the dihydrofolate reductase ( dhfr ) and dihydropteroate synthase dhps genes has spread worldwide. SP remains recommended drug for intermittent preventive treatment malaria pregnancy (IPTp) information on population prevalence of resistance molecular markers pregnant women limited. Methods Temporal trends were investigated 489 parasite samples collected from at...
Although malaria control intervention has greatly decreased morbidity and mortality in many African countries, further decline parasite prevalence stagnated western Kenya. In order to assess if transmission reservoir is associated with this stagnation, submicroscopic infection gametocyte carriage was estimated. Risk factors associations between interventions were investigated study.A total of 996 dried blood spot samples used from two strata, all smear-positives (516 samples) randomly...
Compared with a single-stage antigen-based vaccine, multistage and multivalent Plasmodium falciparum vaccine would be more efficacious by inducing “multiple layers” of immunity. We have constructed synthetic gene that encodes for 12 B cell, 6 T cell proliferative, 3 cytotoxic lymphocyte epitopes derived from 9 stage-specific P. antigens corresponding to the sporozoite, liver, erythrocytic asexual, sexual stages. The was expressed in baculovirus system, 41-kDa antigen, termed CDC/NIIMALVAC-1,...
In vitro studies have shown that inhibition of Plasmodium falciparum blood-stage parasite growth by antibody-dependent cellular is mediated cooperation between malaria-specific IgG1 and IgG3, but not IgG2, monocytes via the Fcγ receptor II (FcγRII). A single amino acid substitution at position 131 in FcγRIIa critical binding human IgG subclasses. The hypothesis FcγRIIa-Arg/Arg131 genotype, which does bind to a host genetic factor for protection against high-density P. infection was tested....
The fifth, and probably last, large-scale, group-randomized, controlled trial of insecticide (permethrin)-treated bed nets (ITNs) showed that ITNs are efficacious in reducing all-cause post-neonatal mortality an area intense, perennial malaria transmission. helped to define pregnant women infants as target groups for this intervention high transmission settings. High population coverage with both non-target may be critical enhance health survival infants. proportion households (coverage),...
We assessed the effect of daily cotrimoxazole, essential for HIV care, on development antifolate-resistant Plasmodium falciparum , naso-pharyngeal Streptococcus pneumoniae (pneumococcus), and commensal Escherichia coli . HIV-positive subjects with CD4 cell count < 350 cells/μL (lower-CD4; N = 692) received cotrimoxazole; ≥ (higher-CD4; 336) HIV-negative ( 132) multivitamins. Specimens were collected at baseline, 2 weeks, monthly, sick visits during 6 months follow-up to compare changes in...
Plasmodium falciparum malaria and human immunodeficiency virus (HIV)-1 adversely interact in the context of pregnancy, however little is known regarding influence co-infection on risk congenital malaria. We aimed to determine prevalence placental impact HIV trans-placental transmission 157 parturient women their infants by microscopy quantitative real-time polymerase chain reaction (PCR) western Kenya. The cord blood infections were 17.2% 0% microscopy, 33.1% 10.8% PCR. was associated with a...
Abstract Background Understanding the origin and spread of mutations associated with drug resistance, especially in context combination therapy, will help guide strategies to halt prevent emergence resistance. Unfortunately, studies have assessed these complex processes when resistance is already highly prevalent. Even further, information on evolutionary dynamics leading multidrug-resistant parasites scattered limited areas low or seasonal malaria transmission. This study describes strong...
Current available malaria diagnostic methods each have some limitations to meet the need for real-time and large-scale screening of asymptomatic low density infection at community level. It was proposed that parasite-specific molecular-weight metabolites could be used as biomarkers development a tool aimed address this challenge. In study, high resolution metabolomics (HRM) employed identify in Plasmodium falciparum vitro culture samples.Supernatants were collected 12 hours interval from 3%...