Myeloperoxidase and Other Markers of Neutrophil Activation Associate With Malaria and Malaria/HIV Coinfection in the Human Placenta.

Introduction: Placental malaria (PM) is characterized by accumulation of inflammatory leukocytes in the placenta, leading to poor pregnancy outcomes. Understanding of the underlying mechanisms remains incomplete. Neutrophils respond to malaria parasites by phagocytosis, generation of oxidants, and externalization of Neutrophil Extracellular Traps (NETs).

Reduced Transplacental Transfer of Antimalarial Antibodies in Kenyan HIV-Exposed Uninfected Infants.

Background: Altered neonatal immune responses may contribute to the increased morbidity observed in HIV-exposed but uninfected (HEU) infants compared with HIV-unexposed uninfected (HUU) infants. We sought to examine the effects of prenatal HIV and malaria exposure on maternal and neonatal plasma cytokine profiles and transplacental antibody transfer.

Methods: Forty-nine HIV+ and 50 HIV- women and their HIV-uninfected neonate pairs from Kenya were assessed.

Iron Deficiency is Prevalent among HIV-Infected Kenyan Adults and is Better Measured by Soluble Transferrin Receptor than Ferritin.

Iron deficiency (ID) and human immunodeficiency virus (HIV) infection frequently coexist. Little data exist on ID in HIV-infected individuals, partly because the iron marker ferritin is altered by inflammation common in HIV infection. We measured iron biomarkers (ferritin, soluble transferrin receptor [sTfR], hepcidin) and red cell indices (hemoglobin, mean corpuscular volume [MCV]) in newly diagnosed, antiretroviral therapy-naive, HIV-infected ( = 138) and uninfected ( = 52) Kenyan adults enrolled in a study of the immune response to malaria.

Seroepidemiological Studies of Arboviruses in Africa.

The literature on sero-epidemiological studies of flaviviral infections in the African continent is quite scarce. Much of the viral epidemiology studies have been focussing on diseases such as HIV/AIDS because of their sheer magnitude and impact on the lives of people in the various affected countries. Increasingly disease outbreaks caused by arboviruses such as the recent cases of chikungunya virus, dengue virus and yellow fever virus have prompted renewed interest in studying these viruses.

Characteristics of Aedes aegypti adult mosquitoes in rural and urban areas of western and coastal Kenya.

Aedes aegypti is the main vector for yellow fever, dengue, chikungunya and Zika viruses. Recent outbreaks of dengue and chikungunya have been reported in Kenya. Presence and abundance of this vector is associated with the risk for the occurrence and transmission of these diseases.

Sero-catalytic and Antibody Acquisition Models to Estimate Differing Malaria Transmission Intensities in Western Kenya.

We sought to identify a subset of Plasmodium falciparum antibody targets that would inform monitoring efforts needed to eliminate malaria in high transmission settings. IgG antibodies to 28 recombinant Pf antigens were measured in residents of two communities in western Kenya examined in 2003 and 2013, when the respective prevalence of asymptomatic parasitemia among children was 81 and 15 percent by microscopy. Annual seroconversion rates based on a sero-catalytic model that dichotomised antibody values to negative versus positive showed that rates were higher in 2003 than 2013 for 1 pre-erythrocytic and 7 blood-stage antigens.

Unrecognized Dengue Virus Infections in Children, Western Kenya, 2014-2015.

We detected a cluster of dengue virus infections in children in Kenya during July 2014-June 2015. Most cases were serotype 1, but we detected all 4 serotypes, including co-infections with 2 serotypes. Our findings implicate dengue as a cause of febrile illness in this population and highlight a need for robust arbovirus surveillance.

Monocyte dysregulation and systemic inflammation during pediatric falciparum malaria.

Background: Inflammation and monocytes are thought to be important to human malaria pathogenesis. However, the relationship of inflammation and various monocyte functions to acute malaria, recovery from acute malaria, and asymptomatic parasitemia in endemic populations is poorly understood.

Methods: We evaluated plasma cytokine levels, monocyte subsets, monocyte functional responses, and monocyte inflammatory transcriptional profiles of 1- to 10-year-old Kenyan children at the time of presentation with acute uncomplicated malaria and at recovery 6 weeks later; these results were compared with analogous data from asymptomatic children and adults in the same community.

Principles, practices and knowledge of clinicians when assessing febrile children: a qualitative study in Kenya.

Background: Clinicians in low resource settings in malaria endemic regions face many challenges in diagnosing and treating febrile illnesses in children. Given the change in WHO guidelines in 2010 that recommend malaria testing prior to treatment, clinicians are now required to expand the differential when malaria testing is negative. Prior studies have indicated that resource availability, need for additional training in differentiating non-malarial illnesses, and lack of understanding within the community of when to seek care play a role in effective diagnosis and treatment.

Development of a Real-Time Reverse Transcription Polymerase Chain Reaction for O'nyong-nyong Virus and Evaluation with Clinical and Mosquito Specimens from Kenya.

O'nyong-nyong virus (ONNV), an alphavirus closely related to chikungunya virus (CHIKV), has been the documented cause of two large outbreaks in east Africa; however, little is known about the contribution of ONNV to cases of acute febrile illness during interepidemic periods. An ONNV real-time reverse transcription polymerase chain reaction (rRT-PCR) was developed and evaluated using clinical and mosquito pool samples. The ONNV rRT-PCR linear range extended from 8.

Malaria and Chikungunya Detected Using Molecular Diagnostics Among Febrile Kenyan Children.

Background: In sub-Saharan Africa, malaria is frequently overdiagnosed as the cause of an undifferentiated febrile illness, whereas arboviral illnesses are presumed to be underdiagnosed.

Methods: Sera from 385 febrile Kenyan children, who presented to 1 of 4 clinical sites, were tested using microscopy and real-time molecular assays for dengue virus (DENV), chikungunya virus (CHIKV), malaria, and .

Results: Malaria was the primary clinical diagnosis for 254 patients, and an arboviral infection (DENV or CHIKV) was the primary diagnosis for 93 patients.

Characterization and productivity profiles of Aedes aegypti (L.) breeding habitats across rural and urban landscapes in western and coastal Kenya.

Background: Aedes aegypti, the principal vector for dengue and other emerging arboviruses, breeds preferentially in various man-made and natural container habitats. In the absence of vaccine, epidemiological surveillance and vector control remain the best practices for preventing dengue outbreaks. Effective vector control depends on a good understanding of larval and adult vector ecology of which little is known in Kenya.

New gorilla adenovirus vaccine vectors induce potent immune responses and protection in a mouse malaria model.

Background: A DNA-human Ad5 (HuAd5) prime-boost malaria vaccine has been shown to protect volunteers against a controlled human malaria infection. The potency of this vaccine, however, appeared to be affected by the presence of pre-existing immunity against the HuAd5 vector. Since HuAd5 seroprevalence is very high in malaria-endemic areas of the world, HuAd5 may not be the most appropriate malaria vaccine vector.

Decrease in Numbers of Naive and Resting B Cells in HIV-Infected Kenyan Adults Leads to a Proportional Increase in Total and Specific Atypical Memory B Cells.

Human immunodeficiency virus type 1 (HIV-1) infection is associated with B cell activation and exhaustion, and hypergammaglobulinemia. How these changes influence B cell responses to coinfections such as malaria is poorly understood. To address this, we compared B cell phenotypes and Abs specific for the vaccine candidate apical membrane Ag-1 (AMA1) in HIV-infected and uninfected adults living in Kenya.

Pneumococcal carriage and antibiotic susceptibility patterns from two cross-sectional colonization surveys among children aged <5 years prior to the introduction of 10-valent pneumococcal conjugate vaccine - Kenya, 2009-2010.

Background: Pneumococci are spread by persons with nasopharyngeal colonization, a necessary precursor to invasive disease. Pneumococcal conjugate vaccines can prevent colonization with vaccine serotype strains. In 2011, Kenya became one of the first African countries to introduce the 10-valent pneumococcal conjugate vaccine (PCV10) into its national immunization program.

Regulatory T Cells in Endemic Burkitt Lymphoma Patients Are Associated with Poor Outcomes: A Prospective, Longitudinal Study.

Deficiencies in Epstein-Barr virus (EBV)-specific T cell immunosurveillance appear to precede the development of endemic Burkitt lymphoma (eBL), a malaria-associated pediatric cancer common in sub-Saharan Africa. However, T cell contributions to eBL disease progression and survival have not been characterized. Our objective was to investigate regulatory and inflammatory T cell responses in eBL patients associated with clinical outcomes.

Menstrual cups and sanitary pads to reduce school attrition, and sexually transmitted and reproductive tract infections: a cluster randomised controlled feasibility study in rural Western Kenya.

Objectives: Conduct a feasibility study on the effect of menstrual hygiene on schoolgirls' school and health (reproductive/sexual) outcomes.

Design: 3-arm single-site open cluster randomised controlled pilot study.

Setting: 30 primary schools in rural western Kenya, within a Health and Demographic Surveillance System.

Evaluation of the efficacy, acceptability and palatability of calcium montmorillonite clay used to reduce aflatoxin B1 dietary exposure in a crossover study in Kenya.

Acute aflatoxin exposure can cause death and disease (aflatoxicosis) in humans. Aflatoxicosis fatality rates have been documented to be as high as 40% in Kenya. The inclusion in the diet of calcium silicate 100 (ACCS100), a calcium montmorillonite clay, may reduce aflatoxin bioavailability, thus potentially decreasing the risk of aflatoxicosis.

Supplementary effect and durability of prototype insecticide-treated eave curtains on indoor resting mosquitoes in Kadibo division, Western Kenya.

Background: Use of insecticide treated bednets (ITNs) was a breakthrough in the fight against malaria. However, ITNs are only effective when properly used. Recent reports indicate low compliance in ITN usage and changes in biting times of malaria vectors with early and late biting cases recorded when people are not sleeping under their nets.

Longevity of Genotype-Specific Immune Responses to Plasmodium falciparum Merozoite Surface Protein 1 in Kenyan Children from Regions of Different Malaria Transmission Intensity.

Naturally acquired immunity to Plasmodium falciparum presents a changing landscape as malaria control programs and vaccine initiatives are implemented. Determining which immunologic indicators remain surrogates of past infection, as opposed to mediators of protection, led us to compare stability of immune responses across regions with divergent malaria transmission intensities. A repeat cross-sectional study of Kenyan children from a malaria-holoendemic area and an epidemic-prone area was used to examine longitudinal antibody and interferon-gamma (IFN-γ) responses to the 3D7 and FVO variants of merozoite surface protein 1 (MSP1).

Factors influencing survival among Kenyan children diagnosed with endemic Burkitt lymphoma between 2003 and 2011: A historical cohort study.

Discovering how to improve survival and establishing clinical reference points for children diagnosed with endemic Burkitt lymphoma (eBL) in resource-constrained settings has recaptured international attention. Using multivariate analyses, we evaluated 428 children with eBL in Kenya for age, gender, tumor stage, nutritional status, hemoglobin, lactate dehydrogenase (LDH), Epstein-Barr virus (EBV) and Plasmodium falciparum prior to induction of chemotherapy (cyclophosphamide, vincristine, methotrexate and doxorubicin) to identify predictive and prognostic biomarkers of survival. During this 10 year prospective study period, 22% died in-hospital and 78% completed six-courses of chemotherapy.

The Relationship Between Distance to Water Source and Moderate-to-Severe Diarrhea in the Global Enterics Multi-Center Study in Kenya, 2008-2011.

In the developing world, fetching water for drinking and other household uses is a substantial burden that affects water quantity and quality in the household. We used logistic regression to examine whether reported household water fetching times were a risk factor for moderate-to-severe diarrhea (MSD) using case-control data of 3,359 households from the Global Enterics Multi-Center Study in Kenya in 2009-2011. We collected additional global positioning system (GPS) data for a subset of 254 randomly selected households and compared GPS-based straight line and actual travel path distances to fetching times reported by respondents.

Prevalence of reproductive tract infections and the predictive value of girls' symptom-based reporting: findings from a cross-sectional survey in rural western Kenya.

Objectives: Reproductive tract infections (RTIs), including sexually acquired, among adolescent girls is a public health concern, but few studies have measured prevalence in low-middle-income countries. The objective of this study was to examine prevalence in rural schoolgirls in Kenya against their reported symptoms.

Methods: In 2013, a survey was conducted in 542 adolescent schoolgirls aged 14-17 years who were enrolled in a menstrual feasibility study.

High Streptococcus pneumoniae colonization prevalence among HIV-infected Kenyan parents in the year before pneumococcal conjugate vaccine introduction.

Background: Streptococcus pneumoniae is a leading cause of pneumonia, meningitis and sepsis in developing countries, particularly among children and HIV-infected persons. Pneumococcal oropharyngeal (OP) or nasopharyngeal (NP) colonization is a precursor to development of invasive disease. New conjugate vaccines hold promise for reducing colonization and disease.