Aedes aegypti mosquitoes are the primary vectors for important arboviral health threats including chikungunya (CHIKV) and dengue (DENV) viruses, primarily breeding in domestic plastic containers. Previous studies have highlighted a severe lack of knowledge about non-malarial mosquito-borne diseases in Kenya, so we proposed a household and school-based educational intervention in urban coastal Kenya to determine whether it could bring about long-term improvements in knowledge, attitudes, and practices related to the source reduction of arboviral disease vectors. In this cluster-randomized controlled trial, 249 households from 5 villages were placed in the intervention arm and 243 households from 5 other similar villages were placed in the control arm.
View Article and Find Full Text PDFis the primary vector of arboviral diseases such as dengue, chikungunya, yellow fever, and Zika, posing significant global health and economic challenges. The effective control of this mosquito species requires understanding its seasonality, feeding behavior, and ecological dynamics. Modern molecular techniques, such as amplicon metagenomic sequencing, provide insights into vector-host interactions and feeding patterns.
View Article and Find Full Text PDFCurr Trop Med Rep
September 2024
Purpose Of Review: This review assessed the impact of climate change on HIV transmission and HIV care of children and adults in Eswatini, and what adaptation strategies can mitigate these impacts.
Recent Findings: The HIV crisis in Eswatini persists alongside the climate emergency, increasing poor health outcomes in individuals living with HIV. Although there is no clinical evidence of a direct influence of climate change on the biological effect of HIV, changing weather patterns have an effect on the livelihoods and sustenance of children, adults, and caregivers, which may consequently increase the likelihood of HIV transmission and disrupt HIV care.
Parasit Vectors
March 2025
Background: Trash piles and abandoned tires that are exposed to the elements collect water and create productive breeding grounds for Aedes aegypti mosquitoes, the primary vector for multiple arboviruses. Unmanned aerial vehicle (UAV) imaging provides a novel approach to efficiently and accurately mapping trash, which could facilitate improved prediction of Ae. aegypti habitat and consequent arbovirus transmission.
View Article and Find Full Text PDFImmunohorizons
February 2025
Chikungunya (CHIKV) and dengue (DENV) are mosquito-borne viruses that cause severe epidemics, often in remote regions. A limitation to our understanding of these pathogens is the difficulty of performing assays of the cellular immune response. To fill this gap, we developed a novel miniaturized automated system capable of processing 250 μl of whole blood for high-throughput cellular analysis.
View Article and Find Full Text PDFDengue virus (DENV) and chikungunya virus (CHIKV) are causes of endemic febrile disease among Kenyan children. The exposure risk to these infections is highly multifactorial and linked to environmental factors and human behavior. We investigated relationships between household, socio-economic, demographic, and behavioral risk factors for DENV and CHIKV seropositivity and seroconversion in four settlements in Kenya.
View Article and Find Full Text PDFRift Valley fever virus (RVFV) is an adaptable arbovirus that can be transmitted by a wide variety of arthropods. Widespread urban transmission of RVFV has not yet occurred, but peri-urban outbreaks of RVFV have recently been documented in East Africa. We previously reported low-level exposure in urban communities and highlighted the risk of introduction via live animal influx.
View Article and Find Full Text PDFAedes aegypti mosquitos are the primary vector for dengue, chikungunya, and Zika viruses and tend to breed in small containers of water, with a propensity to breed in small piles of trash and abandoned tires. This study piloted the use of aerial imaging to map and classify potential Ae. aegypti breeding sites with a specific focus on trash, including discarded tires.
View Article and Find Full Text PDFMicrobiol Spectr
May 2024
Between 2016 and 2018, Brazil experienced major sylvatic yellow fever (YF) outbreaks that caused hundreds of casualties, with Minas Gerais (MG) being the most affected state. These outbreaks provided a unique opportunity to assess the immune response triggered by the wild-type (WT) yellow fever virus (YFV) in humans. The plaque reduction neutralization test (PRNT) is currently the standard method to assess the humoral immune response to YFV by measuring neutralizing antibodies (nAbs).
View Article and Find Full Text PDFAsymptomatic dengue virus (DENV) infections have important public health implications but are challenging to identify. We performed a cross-sectional study of reverse transcription quantitative polymerase chain reaction on pooled sera of asymptomatic individuals from the south coast of Kenya at two time periods to identify cases of asymptomatic viremia. Among 2,460 samples tested in pools of 9 or 10, we found only one positive case (0.
View Article and Find Full Text PDFJ Am Mosq Control Assoc
June 2023
Aedes aegypti is the primary vector of dengue fever virus (DENV) worldwide. Infusions made from organic materials have been shown to act as oviposition attractants for Ae. aegypti; however, studies on locally suitable infusion materials are lacking.
View Article and Find Full Text PDFBackground: Late-relapsing hepatitis after yellow fever (LHep-YF) during the convalescent phase of the disease has been described during recent yellow fever (YF) outbreaks in Brazil. LHep-YF is marked by a rebound in liver enzymes and nonspecific clinical manifestations around 46-60 days after YF symptom onset.
Methods: Here we have characterized the clinical course and risk factors for LHep-YF using data from a representative cohort of patients who survived YF in Brazil, 2017-2018.
Clin Immunol
June 2023
This study described a soluble mediator storm in acute Yellow Fever/YF infection along the kinetics timeline towards convalescent disease. The analyses of the YF Viral RNAnemia, chemokines, cytokines, and growth factors were performed in YF patients at acute/(D1-15) and convalescent/(D16-315) phases. Patients with acute YF infection displayed a trimodal viremia profile spreading along D3, D6, and D8-14.
View Article and Find Full Text PDFRift Valley fever virus (RVFV) is an economically devastating, zoonotic arbovirus endemic across Africa with potential to cause severe disease in livestock and humans. Viral spread is primarily driven by movement of domestic ruminants and there is a high potential for transboundary spread. Despite influx of livestock to urban areas in response to the high demand for meat and animal products, RVFV has not been detected in any urban center.
View Article and Find Full Text PDFPrior studies have demonstrated prolonged presence of yellow fever virus (YFV) RNA in saliva and urine as an alternative to serum. To investigate the presence of YFV RNA in urine, we used RT-PCR for YFV screening in 60 urine samples collected from a large cohort of naturally infected yellow fever (YF) patients during acute and convalescent phases of YF infection from recent YF outbreaks in Brazil (2017 to 2018). Fifteen urine samples from acute phase infection (up to 15 days post-symptom onset) and four urine samples from convalescent phase infection (up to 69 days post-symptom onset), were YFV PCR-positive.
View Article and Find Full Text PDFThis study examined whether Aedes aegypti extends its human blood seeking activity into night hours. Human landing catches (HLC) were conducted hourly from early morning (04:30) to late evening (21:30) in urban and rural sites in Kisumu County in western Kenya, and in Kwale County at the coast. Out of 842 female Ae.
View Article and Find Full Text PDFObjective: Zika virus (ZIKV) targets neural stem cells in the developing brain. However, the majority of ZIKV-exposed children are born without apparent neurological manifestations. It remains unclear if these children were protected from ZIKV neurotropism or if they harbour subtle pathology that is disruptive to brain development.
View Article and Find Full Text PDFPLoS Negl Trop Dis
March 2021
Throughout the last decade, chikungunya virus (CHIKV) and Zika virus (ZIKV) infections have spread globally, causing a spectrum of disease that ranges from self-limited febrile illness to permanent severe disability, congenital anomalies, and early death. Nevertheless, estimates of their aggregate health impact are absent from the literature and are currently omitted from the Global Burden of Disease (GBD) reports. We systematically reviewed published literature and surveillance records to evaluate the global burden caused by CHIKV and ZIKV between 2010 and 2019, to calculate estimates of their disability-adjusted life year (DALY) impact.
View Article and Find Full Text PDFAm J Trop Med Hyg
February 2021
O'nyong-nyong virus (ONNV) is a little-known arbovirus causing intermittent, yet explosive, outbreaks in Africa. It is closely related to chikungunya virus, an emerging infectious disease. O'nyong-nyong virus causes a self-limited illness characterized by bilateral polyarthritis, rash, low-grade fever, and lymphadenopathy.
View Article and Find Full Text PDFMalar J
May 2020
Background: Prevention and treatment of malaria during pregnancy is crucial in dealing with maternal mortality and adverse fetal outcomes. The World Health Organization recommendation to treat all pregnant women with sulfadoxine-pyrimethamine (SP) through antenatal care structures was implemented in Kenya in the year 1998, but concerns about its effectiveness in preventing malaria in pregnancy has arisen due to the spread of SP resistant parasites. This study aimed to determine the prevalence of SP resistance markers in Plasmodium falciparum parasites isolated from pregnant women seeking antenatal care at Msambweni County Referral Hospital, located in coastal Kenya, between the year 2013 and 2015.
View Article and Find Full Text PDFYellow fever (YF) is an acute viral disease, affecting humans and non-human primates (NHP), caused by the yellow fever virus (YFV). Despite the existence of a safe vaccine, YF continues to cause morbidity and mortality in thousands of people in Africa and South America. Since 2016, massive YF outbreaks have taken place in Brazil, reaching YF-free zones, causing thousands of deaths of humans and NHP.
View Article and Find Full Text PDFBMJ Open
June 2019
Anemia is known to impact a child's growth and development, but not all anemias are caused by iron deficiency, and the CDC and WHO have emphasized investigating other contributors to anemia. This cross-sectional sub-study of a 2012-2016 maternal-child cohort in coastal Kenya evaluated 244 children and found 185 (76%) to have been anemic on at least one time point since birth. At the time of assessment in 2016, evaluation included a complete blood count, nutritional assessment, and testing for parasitic infections, focusing on the primary outcome of anemia, defined as hemoglobin (Hb) < 11 g/dL.
View Article and Find Full Text PDFThe International Committee on Taxonomy of Viruses (ICTV) has implemented numerous changes to the taxonomic classification of bunyaviruses over the years. Whereas most changes have been justified and necessary because of the need to accommodate newly discovered and unclassified viruses, other changes are a cause of concern, especially the decision to demote scores of formerly recognized species to essentially strains of newly designated species. This practice was first described in the seventh taxonomy report of the ICTV and has continued in all subsequent reports.
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