Publications by authors named "Leonard Nderitu"

Article Synopsis
  • This study focuses on using historical data from livestock anthrax events in Kenya (1957-2017) to create disease risk maps, aiding in effective disease management in resource-limited countries.
  • By analyzing 666 reported anthrax cases, researchers identified patterns of disease occurrence over time and space, emphasizing areas with higher risks.
  • The findings indicate that anthrax events are spatially clustered, with specific agro-ecological zones being more affected, particularly high-risk areas for cattle, and a noticeable seasonality in case occurrences.
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Arthropod-borne viruses are a major constituent of emerging infectious diseases worldwide, but limited data are available on the prevalence, distribution, and risk factors for transmission in Kenya and East Africa. In this study, we used 1,091 HIV-negative blood specimens from the 2007 Kenya AIDS Indicator Survey (KAIS 2007) to test for the presence of IgG antibodies to dengue virus (DENV), chikungunya virus (CHIKV) and Rift Valley fever virus (RVFV).The KAIS 2007 was a national population-based survey conducted by the Government of Kenya to provide comprehensive information needed to address the HIV/AIDS epidemic.

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Article Synopsis
  • qRT-PCR is a diagnostic tool increasingly used to detect lower respiratory infections by measuring viral load through cycle threshold (CT) values, which can complicate clinical interpretation.
  • A study conducted in rural Kenya assessed CT values from naso/oropharyngeal swabs of patients with varying levels of respiratory illness and found that inpatients had significantly lower CT values compared to controls and outpatients for some viruses, particularly RSV and influenza.
  • The results indicate that CT values from upper respiratory samples are linked to the severity of illness for certain respiratory viruses, suggesting potential for improved clinical assessments in similar cases.
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Background: Few comprehensive data exist on disease incidence for specific etiologies of acute respiratory illness (ARI) in older children and adults in Africa.

Methodology/principal Findings: From March 1, 2007, to February 28, 2010, among a surveillance population of 21,420 persons >5 years old in rural western Kenya, we collected blood for culture and malaria smears, nasopharyngeal and oropharyngeal swabs for quantitative real-time PCR for ten viruses and three atypical bacteria, and urine for pneumococcal antigen testing on outpatients and inpatients meeting a ARI case definition (cough or difficulty breathing or chest pain and temperature >38.0 °C or oxygen saturation <90% or hospitalization).

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Background: Few comprehensive data exist on the etiology of severe acute respiratory illness (SARI) among African children.

Methods: From March 1, 2007 to February 28, 2010, we collected blood for culture and nasopharyngeal and oropharyngeal swabs for real-time quantitative polymerase chain reaction for 10 viruses and 3 atypical bacteria among children aged <5 years with SARI, defined as World Health Organization-classified severe or very severe pneumonia or oxygen saturation <90%, who visited a clinic in rural western Kenya. We collected swabs from controls without febrile or respiratory symptoms.

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Background: During the Rift Valley fever (RVF) epidemic of 2006-2007 in eastern Africa, spatial mapping of the outbreaks across Kenya, Somalia, and Tanzania was performed and the RVF viruses were isolated and genetically characterized.

Methods: Following confirmation of the RVF epidemic in Kenya on 19 December 2006 and in Tanzania on 2 February 2007, teams were sent to the field for case finding. Human, livestock, and mosquito specimens were collected and viruses isolated.

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