Publikationsdatenbank

A stepwise epidemiological Investigation of non-malarial febrile illnesses in Tana River and Garissa Counties of Kenya (2025)

Art

Hochschulschrift

Autor

Kimari, Martin Wainaina (WE 10)

Quelle

Berlin: Mensch und Buch Verlag, 2025 — vi, 148 Seiten

ISBN: 978-3-96729-273-2

Sprache

Englisch

Verweise

URL (Volltext): https://refubium.fu-berlin.de/handle/fub188/46969

Kontakt

Institut für Tier- und Umwelthygiene

Robert-von-Ostertag-Str. 7-13
14169 Berlin
+49 30 838 51845
tierhygiene@vetmed.fu-berlin.de

Abstract / Zusammenfassung

This doctoral work focuses on the epidemiology and public health implications of non-malarial febrile illnesses (NMFIs) in endemic regions. The research delivers a comprehensive investigation of leading causes of NMFIs in febrile patients in Africa and is the first to present them in proportional morbidity rates, an important health metric that shows the relative importance of clinically relevant aetiological agents. While there was a paucity of relevant data across the continent, a remarkable diversity of bacterial, viral, fungal and parasitic infectious agents was found, with most being observed from blood and/or serum samples using both direct and indirect methods. Bacterial agents were the most prominent causes of non-malarial fevers, with viruses following closely. The first meta-analytic summary estimates of selected agents in African patients were also estimated from the work, with Streptococcus being detected using direct methods in 3.2% of the 241,499 patients investigated. A need for more fever studies to even out the regional disparities observed on the continent is discussed, with harmonised protocols for patient selection and diagnosis being needful to lower the high study heterogeneity seen for various agents. An in-depth investigation of febrile patients from Garissa County of Kenya, an arid and semiarid region of Kenya revealed further understanding of NMFIs in an endemic region. A high presence of Brucella was observed (only B. melitensis was found) in the patients examined (19.4% by PCR), much higher than the African average meta-analytic estimates of 3.1% for pathogenic brucellae. Additionally, 1.7% of patients were PCR positive to P1 subclade (formerly termed pathogenic) Leptospira and none (<1%) to C. burnetii which are leading zoonoses prioritised by the country’s health authorities for control. Younger patients (5-17 years old) were at higher odds of being seropositive to leptospires and C. burnetii than adults, showing the urgent need for surveillance and prevention measures to protect vulnerable populations. A metagenomic shotgun sequencing of serum from selected patients also revealed Streptococcus and Moraxella to be possible bloodstream infections, showing the need for the country to expand its surveillance efforts for common but under-investigated bacterial agents using untargeted sequencing or multiplex detection assays. Additional longitudinal follow-up of small ruminants in neighbouring Tana River County presented the country’s first incidence rate estimates for these infectious diseases in animal hosts. A high incidence of Leptospira and C. burnetii was observed in the animal hosts as indicated by seroconversions, and none were observed for Brucella spp. The country lacks a systematic prioritisation of animal diseases which suggests that zoonoses that have a high public Health impact may be overlooked, thereby leading to exposure of vulnerable human populations. There is a need for the adoption of prevention strategies such as vaccinations of humans and animals alike, the use of personal protective equipment and biosecurity measures to Prevent occupational exposures, and treating foods to prevent ingestion of contaminated animalsource foods. Additionally, avoiding contaminated water sources and protecting food stores from reservoir animals such as rodents is vital to prevent exposure.