Prevalence of Mental, Behavioural, and Neurobehavioural Disorders

Individuals with intellectual and developmental disabilities (IDD) are known to be at high risk of developing a comorbid mental or behavioural disorder. However, there has only recently been an increased focus on the epidemiology of such disorders in the older population of people with IDD. Attempting to precisely quantify the prevalence and incidence of disorders in this cohort remain difficult, due to complications associated with diverse sampling methodologies, differing definitions of ‘older’, and variations in diagnostic criteria. Nonetheless, the expanding research base since the 1980s indicates that mental and behavioural disorders occur at higher rates among older people with IDD when compared to their mainstream peers. The prevalence of mental disorders for the older cohort tends to decrease in relation to the severity of the intellectual disability, but the reverse is true for behavioural disorders. Estimated prevalence rates for mental disorders vary considerably, but many studies report rates in the 20–30% range, which is higher than for the general community. Behavioural disorders are also very common in older people with IDD but are again hard to quantify precisely. Observed differences in prevalence between people with IDD and the general community may diminish over the age of 70 as dementias become more commonplace in both populations. Finally, some research indicates a greater likelihood of mental disorder amongst the older female population of people with IDD

Intruders below the Radar: Molecular Pathogenesis of Bartonella spp

Summary: Bartonella spp. are facultative intracellular pathogens that employ a unique stealth infection strategy comprising immune evasion and modulation, intimate interaction with nucleated cells, and intraerythrocytic persistence. Infections with Bartonella are ubiquitous among mammals, and many species can infect humans either as their natural host or incidentally as zoonotic pathogens. Upon inoculation into a naive host, the bartonellae first colonize a primary niche that is widely accepted to involve the manipulation of nucleated host cells, e.g., in the microvasculature. Consistently, in vitro research showed that Bartonella harbors an ample arsenal of virulence factors to modulate the response of such cells, gain entrance, and establish an intracellular niche. Subsequently, the bacteria are seeded into the bloodstream where they invade erythrocytes and give rise to a typically asymptomatic intraerythrocytic bacteremia. While this course of infection is characteristic for natural hosts, zoonotic infections or the infection of immunocompromised patients may alter the path of Bartonella and result in considerable morbidity. In this review we compile current knowledge on the molecular processes underlying both the infection strategy and pathogenesis of Bartonella and discuss their connection to the clinical presentation of human patients, which ranges from minor complaints to life-threatening disease