Natural hearth

In infection biology , a natural focus is defined as a geographically limited area in which certain diseases occur naturally and in which an ecological balance has developed between pathogens , susceptible hosts and vectors. Natural foci develop primarily for tick- or insect- borne diseases such as early summer meningoencephalitis , babesiosis and piroplasmosis . A natural focus develops when a certain type of landscape is necessary as a suitable habitat for vectors and people or animals susceptible to infection. The term was coined by Pavloski in 1939. Like endemics or enzooties , a natural focus is characterized by an increased prevalence and incidence .

Natural focus infections are often characterized by the fact that, due to the high level of contamination, there is a primary latency towards the pathogen, i.e. infections usually run without clinical symptoms (“silent”) or with only minor symptoms. This ensures that the pathogens are constantly passed on to susceptible animals and carriers and that the infection cycle is maintained. However, if other susceptible hosts reach this region, they are defenseless at the mercy of the disease, as the immune system cannot react to the pathogen quickly enough. They then develop - in contrast to the native population - severe clinical pictures. These diseases are also known as "travel sickness".

literature

• Theodor Hiepe: General Parasitology: With the basics of immunology, diagnostics and control . Georg Thieme Verlag, Stuttgart 2006, ISBN 978-3-83-044101-4 , p. 23