Infectious diseases are caused when a microorganism (bacterium, virus, parasite, fungus, etc.) attacks the body. They may be transmitted directly or indirectly from one person to another. Every human being is host to tens of thousands of “useful” bacteria, which only become pathogenic and therefore responsible for an infection in certain cases: in vulnerable individuals (e.g., immunocompromised patients) or in the event of an injury or surgical intervention.
In the case of infectious diseases, in vitro diagnostic tests aim to detect and identify the responsible infectious agent, to establish its origin and to allow physicians to determine the appropriate treatment for the patient. Such tests are also important to prevent potential epidemics.
In the case of a bacterial infection, the choice of the antibiotic is based on identifying the bacteria causing the disease and determining its sensitivity to antibiotics (antibiotic susceptibility testing).
Because bacteria are increasingly resistant to antibiotics, diagnostics play an ever more essential role in the fight against infectious diseases by helping to identify suitable treatments.
According to the World Health Organization, lower respiratory tract infections, diarrheal diseases and tuberculosis are among the 10 leading causes of death in the world in 20161.
In low-income countries, lower respiratory tract infections and diarrheal diseases are even the two leading causes of death.
Several diseases have been eliminated over the last 50 years through improved hygiene, advances in medicine and public health policies. By contrast, globalization, intercontinental travel and the increasing mobility of people and animals contribute to the emergence of new diseases, which are often zoonoses (transmitted by animals).