Infections are frequently unpredictable and have potential for explosive global effects.
Onset can be acute and unambiguous in nature.
Many infectious diseases are acute but most deaths and debility related to infections are due to chronic parasitic, mycobacterial, and viral infections.
In the absence of active therapy, an acute infectious disease may pose an all-or-nothing situation, with the host quickly dying or recovering spontaneously, often with lifelong immunity to the specific infecting pathogen.
Infection is not simply the result of bacterial replication or of bacterial gene products; it’s also a consequence of the hosts response, resulting inflammation and tissue damage.
The respiratory tract is the most common source of infections, caused by a virus is bacteria or fungous.
Infections lead to about 6% of deaths in high income countries.
The respiratory tract is more prone to infections and other organ systems as it frequently comes into contact with numerous pathogens in the environment.
Some infectious diseases are transmissible to others, but transmission mechanisms are relatively few including inoculation, airborne or waterborne transmission.
Transmission mechanisms may be amenable to medical and public health interventions.
Most infections are caused by a single agent, the identification of which allows disease control measures, such as disinfection, and washing, sanitation, vector control, and live specific medical measures such as antimicrobial therapy and vaccination.
Some infectious diseases can be prevented by personal protection measures and general public health measures, and immunologic techniques such as vaccination.
Some infectious diseases, especially those for which no non-human host or major reservoir exists can be eliminated, such diseases include poliomyelitis and smallpox.
Infectious pathogens have adaptability to replicate and to mutate, providing them with advantage over agents and processes aimed at their destruction.
Infectious diseases related to human nature and human behavior as such diseases are acquired specifically as a result of our behavior and lifestyles reflecting social gatherings, travel, sexual activity, occupational exposure, recreational activities, food and drink ingestion, exposure to pets and involvement of healthcare environments.
Risk of infection following splenectomy greatest in the first 2-3 years after splenectomy.
Overall, in most infections males have a higher mortality.
On any given day, about 1 in every 25 hospital patients contracts an infection.
Worse outcome for women than for men with infections in the surgical ICU.
Immune response against infection is largely related to the activation of mature T-helper (Th) cells.
Infectious diseases account for nearly 6 million deaths worldwide annually for children younger than five years.
Infectious disease is a major cause of cancer worldwide, accounting for 2 million cases each year.
Viral infections of the respiratory tract before more numerous than bacterial infections.
As many as 5-20% of the US population contracts influenza annually.
Infectious agents associated with cancers include:Helicobacter pylori, hepatitis B, hepatitis C, Opisthorchis viv2242ini, CLonorchis sine sis, human papilloma virus, Epstein-Barr virus, human T-celllymphotropic virus type 1, human herpes virus type 8, and Schistosoma haematobium.
In many infections, including cellulitis, ventilator associated pneumonia, ventilated associated tracheitis shorter duration of antibiotic treatment is effective as longer duration treatment and yields less colonization and infection with antimicrobial resistant microorganisms.