Infectious diseases include an extensive group of diseases caused by specific pathogenic (pathogenic) pathogens and transmitted from an infected individual to a healthy one. The peculiarities of infectious diseases are their contagiousness (contagiousness), the ability to mass epidemic spread, the cyclical course and the formation of post-infectious immunity. However, these features are expressed to varying degrees in different diseases.
This type of disease develop as a result of a complex biological process of interaction of a pathogenic microorganism with a susceptible macroorganism under certain conditions. There are several periods in the development of infectious diseases: incubation (latent), prodromal (the period of precursors), the period of development of clinical manifestations, the period of the outcome of the disease. The outcome of the infectious process can develop in several ways: convalescence (recovery), lethality, bacterial carrier, transition to a chronic form.
Infectious diseases account for 20 to 40% of the total structure of human diseases. Many medical and microbiological disciplines are engaged in the study, treatment and prevention of infections: actually infectious diseases, epidemiology, venereology, urology, gynecology, therapy, phthisiology, otolaryngology, immunology, virology, etc.
The number of infectious diseases known to science is constantly increasing and currently has more than 1,200 units. During his life, a person comes into contact with a huge number of microorganisms, but only 1/30000 of this community is capable of causing infectious processes. Viruses, rickettsias, bacteria, fungi have pathogenicity properties.
Depending on the location of the predominant localization of the process and a certain mechanism of transmission, infectious diseases are divided into intestinal (dysentery, cholera, salmonellosis, escherichiosis, paratyphs A and B, typhoid fever, food toxicoinfections); respiratory tract infections (ARVI, influenza, chickenpox, measles, mycoplasma respiratory infection); external integuments (erysipelas, anthrax, scabies); blood infections (HIV infection, malaria, yellow fever, recurrent and typhus); infections with multiple transmission routes (enterovirus infections, infectious mononucleosis).
By the nature of the pathogen, infectious diseases are distinguished: viral (viral hepatitis A, B, D, E and C, influenza, rubella, measles, cytomegalovirus and herpes infections, HIV infection, meningococcal infection, hemorrhagic fevers); bacterial (staphylococcal and streptococcal infection, cholera, salmonellosis, plague, dysentery); protozoal (malaria, trichomoniasis, amoebiasis); mycoses or fungal infections (aspergillosis, candidiasis, epidermophytia, cryptococcosis).
Infectious diseases are divided into anthroponotic and zoonotic. Anthroponoses include infections peculiar exclusively to humans and transmitted from person to person (smallpox, diphtheria, typhoid fever, measles, dysentery, cholera, etc.). Zoonoses are animal diseases that can also infect humans (foot-and-mouth disease, anthrax, rabies, tularemia, plague, listeriosis, leptospirosis, brucellosis).
Diseases caused by pathogens of animal origin – parasites (ticks, insects, protozoa) are called invasive or parasitic.
Among infectious diseases, there is a group of particularly dangerous (quarantine) infections with a high degree of contagion, a tendency to rapid spread, a severe epidemic course and a high risk of death in the shortest possible time from the moment of infection. Plague, smallpox (considered eradicated in the world since 1980), cholera, yellow fever (and similar epidemiology of Marburg fever and Ebola) are classified as particularly dangerous infections by the World Health Organization. Tularemia and anthrax are also classified as particularly dangerous infections in our country.
Treatment of patients with infectious diseases is carried out in specialized hospitals or departments, in mild cases – at home. A prerequisite for the successful treatment of infections is compliance with a strict anti-epidemic regime. The prevention of most infectious diseases is the observance of sanitary and hygienic rules and specific immunization.
The medical directory of diseases posted on the website “Medic Journal” contains a special section – where you can find useful information about the causes, mechanisms of development and clinical manifestations of infections, as well as about modern diagnostic and therapeutic techniques used in this field of medicine.
Toxoplasmosis is a zoonotic protozoal infection that has a long course and leads to damage to the nervous, lymphatic, visual, muscular systems, myocardium, liver, spleen. Acute toxoplasmosis occurs with feverish intoxication syndrome, lymphadenopathy, hepatosplenomegaly, skin rashes; in severe cases – with the development of myocarditis, encephalitis, encephalomyelitis. The diagnosis of toxoplasmosis is established by bacteriological…
Toxocariasis is a chronic infectious disease caused by the larvae of the toxocara roundworm. The invasion is characterized by fever, recurrent rashes and an increase in the size of the liver. Pathology is accompanied by damage to the eyeballs and internal organs: heart, brain, lungs. Diagnosis consists in the detection of specific antibodies to the…
Taeniasis is helminthiasis caused by parasitism in the small intestine of pork tapeworm and characterized by signs of digestive disorders and astheno–neurotic manifestations. The course is accompanied by a decrease in appetite, abdominal pain, nausea, vomiting, stool disorders, dizziness and headaches, sleep disorders, fainting states. A dangerous complication of taeniasis can be cysticercosis of the…
Teniarynchosis is a parasitic disease from the group of biohelminthiasis, manifested by symptoms of damage to the digestive tract and toxic-allergic reactions. With teniarynchosis, nausea, abdominal pain, unstable stools, a sharp increase in appetite and weight loss, independent crawling of parasite segments through the anus, asthenovegetative and neurotic syndromes, urticaria are observed. The diagnosis of…
Typhus – rickettsiosis, occurring with destructive changes in the vascular endothelium and the development of generalized thrombovasculitis. The main manifestations of typhus are associated with rickettsiemia and specific vascular changes. They include intoxication, fever, typhoid status, roseolus-petechial rash. Complications of typhus include thrombosis, myocarditis, meningoencephalitis. Confirmation of the diagnosis is facilitated by laboratory tests (RPH,…
Strongyloidiasis is an invasion of round helminths – intestinal acne, occurring with allergic and gastrointestinal syndromes. The manifest course of strongyloidiasis is accompanied by itchy skin rashes, cough with an asthmatic component, nausea, vomiting, diarrhea, myalgia, arthralgia, hepatosplenomegaly, jaundice of the skin and sclera. The diagnosis is confirmed by the detection of worm larvae in feces…
Streptococcal infections are a group of diseases, including infections caused by streptococcal flora of different types and manifested in the form of lesions of the respiratory tract and skin. Streptococcal infections include streptococcal impetigo, streptoderma, streptococcal vasculitis, rheumatism, glomerulonephritis, erysipelas, sore throat, scarlet fever and other diseases. Streptococcal infections are dangerous due to the tendency…
Tetanus is an infectious disease caused by the bacterium Clostridium tetani, with an acute course and a predominant lesion of the nervous system. Spores of the causative agent of tetanus can persist for a long time in the soil, water and on any objects. Human infection occurs when clostridium penetrates through damaged skin or mucous…
Sporotrichosis is a chronic fungal lesion of the body with typical skin manifestations. Isolated pulmonary, osteoarticular and generalized (involving all organs and systems) variants of the disease may be observed. Usually the pathology is accompanied by rashes on the skin and mucous membranes, fever of varying severity. Diagnostics involves the detection of fungus using laboratory…
AIDS is a stage of a chronic infectious disease caused by the human immunodeficiency virus. The manifestations of the disease are caused by a progressive decrease in the immune forces of the body, often have a generalized character and are caused by conditionally pathogenic flora. AIDS diagnostics is aimed at determining the presence and quantity…
