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.
Campylobacteriosis is an acute zoonotic infection caused by Enterobacter Campylobacter and occurring with a predominant lesion of the digestive tract. The localized form of campylobacteriosis in most cases proceeds by the type of gastroenteritis or gastroenterocolitis; the generalized form is accompanied by the development of septicemia or septicopiemia. The diagnosis is confirmed by bacteriological culture…
Infectious mononucleosis is an acute viral infection characterized by a predominant lesion of the oropharynx and lymph nodes, spleen and liver. A specific sign of the disease is the appearance of characteristic cells in the blood – atypical mononuclears. The causative agent of infectious mononucleosis is the Epstein-Barr virus, belonging to the herpesvirus family. Its…
Invasive candidiasis is a generalized fungal infection in which candidemia and damage to internal organs by fungi of the genus Candida are observed. Up to half of the cases of the disease are caused by the pathogen C. albicans, the three most common pathogens are C. parapsilosis and C. glabrata. Clinical manifestations of the disease…
Yersiniosis is an acute anthropozoonous intestinal infection accompanied by a toxic-allergic reaction, characterized by multi-foci. Yersiniosis is characterized by a fecal-oral transmission pathway. Livestock, rodents and dogs are the reservoir of infection. The incubation period of yersiniosis lasts no more than a week. The clinic consists of a general toxic syndrome, spotty papular rashes, dyspeptic…
Yellow fever is an acute natural focal viral infection characterized by a severe course with a predominance of intoxication, jaundice and hemorrhagic syndrome. Yellow fever is among the most dangerous infections. Yellow fever is spread by vector-borne pathways, its carriers are mosquitoes. The incubation period of yellow fever is about a week. her clinic includes…
Dracunculiasis is a helminthic invasion caused by a round worm, a guinea worm, parasitizing in the intermuscular tissue and subcutaneous tissue. Clinical symptoms include allergic reactions (urticaria, suffocation), fever, joint swelling, burning pain, erythema formation, blisters and ulcers at the site of the parasite’s exit from under the skin. The diagnosis is confirmed by the…
Diphtheria is an acute infectious disease of bacterial nature characterized by the development of fibrinous inflammation in the area of the introduction of the pathogen (mainly the upper respiratory tract, the mucous membrane of the oropharynx is affected). Diphtheria is transmitted by airborne droplets and airborne dust. The infection can affect the oropharynx, larynx, trachea…
Diphyllobothriasis is an intestinal parasitosis from the group of cestodoses caused by tapeworms of the family Diphyllobothriidae, most often a broad tapeworm. Disease occurs with nausea, abdominal pain, decreased appetite, salivation, weight loss, stool disorder, anemic syndrome; in severe cases, intestinal obstruction develops. The diagnosis is confirmed by studies of feces, which make it possible…
Dysentery is an acute intestinal infection caused by bacteria of the genus Shigella, characterized by the predominant localization of the pathological process in the mucous membrane of the large intestine. Dysentery is transmitted by fecal-oral route (food or water). Clinically, a dysentery patient has diarrhea, abdominal pain, tenesmus, intoxication syndrome (weakness, weakness, nausea). The diagnosis…
Travelers diarrhea is a polyethological infectious disease manifested by disorders in the digestive tract during travel to another climatogeographic zone. The main manifestation of the disease is a change in character, an increase in the multiplicity and volume of the stool. Nausea, abdominal pain, fever and vomiting are also characteristic. Diagnosis of the condition consists…
