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.
Mumps is an acute infection caused by an RNA-containing virus of the genus Paramyxovirus, mainly affecting salivary glands and nerve cells. The causative agent of mumps is transmitted by airborne droplets, sometimes by contact through objects infected with the patient’s saliva. The clinic of mumps begins with fever and intoxication symptoms, against this background, swelling…
Epidemic myalgia is an acute infectious disease caused by enteroviruses, with a predominantly fecal-oral transmission mechanism. The clinical picture is characterized by an increase in body temperature, the appearance of attacks of pronounced spastic pain in the diaphragm, chest muscles, abdominal wall and extremities. Serological methods, detection of the pathogen’s RNA and the virus itself…
Enterovirus encephalitis is an inflammation of brain tissue caused by pathogens of the genus Enterovirus, which includes polio viruses, Coxsackie A and B, ECHO viruses and human enteroviruses (types 68-72). The disease is manifested by fever, headaches, gastrointestinal tract damage (abdominal pain, nausea, vomiting). Also, with encephalitis, focal symptoms occur, convulsive seizures, rash on the…
Enterovirus infections are a group of infectious diseases that develop when a person is infected with viruses of the genus Enterovirus, characterized by a variety of clinical manifestations. Infection with enteroviruses can occur by food, less often by aerosol. Characterized by high fever, malaise, diarrhea, polymorphic skin rashes. Enterovirus infections can occur in the form…
Schistosomiasis is a helminthic disease caused by blood flukes-schistosomes; occurring with toxic-allergic reactions, damage to the gastrointestinal tract or genitourinary organs. The acute period is characterized by fever, papular rashes and itching of the skin; in the chronic stage, cystitis, pyelonephritis, hydronephrosis, colpitis, prostatitis, epididymitis or colitis, hepatosplenomegaly, ascites may develop. Disease is diagnosed due…
Plague is a highly contagious bacterial infection with multiple transmission routes and epidemic spread, occurring with fever–intoxication syndrome, lymph node, lung and skin lesions. The clinical course of various forms of plague is characterized by high fever, severe intoxication, agitation, excruciating thirst, vomiting, regional lymphadenitis, hemorrhagic rash, DIC syndrome, as well as its own specific…
Tsutsugamushi is an acute rickettsiosis that occurs with fever, focal vasculitis and perivasculitis of various organs – the central nervous system, heart, lungs, kidneys. Clinical manifestations are characterized by the presence of high body temperature, primary affect, spotty-nodular rash on the skin, generalized lymphadenopathy. Frequent complications are meningoencephalitis, myocarditis, pericarditis, pleurisy, glomerulonephritis, peritonitis. The diagnosis…
Cytomegalovirus infection (CMV) is an infectious disease of viral genesis, transmitted sexually, transplacental, household, blood transfusion. Symptomatically proceeds in the form of a persistent cold. There is weakness, malaise, headaches and joint pains, runny nose, enlargement and inflammation of the salivary glands, excessive salivation. It is often asymptomatic. Disease of pregnant women is dangerous: it…
Chronic viral hepatitis is a group of infectious liver lesions occurring with inflammatory dystrophic-proliferative changes in the parenchyma of the organ. Clinical manifestations are dyspeptic, asthenovegetative and hemorrhagic syndromes, persistent hepatosplenomegaly, liver dysfunction. Diagnostics includes determination of markers of hepatitis B, C, D, F and G in serum; assessment of biochemical liver samples, liver ultrasound,…
Chromomycosis is a chronic infectious disease from the group of deep mycoses caused by fungi of certain species and characterized by a long course. A feature of the clinical picture is the lesion of the skin and subcutaneous tissue mainly of the lower extremities with the presence of specific warty growths. Diagnostics is based on…
