ESPECIALLY DANGEROUS DISEASES OF ANIMALS AND PLANTS
Especially dangerous infectious animal diseases – diseases for which characterized by the presence of a specific pathogen, the development cycle, the ability to transmit from infected animal to healthy and take nature of the epidemic.
The wide spread of epizootic process occurs in three forms: sporadic incidence, epidemic, pantote.
Sporidia is the low intensity of the epizootic process is a single or infrequent instances of infectious disease, usually unrelated single source of pathogen infections.
Epizootic – widespread contagious diseases of animals on the farm, district, region, country, characterized by common source of the pathogen, the lesion simultaneity, periodicity, and seasonality. Represents the average degree of intensity (tension) of the epizootic process.
Pansooti the higher the degree of development of the epidemic, it is characterized by an unusually broad spread of infectious disease, covering one state, several countries, the mainland. In recent years examples of such are pansooti bird flu, an intestinal infection of unknown etiology. So, when mass krupnoporistogo disease of cattle spongiform encephalitis in England had to take emergency measures to prevent the infection spread on the European continent: hundreds of thousands of animals were destroyed, the country suffered huge losses, running into billions of dollars.
Depending on the mode of transmission of infectious diseases fall into five groups:
1) alimentary (transmitted via soil, food, water) – for example, foot and mouth disease, anthrax, glanders and brucellosis;
2) respiratory or airborne (transmitted by droplets) – for example, parainfluenza, smallpox of sheep and goats, canine distemper;
3) vector-borne (transmitted by biting insects) – for example, tularemia, infectious anemia of horses;
4) infection, pathogens which are transmitted through the outer skin without the participation of carriers, such as tetanus, rabies, smallpox cows;
5) infections with no identified routes of infection.
FMD – vysokozaraznoe acute viral disease of cloven-hoofed domestic and wild animals. Symptoms: fever and ulcerative lesions of the mucous membrane of the mouth, skin of the udder and extremities.
Most FMD-susceptible cattle and pigs. Source pathogen – sick animals and virus carriers. They shed the virus in saliva, milk, urine and feces, resulting in contamination of the premises, pastures, water sources, feed, vehicles.
Great importance in the spread of FMD virus has people. After contact with animals it can travel long distances, spreading the virus.
Classical swine fever – a highly contagious infectious viral disease of domestic and wild pigs of all ages and breeds. More susceptible to the virus vysokoporodnyh animals.
The main source pathogen – sick animals and virus carriers. Infection occurs when their joint substance from healthy animals, as well as when fed infected feed. Plague can occur at any time of the year, but more often in autumn, during mass movement, sale and slaughter of pigs. New outbreaks in unvaccinated livestock becomes ill at 95-100 %, the mortality rate reaches 100 %. There is no specific treatment, sick animals are immediately killed and the corpses burned.
Pseudocode birds is a highly contagious viral disease of gallinaceous birds that affects the respiratory and digestive system, Central nervous system.
Source pathogen – sick and recovered birds shed the virus with all the secrets, excreta, eggs and exhaled air. Infection occurs through food, water, air in case of joint content of healthy and sick birds. Morbidity 100 %, mortality was 60-90 %.
Specific treatment is not developed. Sick birds are killed and burned, and the economy impose a quarantine.
Especially dangerous diseases of plants is the disruption of the normal metabolism of plants under the influence of fitopatogene or adverse environmental conditions, resulting in lower plant productivity and deterioration in the quality of seeds (fruits) or their complete destruction.
Epidemics is the spread of infectious diseases of plants over a large territory for a certain period of time.
The most malicious sporadically observed in years with mild winters, warm spring and cool wet summer. The grain yield is often reduced to 50 %, and in years with favourable for the fungus (Phytophthora, LPV), the yield can reach 90-100 %.
Potato late blight is a widespread harmful disease leading to loss of crops due to the premature death of the affected plant during the formation of tubers and their mass of rotting in the ground. The causative agent of late blight is a fungus, which during the winter is stored in the tubers. He attacks all ground parts of plant. The disease is detected, usually in late summer. Yield losses reach 15-20% and more.
Yellow rust of wheat – malicious common fungal disease that affects wheat in addition to barley, rye and other cereals. Mainly, the infection is in the presence of moisture and a temperature of +10. +20 °C. In areas with dry and hot climate is very rare.
Stem rust of wheat and rye – the most harmful and widespread disease of cereals, most often affecting wheat and rye. The causative agent – the fungus that destroys the stems and leaves of plants – has a high fertility, so the disease spreads very easily in a short time, damaging large areas of crops. The most dangerous foci of stem rust of wheat and rye are located on Kuban and in Stavropol territory.
1. Biological hazards and their causes. Give examples of biological hazards.
2. The causative agents of infectious diseases. Peculiarities of the action of bacteriological methods of warfare. The signs of accredit.
3. Epidemic, pandemic, epidemic, epidemics.
4. Characteristic of dangerous and particularly dangerous infectious diseases.
5. The actions of the people in the bacteriological destruction.
6. Characteristics of the main anti-epidemic measures.
7. Using literature, make the analysis of major epidemics, epizootics and epiphytoties in the last 5 years in your area.