/kloc-There was a plague epidemic in the 0/4th century, which was called the "Black Death" at that time. It was popular in Asia, Europe, North Africa and also in China. In Europe, the Black Death raged for three centuries, killing more than 25 million people. The pathogen that caused the plague was carried by fleas hidden in the fur of black mice. /kloc-in the 0/4th century, there were many black mice. Once the disease occurs, it will spread quickly. Many people died of the Black Death, so that the labor force lacked food. The whole village is deserted, the farmland is deserted, and the grain output is declining. Famine occurred in many parts of Europe after the Black Death. The labor force is scarce and the economy has been hit hard.

Who knows the detailed history of the Black Death in Europe?

Etiology, Specific Cases and Treatment of the Black Death in Europe

What kind of disease is the Black Death?

How did the Black Death that ravaged Europe disappear?

Can plague and black death be treated?

Who discovered the man who could cure the Black Death?

the spanish flu

The disaster caused by the Spanish epidemic is the worst in the history of influenza epidemic, and it is also the plague with the largest number of deaths in history. It is estimated that the number of patients worldwide exceeds 700 million, the incidence rate is about 20% ~ 40%, and the death toll exceeds 40-50 million. Studies by American scientists show that the Spanish influenza virus that killed 50 million people in1918-1919 probably originated from birds. It's actually a variation of bird flu. Similar to the Black Death, during the flu, the transportation, catering, retail, tourism and entertainment industries were depressed, and hospitals and health services became the biggest winners. It is worth mentioning that the communication industry is developing well.

The Influence of Spanish Influenza on Daily Life

Spanish epidemic, a disease with high mortality in history.

What catastrophic diseases have humans experienced?

There was a plague in Europe, and half the people died. Can you tell us the details?

Why set up hand washing day?

Spanish flu-did anyone die of a cold?

Bovine spongiform encephalopathy

The country of origin is Britain. It is estimated that the death toll is increasing at a rate of about 30% every year. So far, 69 people have died from this epidemic. It has spread to France, Ireland, Canada, Denmark, Portugal, Switzerland, Oman, Germany, Poland, Czech Republic, Hungary, Slovakia, Albania, Estonia, Lithuania and Cyprus. According to CNN, the mad cow disease incident will cause at least billions of dollars in economic losses to the United States.

How to prevent mad cow disease?

If a person gets mad cow disease, will it be transmitted to people who come into contact with him?

Why can't beef infected with mad cow disease virus be eaten?

Why do people get mad cow disease when they eat mad cow disease meat?

About the disaster caused by mad cow disease in Britain

There is no substance in the body of the "culprit" of mad cow disease, only what kind of substance?

foot-and-mouth disease

In 200 1 year, foot-and-mouth disease broke out in Britain, causing nearly 7 million infected livestock to die and burn, and many farmers suffered heavy losses. Most countries in the world, such as America, Canada, Japan, South Korea, Australia, New Zealand and some European countries; Southeast Asian countries, China, Hongkong and Chinese mainland are all "foot-and-mouth disease areas". Foot-and-mouth disease reduced Britain's economic growth rate from the original forecast of 2.3% to 2%, resulting in economic losses of 7 billion pounds. Tourism, one of the pillar industries, was hit hard. According to reports, compared with the same period in 2000, the tourism income in rural areas of Britain alone has decreased by 75%.

Is hand, foot and mouth disease foot and mouth disease?

How to prevent foot-and-mouth disease in livestock?

What medicine does pig foot-and-mouth disease take?

Is there a saying that the foot-and-mouth disease virus will die when the temperature rises to 30 degrees?

Can pasteurization kill foot-and-mouth disease virus

How to treat swine pox, vesicular disease and foot-and-mouth disease?

Severe acute respiratory syndrome

In 2003, SARS broke out in 24 provinces, autonomous regions and municipalities directly under the Central Government in Chinese mainland, affecting 266 counties and cities. As of August 6th 10, there were 5,327 clinically diagnosed cases of atypical pneumonia in Chinese mainland, 4,959 cases were cured and 349 cases died. In 2003, the tourism revenue decreased by about 654.38+0.20 billion yuan, which affected the annual GDP growth by 654.38+0.654.38+0 percentage point. The retail sales of catering industry decreased by about 310.5 billion yuan, which affected the GDP growth by 0.3 percentage points. The overall impact on other consumer goods is small, about 20 billion yuan, affecting GDP growth by 0.2 percentage points. The net export of foreign trade decreased by about $7 billion compared with 2002.

SARS death toll?

Why is SARS not popular in Hainan?

What kind of virus is SARS virus?

What are the similarities and differences between swine flu, avian flu and SARS?

How does SARS virus infect people?

Is SARS a disease name or a virus name?

Highly pathogenic avian influenza (HPAI)

Up to now, 393 people have been infected in 15 countries and regions around the world, of which 248 have died, with a mortality rate of 63%. Since 2003, 3 1 person has been infected with avian influenza in China, and 2 1 person has died. At the beginning of 2004, avian influenza swept across the United States and some Asian countries, and millions of poultry in China, Japan, Viet Nam and other countries were infected and died, and many people may have died of avian influenza virus. By the end of 2005, bird flu has caused more than 65.438+0.5 billion birds to be culled, 63 people died, and the direct economic loss was as high as 65.438+0.0 billion dollars. The scope spread to agriculture, tourism and other industries. The World Bank predicts that bird flu will cause global economic losses of 800 billion US dollars.

What is avian influenza?

Which country did bird flu originate from?

Transmission route of avian influenza

Symptoms of avian influenza

What is the information about bird flu, AIDS and SARS?

Avian influenza death record

swine flu

Mainly in Mexico, the number of confirmed and suspected deaths of swine flu rose to152; There are more than 4,000 suspected cases in China. The number of confirmed cases in the United States rose to 50, and it also spread to Canada, Britain, France, Germany, South Korea, New Zealand, Australia, Italy and other countries 19. The World Bank predicts that the world will lose $3 trillion and the economic recovery will be greatly affected. Swine flu is likely to spread in two ways, from pigs to people and from people to people.

What are the symptoms of people infected with swine flu virus? How to prevent and treat it?

Face swine flu correctly without panic.

Will swine flu affect the catering industry?

Can antiviral oral liquid prevent swine flu?

Will swine flu affect the market price of live pigs?

What are the transmission routes of swine flu? How to prevent it?

Hope to adopt.

Classification of pathogenic microorganisms 1. Plague is a natural focus disease caused by Yersinia pestis, also known as the Black Death. It's bacteria, prokaryotes.

2. Chickenpox is an acute infectious disease caused by the initial infection of varicella-zoster virus (VZV).

Smallpox is a serious infectious disease caused by smallpox virus, and it is also the first infectious disease that has been eliminated by human beings in the world so far.

4. Bovine spongiform encephalopathy

Bovine spongiform encephalopathy (BSE), commonly known as mad cow disease, is a progressive infectious disease of bovine nervous system caused by infectious factors. The main feature of the disease is bovine spongiform encephalopathy, accompanied by brain function degradation, and its clinical manifestations are insanity, dyskinesia, dementia and death.

The pathogen is uncertain, and the medical community has different opinions and has not proved it.

5, foot-and-mouth disease

Acute, hot and highly contagious infectious diseases caused by foot-and-mouth disease virus (FMDV). It mainly affects cloven-hoofed animals, showing fever, blisters and ulceration on oral mucosa, hoof and skin. It is a Class A infectious disease stipulated by the International Bureau of Animal Diseases. It is easy to spread through the air, highly contagious, and spreads rapidly. Occasionally, people are infected, mainly in people who are in close contact with infected animals, and most of them are subclinical infections.

6. Malaria

There are four kinds of plasmodium parasitic on human body, namely vivax malaria, falciparum malaria, three-day malaria and ovoid malaria. Plasmodium proliferates in red blood cells to form merozoites, so that when red blood cells swell and rupture, a large number of merozoites and metabolites of plasmodium enter the blood stream, causing foreign protein reaction, muscle contraction and heat production, and the phagocytosis of reticuloendothelial system is enhanced, which can cause hepatosplenomegaly, anemia and so on. It takes different time for plasmodium to proliferate and mature in red blood cells. Plasmodium vivax and ovomalarial are 48 hours, Plasmodium vivax is 72 hours, and Plasmodium falciparum is 24-48 hours, so there are periodic attacks in clinic. Plasmodium is a unicellular parasitic prokaryote.

7. Escherichia coli is one of the most famous bacteria and prokaryotes in human and animal intestines.

8. Pseudomonas aeruginosa widely exists in nature, and it is a common bacteria and prokaryote of wound infection.

Generally all bacteria are bacteria. Viruses are microorganisms, have no cell structure, and are neither prokaryotic nor eukaryotic.

9. The Black Death, Plague, Smallpox and Influenza used to be called the four plagues, but now they are not.

What pathogenic microorganisms are there in domestic sewage? Please describe the types and names of microorganisms. From the point of view of environmental engineering, the total number of bacteria contained in sewage has a certain relationship with water pollution and treatment degree, but it cannot directly explain whether there are pathogenic microorganisms. The indicator bacteria of fecal pollution generally means that if there are indicator bacteria in the water, it means that the water has been polluted by feces, and there may be (note that this is "possible") intestinal pathogenic microorganisms. Then the water quality is unsafe in health, but the impact on people still varies from person to person.

Commonly used indicator bacteria or other indicator microorganisms include: total coliform, fecal coliform, fecal streptococcus, Clostridium perfringens, Bifidobacterium, enterovirus, Escherichia coli phage, Salmonella, Shigella, Pseudomonas aeruginosa, Staphylococcus, Vibrio parahaemolyticus, etc. In addition, there are aquatic fungi, actinomycetes and nematodes. This is an index of some harmful bacteria in the evaluation of surface water and tap water quality, and sewage is also applicable. After all, tap water pays more attention to people's health and diseases. There are many kinds and names of microorganisms, and the above are basically the main ones. It is estimated that it will be published in full soon. This is probably not clear in one or two sentences. Environmental science, medicine and health diseases need to be answered together.

It should be noted that what I said here in the last paragraph is indicator microorganisms, that is to say, the probability of treating diseases when these microorganisms exist is very high, but it cannot be said that these microorganisms are the root of human diseases, which depends on a series of complex factors such as human immunity and the number of microorganisms.

Infectious diseases are caused by pathogens and can spread between people or between people and animals. Pathogens include viruses, bacteria, fungi and parasites. Infectious diseases are infectious and epidemic.

Basic links in the epidemic of infectious diseases:

Infectious diseases can spread among people, and they must have three basic links at the same time: the source of infection, the route of transmission and the susceptible population. Without any of them, infectious diseases can't be prevalent.

(1) Source of infection: a person or an animal that can transmit pathogens.

(2) Transmission route: the way for pathogens to leave the source of infection and reach healthy people. There are mainly air transmission, saliva transmission, water transmission, food transmission, biological media transmission, contact transmission and so on.

(3) Susceptible population: people who lack immunity to an infectious disease and are susceptible to the disease.

Factors affecting the growth and reproduction of common pathogenic microorganisms temperature

nutrient

PH value (pH value of a solution or substance)

Air (except oxygen-free)

Anti-virus agent

It can be considered from the structure of microorganisms and so on.

1, breathing provides energy-oxygen and nutrients are needed.

2. Microorganisms have protein-

three ...............................................................................................................................................................................

Microorganisms, such as bacteria, have cell walls, so those that affect their cell wall synthesis will not work.

What are the pathogenic microorganisms in the air, such as Staphylococcus albus, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella, Escherichia coli, diphtheria, pneumococcus and tuberculosis, virus particles, amoeba cysts, rickettsia, etc.

What are the basic links in the epidemic of infectious diseases? The spread of infectious diseases in bee colonies must have three basic links: the source of infection, the route of transmission and susceptible animals.

Schematic diagram of three basic links in the epidemic process of infectious diseases

(Animal-like Epidemiology, 1980)

(1) The source of infection refers to the bees whose pathogens parasitize, grow, reproduce and can be excreted continuously.

(2) Transmission route refers to the way that pathogens are discharged from the source of infection and then invade other susceptible animals in a certain way.

(3) Bee colony susceptibility is the antonym of resistance, which refers to the susceptibility of bee colony to a certain disease.

What is a pathogenic microorganism? What kinds of pathogenic microorganisms can cause human and animal diseases? There are eight types of pathogenic microorganisms:

1. Fungi: cause panel diseases. Deep tissue infection.

Actinomycetes: panel, wound infection.

Borrelia: facial diseases, blood infections such as syphilis and leptospirosis.

Bacteria: face plate disease suppuration, upper respiratory tract infection, urinary tract infection, food poisoning, septicemia, acute infectious diseases, etc.

Rickettsia: typhus, etc.

6 according to the original body: trachoma, urogenital tract infection.

Viruses: hepatitis, Japanese encephalitis, measles, AIDS, etc.

Mycoplasma: pneumonia, urinary tract infection.

There are thousands of kinds of microorganisms in the biological world, most of which are beneficial to human beings, and only a few can cause diseases. Some microorganisms are usually not pathogenic, but can cause infection under certain circumstances, which is called conditional pathogenic bacteria. It will cause food to deteriorate and rot, and it is precisely because they decompose natural things that nature can complete the material cycle.

Microorganisms refer to those biological groups whose individual volume and diameter are generally less than 65438±0mm, and their structures are simple, mostly single cells, and some even have no cell structure. People usually use microscopes or electron microscopes to see their shapes and structures clearly. It should be noted that microorganism is a relatively general concept, and the boundaries are sometimes very vague. For example, unicellular algae and some protozoa should also be considered microorganisms, but they are usually not studied in microorganisms.

According to the classification proposed by Chinese scholars, organisms are divided into six kingdoms: virus kingdom, monera kingdom, protozoa kingdom, fungi kingdom, plant kingdom and animal kingdom. It is not difficult to see that microorganisms occupy four of the six realms, so the important position of microorganisms in nature is obvious, and its research objects are also very extensive and rich.

Microorganism (Microani ***) is a general term for a group of microorganisms that are widely present in nature and invisible to the naked eye, and must be magnified hundreds, thousands or even tens of thousands of times by means of optical microscope or electron microscope. They have the advantages of small size, simple structure, fast reproduction, easy variation and strong adaptability to the environment.

There are many kinds of microorganisms, at least more than100000. According to their differences in structure, chemical composition and living habits, they can be divided into three categories.

1. Eukaryotic microorganisms have a high degree of nuclear differentiation, including nuclear membranes, nucleoli and chromosomes; There are complete organelles (such as endoplasmic reticulum, ribosome and mitochondria) in cytoplasm. Fungi belong to this kind of microorganisms.

Second, the degree of nuclear differentiation of prokaryotic microorganisms is low, with only primitive nucleoplasm, no nuclear membrane and nucleoli; The organelles are not perfect. There are many kinds of such microorganisms, including bacteria, spirochetes, mycoplasma, rickettsia, chlamydia and actinomycetes.

3. Cell-free microorganisms have no typical cell structure and no enzyme system to produce energy, and can only grow and reproduce in living cells. Viruses belong to this type of microorganism.

Another classification of microorganisms is non-pathogenic microorganisms and pathogenic microorganisms.

Pathogenic microorganisms refer to microorganisms that can cause some diseases of animals and plants, accounting for a small number. For example, influenza virus can cause human and domestic avian influenza. Others are conditional pathogens.

Most of them are non-pathogenic and even beneficial microorganisms, which widely exist in nature and the mucosal surface of human panels.

What are the pathogenic microorganisms in dairy products? At present, the national standards for milk powder testing in China mainly include protein, fat and microorganism. Microbial detection includes Salmonella, Shigella, Staphylococcus aureus, Listeria, Yersinia, Campylobacter jejuni, Escherichia coli O 157: H7, Vibrio parahaemolyticus, Vibrio cholerae, Vibrio vulnificus and Vibrio alginolyticus, and Enterobacter sakazakii is the key content in microbial detection. For technical details, please refer to the standard SN/T 1632.3-2005 "Detection Method of Enterobacter sakazakii in Milk Powder" adopted in May 2005. The standard stipulates that real-time fluorescence quantitative PCR instrument must be used.

Real-time fluorescence quantitative PCR instrument is an advanced molecular biological pathogen detection instrument, which is necessary for food safety. The national laws and regulations (SN/T 1870-2007 "Real-time fluorescent PCR detection method for pathogenic bacteria in food") have stipulated this instrument as a necessary detection equipment for food production enterprises to apply for production licenses.

It is understood that the real-time fluorescence quantitative pcr instrument does not need to choose expensive imported instruments. Domestic TL988 real-time fluorescence quantitative pcr instrument has been widely used in the inspection and quarantine of food industry, and has been recognized by users and industry!