传染病题库英文题目及答案.docx

1、传染病题库英文题目及答案INTRODUCTION OF COMMUNICABLE DISEASESI .TERMS1）Overt infectionIt indicates that after the microorganism enters the host, it not only induces the immune responses of the host but also produces hisomorphological damage and pathological changes through the role of the microorganism or the a

2、llergic reaction of the host. In most infectious disease such as measles most infected host manifested as overt infection. After overt infection ends the microorganism can be eliminated and the hosts acquitted consolidated immunity. In some infectious diseases (such as bacillary dysentery) the immun

3、ity is temporary. A small amount of overtly infected hosts change to carrier state. It is called “convalescent carrier”.2）Incubation periodThis period is from pathogens invading into human body to clinical symptoms appearing. The incubation period of all infectious diseases has a limit of the time (

4、the shortest and longest) and a normal distribution. It is an important evidence of observing, detecting the contact in quarantine work. It is usually equal to the whole period including the pathogen reproduction, transference, location, tissue damage and function changes before the clinical symptom

5、s to occur. The period length is negative relation with the invading quantity of the pathogens. If the pathophysiologic changes are caused by toxins, the incubation period relates with the time of the toxins production and distribution, e.g. bacterial food poisoning. The toxins have been produced be

6、fore eating. The period can be short to a few hours. The period of rabies determines to the location of virus entry(wound).It has a positive relation with the distance of the wound to the central nervous system.3）Latent infectionWhen the microorganism infected the host and localized in some area of

7、the host, it can latently for along time because the hosts immunity is strong enough to locate the pathogen but can wipes it out. When the hosts immunity decreased, overt infection can occurs. Such latent infection is common in some diseases, e.g. herpes simplex, herpes zoster, malaria, tuberculosis

8、 etc. Generally the microorganism can not be excreted during latent infection, which is a different point from carrier state. Not that every infectious diseases has latent infection.4）Sources of infectionThe microorganisms are able to gain to access to the person or animal, establish itself and prol

9、iferate in vivo and excrete pathogen outside the body, such as patients, the person of covert infection, pathogen carriers and infected animals.5）RelapseAfter the patient has entered convalescent period, the temperature has recovered to normal for a period of time, then the pathogen hidden in some t

10、issue reproduce to a certain degree and make the primary symptoms repeatedly, it is called “relapse”.6）RecrudescenceIn the convalescent period of some patients, the temperature has not stably decreased to normal and the fever rise again, it is called “recrudescence”.7）ZoonosesSome natural ecologic e

11、nvironment is suitable to the transmission of infectious diseases among wild animals. These diseases include plague tsutsugamushi disease, leptospirosis, and so on. The human race may be infected when he get into these areas. These diseases are called “zoonoses”.II. QUESTIONS1）Please briefly describ

12、e the manifestations of infectious diseases (infection spectrum).Infectious process starts when microorganisms enter the human host through various ways. Whether the microorganism is eliminated or colonized in the host, it is mainly dependent on the pathogenicity of the pathogen and the immune funct

13、ion of the host.i. Pathogen is eliminated by host immunity: After the microorganism enters the host it can be wiped out by non-specific immunity, and eradicated or eliminated by specific immunity which the host has got before the infectious process.ii. Covert infection: It refers to that the microor

14、ganism only making the host producing specific immune response not having histomorphological damage or even having mild feature after it enters the host. Clinically, there is no any symptoms and signs or any biochemical changes.iii. Overt infection: It indicates that after the microorganism enters t

15、he host, it not only induces the immune responses of the host but also produces hisomorphological damage and pathological changes through the role of the microorganism or the allergic reaction of the host.iv. Carrier states: It is divided into virus carrier and bacteria carrier according to differen

16、t pathogens. All carrier states have a common characteristic that is no clinical manifestation but the microorganism can be excreted during the state.v. Latent infection: When the microorganism infected the host and localized in some area of the host, it can latently for a long time because the host

17、s immunity is strong enough to locate the pathogen but can not wipe it out. When the hosts immunity decrease, overt infection can occurs.2）Please briefly describe the factors related to the pathogenicity of the pathogen in the infectious process.i. Invasiveness: It refers to its ability to invade th

18、e host and spread within the host.ii. Virulence: It includes the toxins and various enzymes.iii. Number of the pathogen: The number of invading pathogen is positive relation with the pathogenicity in the same infectious disease. The least number of the pathogen to induce disease differ greatly in di

19、fferent diseases.iv. Variability: Pathogens can produce variation due to environmental and hereditary factors. Generally speaking, under the environment of artificial culture, the pathogenicity of the pathogen will decrease. The repeated spread between the hosts will increase the pathogenicity of th

20、e pathogen. The antigenic variation of the pathogen will make the pathogen escape form the specific immunity of the host and continue induce the disease.3）Please briefly describe the basic characteristics of infectious diseases.i. Pathogen: Every infectious disease is caused by a specific pathogen i

21、ncluding microorganism and parasite. In history many infectious diseases were first understood by their clinical manifestations and epidemiologic feature and then the pathogen was found.ii. Infectivity: Infectivity means that the pathogen can be excreted to contaminate the surrounding. It is the mai

22、n distinction between the infectious diseases and other infection. Every infectious disease has considerably a stable infective period, which can be used as a rule to isolate the patient.iii. Epidemiologic feature: Under the influence of natural and social factors the infectious process manifestates

23、 various characteristics. It can be divided into the exoticity and the endemicity. It also can be divided into sporadic, epidemic and pandemic. The distribution of the incidence of the infectious disease in time (seasonal distribution), in space (regional distribution) and different populations (age

24、, sex, and occupation) is also an epidemiologic feature.iv. Postinfection immunity: The host can produce specific protective immunity which is directed at the pathogen or its products after the host was infected by the pathogen. Postinfection immunity belongs to active immunity. The lasting time of

25、postinfection immunity varies with different infectious.VIRUS HEPATITIS BI .TERMS1) Dane particleThe complete HBV is called Dane particle. The 42-nm Dane particle is made up of an outer shell 7 nm thick, containing the hepatitis B surface antigen, glucoprotein and cellular fat, and an inner core 28

26、nm in diameter, which possesses its own specific antigen, the hepatitis core antigen (HBcAg). The Dane particle core can be broken down by treatment with detergent to reveal a DNA polymerase and a double stranded circular DNA genome that can serve as a primary template in vitro for the DNA polymeras

27、e.2) Window phaseAnti-HBc IgM persists 6 to 18 months, so represents an acute response to a newly infection of HBV in acute cases who have cleared the HBsAg but have not demonstrated detectable amounts of anti-HBs, anti-HBc and anti-HBe can be detectable, the serologic gap is called window phase. In

28、 this case, anti-HBc IgM may be the only evidence for diagnosing an acute HBV infection.3) HBsAgIt stands for Hepatitis B surface antigen. It is coded for the protein of the viral envelope by the S gene. There are four antigenic subtypes of HBsAg. They are adr, adw, ayr, and ayw. HBsAg is non-infect

29、ious itself, but HBsAg-positive blood should be considered potentially infectious because it may contain complete HBV (Dane particles).4) Chronic HBsAg carrierSome persons infected with hepatitis B virus develop mild chronic infection state that is asymptomatic and not associated with any significan

30、t liver function tests abnormality except persistent serum HBsAg-positive more than 6 months. However, liver biopsy reveals that only a minority of them is with normal histology; and the majority cases present morphologic liver damage in varying degrees, ranging form minimal inflammation, chronic pe

31、rsistent hepatitis, chromic active hepatitis, or even cirrhosis.5) HBV DNAHepatitis B virus (HBV) contains a small circular DNA molecule that is partially double-stranded, the DNA consists of a long strand (L) of constant length (3,200 bases) in all molecules and a short strand, which varies in leng

32、th between 1,700-2,800 bases in different molecules. A DNA polymerase activity in the virion repairs the single-stranded molecules of 3,200 bases pairs. The four open reading frames of the HBV are termed S, C, P and X.II. QUESTIONS1) Please briefly describe the regions of the HBV gene and the protein they code for.The four open reading frames of the HBV are termed S, C, P and X. The S region codes for the protein of the viral envelope and is divided into the S gene, pre-S1 region and pre-S2 region. The C gene codes for the core protein. The P region, codes for the viral DNA poly