1 State Key Laboratory for Diagnosis and Treatment of Infectious Diseases Introduction of...

State Key Laboratory for Diagnosis and Treatment of Infectious Diseases 11

Introduction of Introduction of Communicable DiseasesCommunicable Diseases

Department of Infectious Diseases,First Affiliated Hospital, School of Medicine

RUAN Bing


Introduce myselfIntroduce myself

M.D. & Ph.D RUAN BingM.D. & Ph.D RUAN Bing 阮冰阮冰

Professor; Doctoral advisor;

Vice-Director of Infectious

Diseases Department

Office: 87236585; Mobile ：13858182230

Email: [email protected]


传染病学科简介传染病学科简介

19961996 年年

20012001 年年

20062006 年年20072007 年年

卫生部卫生部病毒性传染病病毒性传染病重点实验室重点实验室

卫生部卫生部病毒性传染病病毒性传染病重点实验室重点实验室

19561956 年年

国家重点学科国家重点学科内科学内科学

（传染病）（传染病）

国家重点学科国家重点学科内科学内科学

（传染病）（传染病）

浙江省传染病浙江省传染病重点实验室重点实验室

浙江省传染病浙江省传染病重点实验室重点实验室

传染病诊治传染病诊治国家重点国家重点实验室实验室

传染病诊治传染病诊治国家重点国家重点实验室实验室

传染病科和传染病科和传染病研究所传染病研究所

创建创建

传染病科和传染病科和传染病研究所传染病研究所

创建创建学科整体学科整体水平进一水平进一步提升！步提升！

学科整体学科整体水平进一水平进一步提升！步提升！

卫生部传染病卫生部传染病重点实验室重点实验室

卫生部传染病卫生部传染病重点实验室重点实验室

20022002 年年

5555 年前艰难创业，近年蓬勃发展年前艰难创业，近年蓬勃发展


19561956

19561956

1997199720062006


ConceptionConception

Communicable diseases:

caused by various pathogens, transmitted to

others, spread in the population

Infectious diseases:

caused by infection


Why we learn?Why we learn?

In histry, many pestilences were rampant. plague, cholera, smallpox, influenza, malaria,

schistosomiasis, kala-azar



AchievementsYear Scientist achievement

1683 Leeuwen hoek found bacteria

1796 Edward Jenner smallpox vaccine

1876 Robert Koch bacteria of anthrax, cholera, tuberculosis

1880 Louis Pastear vaccines against anthrax, rabies

1892 Dmitri Ivanowsk filterable virus

1898 Beijerinck pick up the virus

1921 Leon Calmette, Camile Guerin B.C.G.Vaccine

1928 Alexander Fleming penicillin

1942 Selmen Waksman streptomycin

1961 Abraham cephalosporin

Controlled and eradicated: smallpox, poliomyelitis, plague, cholera, measles



Many diseases are still popular.

— viral hepatitis, HFRS, infectious diarrhea

— zoonoses (foot and mouth disease, plague,

anthrax, rabies, tuberculosis)



Some “old” diseases are re-emerging

— Tuberculosis

— Schistosomiasis

— Cholera

— Syphilis

— Measles



Some “new” diseases are emerging — Pathogens found in some non-infectious diseases

Helicobacter pyloyi

— Pathogens found in some infectious diseases

hepatitis C/E, lyme disease, legionellosis

— New appeared disease

AIDS, SARS, human avian influenza,

resistant mutants



bioterrorism

— Pathogens may be used as biological weapon

(anthrax, plague, smallpox, Ebola)


Characteristics

Diagnosis

Treatment

Prevention

Communicable diseases

Infection & immunity

Epidemic process


Infection and immunityInfection and immunity Infection and immunityInfection and immunity

13

Section 1


Conception of infectionConception of infection

Infection ： interaction between pathogen and host

Infectious disease ： biochemical, physiologic,

metabolic and immunologic manifestation of the

interaction

How infection occur?

— pathogenic organisms

— human reactions

"opportunistic infection"

environmental factors


Infection spectrumInfection spectrum

(1) Pathogen is eliminated or eradicated

(2) Covert infection

(3) Overt infection

(4) Carrier state

(5) Latent infection


(1) Pathogen is eliminated or eradicated

Non-specific immunity barrier

Specific immunity

— active immunity

— passive immunity


Only make the host producing specific immune response

Not having histomorphological damage

— no symptoms and signs

— no any biochemical changes

— only discovered by immunological examinations

Pathogens can be eradicated or carried

(2) Covert infection


Make the host producing specific immune

response

Having pathological changes

Immunity can be consolidated or temporary

(3) Overt infection


No clinical manifestation but microorganism

excreted

Various forms:

— virus or bacteria carrier

— convalescent, healthy or incubatory carrier

— acute or chronic carrier

(4) Carrier state


Locates the pathogen but can not wipes it out

Can latently for a long time

Can occurs overt infection

What is the different point between latent

infection and carrier state ?

(5) latent infection


The role of pathogen in the infectious processThe role of pathogen in the infectious process

(1) Invasiveness

(2) Virulence

(3) Amount of the pathogen

(4) Variability


Invade directly — Leptospira, Filariform larva of Ancylostoma

Adhere, colonize and produce enterotoxin — Vibrio cholera

Promote spread

— Vi antigen of Salmonella typhi

(1) Invasiveness


Toxins

— Exotoxin (Vibrio cholera ， Corynebacterium diphtheriae,

Clostridium tetani)

— Endotoxin (S. typhi, Sh. dysentery)

Enzymes

(Entamoeba histolytica)

(2) Virulence


Positive relation with pathogenicity

Least number differ greatly

(3) Quantity of pathogens


Factors:

— environmental, drug and hereditary

Various forms:

— pathogenicity variation

— antigenic variation

— drug-resistant variation

(4) Variability


The role of individual immunity in the infectious processThe role of individual immunity in the infectious process

(1) Non-specific immunity

(natural immunity)

— anatomic barriers, phagocytosis, humoral effects

(2) Specific immunity

(acquired, adaptive, or postinfection immunity)

— cell-mediated immunity, humoral immunity


Epidemic process & influenced factorsEpidemic process & influenced factorsEpidemic process & influenced factorsEpidemic process & influenced factors

27

Section 2


Essential conditions of epidemic processEssential conditions of epidemic process

(1) Sources of infection

(2) Routes of transmission

(3) Susceptibility of the population


Patients — measles

Persons of covert infection — poliomyelitis, epidemic cerebrospinal meningitis

Pathogen carriers — typhoid fever, bacillary dysentery

Infected animals — rabies, plague, leptospirosis, scrub typhus

(1) Sources of infection


Air transmission

Water and food transmission

Contagious transmission

Arthropod-bone transmission (blood-sucking arthropods: mosquito, lice, flea, sandfly, mite, tick)

Blood, blood products and body fluid

Mother to infant (vertical transmission)

(2) Routes of transmission


The ratio of susceptible persons decide the crowd

susceptibility

The crowd susceptibility is relation to periodicity

of an epidemic

The periodicity of an epidemic may be prevented

by artificial active immunization

(3) Susceptibility of the population


Influenced factors of epidemic processInfluenced factors of epidemic process

Natural factors — geography; climate; ecology

— focus of infection

— zoonosis (plague, leptospirosis, human avian influenza)

Social factors — social background; economical condition;

cultural level; anti-epidemic measures


Characteristics of communicable diseasesCharacteristics of communicable diseases Characteristics of communicable diseasesCharacteristics of communicable diseases

33

Section 3


Basic characteristicsBasic characteristics

(1) Pathogens

(2) Infectivity

(3) Epidemiologic feature

(4) Postinfection immunity


Specific

Be found with natural science

advancements

(1) Pathogens


As main distinction

“Infective period”

(2) Infectivity


Endemic (sporadic occurrence, epidemic,

pandemic & epidemic outbreak)

Seasonal (distribution in time)

Regional (distribution in space)

Exotic

(3) Epidemiologic feature


Specific, active, protective

Can transfer to newborns through placenta

Lasting time varies with the diseases

“Concomitant immunity” (helminthiasis)

(4) Postinfection immunity


The phase in the development of clinical courseThe phase in the development of clinical course

(1) Incubation period

(2) Prodromal period

(3) Period of apparent manifestation

(4) Convalescent period


Normal distribution (quarantine evidence)

Related with:

— invading quantity of pathogens

— time of the toxin (bacterial food poisoning)

— wound location (rabies)

(1) Incubation period


Non-specific

— headache, fever, fatigue, anorexia, and myalgia

Coexist in many infectious diseases

Usually persist one to three days

even miss (sudden onset)

(2) Prodromal period


Special symptoms and signs presented enough

— rashes, jaundice, heptomegaly, splenomegaly,

meningeal irritation signs

Especially in some acute diseases

— measles & varicella

Abortive type

— poliomyelitis, epidemic encephalitis

(3) Period of apparent manifestation


Immunity increases to a certain level — appetite and physical strength recovered

— residual pathologic & biochemical change

— infectivity may persist (convalescent carrier)

Relapse & recrudescence

— the symptoms repeatedly and fever rise again

(4) Convalescent period


Common symptoms and signsCommon symptoms and signs

Fever

Rash (eruption)

Toxemic symptoms

Mononuclear phagocyte system (MPS)


Three phases — effervescence, fastigium, defervescence

Fever types — sustained — remittent — intermittent — irregular

Fever


Exanthem and enanthem

Appearing, distribution, order, shape

Four groups: (a) mocule & papule (b) petechia & ecchymosis; (c) vesicle & pustule; (d) urticaria

Rash (eruption)


A lot of non-specific symptoms — fever, fatigue, general malaise, anorexia, headache,

myalgia, arthralgia, skeletal pain

In severe patients: — disturbance of consciousness, delirium, meningeal

irritation, toxic encephalopathy, respiratory and

circulatory failure (septic shock)

Toxemic symptoms


Liver

Spleen

Lymph nodes

enlarged

Reactions of MPS


Diagnosis of communicable diseasesDiagnosis of communicable diseases Diagnosis of communicable diseasesDiagnosis of communicable diseases

49

Section 4


Clinical dataClinical data

Detailed history

— way of an onset

— symptoms, accompanied ones

Careful physical examination

— specific signs (rose spot, eschar, Kopliks spots)


Epidemiological dataEpidemiological data

Age, occupation, season and district

Inoculation history and past history

Occurrence in the local or the same unit

Family history


Laboratory data Laboratory data

General laboratory detection

Detection of pathogens

Immunoassay


Method Significance (e.g.)

leucocytes count pyogenic infections

urine routine test leptospirosis

stool routine test helminthiasis

biochemical detection viral hepatitis

General laboratory detection


Method Pathogens (e.g.)

Direct

detection

microscope or

macroscopy

malarial parasites

Isolation with artificial culture

medium

bacteria, spirochete, fungi

Molecular

biological assay

hybridization assay,

polymerase chain

reaction (PCR)

specific viral nucleic acid

(such as HBV DNA)

Detection of pathogens


Laboratory Significances

Serologic

test

enzyme linked immunosorbent assays (ELISA)

immunofluorescence technique

radio-immunoassay (RIA)

specific antibody

Others skin test

detection of immunoglobulin

classification of lymphocytes subsets

humoral immunity

cellular immunity

Immunoassay


Treatment of communicable diseasesTreatment of communicable diseases Treatment of communicable diseasesTreatment of communicable diseases

56

Section 5


General and supportingGeneral and supporting

General therapy

— Isolation, nursing care and psychologic care

Supporting therapy

— Nutrition, balance of water and electrolytes,

Enhancement of immunity by blood

and biologic products transfusion


Anti-pathogenicAnti-pathogenic

Antibiotics

Chemical drugs

Immune serum preparations


SymptomaticSymptomatic

Ease patient’s suffering

Reduce his energy consuming

Protect the main organs from injury

Maintain his functions


Prevention of communicable diseasesPrevention of communicable diseases Prevention of communicable diseasesPrevention of communicable diseases

60

Section 6


ManagementManagement of the sources of infectionof the sources of infection

Diagnosis & treatment

Isolation of patient & carrier

Report disease to CDC

In time


Group Diseases

Group A plague, cholera

Group B infectious atypical pneumonia (SARS), AIDS, viral hepatitis, poliomyelitis, avian influenza, measles, epidemic hemorrhagic fever, rabies, epidemic encephalitis B, dengue fever, anthrax, bacillary and amebic dysentery, pulmonary tuberculosis, typhoid fever and paratyphoid fever, epidemic cerebrospinal meningitis, pertussis (whooping cough), diphtheria, tetanus in neonate, scarlet fever, brucellosis, gonorrhea, syphilis, leptospirosis, schistosomiasis, malaria

Group C influenza, mumps, rubella, acute hemorrhagic conjunctivitis, leprosy, epidemic typhus and endemic typhus, kala-azar, hydatid disease, filariasis, other infectious diarrhea

The lawful communicable diseases in China


Interruption of the route of transmissionInterruption of the route of transmission

Achievement in:

— diseases transmitted by food, water and insets

— parasitic diseases

Methods:

— disinfection, insecticide,

hygiene measures


Protection of susceptible populationProtection of susceptible population

Special immunological method

— active: vaccine, bacterial vaccine, toxoid

— passive: antitoxin, γ- globulin, immunoglobulin

Non-special immunological method

— improvement of nutrition

— physical training


The procedure of a childhood program for immunization The procedure of a childhood program for immunization

Age Vaccine

Neonate BCG HBV

1 months after birth HBV

2 months after birth OPV

3 months after birth OPV DTP

4 months after birth OPV DTP

5 months after birth DTP

6 months after birth HBV

8 months after birth MV

Enhanced: 1.5-2 years DTP

4 years OPV

7 years BCG MV DT


QuestionsQuestions

ReviewsReviews


Pathogen is eliminated or eradicated by host immunity

Covert infection

Overt infection

Carrier state

Latent infection

Conception of infection spectrum ?


Invasiveness

Virulence

Amount of the pathogen

Variability

The role of pathogen in the communicable diseases ?


Sources of infection

Routes of transmission

Susceptibility of the population

Essential conditions of epidemic process with communicable diseases ?


Conception of zoonosis ?

Some natural ecologic environment is suitable to

the transmission of infectious diseases among

wild animals. This area is called “focus of

infection”. The human race may be infected when

they get into these areas. This disease is called

“zoonosis”, such as plague, leptospirosis, human

avian influenza, and so on.


Pathogen

Infectivity

Epidemiologic feature

Postinfection immunity

Basic characteristics of communicable diseases ?


Incubation period

Prodromal period

Period of apparent manifestation

Convalescent period

The clinical phase in the development of acute communicable diseases ?


Management of the sources of

infection

Interruption of the route of

transmission

Protection of susceptible population

Prevention of communicable diseases ?


The system of communicable diseases notification?

It is an important method for discovering communicable

diseases in early, and must be followed.

According to the law of prevention and treatment of

communicable diseases of the People’s Republic of

China and its detailed rules and regulation, the lawful

infectious diseases were divided into three groups.

Group A (plague, cholera) must be reported in 2 hours

in town and 6 hours in rural area, while Group B in 6 and

12 hours, and Group C in 24 hours as well.


ThanksThanks!!

谢谢！谢谢！

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