COMMUNICABLE DISEASE

Views:
 
Category: Entertainment
     
 

Presentation Description

No description available.

Comments

Presentation Transcript

CLASSIFYING DISEASES:

CLASSIFYING DISEASES Acute Diseases Acute diseases are those conditions in which the peak severity of symptoms occurs within three months ( usually sooner ), and recovery in those who survive is usually complete Chronic Diseases Chronic diseases or conditions are those in which symptoms continue longer than three months and in some cases for the remainder of the person’s life. Recovery is slow and sometimes incomplete .

CLASSIFYING DISEASES (cont’d.):

CLASSIFYING DISEASES (cont’d.) Communicable (Infectious) Diseases Diseases for which biological agents or their products are the cause and which are transmissible from one individual to another The disease process begins when the causative agent is able to lodge and grow or reproduce within the body The process of lodgment and growth of a microorganism or virus in the host is termed infection Non-communicable (Noninfectious) Diseases/Illnessses Those diseases or illnesses that cannot be transmitted from an infected person to a susceptible, healthy one Several, or even many, factors may contribute to the development of a given non-communicable health condition The contributing factors may be genetic, environmental, or behavioral in nature

Classification of Diseases Types of Diseases_____Examples______________:

Classification of Diseases Types of Diseases_____Examples______________ Acute Diseases Communicable Common cold, pneumonia, mumps, measles, pertussis, typhoid fever, flu Non-communicable Appendicitis, poisoning, trauma (e.g., (incl. trauma) due to automobile accidence, fires, etc.) Chronic Diseases Communicable Lyme disease, tuberculosis, AIDS, syphilis, rheumatic fever following streptococcal infections, herpes Non-communicable Diabetes, coronary heart disease, osteoarthritis, cirrhosis of the liver dur to alcoholism, hyptertension

Slide 4:

DEATH RATES PER 100,000 POPULATION 1900 - 1989 [Presented on overhead during class. Not available as PowerPoint slide.] _________________________ LEADING UNDERLYING MORTALITY CAUSED BY INFECTIOUS DISEASES IN THE UNITED STATES, 1980 AND 1992 [Presented on overhead during class. Not available as PowerPoint slide.]

Slide 5:

Agent Environment Host

COURSE OF INFECTIOUS DISEASE:

COURSE OF INFECTIOUS DISEASE Exposure/Invasion of Host Incubation -- period of time between exposure and onset of symptoms -- e.g., interval between HIV infection and development of AIDS can be as long as 10-15 years Host reaction Disease runs course -- treatment, recovery/death (most people don’t die from infectious diseases)

INCUBATION PERIOD:

INCUBATION PERIOD Varies by disease Salmonella -- 12-72 hours after infection; symptoms usually resolve in 5-7 days, unless infected person is in a very weakened health status Measles (rubeola) -- approx. 10-12 days (prodomal -- i.e., interval between the earliest symptoms and the appearance of the rash or fever -- rash onset, on average, 14 days HIV -- 6 weeks upward to months; interval between HIV infection and development of AIDS can be as long as 10-15 years 2-6 weeks after infection in many, but not all, diseases, most people develop antibodies against reinfection

Slide 8:

CHAIN OF INFECTION ILLUSTRATION [Presented on overhead in class. Not available as PowerPoint slide]

Slide 9:

[Presented on overhead in class. Not available as PowerPoint slide] HOST, ENVIRONMENT, VECTOR AND AGENT RELATIONSHIPS

MODES OF COMMUNICABLE DISEASE TRANSMISSION :

MODES OF COMMUNICABLE DISEASE TRANSMISSION Direct Transmission Indirect Transmission

DIRECT TRANSMISSION:

DIRECT TRANSMISSION Immediate transfer of the disease agent by direct contact between the infected and the susceptible individuals Occurs through such acts as touching, biting, kissing, sexual intercourse, or by direct projection (droplet spread) by coughing or sneezing within a distance of one meter Examples of diseases for which transmission is usually direct are AIDS, syphilis, gonorrhea, and the common cold

INDIRECT TRANSMISSION:

INDIRECT TRANSMISSION May be one of three types: air-borne, vehicle-borne, or vector-borne Air-borne transmission -- transmission of microbial aerosols to a suitable port of entry, usually the respiratory tract Microbial aerosols are suspensions of dust or droplet nuclei made up wholly or in part by microorganisms -- may be suspended and infective for long periods of time Examples of air-borne diseases include tuberculosis, influenza, histoplasmosis, and legionellosis

INDIRECT TRANSMISSION (cont’d.):

INDIRECT TRANSMISSION (cont’d.) Vehicle-borne transmission -- contaminated materials or objects (fomites) serve as vehicles , nonliving objects by which communicable agents are transferred to a susceptible host The agent may or may not have multiplied or developed on the vehicle Examples of vehicles include toys, handkerchiefs, soiled clothes, bedding, food service utensils, and surgical instruments Also considered vehicles are water, milk, food (e.g., common vehicles) , or biological products such as blood, serum, plasma, organs and tissues Almost any disease can be transmitted by vehicles, including those for which the primary mode of transmission is direct, such as dysentery and hepatitis

INDIRECT TRANSMISSION (cont’d.):

INDIRECT TRANSMISSION (cont’d.) Vector-borne transmission -- disease transfer by a living organism, such as a mosquito, fly, or tick Transmission may be mechanical , via the contaminated mouth parts or feet of the vector , or biological , involving multiplication or developmental changes of the agent in the vector before transmission occurs In mechanical transmission , multiplication and development of the disease do not usually occur -- e.g., organisms that cause dysentery, polio, cholera, and typhoid fever have been isolated from such insects as cockroaches and house flies and could presumably be deposited on food prepared for human consumption

INDIRECT TRANSMISSION (cont’d.):

INDIRECT TRANSMISSION (cont’d.) In biological transmission , multiplication and/or developmental changes of the disease agent occur in the vector before transmission occurs Biological transmission is much more important than mechanical transmission in terms of its impact on public/community health Examples of biological vectors include mosquitoes, fleas, ticks, lice, flies and other insects

INDIRECT TRANSMISSION (cont’d.):

INDIRECT TRANSMISSION (cont’d.) Mosquitoes are extremely important vectors of human diseases -- e.g., they transmit the viruses that cause yellow fever and dengué fever as well as 200 other viruses -- they also transmit malaria, which infects 100 million people in the world each year (most in tropical areas), killing at least 1 million of them each year Ticks are another important biological vector, transmitting Rocky Mountain spotted fever, relapsing fever, and Lyme disease

Slide 17:

FOOD-BORNE DISEASES IN THE U.S. [P resented on overhead in class. Not available as PowerPoint slide]

Slide 18:

CHAIN OF INFECTION MODEL SHOWING DISEASE PREVENTION AND CONTROL STRATEGIES [Presented on overhead in class. Not available as PowerPoint slide]

DISEASE AND INJURY PREVENTION AND CONTROL:

DISEASE AND INJURY PREVENTION AND CONTROL Prevention Includes individual, clinical, or personal health services such as immunizations, screening for high blood pressure and follow-up services, or the use of Pap smears to detect the precursors to cancer of the cervix Protection Includes the activities of organizations, both public and private, to reduce exposure to hazards such as polluted water, contaminated food, traffic accidents, mosquitoes, or use of electric saws without safety devices

Slide 20:

TABLE: Comparison of Maximum and Current Morbdity due to Vaccine-Preventable Diseases [Presented as overhead in class. Not available as PowerPoint slide]

PREVENTION OF COMMUNICABLE DISEASES:

PREVENTION OF COMMUNICABLE DISEASES Primary Prevention In the chain of infection model, primary prevention strategies are evident at each link of the chain Successful application of each strategy can be seen as weakening the link -- with the ultimate goal of interrupting the disease transmission cycle Community measures -- e.g., chlorination of the water supply, inspection of restaurants, immunization programs that reach all citizens, maintenance of a well-functioning sewer system, proper disposal of solid waste, and control of vectors and rodents

PREVENTION OF COMMUNICABLE DISEASES (cont’d.):

PREVENTION OF COMMUNICABLE DISEASES (cont’d.) Personal/Individual actions -- hand washing, proper cooking of foods, adequate clothing and housing, use of condoms, obtaining all of the available immunizations against specific diseases

PREVENTION OF COMMUNICABLE DISEASES (cont’d.):

PREVENTION OF COMMUNICABLE DISEASES (cont’d.) Secondary Prevention Community effort includes measures taken to control or limit the extend of a disease outbreak/epidemic -- e.g., maintaining records of cases and compliance with regulations requiring the reporting of notifiable diseases, investigating cases and contacts, those who may have become infected through contact with cases Individual effort includes either (1) self-diagnosis and self-treatment with nonprescription medications or home remedies, or (2) diagnosis and treatment with an antibiotic or other physician-prescribed medicine

PREVENTION OF COMMUNICABLE DISEASES (cont’d.):

PREVENTION OF COMMUNICABLE DISEASES (cont’d.) Occasionally, secondary disease control measures may include isolation or quarantime Isolation = separation, for the period of communicability, of infected persons or animals from others so as to prevent the direct or indirect transmission of the communicable agent to a susceptible person/host Quarantine = limitation of the freedom of movement of well persons or animals that have been exposed to a communicable disease until the incubation period has passed

PREVENTION OF COMMUNICABLE DISEASES (cont’d.):

PREVENTION OF COMMUNICABLE DISEASES (cont’d.) Further measures may include disinfection -- the killing of communicable agents outside the the host, and mass treatment with antibiotics Public health education and health promotion should also be used as both primary and secondary preventive measures

PREVENTION OF COMMUNICABLE DISEASES (cont’d.):

PREVENTION OF COMMUNICABLE DISEASES (cont’d.) Tertiary Prevention Convalescence from infection, recovery to full or partial health, and return to normal activity In some cases, such as paralytic polio, return to normal activity may not be possible, even with extensive physical therapy At the community level, proper removal of infected items such as clothing, disinfection, and burial of the dead, for example Tertiary prevention may also involve the reapplication of primary and secondary measures to prevent further cases -- e.g., in Japan and South Korea, people with colds or flu wear gauze masks in public to reduce the spread of the disease

TOOLS AVAILABLE TO THE “STATE” FOR THE CONTROL OF COMMUNICABLE DISEASE:

TOOLS AVAILABLE TO THE “STATE” FOR THE CONTROL OF COMMUNICABLE DISEASE REPORTING -- Physicians and other health professionals must report specified diseases to a designated authority, usually to local or state health authority LABORATORY REPORTING -- In many states, licensed laboratories must report positive results for certain diseases to the health department, even though a diagnosis may not have been established SURVEILLANCE -- The systematic measurement of health status and risk factors MONITORING -- Involves the ongoing assessment of a condition after intervention has been initiated

TOOLS AVAILABLE TO THE “STATE” FOR THE CONTROL OF COMMUNICABLE DISEASE:

TOOLS AVAILABLE TO THE “STATE” FOR THE CONTROL OF COMMUNICABLE DISEASE LABORATORY ANALYSIS -- Involves public health laboratories with authority for the study and detection of infectious diseases CONTACT INVESTIGATION -- Once a case of a particular disease has been diagnosed, personnel from the health department are authorized to interview the victim to establish a list of possible contact. (A practice of considerable debate recently because of AIDS.)

TOOLS AVAILABLE TO THE “STATE” FOR THE CONTROL OF COMMUNICABLE DISEASE:

TOOLS AVAILABLE TO THE “STATE” FOR THE CONTROL OF COMMUNICABLE DISEASE TREATMENT -- Public health agencies are required to provide treatment services for specified infectious diseases. (In many cities, special hospitals were built for this purpose.) Local health departments are also required to provide services for people infected with sexually transmitted diseases or tuberculosis. These services are not regarded as welfare services but rather as tools to prevent the spread of dangerous communicable diseases. It is important to note, however, that the state cannot require treatment. The state can only force treatment if it can prove that the victim is (1) gravely disabled, and (2) a danger to self or others because of the disability

TOOLS AVAILABLE TO THE “STATE” FOR THE CONTROL OF COMMUNICABLE DISEASE:

TOOLS AVAILABLE TO THE “STATE” FOR THE CONTROL OF COMMUNICABLE DISEASE ISOLATION -- Means separation of infected people from non-infected people during the period of communicability. Follows the “least restrictive” principle IMMUNIZATION -- All states have requirements for the immunization of children against certain infectious diseases -- most common are diphtheria, pertussis (whooping cough), tetanus, rubella (German measles), and polio. The controlling agency is usually the school system, which is required to prevent entry of any child who has not been properly immunized

TOOLS AVAILABLE TO THE “STATE” FOR THE CONTROL OF COMMUNICABLE DISEASE:

TOOLS AVAILABLE TO THE “STATE” FOR THE CONTROL OF COMMUNICABLE DISEASE INVESTIGATION -- In addition to the specific authorities noted above, most health departments are required to investigate unusual occurrences of disease or injury. This includes the authority to review medical records, to perform laboratory investigations, to examine patients, and to interview both patients and others who may have been exposed to the disease or injury. (The public health authorities may require court authorization to undertake these investigations.)

authorStream Live Help