Kelas Berrtaraf Internasional SMAK PENABUR Gading Serpong 2012/2013 INFECTIOUS DISEASES CHAPTER 13 Leonardus, S.Si

Kelas Berrtaraf Internasional SMAK PENABUR Gading Serpong 2012/2013

INFECTIOUS DISEASES

CHAPTER 13

Leonardus, S.Si.


Content

• Cholera, malaria, tuberculosis (TB) and HIV/AIDS

• Antibiotics


Learning Outcomes

Candidates should be able to:

• (a) define the term disease (see page 37) and explain the difference between an infectious disease and non-infectious diseases (limited to sickle cell anemia and lung cancer; see pages 40 and 41);

• (b) describe the causes of the following diseases: cholera, malaria, TB, HIV/AIDS, smallpox and measles;


Learning Outcomes

• (c) explain how cholera, measles, malaria, TB and HIV/AIDS are transmitted;

• (d) discuss the roles of social, economic and biological factors in the prevention and control of cholera, measles, malaria, TB and HIV/AIDS (a detailed study of the life cycle of the malarial parasite is not required);

• (e) discuss the global patterns of distribution of malaria, TB and HIV/AIDS and assess the importance of these diseases worldwide;


Learning Outcomes

• (f) outline the role of antibiotics in the treatment of infectious diseases;

• (g) use the knowledge gained in this section in new situations or to solve related problems.


• Infection: the invasion of any living organism by disease-causing microorganisms (pathogens), which proceed to establish themselves, multiply and produce various symptoms in their host

• Disease: a condition in which the normal function of some part of the body (cells, tissues or organs) is disturbed


• Infectious diseases are transmissible or communicable diseases. The pathogen can spread from infected people to uninfected people

• The pathogen cannot survive outside the human body, others can survive in water, human food, feces or animals

• Some people may spread a pathogen even though they do not have a disease themselves, such as people are symptom-less carriers


• The way in which a pathogen passes from one host to another is called the transmission cycle

• The pathogen also spread up by:– Respiratory droplets/vomits– Direct body contact/sexual intercourse– Arthropod vectors– Air borne transmission– Water borne transmission– The fecal-oral route


1.It is caused by the bacterium Vibrio cholerae, water borne transmission

2.It occurs where people do not have access to proper sanitation

3.If the bacteria do reach the small intestine they multiply and secrete a toxin, Choleragen, which disrupts the functions of epithelium so that salts and water leave the blood causing severe diarrhea

CHOLERA


Pathogen Vibrio cholerae

Methods of transmission Food-borne, water-borne

Global distribution Asia, Africa, Latin america

Incubation* period 1 – 5 days

Site of action of pathogen Wall of small intestine

Clinical featuresSevere diarrhoea, loss of water and salts, dehydration, weakness

Method of diagnosis Microscopical analysis of feces

Annual incidence worldwide 5,5 million

Annual mortality worldwide 120.000

*Incubation : the phase in the development of an infectious disease between initial infection and the appearance of the first symptoms.

CHOLERA


1.It is caused by the protist Plasmodium, 2.The vector is Arthropod (insect), female

Anopheles mosquitoes3.Malaria may also transmitted during blood

transfusion and when unsterile needles are reuse

4.The sporozoites, merozoites, and tropozoites attack liver and red blood cells

5.If people are continually reinfected they become immune to malaria

MALARIA


Pathogen Plasmodium falciparum, P. vivax, P. ovale, P. malariae

Methods of transmission Insect vector; female Anopheles mosquito

Global distribution Throughout the tropics and subtropics

Incubation* period From week and to a year

Site of action of pathogen Liver, red blood cells, brain

Clinical featuresFever, anemia, nausea*, headaches, muscle pain, shivering, sweating, enlarge spleen

Method of diagnosis Microscopical examination of blood

Annual incidence worldwide

300 million (90% in Africa)

Annual mortality worldwide1,5 – 2,7 million; intropical Africa malaria kills 1 million children under the age of 5

*nausea: A feeling of sickness, with loathing of food and inclination to vomit

MALARIA


Plasmodium malariae

Quarterner Malaria

Plasmodium vivax

Tertiana Malaria

Plasmodium falciparum

Tropical Malaria

MALARIA


1. It is caused by the HIV (Human Immunodeficiency Syndrome) or Retro Virus

2. The virus infects and destroys cells of the body’s immune system T helper Lymphocyte

3. AIDS is not disease, no vector, and cannot survive outside the living things.

4. Spread up by intimate human contact, sexual intercourse, blood donation, sharing of intravenous needles and across the placenta from mother to fetus.

5. Homosexuals has high risk of AIDS Why ???6. HIV is slow virus and after infection there may not

be any symptoms until years later. At this stage a person is HIV positive but does not have AIDS.

Acquired Immuno Deficiency Syndrome (AIDS)


• Structure of HIV and HIV infection

Acquired Immundeficiency Syndrome (AIDS)


Pathogen Human Immunodefeciency Virus (HIV)

Methods of transmission

In semen and vaginal fluids during sexual intercourse, infected blood or blood products, contaminated hypodermic syringes, mother to fetus across placenta, mother to infant in breast milk

Global distributionWorldwide, especially in sub-saharan africa and south-east asia

Incubation* periodInitial incubation a few weeks, but up to ten years or more before symptoms of AIDS may develop

Site of action of pathogen T helper lymphocytes, macrophages, brain cells

Clinical features

HIV infection – flu-like symptoms and then symptomlessAIDS – opportunistic infections including pneumonia, TB, and cancer; weight loss, diarrhoea, fever, sweating, dementia

Method of diagnosis Blood test from antibodies to HIV

Estimated total number of people infected with HIV world wide in 2002

42 million

Estimated number of few cases of HIV infection worldwide in 2002

5 million

Estimated number of deaths from AIDS-related diseases worldwide in 2002

3,1 million (one third due to TB)




HIV Life Cycle


HIV Infection Graphic



There is as yet no cure for AIDS and no vaccine for HIV.

How we stop the spread of HIV ?


AIDS Victims


1. It is caused by two bacteria, Mycobacterium tuberculosis and M. bovis

2.These bacteria particularly attack the lungs, but it can spread throughout the whole body and even infect the bone tissue

3.Some people become infected and develop TB quite quickly, whilst in other the bacteria remain inactive for many years

4.30% of the world’s population is infected whit TB without showing any symptoms of the infection

5.TB is spread when infected people with the active form of the illness cough or sneeze and the bacteria are carried in tiny droplets of liquid

TUBERCULOSIS (TB)


Pathogen Mycobacterium tuberculosis and M. bovis

Methods of transmission Airborne droplets; via unpasteurised milk

Global distribution worldwide

Incubation* period Few weeks or months

Site of action of pathogenPrimary infection in lungs; secondary infection in limph nodes, bones and gut

Clinical featuresRacking cough, coughing blood, chest pain, shortness of breath, fever, sweating, weight loss

Method of diagnosisMicroscopical examination of sputum for bacteria, chest-X ray

Annual incidence worldwide (1998)

8 million (more than 6000 cases in UK)

Annual mortality worldwide (1998)

2 million

TUBERCULOSIS (TB)


TUBERCULOSIS (TB)

Global Distribution of TB

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Kelas Berrtaraf Internasional SMAK PENABUR Gading Serpong 2012/2013 INFECTIOUS DISEASES CHAPTER 13 Leonardus, S.Si