STUDYMATE

DISEASES

 

                                                                                                             Diseases are of two types. They are

 

1.   INFECTIOUS DISEASE: -The disease which spread from one person to another person is called infectious disease. These are caused by micro organisms like bacteria, virus, fungi etc.

  Ex: - AIDS, Cholera, Cold etc.

2.   NON INFECTIOUS DISEASE: -The disease which does not spread from one person to another person is called Non infectious disease.

Ex:- Mal nutrition diseases and hormone deficiency diseases etc.

INFECTIOUS DISEASES

OR

COMMUNICABLE DISEASE

 

Infectious diseases are caused by micro organisms. Based on the causative organism these are classified into different types. They are

 

      i.            VIRAL DISEASE: - It is caused by virus.

Ex: - AIDS, Hepatitis, polio, cold, rabies, Dengue, swine flu, mumps, measles etc.

   ii.             BACTERIAL DISEASE: - It is caused by bacteria.

    Ex:-Cholera, Typhoid, Tuberculosis, syphilis,    

      Tetanus, Anthrax, Diphtheria etc.

iii.            FUNGAL DISEASE: - It is caused by fungus.

    Ex:-Athlete’s foot, ring worm etc.

iv.            PROTOZOAN DISEASE: - It is caused by protozoan parasite.

    Ex: - Malaria, Amoebic dysentery etc.

   v.            HELMINTH DISEASE: - It is caused by helminth parasite.

    Ex: - Filariasis, Teaniasis etc.

 

Infectious Diseases are classified into five types based the mode of infection. They are

 

      i.            AIR BORNE DISEASE: - The disease which spreads through contaminated air droplets.

Ex: - Tuberculosis, cold etc. (Tuberculosis is a bacterial disease and cold is a viral disease but both the diseases spreads through contaminated air.)

   ii.            WATER/FOOD BORNE DISEASE: - The disease which spreads through contaminated water/food.

Ex: - Cholera, Typhoid, Hepatitis-A etc.

iii.            SEXUALLY TRANSMITTED DISEASE (S.T.D):- The disease which spreads through sex or blood. This is also known as blood borne disease.

Ex: - AIDS, Syphilis, gonorrhea, Hepatitis-B etc.

iv.            VECTOR (or) INSECT BORNE DISEASE: - The disease which spreads through Insect bite.

Ex: - Malaria, Filariasis, Dengue etc.

   v.            ZOONOTIC DISEASE: - The disease which spreads through animals other than insects.

Ex: - Rabies, Anthrax etc.

 

AIDS:-ACQUIRED IMMUNO DEFICIENCY SYNDROME.

Causative organism: Virus

Name of the virus: HIV

Mode of infection:-sexually

Target system: Immune system (W.B.C. especially t-cells)

Diagnostic Test: - ELISA, Western blot and PCR.(ELISA is the screening test and western blot is the confirmatory test.)

There is no vaccine to prevent AIDS but we can extend the life time of the patient by using drugs namely Azedothymidine or Zudovudine.

HIV belongs to retroviridae family.

HIV contains an enzyme called reverse transcriptase.

HEPATITIS-B

Causative organism: Virus

Name of the virus: Hepatitis-B

 Mode of infection:-sexually

Target Organ: Liver

 Diagnostic Test: - ELISA

Vaccine: - Hepatitis vaccine

SYPHILIS

Causative organism: Bacteria

Name of the Bacteria: - Tryponema pellidim

 Mode of infection:-sexually

Target Organ: Sexual organs

 Diagnostic Test: - Wassermann test, Kahn test and VDRL

       TUBERCULOSIS

Causative organism: Bacteria

Name of the Bacteria: Mycobacterium tuberculosis

 Mode of infection:-contaminated air droplets

Target Organ: Lungs

 Diagnostic Test: - sputum test, Monteux test

Vaccine: - B.C.G.

DIPHTHERIA

Causative organism: Bacteria

Name of the Bacteria: Corynebacterium diphtheria

 Mode of infection:-contaminated air droplets

Target Organ: Throat

 Diagnostic Test: - Sheik test

Vaccine: - D.P.T. (Triple vaccine)

        COLD

Causative organism: Virus

Name of the virus: Rhino virus

 Mode of infection: - contaminated air droplets

Target Organ: Mucus membrane of nose

        CHOLERA

Causative organism: Bacteria

Name of the Bacteria: Vebrio cholera

 Mode of infection:-contaminated water

Clinical symptoms: - Vomiting and diarrhea which leads to dehydration

Treatment:-Oral Rehydration Solution. (ORS is a mixture of salt, sugar and water)

TYPHOID

Causative organism: Bacteria

Name of the Bacteria: Salmonella typhi

 Mode of infection:-contaminated food, water and milk.

Target Organ: Intestine and stomach

 Diagnostic Test: - Widal test

AMOEBIC DYSENTRY

Causative organism:  Protozoan parasite

Name of the Protozoan: Entamoeba histolytica

 Mode of infection: - contaminated water and food

Clinical symptoms: - Presence of mucus and blood in stool

BACILLARY DYSENTRY

Causative organism:  Bacteria

Name of the Bacteria: - E.Coli and shegella

 Mode of infection: - contaminated water and food

Clinical symptoms: - Presence of mucus and blood in stool

        POLIO

Causative organism: Virus

Name of the virus: Polio mylitis (Entero virus)

 Mode of infection: - contaminated water

Target Organ: Nerve cell

Vaccine: - Polio vaccine (Salk and Sabin)

HEPATITIS-A

Causative organism: Virus

Name of the virus: Hepatitis-A

 Mode of infection: - contaminated water

       Target Organ: Liver

 Diagnostic Test: - ELISA

Vaccine: - Hepatitis vaccine

RABIES

Causative organism: Virus

Name of the virus: - Rabdo virus

 Mode of infection: - Dog bite (Zoonotic disease)

Clinical symptoms: - Hydrophobia

 Diagnostic Test: - Atopsy

Vaccine: - Rabies vaccine

ANTHRAX

Causative organism: Bacteria

Name of the Bacteria: Bacillus anthracis

 Mode of infection:-Meat of infected Goat and Sheep

Target Organ: Lungs

MALARIA

Causative organism:  Protozoan parasite

Name of the Protozoan: Plasmodium

 Mode of infection:-Female Anopheles mosquito bite

Target Organ: Liver and R.B.C.

Clinical symptoms: - Fever at alternative days, cold

Treatment: - Quinine is used in the treatment.

 

DENGUE

Causative organism:  virus

Mode of infection:- Aedes aegypti mosquito bite

Target Organ: platelet cells

Treatment: - Tamiflu is used in the treatment.

 

v Severe acute respiratory syndrome(SARS) is a viral disease.

v Measles and Mumps diseases are caused by paramixovirus.

v Tetanus is a soil or wound borne disease.

v Foot and mouth disease of cattle is caused by virus.

v Liver rot disease is caused by helmenth parasite called fasiola hepatica(liver fluke)

v Blight disease in rice is caused by bacteria.

v Blast disease in rice is caused by fungus.

v Red rot of sugar cane is caused by fungus.

v Tikka disease in ground nut is caused by fungus.

v Smut disease in sorghum is caused by fungus.

v Citrus canker disease is caused by bacteria.

v Mosaic disease in tobacco is caused by tobacco mosaic virus.

                Bacillus is a rod shape bacterium.

v Coccus is a spherical (round) shape bacterium.

v Mesosomes are the respiratory organs of bacteria.

v Virus cannot be grown on artificial medium.

v The genetic material of virus is either DNA or RNA.

v Phytophage is a virus that attacks on plants.

v Zoophage is a virus that attacks on animals.

v Bacteriophage is a virus that attacks on bacteria.

v Mycophage is a virus that attacks on fungus.

v Zymophage is a virus that attacks on yeast.

v Cyanophage is a virus that attacks on blue green algae.

v Bacterium was discovered by Antony van leeuwenloek.

v Virus is visible under electron microscope.

v Electron microscope  was invented by Knoll and Ruska.

v  Filaris is caused by Wuchararia bancrofti( helminth parasite)

v Blood samples are collected only during the night times for the diagnosis of filarial.

v  Ringworm, Athlet’s foot, Candidiasis are caused by fungi.