Disease

2.  Any condition which
interferes with the
normal functioning of
the body is called a
disease.
 Disease may be defined
as a disorder in the
physical, physiological,
psychological or social
state of a person
caused due to
nutritional deficiency,
physiological disorder,

3. Pathogens
Bacteria
Viruses
Fungi
Protozoans
Helminths

4.  Pathogen : Salmonella typhi (Bacteria)
 Target organ - Small intestine
 Mode of transmission :
 Through contaminated food and water
 Confirmation Test - Widal test
 Symptoms :
 High fever (39° to 40°C)
 weakness
 stomach pain
 constipation
 headache and loss of appetite
 In severe cases intestinal perforation and death may
occur.

5.  Pathogen :
 Streptococcus pneumoniae and Haemophilus
influenzae (Bacteria)
 Target organ - Alveoli of the lungs
 Mode of transmission :
 By inhaling the droplets/aerosols released by an
infected person
 By sharing glasses and utensils with an infected
person
 Symptoms :
 Fever, chills, cough and headache
 In severe cases, the lips and finger nails may turn
gray to bluish in colour.

6.  Pathogen :
 Rhino viruses (Virus)
 Target organ - Nose and respiratory passage but
not the lungs.
 Mode of transmission :
 Through droplets from cough or sneezes of an
infected person
 Through contaminated objects such as pens, books,
cups, doorknobs, computer keyboard or mouse, etc.
 Symptoms :
 Nasal congestion and discharge
 Sore throat, hoarseness, cough, headache &

7.  Pathogen :
 Plasmodium vivax, P. malaria, P.falciparum
 Mode of transmission :
 By bite of female Anopheles mosquitoes
 Incubation period :
 Approximately 12 days
 Symptoms
 Headache, nausea and muscular pain.
 Feeling of chilliness and shivering followed by fever
which becomes normal along with sweating after some
time.
 The patient becomes weak and anaemic.
 If not treated properly secondary complications may lead
to death.

8. Prevention and cure:-
 Fitting of double door and windows (with wire
mesh) in the house to prevent entry of
mosquitoes.
 Use of mosquito net and mosquito repellents.
 No water should be allowed to collect in ditches
or other open spaces to prevent mosquito
breeding.
 Sprinkling of kerosene oil in ditches or other open
spaces where water gets collected.
 Antimalarial drugs to be taken.

10.  Pathogen :
 Entamoeba histolytica (Protozoan)
 Target organ - Large intestine of human
 Mode of transmission :
 Houseflies transmit the parasite from faeces of
infected person to food, food products and water.
 Symptoms :
i. Constipation
ii. Abdominal pain and cramps
iii. Stools with excess mucous and blood clots

11.  Pathogen : Ascaris
 Target organ – intestine
 Mode of transmission :
 The eggs of the parasite are
excreted along with the
faeces of infected persons
which contaminate soil,
water, plants, etc.
 contaminated water,
vegetables, fruits, etc.
 Symptoms :
 Internal bleeding
 Muscular pain
 Fever
 Anemia
 Blockage of the intestinal
passage

12.  Pathogen : Wuchereria (W. bancrofti
and W. malayi)
 Target organ –
 Lymphatic vessels of lower limbs
 Mode of transmission :
 bite by female Culex mosquito
 Symptoms :
 Blocked lymph ducts
 Enlarged groin lymph nodes
 Fever
 Thickened skin tissue
 Impaired lymphatic drainage
Elephantiasis

13.  Ringworm is a fungal infection
of the skin.
 The name “ringworm” is a
misnomer, since the infection
is caused by a fungus, not a
worm.
 Pathogens :
 Microsporum
 Trichophyton
 Epidermophyton

14.  Symptoms :
 Appearance of dry, scaly lesions on various parts of
the body such as skin, nails and scalp are the main
symptoms of the disease.
 These lesions are accompanied by intense itching.
 Heat and moisture help these fungi to grow, which
makes them thrive in skin folds such as those in the
groin or between the toes.
 Mode of transmission :
 They acquired from soil or by using towels, clothes
or even the comb of infected individuals.

15.  Maintenance of personal and public hygiene
 Keeping the body clean
 Consumption of clean drinking water, food,
vegetables, fruits, etc.
 Proper disposal of waste and excreta;
 Periodic cleaning and disinfection of water
reservoirs, pools, cesspools and tanks
 Vaccination and immunisation

16. MOSQUITO
MALARIA
DENGUE
FEVER
FILARIASIS
JAPANESE
ENCEPLALITIS
YELLOW
FEVER
CHIKUNGUNYA

17.  To avoid stagnation of water
in and around residential
areas
 Regular cleaning of
household coolers,
 Use of mosquito nets,
 Introducing fishes like
Gambusia in ponds that feed
on mosquito larvae,
 Spraying of insecticides in
ditches, drainage areas and
swamps, etc.
 Doors and windows should be
Gambusia