Communicable diseases, it’s Transmission, Symptoms, Prevention and Control

IMG 20221225 213828

Communicable diseases :-

Communicable diseases are diseases that can transfer from one person to another and caused by microbes like bacteria, protozoa, fungi, viruses, helminthes etc.

Communicable diseases caused by bacteria :-

Tuberculosis, Diphtheria, Whooping cough ( Pertussis ), Cholera, Other diarrheal disease, Leprosy, Tetanus, Gonorrhea, Syphilis etc.

Communicable diseases caused by Viruses :-

Mumps, Measels, Pox, Polio, Trachoma, Rabies, AIDS, Hepatitis COVID – 19 etc.

Communicable diseases caused by Protozoan :-

Malaria, Amoebiasis etc.

Communicable diseases caused by Helminthes :-

Ascariasis , Falariasis, Taeniasis etc.

Transmission, Symptoms, Prevention and Control of Communicable diseases

1. Tuberculosis :-

Disease – Communicable diseases.

Causative agent – Mycobacterium tuberculosis.

222869 web
Fig. 1. Mycobacterium tuberculosis.

Incubation period – week, Month, Year.

Organ effected- Lungs, intestine, meninges, brain, kidney, cervical lymph node ( in child ).

Diagnosis – By chest X- ray, Tuberculin test, Mantoux test, Sputum examination.

Transmission :-

Air born disease by droplet infection through coughing, sneezing, talking, spitting.

Symptoms :-

Low grade fever, malaise, coughing with expectation, loss of body weight, chest pain

  • Bacteria of tuberculosis damaged the tissue, release toxic called tuberculin. Actually tuberculin is antigen structure of mycobacterium tuberculosis, which initiate cell mediated immunity.

Prevention :

By BCG vaccine, Chemoprophylaxis, Improvement of sanitation, Health promotion.

Control :-

  • Use of antibiotic ( Rifampicin, Isoniazid, Ethambutol, Pyrazinamide, Streptomycin ).
  • Rest, Surgery may required, Improve nutrition, Health education.

2. Diphtheria :-

It is a communicable disease and more common in children.

Causative agent – Corynebacterium diphtheriae ( Gram positive bacteria ).

220px Corynebacterium diphtheriae Gram stain
Fig. 2. Corynebacterium diphtheriae.

Organ effected – Nasopharynx, Oropharynx, Tonsil, Larynx and Heart.

Incubation period – 2 to 6 days.

Diagnosis – Throat swab test, Schick test.

Transmission :-

Air born disease ( Droplet infection and droplet nuclei ).

Symptoms :-

Slight fever, sore throat, pain in throat, respiratory obstruction ( in acute condition ) or chocking of respiratory tract.

  • Due to formation of thick tough grey colour membrane in nasopharynx, it’s removal cause bleeding. They formed due to the secretion of semi – solid material by Throat.
  • In acute condition, bacteria may go to heart and causes rapid heart block.

Prevention :-

DPT vaccine.

Control :-

Diphtheria antitoxic ( with 24 hours of appearance of symptom ), Antibiotics ( Penicillin, Erythromycin ), Analgesic, Rest and Surgery of throat may required in acute condition.

3. Cholera :-

it is an acute diarrheal disease. In ayurveda it is called vishuchica. It is a communicable disease.

Causative agent – Vibrio cholerae, infection mainly contaminative.

Incubation period – minimum period half hour, 1 to 2 days.

Symptoms :-

Sudden onset of profused effortless, rise, water like a stool followed by vomiting, rapid dehydration, muscular cramp and suppression of urination.

Even death occurs if proper water and electrolyte balance is not taken.

On examination –

signs of dehydration ( pale skin, sunken eye, dry tongue ).

Rapid thready pulse ( weak ).

Blood pressure low, cold extremity.

Prevention :- 

By cholera vaccine ( provide immunity up to 6 months ).

Control :-

  1. To maintain water electrolyte balance in the body.

( a ) ORT ( oral rehydration therapy ) :

WHO formula

Glucose = 20 gm, KCl = 1•5 gm, NaCl = 3•5 gm, Sodium bicarbonate = 25 gm, Sodium citrate = 29 gm, Water to make = 1 Litre.

Home formula

First full sugar, 1 chutki salt, water to make 1/2 litre.

( b ) In dehydration in acute then use of intravenous fluid therapy.

2. Antibiotic, Antiemetic, for community – blood sanitation.

Other Diarrheal disease :-

Causative agent :-

  1. Bacteria – E. coli, Campylobacter, Salmonella.
  2. Virus – Rotavirus, Echovirus, Enterovirus.
  3. Protozoa – E. histolytica, Giardia.

Transmission :-

Mainly water borne disease through oral route.

Infection – mainly contaminative stool of patient.

Symptoms :-

Dehydration is common.

In case of shigellosis ( frequent passes of stool with blood, mucus and abdominal cramps ).

Control :-

Maintain water electrolyte balance in the body as in cholera.

Antibiotic in case of bacterial infection, Antiemetic, improve sanitation and water supply, food hygiene.

4. Tetanus ( Lock Jaw ) :-

Causative agent – Clostridium tetani ( Anaerobic, Gram negative bacteria ) ,spore bearing Organism.

  • Tetanus is induced by tetanus toxin ( tetanospasmin )
  • Bacteria reservoir – Bacilli of tetanus found in intestine of Cattle, Soil dust through Cattle dung.

Incubation period – 6 to 10 days or 1 month.

Mortality – 40 to 80 %

Diagnosis – By symptoms and history.

Transmission :-

Soil born – Spore get attached to the fresh wound by dust and surgical instrument, application of dust over wound, During umbilical cord clumping by khandani chaku

Symptoms :-

Lock Jaw, spasm of back and neck.

Prevention :-

T – toxoid, DPT Vaccine .

Control :-

T – toxoid, ATS, antibiotics ( Penicillin, Erythromycin ), analgesic, good nursing care.

5. Rabies :-

Disease – Communicable diseases.

Causative agent – Rabies virus.

Reservoir host – Dog, Fox, Wolves, Jackals, Mongoose, Bats, Cats, Coyote and Skunks.

Rabies in wildlife infographic
Fig. 3.

Incubation period – Usually 3 to 8 weeks.

Symptoms :-

In human – Hydrophobia ( fear with water ), sore throat, slight fever, headache, malaise.

  • In rabid dog – running amuck, change in voice, excessive salivation etc.
  • Rabies virus destroy the brain and spinal cord.
  • Rabies is the only communicable disease of a human which is 100% fatal if not controlled immediately.


Prevention :-

Vaccination of rabies to dog, other animals and to human being.

  • Rabid dog should be kill immediately.

Control :-

Injection of vaccine or ARS or vaccine + ARS to the person after biting of rabid dog.

6. polio :-

Causative agent – polio virus.

Transmission :-

Stages and types :- ( 1 ) Abortive polio – Body ache, fever, malaise.

( 2 ) Non – paralytic polio – Stiffness and pain in neck and back.

( 3 ) Paralytic polio – Damage the alpha – motor neuron of spinal cord mainly.

  • Damage of motor neuron, muscle fail to stimulate or contract so the muscle get shrink, painful spasm of muscle.
Polio lores134
Fig. 4. Polio patient.

When the respiratory Center of Brain are attacked by virus.

Result – Nerve impulse to the diaphragm are stopped, breathing fails. In this condition patient needs ‘Iron lungs’ for artificial breathing.

Prevention :-

Polio vaccine – Injectable, Oral.

Control :-

In case of painful muscle spasm –

Good nursing care, steroids, vitamins.

  • In chronic stage – Physiotherapy to limb for regain power.

7. COVID – 19 :-

It is an infectious and pandemic disease.

Causative agent – Corona virus ( newly discovered virus ).

Transmission :-

The COVID – 19 virus is spread primarily through droplet or saliva or discharge from the nose when an infected person coughs or sneezes.

Symptoms :-

More common – Fever, dry cough and tiredness.

Less common – Aches and pains, sore throat, diarrhoea, conjuctivitis, headache, loss of test or smell, a rash on skin.

Prevention :-

The best way to prevent and slow down transmission is to be well informed about the covid-19 virus, the disease it causes and how it spreads.

  • protect yourself and other from infection by washing your hands, social distancing.

Control :-

Stay home from work, school and public area.

  • if you have a chronic medical condition and may have a higher risk of serious illness, check with your doctor about other ways to protect yourself.

Leave a Reply

Your email address will not be published. Required fields are marked *

Move to Top