Diphtheria is a serious bacterial infection. Diphtheria typically causes a bad sore throat, fever, swollen glands and weakness. Diphtheria causes a thick gray coating at the back of the throat, which makes hard for the person to breathe and can result in suffocation. If it is not properly diagnosed and treated it produces a poison in the body that can cause serious complications such as heart failure or paralysis. 

Children younger than 5 years old and adults older than 60 are particularly at risk of contracting diphtheria are:

•  Children and adults who don't have properly immunized
•  People living in unhygienic conditions 
•  People who have a compromised immune system
•  Undernourished or malnutrition child

Causes
Diphtheria is caused by bacteria known as Corynebacterium diphtheriae. These bacteria are Gram-positive, aerobic, nonmotile, rod-shaped bacteria. The bacterium produces a toxin that is carried in the bloodstream. Toxins produced by the bacteria may affect the tissues and organs throughout the body and can result into a serious problem as inflammation of the heart, heart failure and paralysis.

A person who has the disease may get infected within 2-4 weeks, but sometimes when the person does not gets infected then also he may the carrier of the bacteria for a longer. 

 Diphtheria bacteria live in the mouth, nose, throat, or skin of infected persons.
 Diphtheria can also be spread via bloodstream to other organs, where it can cause significant damage.

•  Diphtheria spreads from person to person very easily. 
•  Diphtheria can be spread from close contact with discharges from an infected person's mouth, nose, throat, or skin.
•  Person may get diphtheria after coughing or sneezing by an infected person.
•  The bacteria of diphtheria may increase and multiply on the moist parts of the mouth and throat, where they cause inflammation.
•  Person may get diphtheria by touching the open sores of someone with skin diphtheria. 
•  Transition of bacteria is also possible in crowded conditions and inadequate hygiene.

Diphtheria was once quite common, but has now is a very rare disease and has largely been eradicated in all developed nations.

Signs & Symptoms
Normally in its early stages, diphtheria can be mistaken as bad sore throat. A low-grade fever and swollen neck glands are the other early symptoms. A characteristic sign of this disease is a thick, gray covering which develops at the back of your throat, making it very difficult to breathe. Some other signs and symptoms of diphtheria may include:

•  A sore throat and hoarseness
•  A thick, gray membrane covering your throat and tonsils 
•  Bloody, watery drainage from nose
•  Difficulty breathing or rapid breathing 
•  Diphtheria can also infect your skin. Bluish coloration of the skin may be caused by lack of oxygen. 
•  Drooling
•  Enlarged lymph nodes in your neck 
•  Fatigue
•  Feel weakness
•  Fever and chills 
•  High pulse rate
•  Malaise
•  Nasal discharge 
•  Painful swallowing 
•  Skin lesions can be seen in cutaneous diphtheria
•  Swollen glands

Diagnosis
Diagnosis of diphtheria is done by physician examination and throat culture. Because diphtheria must be treated as quickly as possible, doctors usually make the diagnosis on the basis of the visible symptoms without waiting for test results.

Visible diagnosis

•  The doctor examines the patient's eyes, ears, nose, and throat in order to rule out other diseases that may cause fever and sore throat, such as infectious mononucleosis, a sinus infection, or strep throat.

Laboratory tests

•  The diagnosis of diphtheria can be confirmed by the results of a culture obtained from the infected area. Material from the swab is put on a microscope slide and stained using a procedure called Gram's stain.
•  Another laboratory test involves growing the diphtheria bacillus on a special material called Loeffler's medium.

Preventions
The Diphtheria, Pertussis and Tetanus (DPT) vaccine can prevent diphtheria, but its protection does not last forever. Adults should get another dose, or booster, every 10 years.

•  Universal immunization is the most effective means of preventing diphtheria.
•  The three doses of DPT preparation must be given between two months and six months of age, with booster doses given at 18 months and at entry into school.
•  Diphtheria patients must be isolated for one to seven days or until two successive cultures show that they are no longer contagious.
•  Because diphtheria is highly contagious so, patients are usually given antibiotics for seven days and a booster shot of diphtheria/tetanus toxoid.
•  Reporting is necessary to track potential epidemics, to help doctors identify the specific strain of diphtheria.

Treatments
The only effective treatment of diphtheria is the prompt administration of antitoxin to neutralize any exotoxin still circulating in the bloodstream. 

•  Antitoxin is injected into a vein or into a muscle. 
•  Bed rest and increasing the fluid intake to the patients are helpful in making the patient comfortable.
•  Children and adults who have diphtheria often need to be in the hospital for treatment. 
•  Diphtheria is also treated with antibiotics, such as penicillin or erythromycin. Antibiotics help kill bacteria in the body, clearing up infections.
•  Guava tea is excellent in dissolving dried mucus and killing bacteria in the respiratory tract. 
•  Some patients might need mechanical help in breathing. Persons who have been in close contact with the patient should have throat cultures and be given antibiotics. 
•  The person should be given a medicine (diphtheria antitoxin) to fight the diphtheria poison and antibiotics to fight the diphtheria bacteria.