Diphtheria

Diphtherim is a common infectious disease in India. There are reports to indicate that the prevalence of diphtheria (number of cases of diphtheria in the community) is on the rise in the country. An analysis of admissions to Infectious diseases hospital in Delhi indicates that about 13 per cent cases of diphtheria, among the children under five years of age, end in deaths. The death rate due to diphtheria is also reported to be high. Unfortunately, it is difficult to obtain accurate information about the actual extent of diphtheria in warm climate countries like India because bacteriological confirmation of the disease is not easily available. 

The disease-What causes it? Who gets it? How and when does it spread? 

Diphtheria is caused by Cornyebacterium diphtheriae, a non-motile (not moving) organism. The organism produces a powerful toxin. Three types of diphtheria. bacilli are differentiated. 

1. Gravis : Causing serious type of disease and generally accounts for about a fourth of the cases of diphtheria. 
2. Mitis : Causing milder type of infection contributing to about 65 per cent of the cases. 
3. Intermedius : This accounts for about 10 per cent of the cases. 

Who gets the disease? 

Age : Diphtheria is primarily a disease of children under 15 years of age. You would rarely come across cases of diphtheria in children below the age of 6 months. The highest  number of cases are observed among preschool children i.e. 1-5 year old children. It can also occur in unimmunised adults. 

Sex : It affects both the sexes equally. 

Season : Cases of diphtheria are reported in all the seasons. But, higher numbers of cases are reported during August to October. 

How does it spread? 

Diphtheria spread usually by contact with a patient or a person  having in apparent infection (without any recognizable clinical sign or symptom). The transmission is through droplet infection or infected dust. 

It can also be transmitted if  raw  milk contaminated with discharges from the patients is consumed. However, in India where milk is invariably boiled before consumption transmission by milk is not likely to occur. 

It is rare to contract the  disease by handling articles soiled with discharges from lesions of infected persons. The organism  can sometimes enter through wounded skin and lead to infection. 

Incubation period : Usually 2 to 5 days. 

Period of Communicability : The disease can  spread from an infected person to another unimmunised person as long as the virulent bacilli are present in the discharges of the lesions. Generally, it is communicable for about 2 weeks but  never for more than 4 weeks. 

Susceptibility : Infants born to mothers who are immune do not  get the disease during the first six months of their life. Recovery from an attack of diphtheria is not 

followed by long lasting immunity as in the case of measles. Prolonged active immunity can be induced by giving diphtheria toxoid. 

Symptoms and Complications 

Diphtheria is an acute communicable disease which affects the nose, throat and tonsils. The bacilli  multiply at the site of implantation (insertion into the body), be it throat, nose or tonsils. It produces local lesions at the site of implantation. This lesion is characterized by formation of a patch or patches of greyish false-membrane on the affected parts such as tonsils or larynx (voice box).  It also produces an offensive and strong odour. There will  be redening and swelling of the surrounding tissues. 

The throat is moderately sore when diphtheria affects tonsils, with swelling of the cervical lymph glands (lymph glands in he neck region). This may result in  bull-neck appearance. 

Diphtheria affecting larynx  is serious particularly in infants and children. Most often it leads to death of the affected. 

Nasal diphtheria (of nose) is usually a mild condition marked by one sided discharge in the  nose. 

You should always suspect diphtheria whenever there are cases of sore throat Often. such cases are taken lightly and treated as mild  upper respiratory infection. Administration of antibiotics, assuming that it is ordinary sore-throat delay  diagnosis, endangering the life of the patient. 

Diagnosis is confirmed by examining the lesions for the presence of bacteria. Failure to demonstrate the bacteria under microscope should not, however. be the reason for withholding the treatment for diphtheria. 

Prevention and Management 

How to prevent diphtheria? Preventive measures are simple. Read the following section and find out for yourself: 

1. Immunisation : The only effective way of preventing the disease is by active immunisation by diphtheria toxoid to general population.  It is given as DPT or triple antigen along with immunisation for whooping cough  and tetanus. Three intramuscular injections of 0.5 ml each at intervals of 4 to 6 weeks are given to children at third, fourth and fifth months of life. A booster is given  one year after the third  injection is given. For children over the age of six  years, only DPT containing diphtheria and tetanus toxoids, is given. 
2. Identification of susceptible cases : There is a test  to find out individuals who are susceptible to diphtheria. This test is known as Schick test. This test can also be used for confmation of successful immunisation. The test is an intradermal (injection into the layers of skin) test. A measured amount (0.2 ml) of Schick test toxin is injected  into the skin of the forearm. Toxin inactivated by heat is injected into the opposite arm which is called control arm. In other words the individual has enough antitoxin to neutralize the toxin and fight the disease. The test is positive if  red flushing (colouring) of 1 to 5 cm within 1 to 1 days of injection. The control arm shows no change. This would mean that the person is susceptible to diphtheria. 

The community, particularly the parents of young children, should be encouraged through education to get their children immunised against diphtheria along with the whooping cough and  tetanus. 

Sure prevention is better than cure. But if an individual is suffering from  diphtheria, how to manage such a patient ,Lets consider. 

Management of diphtheria : In all the cases suspected of having diphtheria, antitoxin  should be administered without waiting for bacteriological confirmation. After completion of tests for allergy to the antitoxin, intramuscular administration of antitoxin is recommended. Penicillin and Erythromycin are effective but should be given along with the antitoxin. 

When there are cases of diphtheria, you should immediately take steps to arrange for injections of antitoxins to the patients. In other words, these patients should be taken to the nearest  hospital at the  taluq or district level. The hospital authorities will arrange for laboratory investigations and antibiotic cover. Simultaneously, the close contacts in the family should be investigated and kept under watch thoroughly. It is a sound practice to administer 500-1000 units of diphtheria antitoxin to household contacts and others who have been in recent contact with cases of diphtheria Read Points to Remember given below, which provides a summary of diphtheria.