Diphtheria is an acute infectious disease of upper respiratory system which was a leading cause of childhood morbidity and mortality in the pre-vaccination era. The incidence of diphtheria has gradually declined in developed as well as developing countries owing to effective immunization programs.
However, there has been a re-emergence of diphtheria in many countries, largely attributed to low vaccine coverage and waning vaccine immunity in adults. India accounts for a substantial proportion of global burden of diphtheria and many outbreaks have been reported in recent years. The resurfacing of the deadly disease in the state surely raises questions about our preparedness in tackling the serious issue and the need for an immediate kick- start of efficient awareness programs.
What is Diphtheria?
A serious bacterial infection of the nose and throat that's easily preventable by a vaccine. A sheet of thick, grey matter covers the back of the throat, making breathing hard.
How common is it?
Very rare - fewer than 100 thousand cases per year in India
• Infectious disease
• Preventable by vaccine
• Treatable by a medical professional
• Spreads easily
• Requires a medical diagnosis
• Lab tests or imaging always required
• Short-term: usually resolves within days to weeks
How does it spread?
Diphtheria bacteria live in the mouth, throat, and nose of an infected person and spreads:
• By airborne respiratory droplets -coughs or sneezes.
• By saliva - kissing or shared drinks and food
• By close contact - with discharges from an infected person’s nose, throat, eyes and/or skin lesions.
What are the types?
Depending on the type of infection, it can be classified into
• Anterior Nasal Diphtheria
• Pharyngeal and Tonsillar Diphtheria
• Laryngeal Diphtheria
• Cutaneous (Skin) Diphtheria
Symptoms include sore throat, fever, swollen lymph nodes and weakness.
The following may also be experienced:
Whole body: chills, fatigue, fever, or malaise
Respiratory: noisy breathing or shortness of breath
Skin: rashes or ulcers
Speech: hoarseness or impaired voice
Throat: difficulty swallowing or soreness
Also common: coughing, muscle weakness, runny nose, swelling, or swollen lymph nodes
What is the main cause?
It is caused by the bacterial microorganism known as Corynebacterium diphtheriae. Other Corynebacterium species can be responsible, but is rare. Some strains of this bacterium produce a toxin, and it is this toxin that causes the most serious complications of diphtheria.
What can happen to a person with diphtheria?
Diphtheria can initially cause a sore throat, fever and chills. But if not properly diagnosed and treated it produces a toxin. This toxin damages tissue in the immediate area of infection — usually, the nose and throat and lead to serious complications such as breathing problems, heart failure or paralysis.
Diphtheria may be suspected in a patient who has a sore throat with a grey membrane covering the tonsils and throat. If the doctor needs to confirm the diagnosis, a sample of the affected tissue is sent to a laboratory for tests. A throat culture may also be performed if diphtheria of the skin is suspected.
How long is recovery?
Usually the matter is settled, one way or the other, in 7 to 10 days. Sometimes there are lasting complications such as arthritis, paralysis, or brain damage. Cutaneous diphtheria is not as serious as other forms, but it usually takes up to 3 months to recover – and sometimes a year or more.
How dangerous is diphtheria?
It is a serious and life-threatening infectious disease and can be passed on easily between people. Even with full medical treatment, it causes death in up to 1 in 10 of those who is affected.
Is it life threatening?
Diphtheria is fatal in 5 - 10% of cases, with a higher mortality rate in young children. The toxin kills cells in the mouth, nose and throat. The dead cells quickly build up and form a membrane which can attach to the throat and lead to death by choking.
Diphtheria can be prevented with safe and effective vaccines. Diphtheria vaccine is a bacterial toxoid, ie. a toxin whose toxicity has been inactivated. The vaccine is normally given in combination with other vaccines as DTwP/DTaP vaccine or pentavalent vaccine. For adolescents and adults the diphtheria toxoid is frequently combined with tetanus toxoid in lower concentration (Td vaccine).
WHO recommends a 3-dose primary vaccination series with diphtheria containing vaccine followed by 3 booster doses. The primary series should begin as early as 6-week of age with subsequent doses given with a minimum interval of 4 weeks between doses. The 3 booster doses should preferably be given during the second year of life (12-23 months), at 4-7 years and at 9-15 years of age. Ideally, there should be at least 4 years between booster doses.
Is vaccine necessary?
It is recommended under Universal Immunisation Programme (UIP) in India. Single antigen diphtheria vaccine is not available. The vaccine is normally given in combination with other vaccines as DPT vaccine (Diphtheria+ Pertussis + Tetanus Toxoid) or pentavalent vaccine (DPT+ Hep B+ Hib vaccine).
How long does the vaccine last?
The vaccine protects a person for a maximum of 10 years. Booster doses are needed at appropriate timings to remain protected effectively.
Can one get diphtheria even after vaccination?
One cannot get the disease from vaccine. If immunised effectively, the vaccine helps preventing the disease during the prescribed duration.
Can one get diphtheria more than once?
Affected with diphtheria once doesn't guarantee lifetime immunity, though natural immunity may develop in such cases. One can get diphtheria more than once if not fully immunized against it.
Who is at risk?
Children under 5 and adults over 60 years old are particularly at risk for contracting the infection. People living in crowded or unclean conditions, those who aren't well nourished, and children and adults who don't have up-to-date immunizations are also at risk.
Treatment aimed at countering the bacterial effects has two components:
• Antitoxin - also known as anti-diphtheritic serum - to neutralize the toxin released by the bacteria. The antitoxin that is used cannot fight the diphtheria toxin once it has bound with the tissues and causes the damage.
• Antibiotics - erythromycin or penicillin to eradicate the bacteria and stop it from spreading.
Treatment is most effective when given early, so a quick diagnosis is very important. Patients most likely would be treated in an intensive care unit in the hospital, isolated and closely monitored to prevent the spread of the infection. This will be continued until tests for bacteria repeatedly return negative results in the days following the completion of the course of antibiotics.
Which countries still have reported cases of diphtheria?
Endemic in many countries in Asia, the South Pacific, the Middle East, Eastern Europe, Haiti and the Dominican Republic; outbreaks in Indonesia, Thailand, Laos, South Africa, Sudan, and Pakistan have occurred since 2011. Respiratory and cutaneous diphtheria have been reported in travellers, though rare.
(The author is Director- TGL Foundation, Chairperson -Center for Specially Abled, Editor - The Intl Journal, Sr Dir FWO)