Epidemiology of DIPTHERIA.pptx............

an acute and highly contagious bacterial disease causing inflammation of the mucous membranes, formation of a false membrane in the throat which hinders breathing and swallowing, and potentially fatal heart and nerve damage by a bacterial toxin in the blood. It is now rare in developed countries owing to immunization.

Origin

1. DIPTHERIA Prepared By Krupa Mathew.M , Assistant Professor

2. Diphtheria is a potentially deadly, contagious disease that usually involves the nose, throat and air passages but may also infect the skin. Its most predominant feature is the development of a greyish membrane over the tonsils and upper part of throat. Introduction

3. Is an acute infectious disease caused by toxigenic strains of Cornybacterium diphtheriae . The bacilli multiply locally, usually in the throat, and elaborate a powerful exotoxin which is responsible for the following pathology. The formation of grayish or yellowish membrane (false membrane) commonly over the tonsils, pharynx, with well defined edges and the membrane cannot be wiped away. Marked congestion, edema or local tissue destruction. Enlargement of the regional lymph nodes. Signs and symptoms of toxemia Definition

4. Diphtheria is a infection caused by corynebacterium diphtheriae bacteria . It is a gram positive non motile organism. Source of infection may be case or carrier. Period of infectivity varies from 14 to 28 days. Nasopharyngeal secretions, discharges from the skin lesions, contaminated fomites and dust are infectious. There are nasal and throat carriers; among this nasal carriers are very dangerous because of frequent shedding of organism into environment. Causative Agent

5. Children of 1-5 years of ages are affected Both sexes are affected Infants born of immune mothers are relatively immune during the first few weeks of life People who have not been immunized may get diphtheria at any age Host factors

6. Diphtheria occurs in all seasons although winter months favor its spread Environmental factors

7. Epidemiological determinants Agent – corynebacterium diphtheria Host – both sexes,1- 5 years Environment – Winter months

8. Diphtheria is transmitted from person to person, usually through respiratory droplets, from coughing or sneezing Rarely spreads from skin lesions or clothes that are contaminated with discharges from lesions of an infected person A person also can get infected with diphtheria by coming in contact with an object like toy that has been contaminated with bacteria that cause diphtheria Mode of Transmission

9. Respiratory route Non respiratory route like skin cuts, open wounds, ulcers and umbilicus of newborn Portal of entry

10. 2- 6 days sometimes may be longer Incubation period

11. The signs and symptoms of diphtheria differ depending upon the location of infection. Types of diphtheria Pharyngotonsillar diphtheria Laryngotracheal diphtheria Nasal diphtheria Cutaneous diphtheria Clinical features

12. Sore throat Difficulty in swallowing Low grade fever Pseudomembrane in diphtheria is formed over the nasal tissues, voice box and throat The pseudomembrane is formed from the toxin produced by the bacteria The pseudomembrane may interfere breathing. The toxin may cause damage to the heart, kidneys and nerves Pharyngotonsillar diphtheria

13. Whitish membrane can be wiped off easily over pharynx or tonsil in early stages Later it becomes thick, blue – white to grey or black and becomes adherent . Any attempt to remove it will cause bleeding Mucosal erythema surrounds the membrane

14. Marked edema of submandibular area and the anterior portion of the neck along with lymphadenopathy gives Bull neck appearance. This indicates a high level of exotoxin in the bloodstream Obstruction of the airway may result in respiratory problems and death

15. Hoarseness of voice Croupy cough Laryngotracheal diphtheria

16. Nasal diphtheria the mildest form of respiratory usually localized to the septum or turbinates of one side of the nose Nasal diphtheria

17. Appears as secondary infection Lesion may be surrounded by edema and covered with a membrane. Cutaneous diphtheria

18. Schick test is performed to know whether the individual is susceptible to corynebacterium diphtheriae toxin. 0.1 ml of schick test toxin is injected intradermally into the skin of forearm considered test arm. The same but heat inactivated dose is injected into the skin of the opposite forearm considered control arm. The responses observed are Negative reaction Positive reaction Pseudopositive reaction Combined reaction Schick test

19. The test arm demonstrates a true positive reaction and the control arm shows pseudopositive reaction. This person is susceptible to diphtheria. Combined reaction

20. Prevention and control of diphtheria

21. Early detection Active search for cases should begin in family and school contacts Nasal and throat swab culture tests should be done to detect cases Isolation All cases, suspected cases and carriers should be promptly isolated, preferably in a hospital, for at least 14 days or until proved free of infection. At least 2 consecutive nose and throat swabs , taken 24 hrs apart, should be negative before terminating isolation. Early detection of cases and carriers

22. When diphtheria is suspected, diphtheria antitoxin should be given without delay, IM or IV , in doses ranging from 20,000 to 100,000 units or more, depending on the severity of the case following a test dose of 0.2ml subcutaneously to detect sensitization to horse serum. For mild early pharyngeal or laryngeal disease the dose is 20,000-40,000 units. For moderate nasopharyngeal disease, 40,000-60,000 units is administered. Treatment (Cases)

23. For severe, extensive or late (3 days or more) disease, 80,000-100,000 units. In addition to anti toxin every case should be treated with penicillin or erythromycin for 5 to 6 days to clear the throat of C. diphtheriae (this decreases toxin production)

24. The carriers should be treated with 10 day course of oral erythromycin, which is the most effective drug for the treatment of carriers. The immunity status should be upgraded as follows Treatment (Carriers)

25. Contacts merits special attention. They should be throat swabbed and their immunity status determined. Non immunized close contact should receive prophylactic penicillin or erythromycin. (1000-2000 units of diphtheria antitoxin and actively immunized against diphtheria). Contacts should be under medical surveillance and examined daily for evidence of diphtheria for at least a week after exposure. CONTACTS

26. Effective control measure is by active immunization with diphtheria toxoid of all infants as early in life as possible (national immunization schedule). Subsequent booster doses every 10 years there after. Immunization does not prevent the carrier state. COMMUNITY

27. DPT VACCINE It is a combined vaccine. The preparation of choice is DPT, because it can be immunized simultaneously against three diseases, viz., Diphtheria, pertussis, and tetanus . There are two types of vaccine : plain and adsorbed . Adsorption is usually out on a mineral carrier like aluminum phosphate or hydroxide . Adsorption increases immunological effectiveness of the vaccine. WHO recommends the use of adsorbed vaccines. Immunization

28. DPT/DT vaccine should not be frozen. They should be stored in a refrigerator between 2 to 8 degree Celsius. The vaccine should be used before the date of expiry indicated on the vial. The vaccine will lose it’s potency if it is kept in room temperature over a long period of time. DPT STORAGE

29. AGE INTERVALS BETWEEN VACCINE DOSE ROUTE AND SITE 6 weeks DPT I 0.5 ML IM – Anterolateral side of mid - thigh 10 weeks DPT II 14 weeks DPT III 16-24 months DPT Booster I 5 -6 years DPT Booster II

30. Minor conditions such as cough, cold, mild fever are not contraindications. Seriously ill children are not vaccinated. DPT should not be repeated if a severe reaction occurred after a previous dose. Such reactions include collapse, shock like state, persistent screaming episodes, temperature above 40 degree Celsius, convulsions and other neurological symptoms. DT only is recommended in such case. (2 doses with 4 weeks apart with a booster dose 6 months to one year). Children who have received DPT earlier, should receive only DT as booster at 5-6 years or at school entry. CONTRAINDICATIONS

31. Diphtheria antitoxin prepared from horse serum and used for treatment of diphtheria ANTISERA

32. Respiratory failure – this occurs due to the obstruction of the airway by the membrane developed by diphtheria Myocarditis – this develops by 2 nd week and can further lead to CHF, arrythmia and sudden death Neurological complications include development of palatal palsy ocular palsy, loss of accommodation and polyneuritis etc Renal complications like oliguria and proteinuria Complications of diphtheria