Dr.Eman Adnan Al_kaseer Diphtheria Dr.Eman Adnan Al_kaseer

Identification An acute bacterial disease primarily involving tonsils, pharynx ,larynx,nose,occasionally other mucous membrane or skin ,sometimes vagina or conjunctiva. The characteristic lesion ,caused by liberation of a specific cytotoxin , is an asymmetrical adherent grayish white membrane with surrounding inflammation .

Types 1.Pharyngotonsillar : moderate to sever sore throat with enlarged and tender cervical lymph nodes , in moderate to sever cases there is marked swelling and oedema of the neck with extensive membranes that progress to airway obstruction 2.Nasal diphtheria : can be mild and chronic with one sided serosanguinal nasal discharge and excoriations.

3.vaginal diphtheria : The membrane may extend to the vulva 4.cutaneous diphtheria : are variable and resemble impetigo Inapparent infections outnumber clinical cases. The toxin can cause myocarditis with heart block and progressive congestive failure beginning 1 week after onset , later effects include neuropathies that can mimic Guillain – Barre syndrome. Infectious agent : Corynebacterium diphtheria A.gravis B.mitis C.intermedius (biotypes) Occurrence : a disease of colder months ,primarily involving non immunized children under 15 ; often found among population groups whose immunization was neglected.

Reservoir : Humans Mode of transmission : contact with a patient or carrier ;rarely, contact with articles soiled with discharges from lesions of infected people. Raw milk has served as a vehicle. Incubation period : usually 2 -5 days, occasionally longer. Period of communicability :variable , until virulent bacilli have disappeared from discharges and lesions; usually 2 weeks or less ,seldom more than 4 weeks. The rare chronic carrier may shed organisms for 6 months or more. Effective antibiotics terminate shedding. Susceptibility :infants born to immune mothers have passive protection which is usually lost before the 6th month. Disease or inapparent infection usually but not always includes life long immunity.Imunization with toxoid produces prolonged but not life long immunity.

Methods of control: A. preventive measures : 1.educational measures to the public particularly parents of young children ,of the hazards of the disease and the need for active immunization. 2.the only effective control is wide spread active immunization with diphtheria toxoid. Immunization should be initiated in infancy with a formula containing diphtheria toxoid , tetanus toxoid and either cellular pertussis vaccine or whole cell pertussis vaccine. 3.the schedule recommended in developing countries is at least 3 primary doses IM at 6,10,and 14 weeks of age with a DTP booster at 18 months ,afifth dose is given at 4 – 6 years prior to school entry. If the pertusis component of DTP is contraindicated ,diphtheria and tetanus toxoids for children (DT) should be substituted.

For persons 7 and older : because adverse reactions may increase with age a preparation with a reduced concentration of diphtheria toxoid (adult Td) is usually given after the seventh birthday for booster doses. For a previously unimmunized individual, a primary series of 3 doses of adsorbed tetanus and diphtheria toxoid (Td) is advised,2 doses at 4 to 8 weeks intervals and the third dose 6 months to 1 year after the 2nd dose Active protection should be maintained by administrating a dose of Td every 10 years thereafter.

4.special efforts should be made to ensure that those who are at higher risk of patient exposure such as health workers are fully immunized and receive a booster dose of Td every 10 years. 5.for those who are severly immunocompra mized or infected with HIV diphtheria immunization is indicated ,even though immune response may be suboptimal. B.control of patient ,contacts and immediate environment: 1.report to local health authority 2.isolation : strict isolation for pharyngeal diphtheria, contact isolation for cutaneous diphtheria, until 2 cultures from both throat and nose (and skin in cutaneous diphtheria) not less than 24 hours apart ,and not less than 24 hours after cessation of antibiotic therapy ,fail to show C.diphtheriae

3.concurrent disinfection : of all articles in contact with patient and all articles soiled by discharges of patients. 4.quarantine: adults contacts whose occupations involve handling food(especially milk)or close association with non – immunized children should be excluded from the work until treated and bacteriological examination proves them not to be carriers.

5.management of contacts :all close contacts should have cultures from nose and throat and be kept under surveillance for 7 days. A single dose of benzathine penicillin or a 7-10 days course of erythromycin is recommended for all persons with household exposure to diphtheria, regardless of immunization status. Those who handle food or work with school children should be excluded from work or school until proven not to be carriers .Previously immunized contacts should receive a booster dose of diphtheria toxoid if more than 5 years have elapsed since their last dose ,and a primary series should be initiated in non – immunized contacts ; use Td,DT,DTPdepending on the age of contacts.

6.investigation of contacts and source of infection . 7.specific treatment : sensitivity testing should be undertaken before giving antitoxin .Only antitoxin of equine origin is available. If diphtheria is strongly suspected on the bases of clinical finding , a single dose of antitoxin (in the range of 20000 units for anterior nasal diphtheria to 100000 units for extensive disease of more than 3 days duration) given I.M. for 14 days immediately .

Antibiotics are not a substitute for antitoxin. Procaine penicillin G (I.M.)or parentral erythromycin has been recommended until the patient can swallow comfortably then oral treatment can be given for a period of 14 days. For carriers : a single dose of benzathine penicillin or a 7 – 10 days of erythromycin has been recommended. If culture is positive treat as patients.

C.Epidemic measures: 1.immunize the largest possible population 2.identify close contacts and define population groups at special risk. D.International measures : people travelling to or through countries where diphtheria is common should receive primary immunization necessary ,or a booster dose of Td for those previously immunized.