Diphtheria.Pertussis.Tetanus

Diphtheria Caused by Corynebacterium

diphtheriae An aerobic gram-positive bacillus Man-to-man transmission Incubation period- 2-5 days Primarily a disease of children 75% children immune by 10 years Involves respiratory mucous membrane

Clinical manifestation Tonsillopharyngeal, laryngeal, nasal &

tracheobronchial involvement s/s- fever with systemic toxicity, sore throat,

dysphagia, hoarseness, rhinorrhea, cough, Cxal LNE Characteristic pseudomembrane over tonsils, that

bleeds on attempt to remove Complication- local or toxin mediated Respiratory obstruction Myocarditis- arrythmias &/or heart failure Polyneuritis- IX/X Cr. n., proximaldistal weakness, distal paresthesias Pneumonia

Management Diagnosis- mostly empirical, based on s/s

± pseudomembrane Diphtheria antitoxin- horse antiserum IV infusion over 60 mins 20,000100,000 units, depending on severity Watch for serum sickness Antibiotics- macrolide or penicillin Macrolide or Rifampicin for carriers Vaccination- toxoid- DPT/DT/Td

Pretussis- whooping cough Caused by Bordetella pertussis A gram-negative coccobacillus Man is the only host Transmitted by airborne respiratory

secretions from an infected individual No carrier state Incubation period- 7-10 days

Clinical manifestation 3 stages- clasically Catarrhal- non-specific URTI, most infectious, x 1-2 wk Paroxysmal- bouts of severe cough (whoop),

more at night, x 2-4 wk Convalescent- less intense cough, not infectious, 3-4 wk In adults- prolonged bronchitis Complications- Pneumonia, commonly due to secondary bacterial infection Seizures, encephalopathyFND Otitis media Hemorrhage, due to severe cough

Management Diagnosis- Markedly increased TLC, with lymphocytosis B. pertussis from nasopharyngeal swab Treatment- Supportive care Antibiotics early- macrolide or co-trimoxazole Prophylaxis with macrolide for contacts Vaccination- Adsorbed whole-cell vaccine, part of DPT

Tetanus A neurologic disorder, characterised by

increased muscle tone & spasms Caused by tetanospasmin, a toxin produced

by Clostridium tetani C. tetani- a motile anaerobic gram-positive

bacillus with a terminal spore Sporadic disease, caused by contamination

of wound with spores, that germinate under suitable conditions, to produce neurotoxin

Infectionsymptom- ~7 days

Clinical manifestation Progressive skeletal muscle involvement Trismus, dysphagia Rigid abdomen, stiff proximal limb muscles (hands/feet- spared) Facial grimace Arched back- opisthotonus Paroxysmal painful generalized spasms Complications- Sympathetic overactivity Pneumonia Fractures Asphyxia

Management Diagnosis- clinical Treatment- Supportive care Wound care Antibiotic- Penicillin or Clindamycin Antitoxin- Tetanus immunoglobulin Diazepam & neuromuscular blockade with mech. vent. Course- 4-6 weeks, with complete recovery Prognosis- early disease with short course

has poor prognosis Vaccine- DPT in children & Td in adults