This document provides information on the bacterial infections diphtheria and pertussis. It describes diphtheria as an acute infection caused by Corynebacterium diphtheriae that produces a potent exotoxin. Clinical features include a thick gray membrane in the throat and complications affecting the heart, kidneys and nerves. Pertussis is caused by Bordetella pertussis and is characterized by paroxysmal coughing fits ending in a distinctive whoop. Both are highly contagious and can be prevented by vaccination.

1. DIPHTHERIA

2. Introduction
• Diphtheria is a acute bacterial infection caused
by Corynebacterium diphtheriae
• A gram positive bacillus
• It secretes a potent exotoxin – major
determinant of the pathogenicity
• Diphtheria is endemic in India
• Common below 15 years
• Mostly in winter and autumn seasons
• Both sexes are equally affected

3. Pathogenesis
• Spreads through droplet infection during
coughing, sneezing , talking
• Once infected  remains infected till virulent
bacilli are present in lesions, usually 2-4 weeks
• Diphtheria is a rapidly developing acute febrile
illness with both local and systemic pathology

4. • Primary lesion in upper respiratory tract  necrosis
of epithelium  injury leads to plasma leak, fibrin
network formation with bacteria  pseudo-
membrane formation adherent to underlying
tissue (nose, pharynx, larynx, tonsils) scraping
leads to bleeding
• At this site they produce toxins that is absorbed and
disseminate to whole body
• Exotoxin affects the heart, kidney, liver, spleen,
muscle, peripheral nerves, adrenals

5. Clinical features
• Incubation period is 2-5 days
• Onset with fever, malaise, sore throat, headache,
weakness
• Nasal diphtheria – serosanguineous discharge
• Tonsillar diphththeria – dysphagia, sore throat,
cervical lymph node enlargement
• Laryngeal diphtheria – cough, hoarseness of
voice, inspiratory stridor, dyspnea
• Respiratory distress, retarction, cyanosis,
wheezing , nasal regurgitation of fluids

6. • Toxic looking patient with difficulty in breathing
• Hallmark is thick, gray, leathery membrane over
palate, pharynx, larynx, tonsils, uvula
• Regional lymph nodes are enlarged
• Extensive enlargement of anterior cervical and
submandibular lymph nodes  bull’s neck
appearance

7. Complication
• CVS - typically occurs after 1-2 weeks of illness
- Myocarditis, Arrythmia , CHF
• Resp - Respiratory failure
• Renal – Tubular necrosis , Proteinuria
• Neurological –
- Palatal palsy (2nd week)- nasal regurgitation of
fluid, nasal intonation of voice
- Ocular palsy (3rd week) – deviation of eye
- Loss of accommodation – blurring of vision
- Generalized polyneuritis – 3rd to 6th weeks

8. • Palsy of cranial nerves also seen
• Polyneuritis manifested as motor deficit of
proximal muscle groups
• From weakness to complete paralysis
• Diminished DTR
• Descending paralysis
• Cutaneous diphtheria – painful blister like skin
lesions which breakdown to form a ulcer covered
with gray membrane

9. Diagnosis
• Clinical features with detection of
pseudomembrane
• Albert staining of swab from oropharynx, larynx
• But culture takes 8-10 hrs to be positive
• Don’t wait for the culture to start treatment

12. Management
• In any suspected diphtheria immediately start
treatment with antitoxin and antibiotics
• Antitoxin is the mainstay of treatment to
neutralize the circulating toxin that is not bound
to tissue
• Antibiotics used to eradicate the organism and to
prevent spread
• Supportive treatment

13. • Mechanical ventilation if needed
• Airway obstruction and myocarditis are the main
cause of death
• Dose of antitoxin depends on the site and extent of
disease
• Antibiotics – Penicillin / Erythromycin
• Treatment of carriers

14. Prevention
• Isolation of patients – till two cultures from nose
and throat are negative
• Care of contacts – kept under observation for at
least 7 days. No role of prophylactic antitoxins
• Active immunization
• Repalce TT with Td

15. PERTUSIS

16. Introduction
• Pertusis or whooping cough is caused by a gram
negative coccobacillus Bordetella pertusis
• Highly communicable disease
• It is a disease of infants and young children
• Females are more predisposed than males
• More in malnourished patients, overcrowding,
low socioeconomic status groups
• Common in winter and spring

17. • Disease is characterized by paroxysmal bouts of
cough ending with a whoop lasting for months
• Intense spasmodic cough
• Spreads through droplet infection via respiratory
secretions
• Highly contagious disease with secondary attack
rate of 100%

18. Clinical features
• Incubation period 7-14 days
• Natural course of disease is in 3 phases
• Catarrhal phase  cough, cold, running nose,
mild fever lasting for 10 days
• Paroxysmal phase  bouts of cough ending
with a whoop, face is congested, vomiting
- Classical whoop is the rescue inspiration at the
end of coughing
- Lasts for 2 weeks

19. • Convalescent phase  if no complication then the
disease progresses to this phase
• Relapse of cough is common
• So called as cough of 100 days
• Cough is exhaustive and scaring
• Can lead to apnea, respiratory difficulty, cyanosis

20. Complications
• Subconjunctival hemorrhage
• Nose bleeds
• Hemoptysis
• Intracranial hemorrhage is rare
• Development of hernias
• Pneumothorax
• Secondary infections
• CNS complications due to hypoxia/toxins can
lead to seizures and encephalopathy

21. Management
• Diagnosis is through typical history and swab
culture from nasopharynx
• Treated with antibiotics like Erythromycin/
Azithromycin/ Clarithromycin/Trimethoprim-
sulfamethoxazole for 2 weeks
• Supportive treatment – maintain hydration,
nutrition, hygiene
- Avoid provoking paroxysms of cough
- Comfort during paroxysms of cough

22. • Clearing airway during cough to prevent
aspiration
• Early treatment of complications
• Treatment of contacts with antibiotic
Erythromycin for 2 weeks
• Active immunization

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