Respiratory Diphtheria
Causative organism: Corynebacterium diptheriae
Mode of infection: droplet spread, contact with fomites
Incubation period: 2-5 days
Diagnostic WorkUp
Throat swab/ part of pseudo membrane should be sent for
• Gram Stain: gram-positive, club shaped bacilli in Chinese letter pattern.
• Alberts Stain: Green bacelli with bluish black meta chromatic granules.
• Culture on Blood agar : small, circular, white colonies.
• Culture on Loeffler’s Serum Sloap: growth within 6-8 hours with small, circular, white colonies.
• Culture on Potassium Tellurite agar: Growth appeared on the second day with black colored colonies.
Toxin demonstration with
• Elek’s Gel Precipitation test:
+ve if arrow shaped precipitation band gets formed.
-ve if no band is formed.
• Detection of Tox gene by PCR
• Detection of toxin by ELISA or ICT
Treatment.
• Should be initiated immediately on clinical suspicion.
• Passive immunization with Antidiptheritic serum/ADS/antitoxin
- Mild and early cases: 20,000 - 40,000 units.
- Moderate to severe: 40,000 - 60,000units.
- Severe/Extensive/Late (>3days): 80,000 - 100,000 units
• Penicillin or Erythromycin Antibiotic therapy