Post on 13-Jan-2016
Diphtheria
Revised May 2007
Dr. Sarma R V S NConsultant Physician
Diphtheria
Greek diphthera (leather hide)Caused by Aerobic Gram +ve rods Cornyebacterium diphtheriaeExotoxin production only if
infected by virus phage infected carrying toxin gene
Gram +ve Bacilli and Colonies
Diphtheria Epidemiology
Reservoir Human carriers Usually asymptomatic
Transmission Respiratory Skin and fomites rarely
Temporal pattern Winter and spring
Communicability Up to several weekswithout antibiotics
Diphtheria Clinical Features
Incubation period 2-5 days (range, 1-10 days)
May involve any mucous membraneClassified based on site of infection
anterior nasalpharyngeal and tonsillar laryngealcutaneousoculargenital
Pharyngeal and Tonsillar Diphtheria
Insidious onset of exudative pharyngitisExudate spreads within 2-3 days and may
form adherent pseudo membraneMembrane may cause respiratory
obstructionFever usually not high but patient appears
toxic
Thick Membrane
Pseudo membrane
‘Bull Neck’
Skin Lesions
Diphtheria Complications
Mostly attributable to toxinSeverity generally related to extent of local
diseaseMost common complications are myocarditis
and toxic neuritis with palsyDeath occurs in 5%-10% for respiratory
disease
Diphtheria Antitoxin (DAT)
Produced in horsesFirst used in the U.S. in 1891Used only for treatment of diphtheriaNeutralizes only unbound toxin
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
1940 1950 1960 1970 1980 1990 2000
Cas
esDiphtheria – in USA, 1940-
2005*
Year*2005 provisional total
DTaP, DT, and Td
DTaP, DT
Td, Tdap (adult)
Diphtheria7-8 Lf units
2-2.5 Lf units
Tetanus5-12.5 Lf units
5 Lf units