corynebacterium diphtheria
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Transcript corynebacterium diphtheria
Reemerging of
Corynebacterium Diphtheria
Case Study Number Four
Table #6
Emerita Arias
Ofili Okolonwamu
Romelene Juban
Patient Evaluation
Patient is a 42 year old female
Living in US but born in Russia
Returned to Moscow for a visit on Nov. 22
Dec. 6, experienced onset of fever and sore
throat
Hospitalized on Dec. 7
Physical examination revealed a pharyngeal
membrane
Lab examination of membrane revealed gram
positive rods
Patient’s vaccination history is unknown
Pharyngeal Membrane
Possible Causes of Patient’s Distress
that Need to be Ruled Out:
Severe streptococcal sore throat
Infectious mononucleosis
Vincent’s angina
Pharyngitis
Tonsillitis
Influenza
Lab Tests Need to Support an
Accurate Diagnosis:
Strept test
CBC
Monospot Test
Throat and nares swab test
Culture of pharyngeal membrane
Also, the collection of patient’s data
indispensable:
Patient details, clinical details, contact list, and
traveling history.
Toxigenic Corynebacterum diphtheria
biotype gravis was isolated from the
pharyngeal culture received on Dec. 9
Patient’s Antitoxin Level by Neutralization Assay
Measured at >5 IU/mL
Interpretation of antitoxin levels by in vitro neutralization
assay
Antitoxin level (IU/ml
Interpretation
<0.01
0.01
0.01-0.09
0.1
>1.0
Susceptible
Lowest level of antitoxin/some protection
Levels of antitoxin/some protection
Protecting Level of antitoxin
Level of antitoxin /long term protection
ELISA (EIA) Level for Specific
Human Antibodies was <0.03 IU/ml
Titer (enzyme immunoassay) revealed
that patient had immune response
showing a level of long term protectionlevel due to immune response
Although vaccination history was
unknown, neutralization assay helped
determined that patient was immunize at
certain point
Why Did Patient Contracted
Disease
Traveling to an endemic area
Moscow has a high incidence of diphtheria
Diphtheria is very contagious, transmitted by
air droplets, physical contact, even by a hand
shaking
Patient not having current booster shot
Inadequately immunized-not fully protected
What Accounts for C. diphtheria
Capable of Producing Toxins
Gram positive, fermentative, pleomorphic
rod
Four biotypes: var gravis, var mitis, var
intermedius, and var belfanti
All biotypes, except var belfanti produce
lethal exotoxins.
Pathogenesis based upon two
determinants
Determinants of C. diphtheria
pathogenesis
Ability to colonize the nasopharyngeal
cavity or the skin
Ability to produce diphtheria toxins
Determinants involved in colonization of
host-encoded by the bacteria
Toxin-encoded by corynebacteriophages
Corynebacteriophage (Beta
phage) that carries the tox gene
Toxin Relative Potencies
Toxin
Power Ratio
Cyanide
1
Curare
20
Alfatoxin
25
Snake Venom
167
Diphtheria Toxin
108
Botulinum A Toxin
3.3 x 108
Patient’s Treatment and Prognosis
¤ Patient received 40,000 IU of diphtheria
antitoxin
¤ Penicillin G for six days
¤ Roxithromycin, same as erythromycin in US,
for several days
¤ Delay in treatment can result in death or long
term disease
¤ Patient fully recovered with no complications
¤ May continue to harbor the bacteria in nose, or
throat
¤ Patient’s family and contacts to be checked to
prevent possible recurrences
Could an Epidemic of Diphtheria Occur in
United States?
1990-1994 Outbreak in Russian Federation;
>157,000 cases and 5,000 deaths
Diphtheria can cause epidemic disease in
developed countries like U.S. despite high
vaccination coverage rate in children
Prevalence studies in U.S. show 30% -60%
adults with antitoxin levels below protection
levels
Last cases of diphtheria in U.S.- drug and
alcohol abusers
Diphtheria remains endemic in developing
countries-potential source of entry into the U.S.
References
http://www.astdhppe.org/infect/dip.html
http://www.cdc.gov./ncidod/eid/vol5nos/
http://gsbs.utmb.edu/microbook/ch032.htm
http://www.intmed.mcw.edu/ITC/Diphthe
riaRussia.htm
http://ncid.dcd.gov/travel/yb/utils/ybGet
Lebofe J. Michael. “A Photographic Atlas for
the 3rd Edition Microbiology Laboratory.”
Englewood, Colorado:Morton Publishing
Company, Copyright 2005
Sanford, P. Jay M.D. “The Sanford Guide to
Antimicrobial Therapy 2006 36th Edition.”
VA:Antimicrobial Therapy, Inc. 1969